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General HIFI => Amplification (Pre/Power) => Topic started by: springcreek on June 19, 2013, 12:19:57 PM

Title: My new amp
Post by: springcreek on June 19, 2013, 12:19:57 PM
My Leak stereo 20 has been refurbished with carbon comps and Russian K40y PIO caps. Still a long way way from Stevens but it should be a good start.  ;D

Hopefully should get it in a week or two before a trip to Stevens  8)

Then I can really start to tune it!


Title: Re: My new amp
Post by: springcreek on June 19, 2013, 12:21:07 PM
Not sure why the two pics went up, but twice the joy  ;D
Title: Re: My new amp
Post by: ozmillsy on June 19, 2013, 04:29:24 PM
Looks to be in great condition.   Enjoy !!
Title: Re: My new amp
Post by: springcreek on June 19, 2013, 04:35:54 PM
Thanks Oz will do mate  ;D

Title: Re: My new amp
Post by: stevenvalve on June 19, 2013, 05:20:53 PM
Nice condition. It will eventually be striped to the bone, and rebuilt with the right internal toys. But that is well down the track. Even standard they are nice. And yours is modified with some nice stuff.
Title: Re: My new amp
Post by: springcreek on June 19, 2013, 06:25:03 PM
Damn just drooled on my iPad...again!  ;D

Can't wait to get it to that standard  :o
Title: Re: My new amp
Post by: Jehuty on June 20, 2013, 05:52:17 AM
Congratz Andy. It looks mint!
Title: Re: My new amp
Post by: data on June 21, 2013, 02:46:16 AM
Very nice example of a stereo 20  8)
Title: Re: My new amp
Post by: Jehuty on June 21, 2013, 11:26:12 PM
Nice condition. It will eventually be striped to the bone, and rebuilt with the right internal toys. But that is well down the track. Even standard they are nice. And yours is modified with some nice stuff.

Hi Steve,

I read this post on the US forum about damping bare wires with cotton, see: http://www.audiocircle.com/index.php?topic=54218.msg1227331#msg1227331

Quote
Many people believe lots of things.  I want to BE LIVE.  The only way to know if something is better or not is to experiment and listen on a seriously tweak system, not quote others who "believe" something.  My direct experience tells me that bypassing is really a necessity.  I have never heard a very large cap (1uf or more) that had really great extended highs.  Audio Research bypasses their exotic custom large Teflon caps with smaller values.  They do this because they listen.  A friend just bypassed his Clarity Cap MRs in his speaker with the inexpensive Vishay Roderstein .01s and .1s and says it made a serious improvement.  Audio tweaking is an art.  Certainly you must listen to different combos of caps and all properly burned in, oriented and damped.  All film caps need to be marked for outside foil and oriented so the outside foil is to ground or to the output.  This makes a noticeable improvement.  Also all caps should be damped....ie not dangling in the air....and all long single strand bare wires need to be covered with cotton sleeving to damp them.  All these things are very audible.  A person posted on Audio Asylum that he tried the Vishay Rodersteins as a bypass cap but they sounded seriously bright.  I replied that he probably has them dangling in the air on undamped leads.....he reported back a few days later saying....indeed, I was right...as soon as he damped the caps and wires he now is very happy with the bypasses.  Everything has to be done right!!!!!!  Years ago I modded an Audio Research Preamp that had both Rel-caps and Wondercaps in it.  Audio Research did not know about outside foil then.  So, they just lined all the caps up so the writing was in the same directions for visual coolness.  I removed all the film caps and tested the Rel-caps and marked them for outside foil and put all caps back in, in the electrically correct way (Wonder caps are marked for outside foil via the writing on them)......way frickin better sound.

Many interesting points from his post, not necessarily agree with all of it. I am particularly interested to know your opinion with regards to cotton sleeving compared to teflon as seen in your Leak amp (and other things you built). Could the cotton sound better? Why teflon? Why not cotton? Or even silk like the Henley...not sure where to get the silk sleeving though...

Thanks,
William
Title: Re: My new amp
Post by: springcreek on June 22, 2013, 08:35:03 AM
Thanks guys  ;D Thanks Jehuty this is useful. I have heard others talk about using cotton sleeving on single strand and I have some here that I got from the soundlabs group. Unbleached cotton should be nice, love to know Steve's thoughts on this. I also have some cat 5 here ready for use in the Leak  ;)
Title: Re: My new amp
Post by: galwaybay on June 23, 2013, 09:48:51 AM
Congrats on the new amp Andy. Welcome to the Stereo 20 owners club. Yours looks like a particularly good find, very nice cosmetic condition. In comparison mine looks like it went twelve rounds with Mike Tyson !. You've already got those Russian PIO's installed which is a bonus. They are remarkably good sounding caps IMO. Really flesh out the Leak which can be a bit on the lean and  clean side without a bit of judicious modding. Looking forward to seeing you in mountains in a couple of weeks. Cheers Peter.
Title: Re: My new amp
Post by: springcreek on June 26, 2013, 07:51:49 PM
Thanks Peter

I'm really looking forward to hearing your Leak with the Quads...bet it's delicious. Would love to get some nice 57s one day.

Loving the Axiom 300s at the moment! Damn! Even my wife said they are amazing  :o

See you in a few weeks  ;D

Just need to figure out a way to sneak out Steven's spare Quads...may about 6 am when he is snoozing...after I grab the R2R of course :P
Title: Re: My new amp
Post by: Jehuty on June 26, 2013, 08:16:04 PM
Loving the Axiom 300s at the moment! Damn! Even my wife said they are amazing  :o

Hi Andy, great to hear you like the Axiom 300, can't beat them for the money, what a buy! Where's the obligatory pic?  ;D

after I grab the R2R of course :P

You can try...but beware of how heavy the bloody thing is, you need at least two big (and I mean BIG) blokes to bring it out of his place!!  >:(  Last time he said when it's time to sell the house, the machine goes with it!  ;D
Title: Re: My new amp
Post by: springcreek on June 26, 2013, 09:22:08 PM
Hey William

Well I only have a few hours on the Axiom 300s so far and they are really coming to life. Was playing some jazz tonight and it sounded really good with just a DVD player and the miniwatt  :o As you would expect the midrange is wonderfully open and alive...with my wife (who really doesn't like my audio kit) said they sounded so much more alive than the triaxioms...which are really great themselves. So far no shout or hot top end.

Very lucky score! ;)

Will be some mint Triaxioms on the market soon I think  :D

Will post some pics when I get time
Title: Re: My new amp
Post by: springcreek on June 26, 2013, 09:25:30 PM
Heavy R2R...I am big and ugly and have a trolley  :P
Title: Re: My new amp
Post by: Jehuty on November 02, 2013, 11:30:45 PM
Hi Andy,

How are you going with your Leak? Did you do any mods on the amp? What valves are you running?

Cheers,
William
Title: Re: My new amp
Post by: springcreek on November 03, 2013, 03:10:07 PM
Hi William

Have made a few changes to the Leak. Steven helped me replace a few critical resistors with 2 watt Allen Bradley's. Paul B weaved his magic on the amp replacing the power supply caps with Solen's and the remaining electrolytic's. Paul also replaced many of critical resistors with vintage Phillips. Binding posts were replaced with Eichman's. Still have the Mullard rectifier, and some NEC 12AX7s. Still need to get some Mullard EL84s. Also have a better power cord.

Did you get a Leak?

Cheers, Andy
Title: Re: My new amp
Post by: Jehuty on November 03, 2013, 04:16:15 PM
Hi Andy,

Nothing confirmed yet. I'll update if I do go ahead.

How do you like your Leak so far with your Axiom 300? What coupling caps do you use? I got some boxes from Paul for my Goodmans Twin Axiom. I will also have 2 pairs of ribbon tweeters and a pair of Goodmans Trebax to play around. I plan to run them with a Leak 20, hence my questions. Fun times ahead!  ;D

Cheers,
William
Title: Re: My new amp
Post by: springcreek on November 03, 2013, 08:05:31 PM
Hi William

I like the Leak a lot. Still have Sovteks in it at the moment which are pretty awful. They are really limiting the magic. Also there has been a lot of changes to my system around the same time. I have new speaker cabinets (Shindo style cabinets that Damian made), new speaker wires (Auditorium 23 also from Damian), new turntable (Micro-seiki), new tonearm (Fidelity Research), new cartridge (Garrott P77i), and new phono stage (Graham Slee Reflex M).

I am getting a great result so far, but need to do some tuning as while the bass is very good I'd like it better still. Only minor really, but I'm hoping I can get it sorted. The results are a long way ahead of where I was before!  ;D

I will be replacing the front baffle (see pic) with a veneered one when funds allow.

Let me know how you go with the new speaker cabinets.

Cheers, Andy

Ps. To give some idea of scale the TV is 50 inches.
 
Pps. The Rainbow Diffusor is for sale at $500 a pop  :P
Title: Re: My new amp
Post by: Jehuty on November 03, 2013, 08:30:09 PM
Hi Andy,

I see that you got plenty of new toys! How fun!  ;D

Will keep you posted about my progress.

Cheers,
William
Title: Re: My new amp
Post by: springcreek on November 03, 2013, 09:49:36 PM
Yes lots of new toys for a change  ;D For coupling caps I am using Russian K40y PIO. Not exactly Duelund, but rich and musical caps. Will upgrade to Duelund as my budget allows. Next issue though is getting rid of the Sovtek EL84s.
Title: Re: My new amp
Post by: Jehuty on November 27, 2013, 05:29:44 PM
The Leaks have arrived! Christmas came early this year!
Title: Re: My new amp
Post by: springcreek on November 27, 2013, 07:41:16 PM
Very nice  8) That Santa is a very nice fellow  ;D

Enjoy they should make some really nice music.

Have you tried the Trebax units yet?

Cheers
Title: Re: My new amp
Post by: Jehuty on November 27, 2013, 07:59:53 PM
Hi Andy,

Thanks. Yep, very nice Santa!  ;D

I listened to the Trebax on Steve's system a couple of weeks ago and surprise surprise I liked the Trebax the most. It was compared to Steve's Raven R1, my own Raven R1 (different diaphragm compared to Steve's) and Paul Hedalfa's Raven R2. The ribbons sounded metallic and didn't blend well with the Axiom 80 whereas the Trebax sounded much more natural without the annoying metallic sheen of the Raven's. I am still unconvinced about integrating tweeter/super tweeter with the Axiom 80. To me I like the Axiom 80 running by themselves. Much more coherent and musical. But that's just me  ;)

I bought some Russion K75 PIO (see http://www.ebay.com.au/itm/380504713144) for my Leaks' coupling caps after reading some review on the net, see http://www.enjoythemusic.com/diy/0411/capacitor2.htm, I hope they sound as good as your K40Y. If you would like to try my K75 I can send a quad for you, just let me know  :)

Cheers,
William
Title: Re: My new amp
Post by: springcreek on November 28, 2013, 07:58:42 AM
Hi William

I'm glad the Trebax worked out well. I quite like horn tweeters and I suppose it's no surprise that Goodman's make a great one given how good the rest of their drivers are.

I have pretty mixed feelings about ribbons. My general experience models yours, thin and metallic. They don't move any air and can't usually portray body. Good enough for audiophiles but not music lovers. The exception was been Hedulfa's system. When I first heard it a few years ago the system was great in the mids with Goodman's drivers covering that region but the highs where the ribbons covered were thin, metallic and wiry. The big change came from adding additional ribbons (I think there is now 6 or 8 per side!) and adding the Decca Kelly's. Now they move air and have body...not just thin detail. Paul's is a very special system  8)

I know what you mean about running the Axiom's nude. I always prefer both Steven's and my own system run as a single driver. I really like coherence and crossovers tend to hurt the sound to some degree. They seem to mute the live feeling in music.

Be good to see what you think of the K75 PIO caps. Maybe you can bring your amp to the GTG down here next year  ;D

Cheers, Andy
Title: Re: My new amp
Post by: hedalfa on November 28, 2013, 01:30:38 PM
Hi Andy,

Thanks. Yep, very nice Santa!  ;D

I listened to the Trebax on Steve's system a couple of weeks ago and surprise surprise I liked the Trebax the most. It was compared to Steve's Raven R1, my own Raven R1 (different diaphragm compared to Steve's) and Paul Hedalfa's Raven R2. The ribbons sounded metallic and didn't blend well with the Axiom 80 whereas the Trebax sounded much more natural without the annoying metallic sheen of the Raven's. I am still unconvinced about integrating tweeter/super tweeter with the Axiom 80. To me I like the Axiom 80 running by themselves. Much more coherent and musical. But that's just me  ;)

I bought some Russion K75 PIO (see http://www.ebay.com.au/itm/380504713144) for my Leaks' coupling caps after reading some review on the net, see http://www.enjoythemusic.com/diy/0411/capacitor2.htm, I hope they sound as good as your K40Y. If you would like to try my K75 I can send a quad for you, just let me know  :)

Cheers,
William



For a simple system the trebax would be the easist to work with. Ravens need more work....
Title: Re: My new amp
Post by: vitavoxdude on November 28, 2013, 02:43:59 PM
Goodmans would have had 'master tapes' as a reference for their work, never mind  computers and virtual setups, people with real ears not slide rule, oops wrong generation, mp3 players and sub woofers. :o  Yes there are more natural, accurate systems around but the old Goodman's sound glorious when fed a modern diet.  Valves are even better if you want true scale and explosive dynamics.   ;D

Ted Jordan (Goodmans development engineer) was another pioneer just like Peter Walker of QUAD (quality unit audio domestic) fame, both from the English school, similar work was done by Jim Lancing etc across the pond.  Vitavox is another brand that does real pretty well and then all the copy cats.  Of course Cinema's  were the main thrust of research took place in the 30's to 50's and the big WE and RCA setups will po po over all the modern stuff for tone, dynamics and palatable presence.  Unfortunately, most will never hear such rigs as they are now all in the hands of rich far East gentlemen or chez V  ;).. Field coils / horns / electrostatics AND Plasma tweeters rule, ha ha. Woops, and a Killer Dac fed by a good transport without which things can sound very ordinary and,,,,,,,,,master tape copies replayed back via decent R2R units!  Almost forgot the source is a major part of greatness in any system. ALL IMV, damn :-X.
V
Title: Re: My new amp
Post by: hedalfa on November 28, 2013, 06:01:38 PM
Quote
Unfortunately, most will never hear such rigs as they are now all in the hands of rich far East gentlemen or chez

True but eventually youll hear some old stuff, my 1930s 807 RCA amps. 8) 8) 8)  I wouldn't be surprised they even exceed my expectations. Like the 205D valves all I can say is I hang my head in shame that some people lacking the modern facilities we take for granted so long ago can make things so superbly well. They had ears to really hear in an informed way... and built and tuned to what they heard.

My line stage is given a giant boost by really early RCA filament transformer. Agreed the sounds is so different, most people have no idea what its like. People always talk about thiele small, Jordans work pre dates this he had all worked out mathematically.  Tiele small made the info accessible, but they are not the sole originators of this. There is a reason goodmans are so good, its not chance. Its thoughtful and painstaking work. I just wish goodmans had kept better records so more could be known about them. If I could time travel I definitely visit goodmans in there heyday...

Goodmans would have had 'master tapes' as a reference for their work, never mind  computers and virtual setups, people with real ears not slide rule, oops wrong generation, mp3 players and sub woofers. :o  Yes there are more natural, accurate systems around but the old Goodman's sound glorious when fed a modern diet.  Valves are even better if you want true scale and explosive dynamics.   ;D

Ted Jordan (Goodmans development engineer) was another pioneer just like Peter Walker of QUAD (quality unit audio domestic) fame, both from the English school, similar work was done by Jim Lancing etc across the pond.  Vitavox is another brand that does real pretty well and then all the copy cats.  Of course Cinema's  were the main thrust of research took place in the 30's to 50's and the big WE and RCA setups will po po over all the modern stuff for tone, dynamics and palatable presence.  Unfortunately, most will never hear such rigs as they are now all in the hands of rich far East gentlemen or chez V  ;).. Field coils / horns / electrostatics AND Plasma tweeters rule, ha ha. Woops, and a Killer Dac fed by a good transport without which things can sound very ordinary and,,,,,,,,,master tape copies replayed back via decent R2R units!  Almost forgot the source is a major part of greatness in any system. ALL IMV, damn :-X.
V
Title: Re: My new amp
Post by: springcreek on November 28, 2013, 07:37:06 PM
They are exceptional drivers and I've not heard better on voices...just so natural. Sure I haven't heard WE 555 FC in horns, or Klangfilm or GIP, but not much else I have heard comes close other than Shindo FC and Tannoy's are special. Nothing new has even been in the ballpark if you treasure what the Goodman's excel at.

Ted Jordan certainly new what he was doing, unlike modern designers. World's apart really.

I just wish I was having more success tuning my cabs. Sometimes they sound soo special and other times the bass isn't right. It certainly is a challenge...so darn close!
Title: Re: My new amp
Post by: Jehuty on December 16, 2013, 03:01:05 PM
Let the mods begin!  ;D

I decided to start off with resistors and two tower power supply electrolytics. Only JJ electrolytics as my budget is limited, maybe next year for Jensen if I can be bothered. I got all tantalum resistors however, Shinkoh wherever possible, Audio Note to cover the rest. Cost me about $350, yep, just resistors!  >:(

When I get more money, I'll do the caps, i.e. Solens, Duelunds & Jensens.
Title: Re: My new amp
Post by: springcreek on December 17, 2013, 07:57:06 AM
Awesome William. Some very nice parts there  8)

The Leak can be a fraction lean (for me at least) so be careful with parts choices. I cant wait to get some Mullard EL84's which should help (currently using Australian miniwatt). I'm also thinking that down the track I might replace the power supply caps (currently Solen's) with some big vintage PIO caps to add additional liquidity and richness. That is likely to require a sub chasis to hold them as they are bloody huge  ;D Anyone have any thoughts on this???

Cheers, Andy
Title: Re: My new amp
Post by: Jehuty on December 17, 2013, 01:13:08 PM
Hi Andy,

Thanks. I read from the Leak Yahoo Group that we can modify the power supply and replace the R21 resistor (the green one) with a choke (max 100R resistance). That is essentially turning the power supply into CLC instead of CRC, which can only be a good thing. The recommended choke is Lundahl LL1638, but if we want more liquidity I think vintage oil filled choke and PIO cap input would be the way to go. Once we change the R21 with a choke, we can reduce the first cap input (C13) from 32uF to...say 8uF PIO Dubilier. Problem with the power supply mod is space. So, yeah external power supply would be awesome  8)

Cheers,
William

PS: Check out the Freak Leak 20 pic attached. I don't want mind to look like that although I bet it sounds great with the choke and PIO cap.
Title: Re: My new amp
Post by: springcreek on December 17, 2013, 02:32:35 PM
That is exactly what I want to do! Freak Leak...nice!

I hope to build a seperate chassis with CLC. I like the idea of reducing the size of the input can given the choke and the second PIO can be larger than the standard 32uF. Dubilier PIO would be perfect as would a lovely oil filled choke like a Gardner or something similar. Hedulfa has a surplus PIO cap the size of a brick that might be perfect for my task  8)
Title: Re: My new amp
Post by: springcreek on December 17, 2013, 02:34:53 PM
How about I build you a case when I build mine  8)

Problem with the power supply mod is space. So, yeah external power supply would be awesome 

Title: Re: My new amp
Post by: Jehuty on December 17, 2013, 02:42:57 PM
Hi Andy,

Thanks for the offer, that's very nice of you.

However, I'd like to keep my Leak 20 small and simple. I will try to squeeze every bit of performance out of the Leak before I would consider external power supply.

I will follow your progress though, as I know it would be a massive upgrade once you get CLC power supply mod done  8)

Cheers,
William
Title: Re: My new amp
Post by: springcreek on December 17, 2013, 09:24:04 PM
No probs. Should be an interesting experiment. Hopefully one that produces some real magic.  8)
Title: Re: My new amp
Post by: Jehuty on December 26, 2013, 10:44:32 PM
Hi Andy,

I decided to give the simple power supply mod as suggested by the Leak Yahoo group a go and ordered Panasonic electrolytic (http://www.partsconnexion.com/77651.html). God forbid Mario to see this cheapo electrolytic cap but I thought for a mere $3 I can't go too wrong there  8)

Cheers,
William
Title: Re: My new amp
Post by: Jehuty on December 26, 2013, 10:47:17 PM
When it's done it should look like the attached pic. Let's see what the fuss is all about.  8)
Title: Re: My new amp
Post by: kajak12 on December 26, 2013, 11:10:00 PM
Hi Andy,

I decided to give the simple power supply mod as suggested by the Leak Yahoo group a go and ordered Panasonic electrolytic (http://www.partsconnexion.com/77651.html). God forbid Mario to see this cheapo electrolytic cap but I thought for a mere $3 I can't go too wrong there  8)

Cheers,
William
WTF i understand you bought a house and hifi must be on a budget
Title: Re: My new amp
Post by: Jehuty on December 26, 2013, 11:23:58 PM
LOL... Only temporary Mario, I would buy Jensen next time if the mod does work  ;)
Title: Re: My new amp
Post by: springcreek on January 02, 2014, 08:09:27 PM
Cool let me know how it goes William.

Cheers, Andy
Title: Re: My new amp
Post by: Jehuty on January 03, 2014, 10:22:00 PM
Hi Andy,

If you're looking for an oil filled choke, this could work very well: http://www.ebay.com.au/itm/220793933835

That is the choke that Steve uses in his PX4 amp. I have already got a pair in my type 50 amp. I just measured the resistance and it's 93 ohms, pretty close to 100 ohms  8)

For the money it's a bargain, you only need to convince the seller to ship to Australia which I think it won't be hard since it's been on eBay for ages. Grab a pair while you're at it too!  ;D

Cheers,
William
Title: Re: My new amp
Post by: zenelectro on January 04, 2014, 12:44:20 AM
Hi Andy,

If you're looking for an oil filled choke, this could work very well: http://www.ebay.com.au/itm/220793933835

That is the choke that Steve uses in his PX4 amp. I have already got a pair in my type 50 amp. I just measured the resistance and it's 93 ohms, pretty close to 100 ohms  8)

For the money it's a bargain, you only need to convince the seller to ship to Australia which I think it won't be hard since it's been on eBay for ages. Grab a pair while you're at it too!  ;D

Cheers,
William

Ask the seller - How many Henrys?

That's the important spec.

Z


Title: Re: My new amp
Post by: Jehuty on January 04, 2014, 01:01:49 AM
Hi Terry,

It's 8 henry, 200mA. I knew since I got a pair at home  8)

Cheers,
William
Title: Re: My new amp
Post by: Jehuty on January 04, 2014, 01:07:53 AM
Hi Terry,

While you're at it, what sort of choke specs would you recommend to replace the R21 in the attached schematic? The R21 is on the top right corner next to the C13 and GZ34.

Cheers,
William
Title: Re: My new amp
Post by: zenelectro on January 04, 2014, 10:30:51 AM
Hi Terry,

While you're at it, what sort of choke specs would you recommend to replace the R21 in the attached schematic? The R21 is on the top right corner next to the C13 and GZ34.

Cheers,
William

Hi William,

Replacing R21 with a choke may or may not be an improvement.
You will certainly get lower PS ripple / noise for sure and even 1 Henry will be improvement over straight resistor.

The caveat is that (and not many people understand this) the 2 caps and inductor (choke) resonate, ie;
bounce like an un damped spring depending on the values.

I did a simulation of this circuit and at 1H it is pretty well behaved but at say 5H there is a lot of 'bounce'.
This will have some sonic effect.

Zen idea - You can actually put various damping networks in and get the benefits of a large choke (say 5H / 10H) with
no 'bounce' but I have never seen this done on any classic valve amp.

Maybe time to try this out Steven / Vita - it should have way more impact than any piece of wire etc. :) 

So to answer your question, William - around 1H / probably 4H max at a guess should be good but keep DC R to 100R or less.

Z


Title: Re: My new amp
Post by: Jehuty on January 04, 2014, 12:27:40 PM
Hi Terry,

While you're at it, what sort of choke specs would you recommend to replace the R21 in the attached schematic? The R21 is on the top right corner next to the C13 and GZ34.

Cheers,
William

Hi William,

Replacing R21 with a choke may or may not be an improvement.
You will certainly get lower PS ripple / noise for sure and even 1 Henry will be improvement over straight resistor.

The caveat is that (and not many people understand this) the 2 caps and inductor (choke) resonate, ie;
bounce like an un damped spring depending on the values.

I did a simulation of this circuit and at 1H it is pretty well behaved but at say 5H there is a lot of 'bounce'.
This will have some sonic effect.

Zen idea - You can actually put various damping networks in and get the benefits of a large choke (say 5H / 10H) with
no 'bounce' but I have never seen this done on any classic valve amp.

Maybe time to try this out Steven / Vita - it should have way more impact than any piece of wire etc. :) 

So to answer your question, William - around 1H / probably 4H max at a guess should be good but keep DC R to 100R or less.

Z

Hi Terry,

Thanks for the explanation, always appreciate your input :)

Yes, I read about that resonating power supply on DIY Audio forum (see http://www.diyaudio.com/forums/pass-labs/50061-crcrc-vs-lclclc-better-why.html#post558136) and I was wondering what it meant.

In that thread Nelson Pass suggest we use "porno" big cap after the L and add small value resistors across the inductors to help damping out the system. He did mention the resistors value about 10 ohm or less but he never said anything about the value of the big cap (I guess it all depends on the circuit). Now back to the Leak Stereo 20 circuit I posted above, would 252uF be enough for this? Taking into account using the 8 henry choke on eBay or even bigger like 10 henry.

I asked because I read on the Leak Yahoo Group that paralleling 100uF or bigger to C12 (32uF) would yield improvement in the bass respond and I have already bought a cheapo Panasonic electrolytic 220uF/400VDC just to try this out. It would be good if the increase capacitance in C12 does help damping out the system too. Or should we use even bigger cap say 1000uF? "Porno" big confuses me  ??? ??? ;D

Thanks,
William
Title: Re: My new amp
Post by: zenelectro on January 04, 2014, 01:22:35 PM
Hi Terry,

While you're at it, what sort of choke specs would you recommend to replace the R21 in the attached schematic? The R21 is on the top right corner next to the C13 and GZ34.

Cheers,
William

Hi William,

Replacing R21 with a choke may or may not be an improvement.
You will certainly get lower PS ripple / noise for sure and even 1 Henry will be improvement over straight resistor.

The caveat is that (and not many people understand this) the 2 caps and inductor (choke) resonate, ie;
bounce like an un damped spring depending on the values.

I did a simulation of this circuit and at 1H it is pretty well behaved but at say 5H there is a lot of 'bounce'.
This will have some sonic effect.

Zen idea - You can actually put various damping networks in and get the benefits of a large choke (say 5H / 10H) with
no 'bounce' but I have never seen this done on any classic valve amp.

Maybe time to try this out Steven / Vita - it should have way more impact than any piece of wire etc. :) 

So to answer your question, William - around 1H / probably 4H max at a guess should be good but keep DC R to 100R or less.

Z

Hi Terry,

Thanks for the explanation, always appreciate your input :)

Yes, I read about that resonating power supply on DIY Audio forum (see http://www.diyaudio.com/forums/pass-labs/50061-crcrc-vs-lclclc-better-why.html#post558136) and I was wondering what it meant.

In that thread Nelson Pass suggest we use "porno" big cap after the L and add small value resistors across the inductors to help damping out the system. He did mention the resistors value about 10 ohm or less but he never said anything about the value of the big cap (I guess it all depends on the circuit). Now back to the Leak Stereo 20 circuit I posted above, would 252uF be enough for this? Taking into account using the 8 henry choke on eBay or even bigger like 10 henry.

I asked because I read on the Leak Yahoo Group that paralleling 100uF or bigger to C12 (32uF) would yield improvement in the bass respond and I have already bought a cheapo Panasonic electrolytic 220uF/400VDC just to try this out. It would be good if the increase capacitance in C12 does help damping out the system too. Or should we use even bigger cap say 1000uF? "Porno" big confuses me  ??? ??? ;D

Thanks,
William

The values change for every application.

You have to run it through a simulator and observe the ringing. So what works for Pass amp will be way off
for a tube amp. All the components will 'react' with each other.

For all these upgrades / mods best option is formulate a plan - don't just buy parts at random. You will end
up spending a lot of money.

Z



Title: Re: My new amp
Post by: vitavoxdude on January 04, 2014, 01:41:34 PM
GZ34 should not look into a large cap prior to the inductor, it's currently set at 16 uF, the maximum safe load.  After the resistor (or choke as you want to insert)its a different matter. I would keep the power supply design as is, change out the resistor for a tantalum if you can get the power handling and replace the caps with some Jensen 4 poles.

Porno big, well yes that's an expression to mean huge(as in the male appendages that they hire the blokes for in colourful movies- pornography)! :o  Bigger caps do not always = better sound, as Zen has  mentioned the leak is a tuned circuit which you will potentially upset with a large inductor. 

Large caps can slow down the sound and your amp is never going to be a bass monster so forget about placing massive caps after the resistor.  Even changing to PP caps may unbalance the sound, you can always try them but you may not prefer them.  Now the most important piece of advice I can give, only do one change at a time and see if its better or worse; changing too many things at once its impossible to say which way things are going.  Leak had a whole design team of engineers, I think they would have spent many months finalising the sound to what it currently has, changing the circuit in the way you describe may alter it to being a far worse performer than it is unmodified.

So come on Zen, share this latest supply wonder, is it the 'electronic choke by chance?  ::)

I never denigrate the hard work done by others (and I am thinking of Steve V here) when it comes to the hard yards of trying out many different combinations of components and circuits for the benefit of others; I particularly enjoyed reading the recent experience with the AN resistors, the same material but different outcomes.................. :-X

I suppose I also accept that its all about the circuit and the way various items react with each other and simulations done with the Duncan pwr supply designer etc will not reveal what they sound like, only measure / resonate / bounce. :'(  For the many who took the leap of faith into the NOS world of the KDAC did we all fry our tweeters with the RF noise, well hell no.  I know faith can be blind but perfectly measuring equipment sounds bland and sterile, I have many such pieces gathering dust.  :(

The Leak stereo 20 is not a bad amp, it's not the best Leak by a country mile, messing with the circuit is going to upset it, by all means use the best valves and components but alter the overall circuit at your peril. ::)  IMV the correct biasing of the valves will bring more reward than swapping many components, get that right before attempting any more 'tweaks'.  :o
V :)
V
Title: Re: My new amp
Post by: Jehuty on January 04, 2014, 01:56:40 PM
Thanks for the advice gents. They all make sense and are appreciated  :)

That's actually my plan, not to mess around with the original circuit as I'd like to keep the Leak small and simple. Adding a big choke will probably need external power supply and that defeat the purpose of small and simple. The only thing that I will try is paralleling the C12, it's cheap only $3, doesn't need an external power supply and who knows, I might like it  ;)

Cheers,
William
Title: Re: My new amp
Post by: zenelectro on January 04, 2014, 06:51:37 PM

Leak had a whole design team of engineers, I think they would have spent many months finalising the sound to what it currently has, changing the circuit in the way you describe may alter it to being a far worse performer than it is unmodified.


I think you might be putting just a touch too much subjective wind in these designers sails. These guys didn't really know what they were creating, subjectively speaking in the grand scheme of things.
They were just doing the best they could with what was available. Carbon comp resistors were it, polyester caps were it. 
They were actually mainly going for low measured distortion and linearity hence the Ultra Linear OP stage and plenty of global FB. The same goes for the designers of the very first solid state mixing consoles they
honestly thought they would sound much better than their valve predecessors!

History tells us it didn't quite pan out that way. A friend of mine, years ago interviewed the great Rupert Neve and pretty much same story - he wished for quite a while that all those
early SE / choke loaded SS mix consoles would go away so people would embrace his newer and what he genuinely believed were superior sounding and measuring consoles. A lot of the stuff he does now
goes back to and draws heavily from the early vintage era SE designs - because that is peoples preference.
 
Quote

So come on Zen, share this latest supply wonder, is it the 'electronic choke by chance?  ::)


No I have never been interested in EC's. I have just observed that most of these typical CLC power supplies ring (oscillate) when I put them in a simulator - some quite badly.
My real life experience on various circuit elements supports this. It's a matter of being aware of it and having the counter measure in your 'tool box' to try.

Years ago I did a mix console upgrade in a studio, replaced all opamps, biased them into class A etc. Had to use more local decoupling caps Result was + step in all areas but it sounded a bit edgy and etched.
The engineer said I had increased the HF response. I said no it's something else, the response is flat - thinking on my feet I proceeded to insert a 5 or 10 ohm R feeding every bypass cap to separate them with a lossy type network and bingo - edge gone. They were ringing at some VHF.
 
Quote

I never denigrate the hard work done by others (and I am thinking of Steve V here) when it comes to the hard yards of trying out many different combinations of components and circuits for the benefit of others; I particularly enjoyed reading the recent experience with the AN resistors, the same material but different outcomes.................. :-X


Maybe it's unintentional, however I see quite a degree of denigration - towards more modern designers / designs. A lot of these people have put a huge amount of work into the advancement of audio.
Their intentions are absolutely honorable however full understanding of objective versus subjective can take a lifetime to get a handle on - see R Neve above. Same goes for TDA1540/1, a brilliant Dutch engineers
work. He was doing same thing - just the best he could with the technology at that time. It was a big part fluke that it ended up being subjectively possibly the best sounding DAC ever made.

Quote

I suppose I also accept that its all about the circuit and the way various items react with each other and simulations done with the Duncan pwr supply designer etc will not reveal what they sound like, only measure / resonate / bounce. :'( 


Duncan's is great for quick and dirty - but it does make some interesting mistakes. Spice is the ticket and much better, but as always its GIGO. I use them as helpers to see a potential issue, to tell me where to
look, where to tweak. That's what they are good for.   

Quote

For the many who took the leap of faith into the NOS world of the KDAC did we all fry our tweeters with the RF noise, well hell no.  I know faith can be blind but perfectly measuring equipment sounds bland and sterile, I have many such pieces gathering dust.  :(


I don't think 0 x OS has ever been a major LOF it's not unfiltered DSD :) I'd been meaning to try it for years ever since Kusunoki / Thorsten did it.

In the end this all should be part of a timeline of knowledge gathering - not an absolute serving peoples egos. Too common in this game.

Quote

The Leak stereo 20 is not a bad amp, it's not the best Leak by a country mile, messing with the circuit is going to upset it, by all means use the best valves and components but alter the overall circuit at your peril. ::)  IMV the correct biasing of the valves will bring more reward than swapping many components, get that right before attempting any more 'tweaks'.  :o
V :)
V

I think a small / moderate sized inductor in the power supply to replace the R is a pretty safe bet on an improvement with the Leak. I like the design in general, quite
simple and efficient.


Z

 

Title: Re: My new amp
Post by: Erik van Voorst on January 06, 2014, 03:04:24 AM
Let the mods begin!  ;D

 Only JJ electrolytics as my budget is limited, maybe next year for Jensen if I can be bothered. I got all tantalum resistors however, Shinkoh wherever possible, Audio Note to cover the rest. Cost me about $350, yep, just resistors!  >:(


Do not under estimate the JJ,  in my pre amp it outperformed the Jensen in a listening session..so be cautious not to buy things based on the name...to me there is no such thing as one size fits all... ;)
No need to tell you that resistorwise you chose well...although you can still "season"  your amp with them  8)
Title: Re: My new amp
Post by: Jehuty on January 06, 2014, 03:20:01 AM
Let the mods begin!  ;D

 Only JJ electrolytics as my budget is limited, maybe next year for Jensen if I can be bothered. I got all tantalum resistors however, Shinkoh wherever possible, Audio Note to cover the rest. Cost me about $350, yep, just resistors!  >:(


Do not under estimate the JJ,  in my pre amp it outperformed the Jensen in a listening session..so be cautious not to buy things based on the name...to me there is no such thing as one size fits all... ;)
No need to tell you that resistorwise you chose well...although you can still "season"  your amp with them  8)

Hi Erik,

Thanks for the advice. Yes, I am very well aware that JJ is very good and affordable too, hence I said above "if I can be bothered to change to Jensen"  ;)

I bought some more Allen Bradley 2 watt resistors to "season" more. I would also like to try Riken or Amtrans in the future, all good fun!

Regards,
William
Title: Re: My new amp
Post by: zenelectro on January 06, 2014, 09:10:53 AM
Let the mods begin!  ;D

 Only JJ electrolytics as my budget is limited, maybe next year for Jensen if I can be bothered. I got all tantalum resistors however, Shinkoh wherever possible, Audio Note to cover the rest. Cost me about $350, yep, just resistors!  >:(


Do not under estimate the JJ,  in my pre amp it outperformed the Jensen in a listening session..so be cautious not to buy things based on the name...to me there is no such thing as one size fits all... ;)
No need to tell you that resistorwise you chose well...although you can still "season"  your amp with them  8)

Hi Erik,

Thanks for the advice. Yes, I am very well aware that JJ is very good and affordable too, hence I said above "if I can be bothered to change to Jensen"  ;)

I bought some more Allen Bradley 2 watt resistors to "season" more. I would also like to try Riken or Amtrans in the future, all good fun!

Regards,
William

WRT Jensen also bear in mind 4 pole Jensen versus normal HV types.

The 4 poles IME sound cleaner / clearer and the high voltage types richer. The 4 poles also benefit from utilising the ground connection 'break' which
is not always possible, depends on circuit. 

Z

Title: Re: My new amp
Post by: Jehuty on January 07, 2014, 03:06:17 AM
Z, can we use 4 pole Jensen in the Leak 20? Say for example replacing the C12...
Title: Re: My new amp
Post by: zenelectro on January 07, 2014, 10:50:53 AM
Z, can we use 4 pole Jensen in the Leak 20? Say for example replacing the C12...


Yep, both caps can be replaced with 4 poles and have the benefit of proper 4 pole connection.
The grounding might have to be rewired a little but should be no problems.

In fact by adopting this type of connection you are optimising PS grounding the way it should be done. I see some pretty creative
grounding schemes in my travels :)

Title: Re: My new amp
Post by: springcreek on January 14, 2014, 08:16:00 AM
Hi all

Looks like there has been a great discussion while I've been up in the mountains. Thanks for advancing this guys, some great information.

Does not sound like the CLC is the way to go for the Leak. I don't want to lose the speed of the amp, I was just chasing more wetness and richness.

Zen is there much benefit in going from the Solen I have used in the power supply to Jensen 4 poles? I am still getting some residual hum from the power supply, but that may be reduced by a slightly larger cap?

A am keen to replace most of the remaining cheap carbon resistors with 2 watt Allen Bradley's and a sprinkling of Shinkoh's, especially on the input. I am also keen to get rid of the small electrolytics and was planning to use Solen's here as Steven did. Any thoughts?

I would like to take the Leak as far as possible. I'm not really trying to turn it into a bass monster, but maximise the things it already does well.

Cheers
Title: Re: My new amp
Post by: ozmillsy on January 14, 2014, 10:20:39 PM
If there is a sliding scale from 0 to 10 where....

0 = Full, rich, thick, heavy
10 = Clean, detailed, fast, thin

Then a stock Leak leans towards a 7 to 8, in my opinion.  The best sounding Leak I've heard was SV's Leak,  and he had to work hard to get the body into it that it lacked (cant believe he sold it).  

Building on the strengths that are already there isnt necessarily where the magic is.  Gotta give it what it needs.

The Allen Bradleys should go well. As I understand, they need a bit of time in circuit.

Have fun with it.

Title: Re: My new amp
Post by: springcreek on January 14, 2014, 10:35:57 PM
Well that's what I'm hearing. Keen to add the AB's and see how far that takes me. It is why I was keen on the oil filled choke and vintage PIO caps.

Will try and find some richer, warmer sounding input tubes/phase splitters.

Cheers
Title: Re: My new amp
Post by: zenelectro on January 15, 2014, 11:35:37 AM
Hi all

Looks like there has been a great discussion while I've been up in the mountains. Thanks for advancing this guys, some great information.

Does not sound like the CLC is the way to go for the Leak. I don't want to lose the speed of the amp, I was just chasing more wetness and richness.

Zen is there much benefit in going from the Solen I have used in the power supply to Jensen 4 poles? I am still getting some residual hum from the power supply, but that may be reduced by a slightly larger cap?

A am keen to replace most of the remaining cheap carbon resistors with 2 watt Allen Bradley's and a sprinkling of Shinkoh's, especially on the input. I am also keen to get rid of the small electrolytics and was planning to use Solen's here as Steven did. Any thoughts?

I would like to take the Leak as far as possible. I'm not really trying to turn it into a bass monster, but maximise the things it already does well.

Cheers

WRT Leak sounding clean versus rich - this doesn't surprise me a bit. The design uses lots of feedback both local, in the OP stage itself and global which comes back to V1 under the cathode.

As such it's difficult to 'tune' this amp to sound more like a non feedback SET - whatever you do to add richness - the feedback loop will be fighting against that to bring it back.

WRT PS hum - just make sure it is the power supply and not AC heater bleeding through somewhere.

If you guys are wanting a sound closer to SV's 45 SET amps but with more power, a non feedback, push pull amp, Triode connected is a better way to go. 4 x EL84's will get you about 15 watts.

Check schem below for what I mean - just use 4 OP tubes and 1 IP tube. This will sound really good even with average parts - but you'll need decent transformers.

cheers

Z
Title: Re: My new amp
Post by: springcreek on January 15, 2014, 10:51:16 PM
Thanks Zen

Didn't know there was that much feedback. Explains a lot.

Will see what adding the AB's will do. Craig C and Steven have both managed to get some real magic out of the Leak. Suspect if I don't stray too far from what they did I should be in the ballpark.

Would love to build a copy of Stevens 50 amp one day or maybe a push pull 45.

Cheers, Andy
Title: Re: My new amp
Post by: springcreek on January 16, 2014, 08:31:28 AM
Zen

The guy I bought the Leak off in the UK deals in Leaks and Quads. He converts the Stereo 20 to triode as says he loves what it does. What do you think of doing this?

Cheers, Andy
Title: Re: My new amp
Post by: vitavoxdude on January 16, 2014, 10:13:15 AM
 ;D If you are happy with what Craig and Steve  have achieved with a leak stereo 20 then replicate exactly what they done, simple!
V ;)
Title: Re: My new amp
Post by: zenelectro on January 16, 2014, 01:12:56 PM
Zen

The guy I bought the Leak off in the UK deals in Leaks and Quads. He converts the Stereo 20 to triode as says he loves what it does. What do you think of doing this?

Cheers, Andy

Hi Andy,

The existing circuit is designed and optimized for Pentode operation (which has more gain).
It works with feedback wrapped around the whole thing to get low OP impedance / lower distortion.   

With Triode operation the power is around 1/2 of Pentode so you need to double up on OP tubes to get same power.
However, Triode operation is more linear, has lower distortion and OP impedance than Pentode.
As such the amp can run without any feedback - which nearly always sounds better - for a given parts quality.

The Leak cct design is pretty standard approach for the day, simple and worked very well being fairly tolerant of layout parts drift / quality.
To make major change the existing amp is not really recommended. I can certainly do it but OP power will 1/2 and it's a significant design change.   

However if the quest is the best sounding low (or high) power PP amp - then I think a better foundation to start with is definitely the triode / NFB approach.


cheers

Z
Title: Re: My new amp
Post by: springcreek on January 17, 2014, 08:12:38 AM
Thanks for the advice guys. I will stick to the original circuit and make changes according to what Steven and Craig have done. Have orderd some Shinkoh's for critical spots and will order the rest of the Allen Bradleys soon.

Appreciate the input everyone has provided in this thread...will report back soon  ;D

Cheers
Title: Re: My new amp
Post by: zenelectro on January 17, 2014, 10:37:18 AM
Thanks for the advice guys. I will stick to the original circuit and make changes according to what Steven and Craig have done. Have orderd some Shinkoh's for critical spots and will order the rest of the Allen Bradleys soon.

Appreciate the input everyone has provided in this thread...will report back soon  ;D

Cheers

No worries.

WRT 'critical' components - ref circuit diag below. IME these parts being part of the feedback loop itself always make a big difference to sound.

Anything you change 'inside' the feedback loop, the amp will try to null that change to a degree or make the change less.
The components circled will have a direct and profound influence.

As an example, I repaired / modded a 200W Marshall Major amp last year. The tone controls were inside the FB loop... very strange ??
The first thing I thought on listening to it, 'why don't the tone controls work properly'? Being inside the loop the amp is nullify their very operation.

Disconnected FB loop - much better sound (no esoteric parts required), tone controls work as they should. Owner V happy. :)
 
Z

Title: Re: My new amp
Post by: Jehuty on January 18, 2014, 12:32:48 AM
Zen, I would like to try remove the local feedback cap (C9) completely. Would this be a problem?

Thanks,
William
Title: Re: My new amp
Post by: stevenvalve on January 18, 2014, 01:33:14 AM
William take out the 22K from the R2R and R2L positions, leave it out, but leave the 1M to ground and make it a shinkoh 2 watt tantalum.
Title: Re: My new amp
Post by: zenelectro on January 18, 2014, 01:35:41 AM
Zen, I would like to try remove the local feedback cap (C9) completely. Would this be a problem?

Thanks,
William

Yep - could be. The amp may well oscillate if the cap is removed, or if not it may be less stable.

Unless you can check it with a CRO, I recommend leaving it there, just use a good qual film cap.
Wima FKP are not bad. If there are any Ceramic disc caps in the amp, I recommend replacing them. 

cheers

Z   
Title: Re: My new amp
Post by: zenelectro on January 18, 2014, 01:41:23 AM
William take out the 22K from the R2R and R2L positions, leave it out, but leave the 1M to ground and make it a shinkoh 2 watt tantalum.

Yep, that's worth doing - it's also outside the FB loop.

Grid resistors used on fast tubes like 437A 417A etc to stop oscillation and RF issues. With 12AX7 not generally necessary.

Z
Title: Re: My new amp
Post by: Jehuty on January 18, 2014, 01:50:06 AM
Great advice gents. Thanks heaps  :)
Title: Re: My new amp
Post by: stevenvalve on January 24, 2014, 01:48:34 AM
Having fun, Because the leak Stereo 20 found its way back home. The buyer sold it back to me (Crazy). I put it on straight away and was amazed at how good it sounded. So I decided to start working on it. The duelunds where removed when I sold it. I will decided later if they go back in, at the moment it uses 4 old NOS Mullard mustard caps, they are very good sounding. As you can see no posts on the back, Eichmann's are coming, I must say, the leak sounds incredible.
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 02:36:22 AM
We need to figure out how to extract more body and weight from the Leak. But I guess if the Leal is run with reel to reel setup we will have more body and weight.

Steve, forget the binding posts, just solder the speaker cable directly!  ;D
Title: Re: My new amp
Post by: springcreek on January 24, 2014, 08:22:57 AM
Yes more body is what the Leak needs.

I have Eichmans on mine  ;D

Keen to get some Cu WBT's on the input.
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 12:53:27 PM
I got this Cardas CCBP-s unplated pure copper as my binding posts: http://www.partsconnexion.com/product7444.html

I chose it over Eichmann because I think the Eichmann is a bit flimsy. I broke a couple already  >:(

I hope the Cardas sounds as good as the Eichmann.

Andy, the Cu WBT next gen is the one to get US$ 88: http://www.partsconnexion.com/product9725.html

There's another Cu WBT on sale US$ 39.95, could be pretty good and save you some bucks: http://www.partsconnexion.com/wbt0274cu.html

 ;D
Title: Re: My new amp
Post by: springcreek on January 24, 2014, 01:39:10 PM
Cool thanks William, nice looking posts.

I need three sets of next gens. One set for the Leak and two for my volume control....ouch!
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 02:11:27 PM
Hi William

I like the Leak a lot. Still have Sovteks in it at the moment which are pretty awful. They are really limiting the magic. Also there has been a lot of changes to my system around the same time. I have new speaker cabinets (Shindo style cabinets that Damian made), new speaker wires (Auditorium 23 also from Damian), new turntable (Micro-seiki), new tonearm (Fidelity Research), new cartridge (Garrott P77i), and new phono stage (Graham Slee Reflex M).

I am getting a great result so far, but need to do some tuning as while the bass is very good I'd like it better still. Only minor really, but I'm hoping I can get it sorted. The results are a long way ahead of where I was before!  ;D

I will be replacing the front baffle (see pic) with a veneered one when funds allow.

Let me know how you go with the new speaker cabinets.

Cheers, Andy

Ps. To give some idea of scale the TV is 50 inches.
 
Pps. The Rainbow Diffusor is for sale at $500 a pop  :P

I finally got a chance to have a good listen to Andy's new system a couple of days ago.

As you can see in the attached pic, Andy's using a Shindo style cabinet where the back panel is half open. Beautiful cabinet! Thumbs up! To Damian, I'd like to order some cabinets and hifi racks please  ;D

During listening session, Andy covered his 55 inch LED TV with a blanket, wise move there as I usually find the reflection from the glass panel can be a bit distracting. What I like the most about his system is that how his system can convey music in the most musical way, gone are the edginess and brittleness of the modern hifi sound. People will say it's coloured but when the media and the so called expert hifi reviewers in general tell us that lean and analytical sounding is fcukin' ACCURATE  >:(  then I will choose coloured anytime anywhere.

I notice his system has all the fundamental attributes to be a great one such as sheer musicality, very engaging and organic, would love to have more harmonic richness, it's there but more would be better. No digital harshness I could detect anywhere. Some things that he needs to address are slight dryness and thinness. His system needs more body and weight. I believe he's got a few tricks up on his sleeves already with the help of our friend Duc in Melbourne  ;)

There's also a bit of smear in sound when he was playing bass heavy track. I could hear the vibration of the cabinets causing the smear and the sound became less focus. He's already got a pair of vintage Goodmans Sherwood cabinets to address this issue. I just hope the new cabinets will not thin out his system more. This is a very hard thing to get balance.

Andy, you've done very well there with your Goodmans Axiom 300 (great driver by the way!) and the Leak Stereo 20. Not far away from a great sounding system that we always crave. I personally can't wait to listen to your system again with the new upgrades on the way. I wish you all the best in your journey! Thanks so much for a nice listening session, man I stayed there for 3 hours and it simply felt like 10 minutes at most, I guess that what usually happens when an engaging and musical system is presented, just like when I first listened to stevenvalve's system in the mountains.

Cheers,
William
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 02:13:31 PM
Cool thanks William, nice looking posts.

I need three sets of next gens. One set for the Leak and two for my volume control....ouch!

Yeah, a lot of money but it's worth it. Just buy a pair every month like what I've been doing and you can end up like me having a stash of it  ;D
Title: Re: My new amp
Post by: springcreek on January 24, 2014, 03:16:41 PM
Great write up William, as always it was a pleasure to have you here. I think you captured the system perfectly.

The lack of body is a real issue for me as is the tonal dryness that the Graham Slee phono adds or at least accentuates. Hopefully the changes on the way will address these issues. I am always looking for ways to add more body to the system.

One thing the system does very well is highlight the differences between recordings. I love the trait and don't want to lose it, even if the end result can be somewhat confronting or not what you expect.

As a few of you know Heldulfa and I are planning another GTG later this year. I am on a mission to have the system really singing by then.

Hopefully you guys can make it!

I will post more soon when we set a date, nominally it will be either the last two weeks of April or the first week's of May.

Thanks again for an enjoyable listening session and write up William.

Cheers, Andy
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 03:25:34 PM
One thing the system does very well is highlight the differences between recordings.

That is so true. I should add that initially I thought the system didn't have enough high frequency extension and not open enough but then when you started to play better records the system certainly showed the high frequency extension which was missing in the lesser quality records and it was actually very open sounding too.
Title: Re: My new amp
Post by: gamve on January 24, 2014, 04:15:46 PM
I got this Cardas CCBP-s unplated pure copper as my binding posts: http://www.partsconnexion.com/product7444.html

I chose it over Eichmann because I think the Eichmann is a bit flimsy. I broke a couple already  >:(

I hope the Cardas sounds as good as the Eichmann.

Andy, the Cu WBT next gen is the one to get US$ 88: http://www.partsconnexion.com/product9725.html

There's another Cu WBT on sale US$ 39.95, could be pretty good and save you some bucks: http://www.partsconnexion.com/wbt0274cu.html


 ;D

Hi William,
These terilliam copper posts are very good sounding units. The copper is very soft be careful that you do not overtighten them.
You might find that these posts are not much stronger mechanically than the Eichmans.
Cheers
Graham
Title: Re: My new amp
Post by: hedalfa on January 24, 2014, 05:49:17 PM
Hi William

I like the Leak a lot. Still have Sovteks in it at the moment which are pretty awful. They are really limiting the magic. Also there has been a lot of changes to my system around the same time. I have new speaker cabinets (Shindo style cabinets that Damian made), new speaker wires (Auditorium 23 also from Damian), new turntable (Micro-seiki), new tonearm (Fidelity Research), new cartridge (Garrott P77i), and new phono stage (Graham Slee Reflex M).

I am getting a great result so far, but need to do some tuning as while the bass is very good I'd like it better still. Only minor really, but I'm hoping I can get it sorted. The results are a long way ahead of where I was before!  ;D

I will be replacing the front baffle (see pic) with a veneered one when funds allow.

Let me know how you go with the new speaker cabinets.

Cheers, Andy

Ps. To give some idea of scale the TV is 50 inches.
 
Pps. The Rainbow Diffusor is for sale at $500 a pop  :P

I finally got a chance to have a good listen to Andy's new system a couple of days ago.

As you can see in the attached pic, Andy's using a Shindo style cabinet where the back panel is half open. Beautiful cabinet! Thumbs up! To Damian, I'd like to order some cabinets and hifi racks please  ;D

During listening session, Andy covered his 55 inch LED TV with a blanket, wise move there as I usually find the reflection from the glass panel can be a bit distracting. What I like the most about his system is that how his system can convey music in the most musical way, gone are the edginess and brittleness of the modern hifi sound. People will say it's coloured but when the media and the so called expert hifi reviewers in general tell us that lean and analytical sounding is fcukin' ACCURATE  >:(  then I will choose coloured anytime anywhere.

I notice his system has all the fundamental attributes to be a great one such as sheer musicality, very engaging and organic, would love to have more harmonic richness, it's there but more would be better. No digital harshness I could detect anywhere. Some things that he needs to address are slight dryness and thinness. His system needs more body and weight. I believe he's got a few tricks up on his sleeves already with the help of our friend Duc in Melbourne  ;)

There's also a bit of smear in sound when he was playing bass heavy track. I could hear the vibration of the cabinets causing the smear and the sound became less focus. He's already got a pair of vintage Goodmans Sherwood cabinets to address this issue. I just hope the new cabinets will not thin out his system more. This is a very hard thing to get balance.

Andy, you've done very well there with your Goodmans Axiom 300 (great driver by the way!) and the Leak Stereo 20. Not far away from a great sounding system that we always crave. I personally can't wait to listen to your system again with the new upgrades on the way. I wish you all the best in your journey! Thanks so much for a nice listening session, man I stayed there for 3 hours and it simply felt like 10 minutes at most, I guess that what usually happens when an engaging and musical system is presented, just like when I first listened to stevenvalve's system in the mountains.

Cheers,
William


Good review William, one which highlights strengths as well as things to possibly work on is appreciated. There is a lot of potential locked up in these Goodmans drivers they have much more resolution than many people realise.  8) 8) 8) 8)  People may be surprised when Andy has these at the next level.  
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 06:05:17 PM
I have no doubt that the Goodmans Axiom 300 can be a lot better again! Far out, for the price Andy's got the drivers it's a STEAL!
Title: Re: My new amp
Post by: Jehuty on January 24, 2014, 06:07:11 PM
Hi William,
These terilliam copper posts are very good sounding units. The copper is very soft be careful that you do not overtighten them.
You might find that these posts are not much stronger mechanically than the Eichmans.
Cheers
Graham

Hi Graham,

Thanks for the warning, I'll keep that in mind not to overtighten them. Good to know that they sound pretty good  :)

Cheers,
William
Title: Re: My new amp
Post by: ozmillsy on January 24, 2014, 09:19:31 PM
It's the hardest balance to get,  that fine line between lovely rich (flesh on bone) body,  and extended air detail and speed.

I reckon real 'presence' is easy to lose, and hard to get back.   As Steven and Mario keep saying (and it has sunk in with me guys) it all starts at the source. 

The phono upgrade looks to be a great move.   Alot of people rate the slee's,  but they'll never do what a good tube phono can, IMHO.

Pick a date Andy, so we can all set it aside. :)
Title: Re: My new amp
Post by: ozmillsy on January 24, 2014, 09:42:45 PM
Oh BTW, great write up William.

We should have a house rule that open feedback is always welcomed.

The only way to move forward, is by working together and sharing honestly what we hear.  

Next time you visit William, I expect some feedback, warts and all.  ;)
Title: Re: My new amp
Post by: springcreek on January 24, 2014, 10:36:32 PM
Good points Oz, advice and constructive criticism is always welcome.

I am always craving more body, weight and wetness, but it is easy to go too far. The new phono stage should be a big step forward and allow me to tune things further.

I will set a date in the coming days.

Cheers
Title: Re: My new amp
Post by: Jehuty on January 25, 2014, 11:40:02 AM
Hi Andrew,

Thanks. I'd like to hear your improved Radford vs Leak again if possible. That would be very interesting.

Cheers,
William
Title: Re: My new amp
Post by: ozmillsy on January 25, 2014, 12:56:31 PM
Thanks. I'd like to hear your improved Radford vs Leak again if possible. That would be very interesting.
You're welcome to bring around the Leak anytime.  The Radford has been 'fixed' rather than improved,  all I did was put back in some caps (that had previously been removed).

Getting feedback from visitors is really invaluable, IMHO.  Our audio systems are like coffee.  If you drink the same brand/type of coffee everyday, you get accustomed to the taste and it seems normal.  Audio is the same.

A fresh set of ears, and willingess to describe what you hear,  goes a long way for the owner.
Title: Re: My new amp
Post by: vitavoxdude on January 25, 2014, 03:20:03 PM
Oz

Quote
Getting feedback from visitors is really invaluable, IMHO.  Our audio systems are like coffee.  If you drink the same brand/type of coffee everyday, you get accustomed to the taste and it seems normal.  Audio is the same.

I think this can also lead to an endless merry go round of upgrades; whilst this is fine if you actively seek the comments from others if you are happy with what you have then keep it.  To be told negative things just pulls the smile form your face and is not too healthy long term IMV.  It's a bit like life partners, we all know they are not exactly what we'd like but substituting them for a different model does not always bring long term satisfaction.

Changing out items such as binding posts will bring a tiny incremental improvement but if the amp is not up to driving the speakers in the room you have then wasted time / money.  I do applaud those dedicated types who are willing to experiment but taking a 1000 dollar amp and spending another 1K on it does not turn it into a 2K + amp.

I read that more body and wetness is looked for.  I'd suggest looking at different valves and amps long term.  I have owned a Leak Stereo 20 and Leak TL12.1's; the later totally kicks sand in the face of its cheaper sibling, a case of the top of the line being compared to the cheaper model, harsh but the truth.  A friend of mine used to use the term " it's pointless polishing a turd as at the end of it all you are still left with a turd".  In car terms it would be taking a ford fiesta and trying to turn it into F1 car, they all have 4 wheels but the end result is quite different.

My end advice is get the pair of speakers you can live with in the room where you relax and enjoy music then put the best source (KDAC) up front and fit an amp to taste be it Vv or SS in between.  Speakers set the major tonality of the outcome and everything else like the detail and rhythm comes from the front end.  It's a shame all the dealers moved away from the switchable speaker banks, at least this enabled rapid changes on the back end, this enabled you to hear how bright the yamahas were in comparison to the like's of Kef' and Celestions, how efficient the Klipsh's were compared to most others etc.

Beauty is in the eye and ear of the beholder, magazines and others views on your 'system' will keep you ever chasing your tail and a trail as long as your arm of discarded / sold equipment.  Check out SNA second hand section of for sale items........................

By all means change your brand of coffee, but if you love the one you have, why change it.  This sounds like a feminine thing of change for changes sake.  Before I'd be thinking of changing out binding posts I would want to make sure that all the rubbish speaker manufactures fit inside their built down to a price boxes is improved first, then the caps etc.  Trying to change the basic character of a system requires a change in approach to the design, beyond most and totally impractical IMO.

Anyway enough wittering from me, just bear in mind the end game and spend accordingly.  Enjoy your travels and try to avoid the audionovosa of doubting thomas; 10 people will all criticise different elements and struggle to agree most things audio!
V ;)
Title: Re: My new amp
Post by: hedalfa on January 25, 2014, 05:43:34 PM
Oz

Quote
Getting feedback from visitors is really invaluable, IMHO.  Our audio systems are like coffee.  If you drink the same brand/type of coffee everyday, you get accustomed to the taste and it seems normal.  Audio is the same.

I think this can also lead to an endless merry go round of upgrades; whilst this is fine if you actively seek the comments from others if you are happy with what you have then keep it.  To be told negative things just pulls the smile form your face and is not too healthy long term IMV.  It's a bit like life partners, we all know they are not exactly what we'd like but substituting them for a different model does not always bring long term satisfaction.

Changing out items such as binding posts will bring a tiny incremental improvement but if the amp is not up to driving the speakers in the room you have then wasted time / money.  I do applaud those dedicated types who are willing to experiment but taking a 1000 dollar amp and spending another 1K on it does not turn it into a 2K + amp.

I read that more body and wetness is looked for.  I'd suggest looking at different valves and amps long term.  I have owned a Leak Stereo 20 and Leak TL12.1's; the later totally kicks sand in the face of its cheaper sibling, a case of the top of the line being compared to the cheaper model, harsh but the truth.  A friend of mine used to use the term " it's pointless polishing a turd as at the end of it all you are still left with a turd".  In car terms it would be taking a ford fiesta and trying to turn it into F1 car, they all have 4 wheels but the end result is quite different.

My end advice is get the pair of speakers you can live with in the room where you relax and enjoy music then put the best source (KDAC) up front and fit an amp to taste be it Vv or SS in between.  Speakers set the major tonality of the outcome and everything else like the detail and rhythm comes from the front end.  It's a shame all the dealers moved away from the switchable speaker banks, at least this enabled rapid changes on the back end, this enabled you to hear how bright the yamahas were in comparison to the like's of Kef' and Celestions, how efficient the Klipsh's were compared to most others etc.

Beauty is in the eye and ear of the beholder, magazines and others views on your 'system' will keep you ever chasing your tail and a trail as long as your arm of discarded / sold equipment.  Check out SNA second hand section of for sale items........................

By all means change your brand of coffee, but if you love the one you have, why change it.  This sounds like a feminine thing of change for changes sake.  Before I'd be thinking of changing out binding posts I would want to make sure that all the rubbish speaker manufactures fit inside their built down to a price boxes is improved first, then the caps etc.  Trying to change the basic character of a system requires a change in approach to the design, beyond most and totally impractical IMO.

Anyway enough wittering from me, just bear in mind the end game and spend accordingly.  Enjoy your travels and try to avoid the audionovosa of doubting thomas; 10 people will all criticise different elements and struggle to agree most things audio!
V ;)

Lots of good points here.  I have gone through a few amps rather than go through extensive upgrades. Though if an is amp doing a lot of things right its worth persisting with. Yet buying amp mainly because its cheap and then throwing the kitchen sink at it may not be ideal. Paul Baker fixed some issues with some prior work on my VAC 300B amp. He still rated it behind Marios amps, maybe it still is. Yet putting in RCA red base valves made a huge difference it was the synergy thing it really just came on song. Glad I persisted with as it now sounds like it should as it wasn't build in a way that cut corners. It has amazing drive more than other amps I have heard that have higher quoted output but doesn't sound rough around the edges.  
Title: Re: My new amp
Post by: ozmillsy on January 25, 2014, 05:49:41 PM
Synergy is balancing on a knifes edge.  It doesnt take much to lose the magic, and likewise sometimes all it takes is a few tweaks.

Geez it's a bit absurd to be comparing a Leak 20 to a turd !!!     I thought Stevens 20 sounded just superb.
Title: Re: My new amp
Post by: ozmillsy on January 25, 2014, 06:01:00 PM
Anyway enough wittering from me, just bear in mind the end game and spend accordingly.  Enjoy your travels and try to avoid the audionovosa of doubting thomas; 10 people will all criticise different elements and struggle to agree most things audio!
V, there is alot of wisdom in your wittering. 

 Feedback is to be taken in context,  no one knows your system better than you do. You spend the most time in front of it.   I will always listen and consider what people say.   Whether I action anything is a totally different matter.  Give people a little credit.
Title: Re: My new amp
Post by: springcreek on January 25, 2014, 09:31:03 PM
I certainly tune to my taste, not others but I still value their opinion even if I don't always follow their advice.

I think the stock Stereo 20 is good but quite limited, but fully tweaked is a different beast altogether. Better than any commercial amp I've heard so far and tuned to my taste.

Being able to take decent kit like the Leak and Axiom 300 and tune my system to get the sound I want is key to my audio happiness...beats the buying and selling treadmill most audiophiles seem to be on. Also helps to have a sound in your head that you are chasing.
Title: Re: My new amp
Post by: Jehuty on January 25, 2014, 10:50:45 PM
I thought Stevens 20 sounded just superb.

So did I...and probably for all attendees of last year's Canberra GTG. It just does almost everything right. I love that little amp.
Title: Re: My new amp
Post by: springcreek on January 25, 2014, 10:56:35 PM
Agree Stevens Leak was great and sent me on the path to find one  ;D
Title: Re: My new amp
Post by: Jehuty on January 25, 2014, 11:04:53 PM
taking a 1000 dollar amp and spending another 1K on it does not turn it into a 2K + amp.

No, it doesn't. It goes for A LOT more than that  ;D

Would you like to read some interesting comments on SNA when the Leak was pitted against big dollar Gryphon and Arion monoblocks? Here where it started V: http://www.stereo.net.au/forums/index.php?/topic/53554-amp-gtg/page-3#entry993085

How I'd love to have a pair of Leak TL12.1 but at the rate they're going now I need to win a lotto....or sell a kidney maybe...

Cheers,
William
Title: Re: My new amp
Post by: vitavoxdude on January 26, 2014, 02:39:50 PM
Yes sorry about the analogy of turds and hifi, it was not meant as a slur on the Leak.  Harold J Leak stole others circuitry  because he could (his lawyers were more expensive - do your research) so it does not put him in a favorable light for some.  The TL12's and Troughline tuner were the companies best products.

You have to have been there to know how the stereo 20 stacks up against other valve amps and whilst it's a nice sounding unit with the 'right' speakers it no goliath slayer.  By all means spend bucks on improving components but remember at the end of it all its the same amp with top parts.  The el84 valve sounds good with QUAD electrostatics (57's) and Lowthers in large horns in that design but falls a bit flat with more difficult speakers.

If you do a direct comparison with the TL12 / Williamson / Radford St15 you can draw your own conclusions.  As this site is all about sharing knowledge for the betterment of its members I thought it prudent just to put things into a proper perspective.

My bias having owned probably >40 amplifiers is the zero feedback SE valves produce the most music but limits your choice in speakers to horns or large reflex designs where efficiency is the most important feature.

It is still a classic amp but so are those Macintosh, Lumlies, Lux etc where the design is less limited by power output / circuit / output transformers.
V ;)
Title: Re: My new amp
Post by: Jehuty on January 26, 2014, 10:52:47 PM
Well said V. When I have money, I'll hunt those TL12 monoblocks  8)
Title: Re: My new amp
Post by: stevenvalve on January 27, 2014, 01:55:18 AM
Yes sorry about the analogy of turds and hifi, it was not meant as a slur on the Leak.  Harold J Leak stole others circuitry  because he could (his lawyers were more expensive - do your research) so it does not put him in a favorable light for some.  The TL12's and Troughline tuner were the companies best products.

You have to have been there to know how the stereo 20 stacks up against other valve amps and whilst it's a nice sounding unit with the 'right' speakers it no goliath slayer.  By all means spend bucks on improving components but remember at the end of it all its the same amp with top parts.  The el84 valve sounds good with QUAD electrostatics (57's) and Lowthers in large horns in that design but falls a bit flat with more difficult speakers.

If you do a direct comparison with the TL12 / Williamson / Radford St15 you can draw your own conclusions.  As this site is all about sharing knowledge for the betterment of its members I thought it prudent just to put things into a proper perspective.

My bias having owned probably >40 amplifiers is the zero feedback SE valves produce the most music but limits your choice in speakers to horns or large reflex designs where efficiency is the most important feature.

It is still a classic amp but so are those Macintosh, Lumlies, Lux etc where the design is less limited by power output / circuit / output transformers.
V ;)
Well said V. A world beater no, and not for head bangers, No real power, not much bass weight, But I like my full on modified Leak stereo 20, I do for a few reasons, in a highly modified state, they sound involving, sweet, and pretty, they are just the best amp on violins I have heard, and for many reasons the best amp I have heard in along time. 
Title: Re: My new amp
Post by: ozmillsy on January 28, 2014, 08:19:11 AM
If you do a direct comparison with the TL12 / Williamson / Radford St15 you can draw your own conclusions.  

The Garland modified Leak 20 was compared to the Garland modified Radford ST15 at the ACT GTG last year,   and the result didn't go the way I expected.    That day the Leak 20 trounced the Radford.    And everyone in the room drew their conclusions.

It's hard to quantify the value of modifications, but I value them greatly.    I'm firmly of the opinion that to get great sound, cant easily be done by riding the hifi merry-go-round, hoping to find synergy with stock components.    To get just the right sound, for your tastes, and system, needs tweaking of some kind.

But tweaking often isnt a step forward, the Radford was knobbled due to a change I had made (prior to the GTG).  I had removed some caps,  1 cap had burst due to suspected flaky tube, and I had no spares at the time. The advise received, by removing them was I'd just lose some volume.        Anyway, that change set me back for a long time,  removing the caps changed the sound of the amp,  I didn't just lose volume.    On my system,  I was rebalancing the sound with the treble controls on the Golds. The flavour of coffee was ok (to me) after adjusting the treble.  But more than 1 visitor let me know that the top end wasn't sounding as it should, it was a consistent message I got.   The amp comparison highlighted that the Radford was sounding flat compared to the Leak.  Prior System Feedback + Amp Comparison result on a different system, was pretty conclusive now - something was wrong with the Radford.  

Since then the Caps are now back into circuit (new elna cerafines), along with some magic wire blessed by Tibetan monks, and the Radford/system is singing again.   Sometimes it takes some feedback, and willingness to take it on board,  in order to move forward.

Making modifications can be a slippery slope, down into a maddening dark world of black art,  but it's lucky I don't ride the merry-go-round,  as a great amp would have been sold if I did.
Title: Re: My new amp
Post by: springcreek on January 28, 2014, 09:36:40 AM
Yep that's what we heard. The Radford was clearly warmer, with much deeper bass and the Leak was tilted up due to the tubes. But for sheer musicality the Leak was substantially ahead. Glad the Radford has it's mojo back, it's a beautiful amp.  8) Definitely a keeper!
Title: Re: My new amp
Post by: springcreek on January 28, 2014, 09:43:12 AM
I take V's point though that SET's done well with the right speakers tend to be the ultimate, and it comes out is spades in Stevens system. A lack of blur, a directness and palpable sense of reality.

Hopefully I'll have one when funds allow, for now the Leak delivers magic in spades.
Title: Re: My new amp
Post by: ozmillsy on January 28, 2014, 10:21:26 AM
But for sheer musicality the Leak was substantially ahead.
It was on that given day, with the Radford in that sub-standard state,  no doubt.

As I said,  I thought the Leak sounded superb.   It's a great value amp.

I take V's point though that SET's done well with the right speakers tend to be the ultimate, and it comes out is spades in Stevens system. A lack of blur, a directness and palpable sense of reality.
Stevens system does a remarkable job of disappearing in front of our eyes.   All I see and hear are musicians performing in front of me.

The SET amps are a big part of that, no doubt.    I should have snapped up those killer bee's,  when I had the chance.    8)
Title: Re: My new amp
Post by: zenelectro on January 28, 2014, 01:24:45 PM
If you do a direct comparison with the TL12 / Williamson / Radford St15 you can draw your own conclusions.  

The Garland modified Leak 20 was compared to the Garland modified Radford ST15 at the ACT GTG last year,   and the result didn't go the way I expected.    That day the Leak 20 trounced the Radford.    And everyone in the room drew their conclusions.


In the musicality / sweetness / emotional connection department, in general comparing an EL34 based amp to an EL84 one always goes in the 84's favor.
It goes the same way with musical instrument amps - EL84's just sound better where it matters - I use one myself.
At an educated guess, in general the original amp designers didn't really understand this and as soon as more than 10 to 15 watts was required, EL84's were not generally considered an option.

IMO the amp that you are probably looking for uses  a quad or even sextet of EL84's in push pull triode mode = 15 to 20 watts of class A triode power. 
This will get you some useable power / bottom end but still retain the lovely character of EL84's.  I don't know that there are hi fi amps of this configuration around. 

Z
Title: Re: My new amp
Post by: ozmillsy on January 28, 2014, 03:56:49 PM
You're probably right in a general characteristic sense.   But not all EL34's are equal.

Drive and weight are just as important (to me) as sweetness.

Build one Zen,  bring it to the next GTG (around April),   if it lives up to the theory of delivering both the weight and sweetness,  I'm sure someone will snaffle it.    ???

But hang on,,,,,,  there's other stuff to do.   :-\  :P  
Title: Re: My new amp
Post by: hedalfa on January 28, 2014, 05:34:41 PM
You're probably right in a general characteristic sense.   But not all EL34's are equal.

Drive and weight are just as important (to me) as sweetness.

Build one Zen,  bring it to the next GTG (around April),   if it lives up to the theory of delivering both the weight and sweetness,  I'm sure someone will snaffle it.    ???

But hang on,,,,,,  there's other stuff to do.   :-\  :P  

I have to agree here not EL34's are equal.  There some nice sounding el34 valves and I like el34 run in triode mode.
 





Title: Re: My new amp
Post by: Jehuty on January 28, 2014, 10:35:10 PM
IMO the amp that you are probably looking for uses  a quad or even sextet of EL84's in push pull triode mode = 15 to 20 watts of class A triode power.

Here you go Zen, the Beard P35 amp. Rawl99 got one for a bargain. He should start modifying the Beard and ditch the Leak  ;D Haha kidding of course!
Title: Re: My new amp
Post by: zenelectro on January 29, 2014, 12:38:16 AM
You're probably right in a general characteristic sense.   But not all EL34's are equal.

Drive and weight are just as important (to me) as sweetness.

Build one Zen,  bring it to the next GTG (around April),   if it lives up to the theory of delivering both the weight and sweetness,  I'm sure someone will snaffle it.    ???

But hang on,,,,,,  there's other stuff to do.   :-\  :P  

Exactly - I have other fish to fry and they are well on the way   ;D - I am just doing a well calculated hypothetical based on experience.

Z
Title: Re: My new amp
Post by: zenelectro on January 29, 2014, 12:54:13 AM
IMO the amp that you are probably looking for uses  a quad or even sextet of EL84's in push pull triode mode = 15 to 20 watts of class A triode power.

Here you go Zen, the Beard P35 amp. Rawl99 got one for a bargain. He should start modifying the Beard and ditch the Leak  ;D Haha kidding of course!

Yep, seen the Beard schematic. Again, same old same old, ultralinear OP stage, global feedback, solid state rectifier...... how to make a great tube sound average.


Z
 
Title: Re: My new amp
Post by: Jehuty on January 29, 2014, 01:28:21 AM
I thought they were pretty highly regarded. I would love to hear one and see if they're any good. The solid state rectifier is indeed the glaring weakness.
Title: Re: My new amp
Post by: zenelectro on January 31, 2014, 10:13:26 AM
Speaking of EL84's - what type / brand is everyone running in their Leaks?

I'm currently looking at trying some 7189 types for their better durability, has anyone tried 'em?

cheers

Z
Title: Re: My new amp
Post by: vitavoxdude on January 31, 2014, 02:37:03 PM
Always used Mullards.................................this probably does not help, sorry.
V
Title: Re: My new amp
Post by: stevenvalve on January 31, 2014, 03:27:59 PM
Speaking of EL84's - what type / brand is everyone running in their Leaks?

I'm currently looking at trying some 7189 types for their better durability, has anyone tried 'em?

cheers

Z
I have tried most EL84s, the best is the Mullard with the hole in the plate, next genuine Holland Amperex with the half triangle. I use GE 7189 in my 1960s Fisher amp but the problem is, most 7189s you can buy are the GE brand, and that is not good. They Do have more output than the stranded EL84.  
Title: Re: My new amp
Post by: zenelectro on February 01, 2014, 12:42:38 PM
Always used Mullards.................................this probably does not help, sorry.
V

Thanks Vita, yes it does help - I haven't tried original Mullards.

I do have clients that want to pay for better NOS tubes. As an example last year restored an original Vox AC30 for a session player, it had a quad of old Telefunkens in it which will need replacing.
I don't want to put JJ's in that! :)

I was using Russian NOS 6P14P-EV tubes imported from Ukraine which are now re labelled and sold as special quality 7189's. They were cheap, very robust and sounded pretty good for new tubes.
But everyone got on to them and stocks are getting scarce.

cheers

Title: Re: My new amp
Post by: zenelectro on February 01, 2014, 01:22:11 PM
Speaking of EL84's - what type / brand is everyone running in their Leaks?

I'm currently looking at trying some 7189 types for their better durability, has anyone tried 'em?

cheers

Z
I have tried most EL84s, the best is the Mullard with the hole in the plate, next genuine Holland Amperex with the half triangle. I use GE 7189 in my 1960s Fisher amp but the problem is, most 7189s you can buy are the GE brand, and that is not good. They Do have more output than the stranded EL84.  

Thanks Steve. Yep, checked those out they look interesting. What is a decent price for a quad? I'm assuming they are fairly thin on the ground so to speak.





Title: Re: My new amp
Post by: gamve on February 01, 2014, 04:09:05 PM
Speaking of EL84's - what type / brand is everyone running in their Leaks?

I'm currently looking at trying some 7189 types for their better durability, has anyone tried 'em?

cheers

Z
I have tried most EL84s, the best is the Mullard with the hole in the plate, next genuine Holland Amperex with the half triangle. I use GE 7189 in my 1960s Fisher amp but the problem is, most 7189s you can buy are the GE brand, and that is not good. They Do have more output than the stranded EL84.  

Thanks Steve. Yep, checked those out they look interesting. What is a decent price for a quad? I'm assuming they are fairly thin on the ground so to speak.







Hi Z,
these usually go for at least $300 for a matched quad branded Mullard. You can get lucky if you look for the same tubes branded phillips. If you know what the mullards look like with the hole half way down the plate, the other branded tubes with the hole are mullards.
Title: Re: My new amp
Post by: stevenvalve on February 01, 2014, 05:06:45 PM
I just sold 3 sets of new mullards, EL84s with the hole in the plate. all of mine where the best, with the B (Blackburn factory) Price is give or take $300.
Title: Re: My new amp
Post by: vitavoxdude on February 02, 2014, 10:47:49 PM
Link to Hifi world article (short) on the Leak stereo 20.  Enjoy:

http://www.hi-fiworld.co.uk/index.php/olde-worlde/225-leak-stereo-20-valve-amplifier.html

V :D
Title: Re: My new amp
Post by: stevenvalve on February 03, 2014, 01:06:45 AM
Link to Hifi world article (short) on the Leak stereo 20.  Enjoy:

http://www.hi-fiworld.co.uk/index.php/olde-worlde/225-leak-stereo-20-valve-amplifier.html

V :D
I love the prices they quote here for a Leak stereo 20, But how times have changed

But the main thing is the great sound of the Stereo 20. The quality of its output transformers was impressive, and due to this the performance  considering its price in standard form is excellent. Pay about 200 for an un-modded Stereo 20, less for a non-mint example and up to about 350 for a fully rebuilt and modified version.
Title: Re: My new amp
Post by: springcreek on February 06, 2014, 12:08:57 PM
Something new turned up in the post yesterday

It's beautiful. Still running in but sounds brilliant.

Happy camper  ;D ;D ;D
Title: Re: My new amp
Post by: kajak12 on February 06, 2014, 12:10:33 PM
ducs phono stage  8)
Title: Re: My new amp
Post by: springcreek on February 06, 2014, 12:24:34 PM
Yup  8)

I bit like the Kdac of vinyl  ;D
Title: Re: My new amp
Post by: springcreek on February 06, 2014, 12:25:41 PM
The lack of richness and weight I have been trying to overcome in the Leak is now completely gone with a change in cabinets from thin walled no damping Shindo style to original Goodman's Sherwoods (thanks Steven, William and Paul) and the addition of the new phono stage. I also have all the quality bass I want for my room.

Still have plenty of tweaking to do as the Sherwoods have loads of damping material inside (3 layers on each surface) which seems to be overdamping them. Hopefully by reducing the damping material in stages I can figure out the right compromise for me. I really liked the Shindo style cabs for some things, as they sounded live and had great dynamic life and resolution. Though, combined with the Axiom 300s run full range, you certainly know it if you put on an average recording as there was NOWHERE to hide!
Title: Re: My new amp
Post by: Jehuty on February 06, 2014, 01:59:06 PM
Beautiful phono stage Andy! Duc certainly knows what he's doing, I really liked his system last time I was in Melbourne. Can't wait to have another listen to your system again!  ;D
Title: Re: My new amp
Post by: Jehuty on February 06, 2014, 02:04:13 PM
So to answer your question, William - around 1H / probably 4H max at a guess should be good but keep DC R to 100R or less.

Zen, I am about to order a Hammond 157Q choke. Spec is 3.5 H, 150 ma, 98 Ohms, 400VDC. I know it's not an oil-filled choke but I found that my Leak Stereo 20 was a bit noisy so I'd like to address this issue with the choke. What do you reckon?

Thanks,
William
Title: Re: My new amp
Post by: gamve on February 06, 2014, 02:56:48 PM
Something new turned up in the post yesterday

It's beautiful. Still running in but sounds brilliant.

Happy camper  ;D ;D ;D

Looks nice Andy. What valves does it run? What Does Duc charge for these?
Cheers
Graham
Title: Re: My new amp
Post by: springcreek on February 06, 2014, 04:14:05 PM
Hi Graham

Yes I went with my heart mate, it is a wonderful phono stage. Duc builds them with 2 x 6GC7, 2 x 12AT7 tubes and a GZ34. All valves were NOS and a great bunch of parts. There is more info on the Golden Age Audio site. Steve M bought one and loves it.

I do have some noise I need to address, but quite a bit of that comes from the Leak.

Duc charges $2850 for them, great value when you look at the quality of the build and the sound. Duc has put it up very favourably with some very big names including FM Acoustics, Shindo, RCM, etc.

Andy R's phono would have been nice but I really wanted an all analog system full of very nice NOS valves.

Cheers
Title: Re: My new amp
Post by: springcreek on February 06, 2014, 06:37:41 PM
Hi William

You would love it mate! Looking forward to getting you back for a listen.

Let me know how you go with the choke, O need to drop the noise!

Cheers, Andy
Title: Re: My new amp
Post by: ozmillsy on February 06, 2014, 07:00:26 PM
Nice phono Andy !!
Title: Re: My new amp
Post by: springcreek on February 06, 2014, 07:24:32 PM
Thanks Andrew  ;D

Hope you can come and have a listen
Title: Re: My new amp
Post by: hedalfa on February 06, 2014, 07:33:39 PM
The lack of richness and weight I have been trying to overcome in the Leak is now completely gone with a change in cabinets from thin walled no damping Shindo style to original Goodman's Sherwoods (thanks Steven, William and Paul) and the addition of the new phono stage. I also have all the quality bass I want for my room.

Still have plenty of tweaking to do as the Sherwoods have loads of damping material inside (3 layers on each surface) which seems to be overdamping them. Hopefully by reducing the damping material in stages I can figure out the right compromise for me. I really liked the Shindo style cabs for some things, as they sounded live and had great dynamic life and resolution. Though, combined with the Axiom 300s run full range, you certainly know it if you put on an average recording as there was NOWHERE to hide!


Massive improvement for the better with the Sherwoods. 8) 8) 8) 8) 8) 8) 
Title: Re: My new amp
Post by: ozmillsy on February 06, 2014, 10:31:00 PM
Hope you can come and have a listen
I'd love to Andy.     
Title: Re: My new amp
Post by: Jehuty on February 06, 2014, 11:03:19 PM
Hi William

You would love it mate! Looking forward to getting you back for a listen.

Let me know how you go with the choke, O need to drop the noise!

Cheers, Andy

Can't wait to go back! Will report once I get the choke and install it. Hope it helps to lower the noise. Looks like I'm going down to the Freak Leak way!  ;D
Title: Re: My new amp
Post by: stevenvalve on February 16, 2014, 01:58:57 AM
Funny how things happen sometimes. A leak stereo 20 has just been offered to me at the right price, and attached is a mint leak preamp, how can I refuse another leak. What do I do with 2 leak stereo 20s, well what if I fill it full of toys, and then change it to run triode, half the power but it may sound incredible.
Title: Re: My new amp
Post by: ozmillsy on February 16, 2014, 04:38:54 PM
It sure would be interesting to hear them side by side, 1 in triode mode, the other not.

Maybe for the May GTG ?
Title: Re: My new amp
Post by: springcreek on February 16, 2014, 09:50:41 PM
Do it, bring it to the GTG  8)

I would love to how it sounds. The guy I got my Leak from in the UK deals in Leaks and Quads ESLs and converts stereo 20s to triode to drive 57 Quads...said it is a major improvement.  ;D
Title: Re: My new amp
Post by: springcreek on April 02, 2014, 08:44:07 AM
The Leak gets sent off to Paul B this week to see if he can sort out the hum issue. Steven and Rawl have no hum in their Leaks, noting the difference in speaker sensitivity. Combined with the mild hum from the valve phono and high sensitivity speakers it is rather distracting. Will get Paul to stick in the rest of the ABs and Shinkohs while he is at it and remove the last few electrolytics and whack in some Eichmann RCA sockets.

Rawl currently has my Axiom II passive to add in the 2W Shinkoh's, reconfigure the circuit slightly, whack in some better wire and put on two sets of WBT RCA sockets.

Looking forward to getting them back!

Also got some nice vintage PIO caps (thanks D) so I can try out the compression horns...will see if I like them better than just the single FR driver.

 ;D
Title: Re: My new amp
Post by: Jehuty on April 02, 2014, 09:07:02 AM
Nice, will it be ready for the Leak wars?  ;D

Meh..I"m not concerned about it. As long as I can get it to sound as good as Steve's I'll be happy  :)
Title: Re: My new amp
Post by: springcreek on April 02, 2014, 11:07:06 AM
Yep me too, that is my aim
Title: Re: My new amp
Post by: hedalfa on April 02, 2014, 11:15:51 AM
Yep me too, that is my aim

Does the winner of the leak wars get a prize 8) 8)
Title: Re: My new amp
Post by: springcreek on April 02, 2014, 12:19:33 PM
Yes a free beer while I steal their amp.

King of Leakiness  :P
Title: Re: My new amp
Post by: ozmillsy on April 02, 2014, 09:34:56 PM
Meh..I"m not concerned about it. As long as I can get it to sound as good as Steve's I'll be happy  :)
Isn't that the purpose of the Leak wars.   Get them in a room, and compare them all,  1 after the other?

 8)
Title: Re: My new amp
Post by: ozmillsy on April 02, 2014, 09:39:49 PM
Combined with the mild hum from the valve phono and high sensitivity speakers it is rather distracting.
Mate, that is a bit of a worry.   ::)   Hums are a bastard, and definitely it can be an accumulation effect.  Layers of hum, adding up.   ???

But the phono shouldn't hum mate.   My 834p tube phono doesn't hum.   Just because it's a tube phono, doesn't mean that mild hum is to be expected.    That's something to discuss with Duc,  he has higher sensitivity speakers than yours, and they don't hum at all with his phono (not that I noticed).
Title: Re: My new amp
Post by: ozmillsy on April 02, 2014, 09:49:37 PM
I should add,  that certain interconnects have a tendency to pick up hums more than others (on my system).   

I was chasing hums on my system for ages.   In the end I ,,,,
- found and replaced some microphonic tubes in my m3
- replaced Aurealis Ic's with others I had on hand
- changed my eastern electric phono stage to 834p

I'm pretty good now, with those 3 things.     Worth playing around with the first 2 points.

  The only issue I have left,  is a very small amount of transformer hum, when the radford has been running for 2+ hours (ear against driver detectable level).  Don't think I'll ever fix that.  But that's ok,  it's fine, given the other hum improvements.

I know your pain man.   :-\  ???  ::)
Title: Re: My new amp
Post by: springcreek on April 02, 2014, 10:38:14 PM
Hey Oz

Thanks for the advice mate. Glad you got it under control, hope for me yet  ???

Yes a real bummer to have hum in both the Leak and phono. Duc said his phono has some residual hum, and if he adds bigger chokes and caps to eliminate it he loses the magic. I could probably live with just the hum from the phono, but combined with what the amp has in a bit too much.

I am hoping Paul can stick the Leak on the CRO and track it down.

I will try some different interconnects to see if that helps with the phono hum.

I have tried moving the phono, dressing the cables, using basic vibration isolation but nothing has worked so far.

Quite frustrating!  :(
Title: Re: My new amp
Post by: Jehuty on April 03, 2014, 01:22:37 AM
Isn't that the purpose of the Leak wars.   Get them in a room, and compare them all,  1 after the other?

 8)
I hope none gets killed! I will only use lowly priced Hovland Musicaps, hard to win the war, especially without the expensive Duelunds VSF. It would be a different story if I could get the special pricing  :P
Title: Re: My new amp
Post by: data on April 03, 2014, 03:29:45 AM
Never know, the Hovland's may work well, might get some synergy happening with the right mix :)
Title: Re: My new amp
Post by: ozmillsy on April 03, 2014, 12:33:21 PM
Blind Testing posts moved here,,,,,
http://killerdac.com/forum/index.php/topic,2658.0.html (http://killerdac.com/forum/index.php/topic,2658.0.html)
Title: Re: My new amp
Post by: Jehuty on April 03, 2014, 12:36:48 PM
Never know, the Hovland's may work well, might get some synergy happening with the right mix :)

That's what I aim to do. At the moment my Leak's sounding thick and lost a bit of sweetness once I put some Solens PA in. I hope the Hovland can bring what was lost and smooth things out. All for learning purpose, I could have put the right Solen PB as always suggested by Steve but I want to learn  :)

Edit: Just realised the time of your post, insomniac? Just like me  ;D
Title: Re: My new amp
Post by: Tuyen on April 03, 2014, 12:41:30 PM
If the guys who are spending big dollars on modifications to their components  (eg. duelund caps)  and (if being honest with themselves) can't hear much/any improvements, but yet proclaim otherwise, in my view, they are the only ones who are losing out, as it is their own money they are spending.

Why bother trying to 'catch them out' with asking to BT.    Focus and have fun on your own journey I say!  ;D
Title: Re: My new amp
Post by: Tuyen on April 03, 2014, 12:44:52 PM
I had Hovlands Musicaps  in my old killerAmp (8x EL34) that Paul built.     Was really nice!     Preferred it over my mate's Kamp where Paul used Mundorf Supremes.    Bit more tonally sweeter and 'fuller'.   Prob not as 'airy'  as the mundorfs though, if that is your thing.


I had thought the Musicaps are discontinued a while ago and only recently Hovland started making new line called the SuperCaps?

http://www.partsconnexion.com/capacitor_film_hovland_supercap.html (http://www.partsconnexion.com/capacitor_film_hovland_supercap.html)
Title: Re: My new amp
Post by: springcreek on April 03, 2014, 12:52:31 PM
Blind testing will be banned at the Canberra GTG  8)

Will be nice to hear the difference in bits given the same topology. I am using Russian K40Y and Solen PB in mine. Maybe a mustard cap or two  ;D

Maybe these for those that can't hear the difference  :P
Title: Re: My new amp
Post by: Jehuty on April 03, 2014, 12:55:38 PM
I had Hovlands Musicaps  in my old killerAmp (8x EL34) that Paul built.     Was really nice!     Preferred it over my mate's Kamp where Paul used Mundorf Supremes.    Bit more tonally sweeter and 'fuller'.   Prob not as 'airy'  as the mundorfs though, if that is your thing.


I had thought the Musicaps are discontinued a while ago and only recently Hovland started making new line called the SuperCaps?

http://www.partsconnexion.com/capacitor_film_hovland_supercap.html (http://www.partsconnexion.com/capacitor_film_hovland_supercap.html)

Thanks for sharing Tuyen. I have good hopes that the Musicap will sound good in my Leak  :)

Yes, the Musicaps were discontinued. Some retailers still have the new old stock so I bought a few from them. Not keen to try the SuperCaps because they're at least double the price and unknown quality.
Title: Re: My new amp
Post by: omodo on April 03, 2014, 01:14:50 PM
But the phono shouldn't hum mate.  Just because it's a tube phono, doesn't mean that mild hum is to be expected.    That's something to discuss with Duc,  he has higher sensitivity speakers than yours, and they don't hum at all with his phono (not that I noticed).

agree with Oz, also it's only an MM phono (iirc) so no overly sensitive. a slight amount of residual hum/noise isn't the end of the world, like you said sometimes trade-offs are made

It could be as simple as a ground loop, do you have a cheater plug or a way to lift the safety ground of one component?
Title: Re: My new amp
Post by: ozmillsy on April 03, 2014, 02:33:12 PM
Why bother trying to 'catch them out' with asking to BT.    Focus and have fun on your own journey I say!  ;D
Did you miss my [Jk] ?   :)    I agree with you.
Title: Re: My new amp
Post by: gamve on April 03, 2014, 09:12:56 PM
Blind testing will be banned at the Canberra GTG  8)

Will be nice to hear the difference in bits given the same topology. I am using Russian K40Y and Solen PB in mine. Maybe a mustard cap or two  ;D

Maybe these for those that can't hear the difference  :P

Yeah Andy, Now your talking. Order me a set  ;D
Title: Re: My new amp
Post by: springcreek on April 03, 2014, 09:50:02 PM
D speak English man.  :P Is it safe to use cheater plugs, not that I no what one is? How does one lift the safety ground?

Title: Re: My new amp
Post by: springcreek on April 03, 2014, 09:51:50 PM
I'll ha've a set ready for you Graham  ;D
Title: Re: My new amp
Post by: data on April 04, 2014, 11:43:16 AM
That's what I aim to do. At the moment my Leak's sounding thick and lost a bit of sweetness once I put some Solens PA in. I hope the Hovland can bring what was lost and smooth things out. All for learning purpose, I could have put the right Solen PB as always suggested by Steve but I want to learn  :)

Edit: Just realised the time of your post, insomniac? Just like me  ;D
Yup, sleep is an ever elusive thing here, sucks it does :)

Damn, these Leak-wars should be a great time, will be an extremely interesting day for all  8)
Title: Re: My new amp
Post by: ozmillsy on April 05, 2014, 03:16:56 PM
Duc said his phono has some residual hum, and if he adds bigger chokes and caps to eliminate it he loses the magic. I could probably live with just the hum from the phono, but combined with what the amp has in a bit too much.
This is still troubling me.   I can understand the feedback from Duc,,,, we dont want to lose the magic,  but, it still worries me.     

Good luck man.   Maybe a short phono comparo at the May GTG will be useful?
Title: Re: My new amp
Post by: Jehuty on April 22, 2015, 03:55:34 PM
Hi Andy,

Nice wood chassis for the Leak 20, see attached pics.

Cheers,
Will
Title: Re: My new amp
Post by: springcreek on April 22, 2015, 09:55:26 PM
Thanks William

Is this a one off or a product?

Cheers, Andy
Title: Re: My new amp
Post by: brenden on April 22, 2015, 10:07:45 PM
The wood base really adds a bit  class to the chassis of the leak 20 ,and a definite improvement IMO .Great work.
Title: Re: My new amp
Post by: Jehuty on April 23, 2015, 12:00:34 AM
I think it's a DIY, I found it on eBay: http://www.ebay.com.au/itm/Leak-20-Stereo-Tubes-Amplifier-/141641603712

And I thought it'd be nice to share the idea amongst us  :)
Title: Re: My new amp
Post by: ozmillsy on April 23, 2015, 12:41:37 PM
Is it purely cosmetic?  Or did it change the sound?

I have found that amps can be quite sensitive to what they are sitting on (along with dacs, and everything else). :)
Title: Re: My new amp
Post by: springcreek on April 24, 2015, 12:39:57 PM
Thanks William it looks great
Title: Re: My new amp
Post by: Jehuty on April 24, 2015, 02:27:26 PM
Is it purely cosmetic?  Or did it change the sound?

I have found that amps can be quite sensitive to what they are sitting on (along with dacs, and everything else). :)

Hi Oz, in my experience it does change the sound. I use and like Herbie's tenderfeet a lot for my system. I also like what Steve uses for his Leak and other components in his system but as usual his stuff are unobtainium so I have to settle with the Herbie's  :D
Title: Re: My new amp
Post by: ozmillsy on April 24, 2015, 06:47:26 PM
Hey William,

If i was to compare,,,,,,

* Leak + herbies tenderfeet
* Leak + wooden case + herbies tenderfeet

Are they pretty close?   Is the tenderfeet making both scenarios sound kinda the same?
Title: Re: My new amp
Post by: Jehuty on April 24, 2015, 10:26:10 PM
Hey William,

If i was to compare,,,,,,

* Leak + herbies tenderfeet
* Leak + wooden case + herbies tenderfeet

Are they pretty close?   Is the tenderfeet making both scenarios sound kinda the same?

Hi Oz, good question! I never try the second scenario so I do not know if they would sound the same.