The KillerDAC Audio forum

General HIFI => Amplification (Pre/Power) => Topic started by: stevenvalve on November 28, 2010, 06:57:41 PM

Title: How to Build a killer Amp
Post by: stevenvalve on November 28, 2010, 06:57:41 PM
Here are some pictures of the single ended class a triode amp, that i have finally finished. It runs, any of these tubes, 50-45 type tubes (RCA 250s Cunningham 350s PX25s- PX4s- RCA 245 45s) The driver tubes are Mullard- ECC32,or RCA-5691s,or 6SL7s, rectifier tubes are GEC Genalex- U52,  GEC- 5U4G, or nearly any rectifier tube. This is a full on unit, the parts are not cheap. but you can use want ever parts you like. This amp has choke input. I will show you how to make one, or more, if you want to build the best there is, but you need efficient speakers, you will have 2- 4.6 watts to play with. PX25s about 8-10 watts.  More soon, if there is any interest. How will it sound. Unsurpassed Magic.
Title: Re: How to Build a killer Amp
Post by: tuyen on November 29, 2010, 01:41:39 PM
Hi Steve,

Just creamed my pants.

Cheers,
Tuyen
Title: Re: How to Build a killer Amp
Post by: ozcal on November 29, 2010, 01:53:29 PM
Beautiful work Steven.
Looking forward to learning from you.
Gordon
Title: Re: How to Build a killer Amp
Post by: crazikid on November 29, 2010, 04:03:37 PM
sweet jesus.. look at all that unobtainium...
Title: Re: How to Build a killer Amp
Post by: gamve on November 29, 2010, 05:59:47 PM
Hi Steve,
Will be watching this thread for developments and eagerly await your instructions. Jezz have a couple of sets of speakers crying out for this type of amplification. Some 16 ohm Tannoys, enclosures and cross overs not yet built and some Coral flat 10's. I still might chase the axiom 80's that are here locally and get them up to standard. Very kind of you to share your extensive knowledge on these amps.
Title: Re: How to Build a killer Amp
Post by: omodo on November 29, 2010, 07:54:15 PM
yes piss the 89db speaker chat off to a thread about naksa amps or something ;)

any more details on the amp, schematics, etc? thread is a bit light on details to commit money on building it... or will we get there eventually?

choke input is good, nice big transformers, lots of film caps and 4 pole caps, looks like it has potential :)
Title: Re: How to Build a killer Amp
Post by: Jehuty on December 26, 2010, 01:06:43 PM
Hi Steve,

Could you please tell us what parts do we need to build this amp? I'm in no rush to build this amp as I still need to get suitable speakers but I can always start to gather all the parts needed.

Thanks and Merry Christmas Steve  :)

William
Title: Re: How to Build a killer Amp
Post by: stevenvalve on December 31, 2010, 07:45:30 PM
Hi Steve,

Could you please tell us what parts do we need to build this amp? I'm in no rush to build this amp as I still need to get suitable speakers but I can always start to gather all the parts needed.

Thanks and Merry Christmas Steve  :)

William
OK, lets start. Guys i what you to get these parts ASAP (Shinko Tantalums)  because they are running out and very very good. Go to Parts connection. You need 4 -1K2.  2- 56k. 2- 10k. 2 - 330K.  you want the 2 watt version. 1 watt will do but not as good.    SHINKOH-72854              SHINKOH-72860     SHINKOH-68192      

SHINKOH-72862  Allen bradleys are good,  2Watt only
Title: Re: How to Build a killer Amp
Post by: stevenvalve on December 31, 2010, 08:01:48 PM
And these ( 3 - CMC 8-pin Gold Plated Teflon Tube Socket) plus these (2 - CMC 4-pin Gold Plated Teflon Tube Socket 2) Cheap off Ebay. You will run, 1 Rectifier, 2 driver, and 2 power valves. There will be more parts that you can get from parts connection but they are not that cheap.
Title: Re: How to Build a killer Amp
Post by: stevenvalve on December 31, 2010, 08:12:47 PM
These.  2- SOLEN-116-62332-200uf / 400VDC, PB Series.  2- SOLEN-108-51569-  100uf / 400VDC, PB Series, 2- JENSEN-71025-  470uf / 450v,   4 - pole,  Get these parts anywhere if its cheaper.

 

 
 

   
 
Title: Re: How to Build a killer Amp
Post by: stevenvalve on December 31, 2010, 08:23:40 PM
You will need two trim pots, 2-100R is about right. I have some parts here if anyone whats them. I have a few mains transformers, Chokes,  trim pots and such stuff. All great vintage, not the rubbish they make today. i will list them here soon.
Title: Re: How to Build a killer Amp
Post by: omodo on December 31, 2010, 09:00:20 PM
thanks for the updates, I'm currently researching/evaluating some options for a new power amp project so this amp definitely has my interest, and if your dac is anything to go by it should sound very good

looking at the pics it looks dc coupled, is this a loftin-white derivative? any chance of a schematic or some more details on the circuit?
Title: Re: How to Build a killer Amp
Post by: gamve on January 02, 2011, 04:46:34 PM
Ok, Shinkohs, capacitors and valve sockets ordered. Looks like the shinkoh 56K 2W ones will be hard to find. Any other ideas Stevenvalve on where to find them? Tried HI-Fi Collective in the UK as well as parts connection with no luck.
Title: Re: How to Build a killer Amp
Post by: kajak12 on January 02, 2011, 06:10:33 PM
Ok, Shinkohs, capacitors and valve sockets ordered. Looks like the shinkoh 56K 2W ones will be hard to find. Any other ideas Stevenvalve on where to find them? Tried HI-Fi Collective in the UK as well as parts connection with no luck.
visit steve wait until he falls asleep and take them out of his amp! ;D
Title: Re: How to Build a killer Amp
Post by: gamve on January 02, 2011, 06:17:13 PM
Hi Mario, I'm sure steven would appreciate that  ::)
Title: Re: How to Build a killer Amp
Post by: kajak12 on January 02, 2011, 06:21:18 PM
Hi Mario, I'm sure steven would appreciate that  ::)
dont worry about steve just replace them with similar value he will tweak and modd for 6 months to get his sound back again

Title: Re: How to Build a killer Amp
Post by: kajak12 on January 02, 2011, 06:41:24 PM
Ok, Shinkohs, capacitors and valve sockets ordered. Looks like the shinkoh 56K 2W ones will be hard to find. Any other ideas Stevenvalve on where to find them? Tried HI-Fi Collective in the UK as well as parts connection with no luck.
try posting on diy audio you never know somebody on our planet will have some

gamve havent you got enough hifi?
tasmania is a small island with the most hifi per person thanks to you
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 02, 2011, 10:57:16 PM
Ok, Shinkohs, capacitors and valve sockets ordered. Looks like the shinkoh 56K 2W ones will be hard to find. Any other ideas Stevenvalve on where to find them? Tried HI-Fi Collective in the UK as well as parts connection with no luck.
Use an allan bradley or audio note. You can get away with a shinkoh 50K 2W, if you can find it.  A 1 watt shinkoh 56K is OK. it will do.
Title: Re: How to Build a killer Amp
Post by: gamve on January 02, 2011, 11:50:42 PM
Thanks Steven. Will search for these others
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 03, 2011, 12:00:32 AM
Now for the fun part. You need to find 2 chokes, but not just any chokes, but vintage potted oil, or potted 1930 -40s- 50s -60s chokes Chicago or UTC or what i use 1940s Freed oil, there is many more types, see what you can find on ebay or elsewhere. you will need no less than 10H  to 20H at about 100ohm  and around 180-200 ma, 400+ v. If you go too small  in Henry's, you will have more hum. There will be no feedback in this amp at all. We will passively minimise the hum latter, for some, with either choke imput and or other means, and that will depending on how much voltage we have at the tube. we are aiming at about 250 volt at the tube (1.5 watt) to 350 volt (2.5watt) and with a 250 globe 450v (4.6watts) at the tube, As we up the voltage to the tube the more power it will put out..  The mains trans will be around  350- 0 - 350, higher or lower depending on what you can find in the vintage market or make or get newer transformers. So we need about 350-0-350/ more or less, 1/ 5v (3amp) for rectifier, U52 or 5U4G.   2/ 6.3v ( 2-3amp) for drivers. RCA 5691or ECC32.  2/ 2.5v (3amp) for RCA 245 Globes or Rodgers long plate 45s.  2/ 7.5v (3amp) for RCA250 Globes  2 / 4v(3amp) for PX25s. Don't ask for schematics. His amp is for anyone to build, with no knowledge of drawings. You just need to be able to solder, cut copper. use wood, and use a sledge hammer, HA HA .  I will post close up pictures of my amps (section by section) and all you do is copy it monkey fashion. OK
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 03, 2011, 12:08:35 AM
 Here is a link to give you an idea of what you are looking for, example chokes. But these are a little low in Hennri. With these you will need to run choke imput
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=350423359718&ssPageName=STRK:MEWAX:IT
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 03, 2011, 12:13:50 AM
To run choke imput, a nice choke for that, is 1/ UTC- CG 40  10H about 200 ma, 1950s. United transformer company, New York
Title: Re: How to Build a killer Amp
Post by: gamve on January 03, 2011, 12:34:49 AM
Hi Steven,
Are these suitable http://cgi.ebay.com.au/2-X-POTTED-ATC-10H-200mA-150-OHM-FILTER-CHOKE-/290488109946?pt=Vintage_Electronics_R2&hash=item43a270cb7a#ht_1879wt_1026
or would they suit the KD. I have some UTC here already marked CG-40, 10 HYS, 200 ma DC, DCR 10 ohms, MIPOT 1750 V RMS. I got these earlier for my KD.
Ha Ha...are you a mind reader? Beat me to the post
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 03, 2011, 12:41:51 AM
Hi Steven,
Are these suitable http://cgi.ebay.com.au/2-X-POTTED-ATC-10H-200mA-150-OHM-FILTER-CHOKE-/290488109946?pt=Vintage_Electronics_R2&hash=item43a270cb7a#ht_1879wt_1026
or would they suit the KD. I have some UTC here already marked CG-40, 10 HYS, 200 ma DC, DCR 10 ohms, MIPOT 1750 V RMS. I got these earlier for my KD.
Ha Ha...are you a mind reader? Beat me to the post
look at the max working voltage, its to low. even for killerdac. the chokes need to be good for 400+v, most are, but these are aeroplane chokes and often too low on voltage.
Title: Re: How to Build a killer Amp
Post by: gamve on January 03, 2011, 12:48:53 AM
Yep see what you mean. Am I best to try and get another pair the same. Is it true that you need similar for both the amp and the KD?
Sorry for the novice questions.
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 03, 2011, 12:52:56 AM
Yep see what you mean. Am I best to try and get another pair the same. Is it true that you need similar for both the amp and the KD?
Sorry for the novice questions.
No, they do not have to be the same,  I have some 2/ CG40s. mite sell them, let you know.
Title: Re: How to Build a killer Amp
Post by: gamve on January 03, 2011, 01:02:21 AM
Now for the fun part. You need to find 2 chokes, but not just any chokes, but vintage potted oil, or potted 1930 -40s- 50s -60s chokes Chicago or UTC or what i use 1940s Freed oil, there is many more types, see what you can find on ebay or elsewhere. you will need no less than 10H  to 20H at about 100ohm  and around 180-200 ma, 400+ v. If you go too small  in Henry's, you will have more hum. There will be no feedback in this amp at all. We will passively minimise the hum latter, for some, with either choke imput and or other means, and that will depending on how much voltage we have at the tube. we are aiming at about 250 volt at the tube (1.5 watt) to 350 volt (2.5watt) and with a 250 globe 450v (4.6watts) at the tube, As we up the voltage to the tube the more power it will put out..  The mains trans will be around  350- 0 - 350, higher or lower depending on what you can find in the vintage market or make or get newer transformers. So we need about 350-0-350/ more or less, 1/ 5v (3amp) for rectifier, U52 or 5U4G.   2/ 6.3v ( 2-3amp) for drivers. RCA 5691or ECC32.  2/ 2.5v (3amp) for RCA 245 Globes or Rodgers long plate 45s.  2/ 7.5v (3amp) for RCA250 Globes  2 / 4v(3amp) for PX25s. Don't ask for schematics. His amp is for anyone to build, with no knowledge of drawings. You just need to be able to solder, cut copper. use wood, and use a sledge hammer, HA HA .  I will post close up pictures of my amps (section by section) and all you do is copy it monkey fashion. OK

Hi Steven
Looks like a decision needs to be made on what output is needed before searching for a power transformer. Only guessing but 97db at 1W efficient speakers 2.5 to 4.6 watts should be more than ample? What are your thoughts on this or more importantly how much difference does the extra headroom add/detract from the sound quality.
Title: Re: How to Build a killer Amp
Post by: gamve on January 03, 2011, 01:12:59 PM
Hi Fi Collective UK have the 56K 2W tantalum resistors....not cheap... :o
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 06, 2011, 04:51:29 PM
I have put some transformers and stuff in the parts section for the killer amp
All about the Killerdac > Buy/Sell/Give/Take > DIY parts or services for sale
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 11, 2011, 05:59:27 PM
Here is a picture of the underside driver tube. I will post a series of pictures soon.
Title: Re: How to Build a killer Amp
Post by: crazikid on January 11, 2011, 09:02:23 PM
how are the duelunds sounding in your amp?
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 11, 2011, 11:31:52 PM
how are the duelunds sounding in your amp?
I have just put in 400Volt duelunds into the DAC, will let you guys know soon,  if they cut it after run in.
Title: Re: How to Build a killer Amp
Post by: crazikid on January 12, 2011, 09:28:28 AM
I have just put in 400Volt duelunds into the DAC, will let you guys know soon,  if they cut it after run in.

Does it matter what uF size cap can be used??
Title: Re: How to Build a killer Amp
Post by: kajak12 on January 12, 2011, 09:05:53 PM
I HAVE USED 2.2 UF AND 2.7UF  (THE 2.7 uf more weight)  had to retune my fcuken system for it
Title: Re: How to Build a killer Amp
Post by: gamve on January 17, 2011, 05:04:23 PM
Hi Steve,
Noticed the duelands in the last picture. Do we need to get these underway or are you just trying them out at the moment? From what I can gather the duelands take a while to get. What type and voltage are they/
Cheers
Gamve
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 21, 2011, 12:40:16 AM
Hi Steve,
Noticed the duelands in the last picture. Do we need to get these underway or are you just trying them out at the moment? From what I can gather the duelands take a while to get. What type and voltage are they/
Cheers
Gamve
I use dueland 400v .47 in the amps. also very good, is the audionote copper pipe paper in oil .47 not the newer oil audionotes, they are not as good. The duelands take forever to get, dont get them from partsconnection unless they are in stock, but they lie a lot, take your money and then tell you they dont have them.
Title: Re: How to Build a killer Amp
Post by: gamve on January 21, 2011, 06:32:01 PM

I use dueland 400v .47 in the amps. also very good, is the audionote copper pipe paper in oil .47 not the newer oil audionotes, they are not as good. The duelands take forever to get, dont get them from partsconnection unless they are in stock, but they lie a lot, take your money and then tell you they dont have them.

My other parts turned up today from Partsconnections
Do you know if Mike Lenehan gets the duelands quicker or cheaper? It took months to get the caps for my ML1 ultra upgrade. Will ring Mike and ask. Would the paper in oil Ampohm caps be worth a try?
Title: Re: How to Build a killer Amp
Post by: stevenvalve on January 22, 2011, 12:33:34 AM

I use dueland 400v .47 in the amps. also very good, is the audionote copper pipe paper in oil .47 not the newer oil audionotes, they are not as good. The duelands take forever to get, dont get them from partsconnection unless they are in stock, but they lie a lot, take your money and then tell you they dont have them.

My other parts turned up today from Partsconnections
Do you know if Mike Lenehan gets the duelands quicker or cheaper? It took months to get the caps for my ML1 ultra upgrade. Will ring Mike and ask. Would the paper in oil Ampohm caps be worth a try?
ask someone who has tried them.
Title: Re: How to Build a killer Amp
Post by: gamve on January 24, 2011, 11:46:04 PM
Mike had a pair of dueland VSF 400V 0.47uf in stock....no waiting for these...timing himing  ;)
Title: Re: How to Build a killer Amp
Post by: kajak12 on January 30, 2011, 03:02:23 AM
killer amp
Title: Re: How to Build a killer Amp
Post by: omodo on January 30, 2011, 10:38:33 AM
Lundahl OPTs ?

Title: Re: How to Build a killer Amp
Post by: Jehuty on July 05, 2011, 06:57:17 PM
Steve, I found these NOS UTC output transformers on eBay, could you tell us if we can use these for the killer amp?

http://www.ebay.com.au/itm/UTC-S-16-output-transformer-matching-pair-NOS-tested-/180690089283?pt=Vintage_Electronics_R2&hash=item2a11f7f543
Item number: 180690089283
BIN: USD 599
Shipping to Australia: USD 43.23
Additional info: Date/run number is GV21. The primary specs are as follows: 3000 ohm for 45/2a3/6a3/6a5/6b4, 6000ohm for 2a5/6f6/6as7/46/6a6/6n7, 9000/10000 ohm 45/2a5/6ac5/6b5/6f6/6l6/6v6/807. The secondary is as follows 8 ohm/15 ohm and 500 ohm. Impedance and tube type data as published in radio master catalog.
Some pics attached.

I know it's pricey but hey this is a killer amp and if these UTCs sound a killer then I shall go for them!  8)

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: stevenvalve on July 06, 2011, 04:34:35 PM
Steve, I found these NOS UTC output transformers on eBay, could you tell us if we can use these for the killer amp?

http://www.ebay.com.au/itm/UTC-S-16-output-transformer-matching-pair-NOS-tested-/180690089283?pt=Vintage_Electronics_R2&hash=item2a11f7f543
Item number: 180690089283
BIN: USD 599
Shipping to Australia: USD 43.23
Additional info: Date/run number is GV21. The primary specs are as follows: 3000 ohm for 45/2a3/6a3/6a5/6b4, 6000ohm for 2a5/6f6/6as7/46/6a6/6n7, 9000/10000 ohm 45/2a5/6ac5/6b5/6f6/6l6/6v6/807. The secondary is as follows 8 ohm/15 ohm and 500 ohm. Impedance and tube type data as published in radio master catalog.
Some pics attached.

I know it's pricey but hey this is a killer amp and if these UTCs sound a killer then I shall go for them!  8)

Cheers,
William
William they are too pricey, but more importantly, sound wise unknown. Leave them there is better out there for the money.
Title: Re: How to Build a killer Amp
Post by: Jehuty on July 06, 2011, 05:04:44 PM
Steve, I found these NOS UTC output transformers on eBay, could you tell us if we can use these for the killer amp?

http://www.ebay.com.au/itm/UTC-S-16-output-transformer-matching-pair-NOS-tested-/180690089283?pt=Vintage_Electronics_R2&hash=item2a11f7f543
Item number: 180690089283
BIN: USD 599
Shipping to Australia: USD 43.23
Additional info: Date/run number is GV21. The primary specs are as follows: 3000 ohm for 45/2a3/6a3/6a5/6b4, 6000ohm for 2a5/6f6/6as7/46/6a6/6n7, 9000/10000 ohm 45/2a5/6ac5/6b5/6f6/6l6/6v6/807. The secondary is as follows 8 ohm/15 ohm and 500 ohm. Impedance and tube type data as published in radio master catalog.
Some pics attached.

I know it's pricey but hey this is a killer amp and if these UTCs sound a killer then I shall go for them!  8)

Cheers,
William

William they are too pricey, but more importantly, sound wise unknown. Leave them there is better out there for the money.

Thanks Steve, you saved me lots of money there! Next time if these UTCs come up again and not that dear, I'll get them and let you play around with.  ;)
Title: Re: How to Build a killer Amp
Post by: Jehuty on July 30, 2011, 10:37:35 PM
To run choke imput, a nice choke for that, is 1/ UTC- CG 40  10H about 200 ma, 1950s. United transformer company, New York

Steven,

There's a Triad C-16A choke on eBay:
Item number: 370529262048
Spec: 10H, 200mA, 150 OHMS, 2500 volts
Link: http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=370529262048&ssPageName=STRK:MEWAX:IT

Is it good for input choke?

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: Jehuty on July 31, 2011, 07:52:31 PM
Just talked to Steven, it looks like it's got flying leads underneath which probably made of tinned copper which doesn't sound good so I'd better stay away  ;D
Title: Re: How to Build a killer Amp
Post by: Jehuty on December 09, 2011, 03:08:38 AM
Hi everyone,

I am building my dream amp with Steven's guidance at the moment and I need to get a pair of output transformers for the RCA UX-250 SET amp.

I've got a few options: Tamura F7001 or F7002, Hashimoto H-30-3.5S, Tango X3.5S - pre ISO Tango (doubt it because of the high price) and Tribute output transformers. I am currently leaning to Tribute because it's custom made and the price is very reasonable, so I need some advice about the most appropriate OPT spec to run the RCA UX-250.

I did send email to Pieter, see below:

Hello William,

Thanks for enquiring.

UX-250 is some 20 watts maximum plate dissipation, Rp 1k8, 50 mA DC.
I guess primary impedance 5k.
Basically two options: wound on HiB silicon steel c-cores, or amorphous alloy c-cores.
Price for a pair 325,- Euro (HiB), or 375,- Euro (amorphous).
These prices are without VAT (when you live inside the EEC, there is additional VAT of 19%).
Shipping not included.
Transformers are potted and finished, ready for chassis mounting.

Best regards,

Pieter Treurniet
Tribute Audio Transformers


What do you guys think? Is 5k impedance suitable? The Tamuras, Tango and Hashimoto are about 3 to 3.5k impedance and the Tamura F7001 did work on Steven's amp from what he told me. Is the primary max DC 50 mA good enough? And what is "Rp 1k8"? :-[

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: Jehuty on January 07, 2012, 05:41:18 AM
After quite a lenghty discussion with Pieter, I decided to put an order for a pair of his OPTs, spec: 2 SE output transformers HiB c-cores 3k5-5k/8-16R/100mA, potted 12x12cm, 6kg each, good enough to run 300B or PX25 if I need more watts.

It's a bit of gamble to order without listening but I hope the review on the net is not very wrong, otherwise Steven's Tamura F7001s will be gone before he knows it  ;D
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 07, 2012, 10:35:55 AM
Jehuty,

These Tribute transformers look very nice.

The fact that he is conversant with a wide range of applications, for example stepped TVC toroid style, indicates a depth of knowledge and lateral approach.

I'm not sure about potting or varnishing OP transformers. Speak to Steven WRT this.

cheers

 
Title: Re: How to Build a killer Amp
Post by: Jehuty on January 08, 2012, 06:56:32 PM
Thanks T, it's good to know that he's knowledgeable and from what I read on the net, his OPTs are up there with some of the best OPTs you can get. I have high expectation and I might try his chokes too if I like his OPTs  :)

Steve doesn't like potted OPT because the pot could potentially dampen the OPT too much and take away the life of music... I personally like it potted because it's neater and the Tamura F7001s (damn fine OPTs) I heard at Steven's were potted too...so personal choice plays a role here, hopefully I got this one right, now the long wait begins....
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 08, 2012, 09:57:19 PM
Thanks T, it's good to know that he's knowledgeable and from what I read on the net, his OPTs are up there with some of the best OPTs you can get. I have high expectation and I might try his chokes too if I like his OPTs  :)

Steve doesn't like potted OPT because the pot could potentially dampen the OPT too much and take away the life of music... I personally like it potted because it's neater and the Tamura F7001s (damn fine OPTs) I heard at Steven's were potted too...so personal choice plays a role here, hopefully I got this one right, now the long wait begins....

I was actually thinking more of the resin and varnish having certain dielectric properties. However it is probably a combination of dielectrics + microphonics.

Less spectacular description, sorry. :)

Looking at a parallel audio field, I'm thinking guitar pickups here. 100's of thousands are made / sold yearly trying to re create / improve
vintage Fender / Gibson pickups and a huge of research has gone into it.

The findings: Dry winds are generally superior sound wise and also type of wire insulation. Apparently some of the older insulations are not available any more.

They do other tricky stuff that I'm not even going to talk about because it's also applicable to chokes / transformers.

Good luck with the transformers.

Title: Re: How to Build a killer Amp
Post by: springcreek on January 08, 2012, 10:27:55 PM
Hi Jehuty

Have you thought about getting Dave Slaggle from Intact Audio http://www.intactaudio.com/tran.html in the states to make you a pair? Dave has an amazing reputation for winding great transformers for SETs and his favourite tube is...you guessed it the 50! He makes a high nickel content transformer that is supposed to be 'better' than amorphous. I have heard the description of the two described in terms of food, amorphous is like a really high quality meal from a great restaurant and high nickel content is like the soul food you always want to come home to.

I hope to build Steven's 50 amp in the future (when I can afford it and after I've done up the Fisher!). I think I will get Dave to make me some trannies for me.

Dave and amp builder Jeffery Jackson (who makes great 50 amps himself http://www.jeffreywjackson.com/amplifiers.htm) have a blog called hifi heroin http://www.hifiheroin.blogspot.com/.

Hope it's useful.

Cheers, Andy
 
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 08, 2012, 10:49:40 PM
Hi Jehuty

Have you thought about getting Dave Slaggle from Intact Audio http://www.intactaudio.com/tran.html in the states to make you a pair? Dave has an amazing reputation for winding great transformers for SETs and his favourite tube is...you guessed it the 50! He makes a high nickel content transformer that is supposed to be 'better' than amorphous. I have heard the description of the two described in terms of food, amorphous is like a really high quality meal from a great restaurant and high nickel content is like the soul food you always want to come home to.


Andy

Traditionally high nickel or similar are the best cores for low level (signal) but are difficult to use for audio outputs.

If Dave has managed to do it that's definitely worth checking out.

I suppose at 2 or 3 watts it's almost somewhere between signal and audio OP :)

T




Title: Re: How to Build a killer Amp
Post by: Jehuty on January 09, 2012, 12:12:40 AM
Hi Jehuty

Have you thought about getting Dave Slaggle from Intact Audio http://www.intactaudio.com/tran.html in the states to make you a pair? Dave has an amazing reputation for winding great transformers for SETs and his favourite tube is...you guessed it the 50! He makes a high nickel content transformer that is supposed to be 'better' than amorphous. I have heard the description of the two described in terms of food, amorphous is like a really high quality meal from a great restaurant and high nickel content is like the soul food you always want to come home to.

I hope to build Steven's 50 amp in the future (when I can afford it and after I've done up the Fisher!). I think I will get Dave to make me some trannies for me.

Dave and amp builder Jeffery Jackson (who makes great 50 amps himself http://www.jeffreywjackson.com/amplifiers.htm) have a blog called hifi heroin http://www.hifiheroin.blogspot.com/.

Hope it's useful.

Cheers, Andy
  

I wish you had told me earlier about this Andy.....thanks for the info by the way, still very useful  :)

Oh well....I'll play around with the Tribute and if I'm not happy with them I'll just use them for my bass amp...Oh yeah I'm going to build another one in the future ;D

I'd like to hear what you think about the Intact OPT when you get them, apparently Audio Note UK uses nickel core too for their top of the line OPT... http://www.audionote.co.uk/articles/art_transformer_design.shtml and http://www.audionote.co.uk/comp/trans/trans_01_tx_news.shtml

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: Jehuty on January 09, 2012, 12:27:33 AM
I was actually thinking more of the resin and varnish having certain dielectric properties. However it is probably a combination of dielectrics + microphonics.

Less spectacular description, sorry. :)

Looking at a parallel audio field, I'm thinking guitar pickups here. 100's of thousands are made / sold yearly trying to re create / improve
vintage Fender / Gibson pickups and a huge of research has gone into it.

The findings: Dry winds are generally superior sound wise and also type of wire insulation. Apparently some of the older insulations are not available any more.

They do other tricky stuff that I'm not even going to talk about because it's also applicable to chokes / transformers.

Good luck with the transformers.



Thanks T, any information you share is always appreciated.

Interesting you mentioned that some older insulations are better, that may be one of the factors Steve likes the silk insulated Hanley wires, you know he calls it the holy wire  ;D

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: springcreek on January 09, 2012, 10:03:26 PM
Terry and William

Dave seems to have it well sorted and is now making 80% nickel transformers, chokes and autoformers. Jeff Jackson thinks of all the stuff he has tried, the high nickel presevers the low signals best as Terry says. Jeff uses lots of this stuff in his amps plus mercury rectifiers and a lot of chokes and PIO caps to filter the supplies. Very cool and very heavy amps. Given these guys are horn nuts they make there stuff quiet and dynamic. Would love to hear such a system! :o

I asked Dave to give me an idea on price for some of his kit. Will let you know.

Still loving the Fisher with the Goodmans Triaxioms. Will be interesting to see how far I can take the Fisher. Ordered some Russion PIO K40y caps the other day so I'll see how they sound. I had to order a dozen so let me know if anyone wants some to try them and I'll send some through, though they are only small values 0.047uF 630V. Should be ordering some new 2W Allen Bradleys in the coming week.
And my lovely wife is going to get me a new soldering station for my birthday  ;D

William good luck with the Tribute trannies, let us know how they go. ;)

Cheers, Andy
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 10, 2012, 01:17:01 AM
Terry and William


And my lovely wife is going to get me a new soldering station for my birthday  ;D

Cheers, Andy

It's hard to believe but these are actually pretty good.

http://www.ebay.com.au/itm/60W-Soldering-Iron-Station-Digital-Temperature-Control-/200690433764?pt=LH_DefaultDomain_15&hash=item2eba14fee4

I got about 18 months out of one and it works all day every day = probably 12 hrs on. I've trashed $300 units in 6 months.

T

Title: Re: How to Build a killer Amp
Post by: springcreek on January 10, 2012, 07:38:07 AM
Thanks Terry

I will check it out.

I was thinking of getting one of these http://www.rhinotools.com.au/soldering-station/124-soldering-station-digital-48w.html

Cheers, Andy
Title: Re: How to Build a killer Amp
Post by: gamve on January 10, 2012, 11:46:03 AM
Guys, I brought a Rhino Tools de-soldering station a while back. Only used it a couple of times so far
but it works really well. Looks are similar to the link like terrys. They also do a dual unit with a both.
Title: Re: How to Build a killer Amp
Post by: ozcal on January 10, 2012, 12:49:20 PM
Guys, I brought a Rhino Tools de-soldering station a while back. Only used it a couple of times so far
but it works really well. Looks are similar to the link like terrys. They also do a dual unit with a both.
Thanks for the heads up GM , will grab one when I have the cash.
Title: Re: How to Build a killer Amp
Post by: springcreek on January 10, 2012, 01:20:45 PM
Cool checked out the link Terry will order one in the next week or two.
Good to know that it is a decent unit...if Terry gets 18 months I should get about 18 years!
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 10, 2012, 01:50:00 PM
Thanks Terry

I will check it out.

I was thinking of getting one of these http://www.rhinotools.com.au/soldering-station/124-soldering-station-digital-48w.html

Cheers, Andy

Note the one I linked to is 60W. Whatever you get I recommend 60W it makes a big difference. This is also thermostatically controlled
and also has a 'sleep' mode.

cheers
Title: Re: How to Build a killer Amp
Post by: springcreek on January 10, 2012, 05:14:54 PM
Yep will get the 60w version. Got a multimeter for Christmas, any other essentials that would be worth getting? Looking forward to sniffing some solder  ;D
Title: Re: How to Build a killer Amp
Post by: Jehuty on January 10, 2012, 05:44:05 PM
Yep will get the 60w version. Got a multimeter for Christmas, any other essentials that would be worth getting? Looking forward to sniffing some solder  ;D

Third hand soldering station, solder sucker (Steven has a very good one, don't know where to get it though)....and an LCR meter if you're into chokes, caps and resistors, Jaycar got one, I bought it for $50 and came with a lifetime warranty  ;D

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 10, 2012, 06:39:05 PM
Yep will get the 60w version. Got a multimeter for Christmas, any other essentials that would be worth getting? Looking forward to sniffing some solder  ;D

It's actually a hazard WRT heavy metal buildup in your body.  Those big spring loaded solder suckers are particularly bad as they atomise
tiny particles of lead.

My first choice is electrical de-soldering station, 2nd is solder wick, 3rd is the 'big gun'

I also try to eat plenty of corriander and do plenty of excercise.

http://drumweaver.hubpages.com/hub/cilantro-chelates

cheers

T

Title: Re: How to Build a killer Amp
Post by: Jehuty on January 10, 2012, 06:46:28 PM
Yep will get the 60w version. Got a multimeter for Christmas, any other essentials that would be worth getting? Looking forward to sniffing some solder  ;D

It's actually a hazard WRT heavy metal buildup in your body.  Those big spring loaded solder suckers are particularly bad as they atomise
tiny particles of lead.

My first choice is electrical de-soldering station, 2nd is solder wick, 3rd is the 'big gun'

I also try to eat plenty of corriander and do plenty of excercise.

http://drumweaver.hubpages.com/hub/cilantro-chelates

cheers

T

Wow, didn't know the hazard of solder sucker! Thanks again Terry, I'll exchange my solder sucker with solder wick or...could you recommend a good electrical de-soldering station?

Love coriander, so it'll be on my daily menu  ;D

Cheers,
William

Edit: looks like the Rhino desoldering station is good as suggested by gamve, expensive though, I'll probably go with the solder wick then...
Title: Re: How to Build a killer Amp
Post by: kajak12 on January 10, 2012, 08:24:06 PM
Yep will get the 60w version. Got a multimeter for Christmas, any other essentials that would be worth getting? Looking forward to sniffing some solder  ;D

It's actually a hazard WRT heavy metal buildup in your body.  Those big spring loaded solder suckers are particularly bad as they atomise
tiny particles of lead.

My first choice is electrical de-soldering station, 2nd is solder wick, 3rd is the 'big gun'

I also try to eat plenty of corriander and do plenty of excercise.

http://drumweaver.hubpages.com/hub/cilantro-chelates

cheers

T


Thanks zenelectro being a welder a bit of lead is nothing :P
Try welding copper/nickel and measure the fumes :'( :'(
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 10, 2012, 09:26:08 PM

Thanks zenelectro being a welder a bit of lead is nothing :P
Try welding copper/nickel and measure the fumes :'( :'(

I believe it's an accumulative thing and builds up over many years - so you don't want to end up like Beethoven do ya :)

http://www.washingtonpost.com/wp-dyn/content/article/2005/12/05/AR2005120501937.html

They put a few locks of his hair in a particle accelerator and found out.

When they put my hair in the particle accelerator they will find high concentrations of carlsberg.  ;D
Title: Re: How to Build a killer Amp
Post by: zenelectro on January 10, 2012, 09:32:17 PM

Wow, didn't know the hazard of solder sucker! Thanks again Terry, I'll exchange my solder sucker with solder wick or...could you recommend a good electrical de-soldering station?

Edit: looks like the Rhino desoldering station is good as suggested by gamve, expensive though, I'll probably go with the solder wick then...

I don't think you've got anything to worry about. I solder sometimes 12 hrs a day so that's a different matter.

The desoldering stations are much more finicky and prone to trouble. You have to clean them regularly and it's a
very messy business. The mob who sells my soldering iron also do a DS station for $100. But I'm on my third
now.

Title: Re: How to Build a killer Amp
Post by: springcreek on January 10, 2012, 10:20:28 PM
Thanks Terry point taken - nasty stuff - hopefully low exposure with the amount I'll do. Good to know though  ;D
Title: Re: How to Build a killer Amp
Post by: vitavoxdude on January 10, 2012, 11:05:34 PM

Thanks zenelectro being a welder a bit of lead is nothing :P
Try welding copper/nickel and measure the fumes :'( :'(

I believe it's an accumulative thing and builds up over many years - so you don't want to end up like Beethoven do ya :)

http://www.washingtonpost.com/wp-dyn/content/article/2005/12/05/AR2005120501937.html

They put a few locks of his hair in a particle accelerator and found out.

When they put my hair in the particle accelerator they will find high concentrations of carlsberg.  ;D

Carlsberg, argggh....a man of taste. ;D ;D ;D ;D ;D ;D ;D ;D
Title: Re: How to Build a killer Amp
Post by: springcreek on January 11, 2012, 12:44:48 PM
(Third hand soldering station, solder sucker (Steven has a very good one, don't know where to get it though)....and an LCR meter if you're into chokes, caps and resistors, Jaycar got one, I bought it for $50 and came with a lifetime warranty) 

Thanks William very useful. So to clarify an LCR meter measures more than what a typical multimeter does?

Yep, with you guys on the Carlsberg  ;D

Bugger now i can't stop thinking about beer  ;D
Title: Re: How to Build a killer Amp
Post by: Jehuty on January 11, 2012, 09:09:19 PM
Hi Andy, LCR meter measures inductance, capacitance and resistance, with normal multimeter you will be able to measure resistance but not inductance and capacitance :)
Title: Re: How to Build a killer Amp
Post by: springcreek on January 12, 2012, 07:40:27 AM
Thanks William, I'll get one  ;D
Title: Re: How to Build a killer Amp
Post by: Jehuty on March 30, 2012, 10:31:42 PM
After quite a lenghty discussion with Pieter, I decided to put an order for a pair of his OPTs, spec: 2 SE output transformers HiB c-cores 3k5-5k/8-16R/100mA, potted 12x12cm, 6kg each, good enough to run 300B or PX25 if I need more watts.

It's a bit of gamble to order without listening but I hope the review on the net is not very wrong, otherwise Steven's Tamura F7001s will be gone before he knows it  ;D

The Tributes are here, celebrity death match tomorrow at Steven's, Tribute vs. Tamura and Steven's Bumblebee OPTs  :P
Title: Re: How to Build a killer Amp
Post by: gamve on March 30, 2012, 11:56:16 PM
After quite a lenghty discussion with Pieter, I decided to put an order for a pair of his OPTs, spec: 2 SE output transformers HiB c-cores 3k5-5k/8-16R/100mA, potted 12x12cm, 6kg each, good enough to run 300B or PX25 if I need more watts.

It's a bit of gamble to order without listening but I hope the review on the net is not very wrong, otherwise Steven's Tamura F7001s will be gone before he knows it  ;D

The Tributes are here, celebrity death match tomorrow at Steven's, Tribute vs. Tamura and Steven's Bumblebee OPTs  :P

Good luck Wil. Hope your OP transformers sound as good as they look  :)
Title: Re: How to Build a killer Amp
Post by: Jehuty on March 30, 2012, 11:57:26 PM
Thanks Graham  :)
Title: Re: How to Build a killer Amp
Post by: kajak12 on March 31, 2012, 12:17:12 AM
After quite a lenghty discussion with Pieter, I decided to put an order for a pair of his OPTs, spec: 2 SE output transformers HiB c-cores 3k5-5k/8-16R/100mA, potted 12x12cm, 6kg each, good enough to run 300B or PX25 if I need more watts.

It's a bit of gamble to order without listening but I hope the review on the net is not very wrong, otherwise Steven's Tamura F7001s will be gone before he knows it  ;D

The Tributes are here, celebrity death match tomorrow at Steven's, Tribute vs. Tamura and Steven's Bumblebee OPTs  :P
I hope you win a prize jehunty a nos u52
Title: Re: How to Build a killer Amp
Post by: Jehuty on March 31, 2012, 12:28:51 AM
Hahaha....I don't really expect to win, to get a similar or close to the Bumblebee is good enough for me. Winning NOS U52?  :o Oh how I wish that is a possibility!
Title: Re: How to Build a killer Amp
Post by: data on March 31, 2012, 01:18:07 AM
Those transformers do look nice  8)
Title: Re: How to Build a killer Amp
Post by: audiophool on March 31, 2012, 04:05:57 AM
Ooooer Willem, the Wallabys could use a couple of bookends like those :D
Title: Re: How to Build a killer Amp
Post by: Jehuty on April 01, 2012, 11:16:18 AM
Ooooer Willem, the Wallabys could use a couple of bookends like those :D

Or door stops  :P

For bigger door you need a bigger trannie....
Title: Re: How to Build a killer Amp
Post by: audiophool on April 01, 2012, 03:53:37 PM
So how did the comparison go ?
Enquiring minds want to know  ???
and it's after midday so we can believe you now  :-\
Title: Re: How to Build a killer Amp
Post by: Jehuty on April 01, 2012, 04:06:29 PM
Sorry guys, didn't get the time to hook up the OPTs. We were too busy ripping apart my dac, a few upgrades were done and by the time we finished it's already very late and I had to get back to Sydney. To be continued...(hopefully next week during Easter holiday).
Title: Re: How to Build a killer Amp
Post by: stevenvalve on April 05, 2012, 04:33:33 PM
Sorry guys, didn't get the time to hook up the OPTs. We were too busy ripping apart my dac, a few upgrades were done and by the time we finished it's already very late and I had to get back to Sydney. To be continued...(hopefully next week during Easter holiday).
Well i have had a listen to the Tribute C core out put transformers ($600 landed) and i must say they are very good. My output C core transformers are In a league of there own so i did not expect these to compare. The Tributes have the same kind of balance as mine,  Full with weight and body, they are also very transparent smooth and relaxed, but i detected some whiteness or (as vitavoxdude would say greyness)  that reminds me of the sound of silver, but the company (Tribute) has said to William via email, that there is no silver in them, but if you look at the picture, those lead out wires look silver, and in the flesh, in front of me they look to be silver. Remember that picture is before they are potted with black resin.  All up these are very very good transformers and if you have some made make sure they use copper solid core for the lead out wire not silver or tin plated copper.
Title: Re: How to Build a killer Amp
Post by: data on April 05, 2012, 05:24:51 PM
They sound like a very nice buy, 600 is a bargain for a big set of nice OT's, and landed  8)
Title: Re: How to Build a killer Amp
Post by: Jehuty on April 05, 2012, 05:59:41 PM
Sorry guys, didn't get the time to hook up the OPTs. We were too busy ripping apart my dac, a few upgrades were done and by the time we finished it's already very late and I had to get back to Sydney. To be continued...(hopefully next week during Easter holiday).
Well i have had a listen to the Tribute C core out put transformers ($600 landed) and i must say they are very good. My output C core out put transformers are In a league of there own so i did not expect these to compare. The Tributes have the same kind of balance as mine,  Full with weight and body, they are also very transparent smooth and relaxed, but i detected some whiteness or (as vitavoxdude would say greyness)  that reminds me of the sound of silver, but the company (Tribute) has said to William via email, that there is no silver in them, but if you look at the picture, those lead out wires look silver, and in the flesh, in front of me they look to be silver. Remember that picture is before they are potted with black resin.  All up these are very very good transformers and if you have some made make sure they use copper solid core for the lead out wire not silver or tin plated copper.

Wow Steve, thank you so much for the write up, very generous review there.

I have indeed asked Pieter T about the silver and his replied was "No, there is no silver in the transformers.
Cores are HiB silicon steel double c-cores; coils are wound with normal copper magnet wire." I tried a follow up email asking about the wires he used to connect the coils to the terminals, I haven't heard back from him yet. He's a very busy person because Tribute is basically a one man operation manufacturer so I guess if he doesn't reply that just means the wires are copper. See attached pic, one of the factor I made my decision to go for Tribute was because of that picture, I can't see any silver in that power transformer...At the end of the day, the proof is in the pudding and as Steve said there's a whiteness in them, it could be because of silver or simply because of Tribute's fundamental design that makes them to sound like that.

Well for me it seems that all the attributes of great output transformers are already there, except for that whiteness...of which I haven't been able to really understand what it is, so I guess I should be happy with this purchase, at least I will be able to use them for my bass amp. My search for output transformers continues...
Title: Re: How to Build a killer Amp
Post by: vitavoxdude on April 05, 2012, 10:10:32 PM
Hmmm, the previous image showing the transformer clearly showed the output terminals connected to the windings with either a plated wire or even possibly Ag wire.  The second image does not have the same connecting technique so which one is which?????  :-\

OK here is my attempt at flushing out the whiteness or greyness as I prefer to call it.  By having multiple materials employed you are going to introduce different shades / thinness/ colour added to the mix as well as different characteristic velocity properties.  When a less good component or wire is introduced something is taken away in the overall result, e.g. all the notes are there but they appear washed out and not colourful and entertaining as a different combination; detail whilst itís what we are all striving for is not the whole picture without vividness and a sense of being real.

I have had many systems which throw detail at you but sound thin, not really alive and washed out and grey in nature.  Contrast this with more colourful systems usually valve based and the picture nearly always changes, that is to say detail does not get thrust into you face but is provided in a less obvious way. So to equate and support the greyness issue I draw on photography as a comparison.  Fuji Film favoured the primary colours differently to Kodak film; clearly a lot of pro's could differentiate between the two and express their preferences.  Vibrant reds and oranges as opposed to more blue make a substantial difference to the results and we are talking film here.  Photos taken at first light or sundown produces more glow (orange) and gives photos more punch and pleasure to the eye.   Which one is more accurate?  Well does it really matter, one conveys more humanness and draws you to enjoying the image and the other is just another picture.  One could therefore conclude that the greater colour saturation the more pleasing to the eye, simmerly the fuller harmonically rich sounds are more pleasing than the grey 'sterile' depiction of the original recording via less natural amplification etc. :-X

V ;D
Title: Re: How to Build a killer Amp
Post by: zenelectro on April 06, 2012, 01:50:39 AM

OK here is my attempt at flushing out the whiteness or greyness as I prefer to call it.  By having multiple materials employed you are going to introduce different shades / thinness/ colour added to the mix as well as different characteristic velocity properties.  When a less good component or wire is introduced something is taken away in the overall result, e.g. all the notes are there but they appear washed out and not colourful and entertaining as a different combination; detail whilst itís what we are all striving for is not the whole picture without vividness and a sense of being real.


It's most likely got more to do with the winding geometry and inter layer insulation material.

Check the pic, these traffos have more interleaved P/S windings than I have ever seen on an audio OP traffo.

WRT winding interleaving, the theory of some's good, more's better, too much = just enough doesn't necessarily hold.
There is an optimum number after which the whole thing starts to look more like a big capacitor (= simple explanation).

Do you know what he uses for inter layer insulation. This is very important.

My 2c worth - I used to work at a transformer manufacturer.

PS - I'll do a backflip if those conn wires are not silver :)

PSS - WRT quality of construction, they look bloody nice 

T
Title: Re: How to Build a killer Amp
Post by: audiophool on April 06, 2012, 08:30:50 AM
Very interesting reading, big thanks to all for their contributions.
Title: Re: How to Build a killer Amp
Post by: Jehuty on April 06, 2012, 08:55:57 AM
Do you know what he uses for inter layer insulation. This is very important.

Hi T,

I gathered the information from his postings on diyaudio, here it is:

"There has been quite some development in interleaving materials.
I don't vacuum impregnate audio transformers for the reason you mentioned, but nevertheless I use kraft paper. The material I use is actually a sandwich consisting of two layers of kraftpaper with a layer of mylar in between, and can withstand a voltage differential of 6 kV which should be good enough for audio transformers. Total thickness is 5 mils (0,13 mm).
I think paper has a slight advantage over mylar when we speak of dielectric, teflon is even better but pretty expensive and more difficult to apply. "

Source: http://www.diyaudio.com/forums/tubes-valves/197999-transformer-potting-material-what-material-3.html#post2737815

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: zenelectro on April 06, 2012, 11:24:01 AM
Do you know what he uses for inter layer insulation. This is very important.

Hi T,

I gathered the information from his postings on diyaudio, here it is:

"There has been quite some development in interleaving materials.
I don't vacuum impregnate audio transformers for the reason you mentioned, but nevertheless I use kraft paper. The material I use is actually a sandwich consisting of two layers of kraftpaper with a layer of mylar in between, and can withstand a voltage differential of 6 kV which should be good enough for audio transformers. Total thickness is 5 mils (0,13 mm).
I think paper has a slight advantage over mylar when we speak of dielectric, teflon is even better but pretty expensive and more difficult to apply. "

Source: http://www.diyaudio.com/forums/tubes-valves/197999-transformer-potting-material-what-material-3.html#post2737815

Cheers,
William


There may possibly be your answer, it is difficult to know.

Mylar = Polyester. As a generalization is not best sounding dielectric for capacitors.

However, until you try a bunch of insulating materials with all else the same it's all conjecture.


cheers

T
Title: Re: How to Build a killer Amp
Post by: stevenvalve on April 06, 2012, 12:08:00 PM
Do you know what he uses for inter layer insulation. This is very important.

Hi T,

I gathered the information from his postings on diyaudio, here it is:

"There has been quite some development in interleaving materials.
I don't vacuum impregnate audio transformers for the reason you mentioned, but nevertheless I use kraft paper. The material I use is actually a sandwich consisting of two layers of kraftpaper with a layer of mylar in between, and can withstand a voltage differential of 6 kV which should be good enough for audio transformers. Total thickness is 5 mils (0,13 mm).
I think paper has a slight advantage over mylar when we speak of dielectric, teflon is even better but pretty expensive and more difficult to apply. "

Source: http://www.diyaudio.com/forums/tubes-valves/197999-transformer-potting-material-what-material-3.html#post2737815

Cheers,
William


There may possibly be your answer, it is difficult to know.

Mylar = Polyester. As a generalization is not best sounding dielectric for capacitors.

However, until you try a bunch of insulating materials with all else the same it's all conjecture.


cheers

T

Yes indeed Mylar = Polyester when i have tried caps with this stuff as the dielectric, they had the same flavor as these output tranformers. 
Title: Re: How to Build a killer Amp
Post by: springcreek on May 04, 2012, 09:22:06 AM
William I'm looking forward to hearding your amp when it's finished...hope to build one just like it. ;)
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 04, 2012, 08:01:45 PM
Hi Andy,

You're welcome to have a listen whenever you're around my place. I'll be working on my amp again tomorrow at Steve's and hopefully it will be ready to run afterwards :)

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: springcreek on May 06, 2012, 09:58:41 AM
William did you guys get it finished? Love to see some pics mate.
Did you have a listen? If you get stuck for somewhere to store it until you get you speaker cabs... I might know a place :0)
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 06, 2012, 07:02:23 PM
Hi Andy, it's ready to run but we didn't get the chance to do it due to my commitments on other matter today. The first trial will be run next week, I'll keep you posted.

PS: I don't think you would like to have that amp in your place, ugly, big and super heavy just like frankenstein :D
Title: Re: How to Build a killer Amp
Post by: kajak12 on May 06, 2012, 10:18:08 PM


PS: I don't think you would like to have that amp in your place, ugly, big and super heavy just like frankenstein :D
That sounds like stevenvalve :D
Title: Re: How to Build a killer Amp
Post by: springcreek on May 09, 2012, 06:30:12 AM
Well I am a scientist so it would fit right in around here  :P

Good luck when you start it up...hopefully not full of smoke  ;D

Cheers, Andy
Title: Re: How to Build a killer Amp
Post by: omodo on May 09, 2012, 08:43:39 AM
all electronics are full of smoke, the trick is not letting it escape ;) ;D
Title: Re: How to Build a killer Amp
Post by: data on May 09, 2012, 04:05:39 PM
Hi Andy, it's ready to run but we didn't get the chance to do it due to my commitments on other matter today. The first trial will be run next week, I'll keep you posted.
Sweet!

Should be a fun and exciting day.

Looking forward to ya' write up  8)
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 19, 2012, 01:58:28 AM
It LIVES!  ;D

Sorry to disappoint anyone who is expecting a decent looking tube amp. I know I still have a looooong way to go...

Thanks to Mr. Garland, I am one step closer to starting my dream journey :)

I'll call my amp Gargoyle 50 from now on :D
Title: Re: How to Build a killer Amp
Post by: data on May 19, 2012, 02:24:36 AM
Looks fine to me  :)

Awesome to be so close  8)
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 19, 2012, 02:30:21 AM
Looks fine to me  :)

Awesome to be so close  8)

Thanks Ian. It will look better, rest assured ;) But the most important thing is, how it sounds and to me I can hear huge potential of this amp, Steve really knows his stuff :)
Title: Re: How to Build a killer Amp
Post by: data on May 19, 2012, 02:59:09 AM
Hay, it really does look fine to me, mine's finished and that looks near as good as it :)

Looks fine to me also, because it is the sound that matters *thumbs up*
Title: Re: How to Build a killer Amp
Post by: crazikid on May 19, 2012, 09:47:54 AM
nice william.. got your speakers?
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 19, 2012, 10:31:28 AM
Hi James, the plan is to get my boxes in June, I'll be in touch when I come up there :)
Title: Re: How to Build a killer Amp
Post by: rab on May 19, 2012, 09:22:39 PM
Wow - congratulations William! -- love those bolts: did someone mention franken-amp?

- rab
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 19, 2012, 09:45:00 PM
Thanks rab. Are you going to build one soon for your horn system? :)
Title: Re: How to Build a killer Amp
Post by: springcreek on May 21, 2012, 09:45:30 PM
Congrats William  ;D Well done  8)

Dang it I want one...have started dreaming about bloody 50 tubes...silly bloody hobby has consumed more of my life than my PhD.

Hopefully I can build one soon or work on building my horns or mod the 960 aaaaarrrrggh ???

Cheers, Andy
Title: Re: How to Build a killer Amp
Post by: Jehuty on May 21, 2012, 10:02:07 PM
Hi Andy,

I started very slow, didn't have the cash to burn so I was slowly saving up and buying the parts little by litle...and man how I enjoyed the process of getting the right parts at a bargain price, ask Steve about my pair of Axiom 80  ;D

My stereo hobby has consumed more of my life too and I regret nothing, in fact I feel alive when I go up to Steve's (5 hours return trip that is) or listen to my system after a boring week of work.

Things will come together Andy and I am sure you know this too :)

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: gamve on May 21, 2012, 10:37:47 PM
"ask Steve about my pair of Axiom 80"... Yeah ask MEEEEEEE.  :'(
Title: Re: How to Build a killer Amp
Post by: springcreek on May 22, 2012, 08:36:38 PM
Thanks mate, yes loving the journey, just wish it went a bit faster sometimes  ;D
Title: Re: How to Build a killer Amp
Post by: tuyen on October 04, 2012, 06:15:26 PM
Hi William,

How is your Gargoyle 50 amp project going?

My system is at the point where it only needs a couple of good quality watts to run the drivers, so have been toying with the idea of building something similar myself.
Title: Re: How to Build a killer Amp
Post by: Jehuty on October 04, 2012, 08:41:50 PM
Hi Tuyen,

I haven't had time to complete the project yet, was very busy with work until last month.

The amp was running fine but I've burnt out two type 50 globes because the filament was too hot so I need to change the filament transformers. I will update this thread when I do that.

Running your horns with SET amps sounds like a good idea but you might want to ask around because last time Brian had one built for his horns but I heard he didn't use it because it's too much for his horns and the sound became bloated.

Cheers,
William
Title: Re: How to Build a killer Amp
Post by: tuyen on October 04, 2012, 11:34:47 PM
Thanks William.  Look forward to some updates later on when you make further progress.

I've ran a few SET amps on my system already (300B and 6L6).  Just now wanting to go a lower more 'pure' 45/46/50 SET :)  
Title: Re: How to Build a killer Amp
Post by: stevenvalve on October 29, 2012, 12:53:30 PM
Speaking of killer amps,  look at this pair of mono blocks, owned by Peter Ashton.  They run huge STC 212e valves and output about 70 watts single ended class A. When he switches them on the lights in his suburb dim. You can get an idea of how big the 212s valves are by looking at the 5U4G rectifiers nearby.
Title: Re: How to Build a killer Amp
Post by: vitavoxdude on October 29, 2012, 02:18:10 PM
STC 212c...........Niiiiiiiiiiiiiiiiiice valve of the 'adult size' but valve amps on the carpet :o

70 w of pure class A is really cooking and should drive anything with some authority, my poor old 211's pale into wimps in comparison despite having a B+ >1000v volt rail, they get really hot too so supports and ventilation require some thought.  Where is the circuit design for that amp and who built the amps?  I would love to be able to clap ears on them at some point as it could be a step up from the Ongaku 'sound' or may be similar but with more drive and 'balls'.
V
Title: Re: How to Build a killer Amp
Post by: stevenvalve on October 30, 2012, 10:34:15 PM
Speaking of killer amps,  look at this pair of mono blocks, owned by Peter Ashton.  They run huge STC 212C valves and output about 70 watts single ended class A. When he switches them on the lights in his suburb dim. You can get an idea of how big the 212s valves are by looking at the 5U4G rectifiers nearby.
You can get these tubes here.  David Crittle,      http://www.retrovox.com.au/ebay/stc4212e.html
Similar tubes here
 http://www.andycowley.com/valves/power/rf/MZ2-200/MZ2-200.html
 http://www.r-type.org/exhib/aaa0529.htm
 http://www.novacon.com.br/audiolabsta2.htm
Reveue of a similar amp here    http://www.6moons.com/audioreviews/roadtour14/roadtour14.html
  

 
 
 
Title: Re: How to Build a killer Amp
Post by: Peter A on October 31, 2012, 09:33:47 PM
Steve, the output from these amps is only 40 watts class A.  The HT voltage is 1250 volts.  14 volts dc at 6 amps on the heaters. 

Peter
Title: Re: How to Build a killer Amp
Post by: stevenvalve on October 31, 2012, 10:54:17 PM
Steve, the output from these amps is only 40 watts class A.  The HT voltage is 1250 volts.  14 volts dc at 6 amps on the heaters.  

Peter
Peter. Well they are only tiny then.  Only 37 watts more than mine, amazing amps.  Can you give more info on them.
Title: Re: How to Build a killer Amp
Post by: kajak12 on November 01, 2012, 12:30:12 AM
Steve, the output from these amps is only 40 watts class A.  The HT voltage is 1250 volts.  14 volts dc at 6 amps on the heaters. 

Peter
1250v  life insurance recommended to work on them
Title: Re: How to Build a killer Amp
Post by: Peter A on November 01, 2012, 09:29:39 PM
The STC 4212E amp tube complement:  Mullard E80CC for the input tubes, TT21 GEC tube for the interstage tube and STC 4212E tube for the output tube.  There are four RCA 5R5GY tubes as a bridge rectifier for supplying HT of the 4212E tube.  These is also one 5R4GY tube supplying rectification for the TT21 and E80CC tubes.  See attached picture for the amplifier circuit.  Donald Tan from Brisbane helped me with drawing up the circuit. 

Lucas Cant from Blackart Audio in Melbourne made the two mono STC 4212E amps.  All Power, Choke, Interstage and Output Transformers were designed and manufactured by Lucas.  It was a labour of love or hate for Lucas to design and build.  This is an original tube design for the 4212E tube. 

Steve, Graham and Craig have all listened to my system and they can describe the sound they heard when I changed the tube in the DIYHIFI Supply Tram2 Pre-amp to a RCA 45 tube.  Over to you Steve.
Title: Re: How to Build a killer Amp
Post by: stevenvalve on November 02, 2012, 02:34:22 PM
Listening to these unique power amps, was one of the highlights of my Queensland visit. What do you get from amps like this, A single ended sound with all the benefits of power. These amps have a lot of power and you can hear it in its relaxed presentation, so liquid you can cut it with a knife, a huge sound stage with max body and warmth that envelopes you in the music without a hint of strain, a wall of sound that you really can immerse yourself in. I think that a great plus for this type of amp is that you can drive most speakers on the planet and do not have to worry about efficient drivers. One draw back is the price of these tubes (STC4212Es) I wonder how expensive the western electric (212E) versions are.
Title: Re: How to Build a killer Amp
Post by: tuyen on November 02, 2012, 02:49:10 PM
Awesome looking units. Thanks for sharing Peter and Steve.

Your experience mimics how I felt when listened to amps at Feastrex that use the Telefunken RV25 tubes.   Photos below for you tube lovers

(http://i25.tinypic.com/2sadzpu.jpg)

(http://shinshu.fm/MHz/06.94/images/NlC2m0PB.jpg)

(http://shinshu.fm/MHz/06.94/images/aegeJAyc.jpg)

(http://shinshu.fm/MHz/06.94/images/iT0N3ZqT.jpg)

(http://shinshu.fm/MHz/06.94/images/xf1pWjCD.jpg)

(http://shinshu.fm/MHz/06.94/images/juwHzB2q.jpg)

(http://shinshu.fm/MHz/06.94/images/TCgCfe7m.jpg)

(http://shinshu.fm/MHz/06.94/images/uqJ57W96.jpg)
Title: Re: How to Build a killer Amp
Post by: Peter A on November 02, 2012, 06:05:24 PM
Very nice amps.  A top cap to boot.  My top capped NOS GEC TT21 tetrode sounds so much better than the NOS GEC KT88 tube in the 4212E amp.   

For Steve, have a look at:

http://www.ebay.com/itm/Western-Electric-212D-Power-Triode-Tube-/150933327772?pt=Vintage_Electronics_R2&hash=item232453cf9c

Steve, have you contacted David Crittle regarding the STC 4212E tubes.  If so, what is his price for this mighty tube.

Steve, thanks for the glowing opinion of my audio system.    It's a step up from my old 45 tube amp. 

Peter
Title: Re: How to Build a killer Amp
Post by: Peter A on November 02, 2012, 06:15:32 PM
I forgot to mention, the interconnects and speaker cables used when Steve auditioned my STC 4212E system comes from the Keith Eichmann Innovations and not ETI-research.  Keith has released a range of interconnects and speaker cables.  Keith was very kind to lend them to me for my audio afternoon a few months ago and when Steve, Graham and Craig heard my system.

Peter
Title: Re: How to Build a killer Amp
Post by: tuyen on November 02, 2012, 06:54:30 PM
Very kind of you for sharing info and schematics of amp to all Peter.   Any photos of amp innards? As I'm sure you know that stuff is what gets some of us excited around here :)

Also what speakers are those that you are using? Look really nice and the extra subwoofers are active?
Title: Re: How to Build a killer Amp
Post by: stevenvalve on November 02, 2012, 07:37:38 PM
I forgot to mention, the interconnects and speaker cables used when Steve auditioned my STC 4212E system comes from the Keith Eichmann Innovations and not ETI-research.  Keith has released a range of interconnects and speaker cables.  Keith was very kind to lend them to me for my audio afternoon a few months ago and when Steve, Graham and Craig heard my system.

Peter
I can only imagine what they sounded like when you where using Craigs Wadia transport plus killerdac.
Title: Re: How to Build a killer Amp
Post by: Peter A on November 02, 2012, 08:17:11 PM
With Craig's Wadia and Killerdac the sound was a lot better an what you heard with the Njoe Tjoeb CD Player.  I loved the sound of the Wadia and Killerdac over my Njoe Tjoeb CD player.  Everyone at my audio meeting listened to the music.  That is a very good indication of the very good sound of a system.

Craig, what are your thoughts.

Peter
Title: Re: How to Build a killer Amp
Post by: gamve on November 02, 2012, 09:20:35 PM
Hi Peter,
Thanks again for having us around to listen to your very individual system. I can only add to Steve's comments about the experience. I enjoyed the powerful effortless and liquid delivery these huge amps provide. Your speaker choice worked very well and seemed well suited to the amps. I thought your tube output CD player acquitted itself very well but I can only imagine how the system sounded with Craig's Wadia and Killerdac in the system. It's a pity there was a noise with the 2A3 monoplates but the Tram 2 fitted with the RCA 45's brought the system even more alive regardless. It's been some journey for you getting these monsters up and running and I admire your dedication with the project. Thanks again for the chance to hear your system.
Cheers
Graham
Title: Re: How to Build a killer Amp
Post by: Peter A on November 02, 2012, 09:50:20 PM
The speakers I am using are from New Zealand.  They are: http://www.imageloudspeakers.com/products/revelation.asp

For Tuyen.  Some pictures of the internals of my amp.

Thanks Graham for you review response.  
Title: Re: How to Build a killer Amp
Post by: Peter A on November 02, 2012, 09:57:41 PM
More pictures
Title: Re: How to Build a killer Amp
Post by: tuyen on November 03, 2012, 10:01:28 AM
Cheers for sharing Peter!   Speakers and amp look great.  I can picture those amps doubling as excellent room heaters for the winter season :)
Title: Re: How to Build a killer Amp
Post by: Peter A on November 03, 2012, 11:17:38 AM
Tuyen, surprisingly, the amps don't produce alot of heat.  At 14 volts 6 amps equals 74 watt bulb for each STC 4212E tube.  There is only a 2 amp 240 volt slow blow fuse at each power socket for the amps.

Peter
Title: Re: How to Build a killer Amp
Post by: rab on November 03, 2012, 10:11:05 PM
What beautiful amplifiers! ... Indeed, I recall seeing a pair of similar monoblocks at Lucas' place a few years ago (still being built at the time), and can't help wondering these might be the very same ones...?

- r.
Title: Re: How to Build a killer Amp
Post by: flemo on November 03, 2012, 11:17:31 PM
Wow, those amps look serious!  Big tubes, big sound!  8)
Title: Re: How to Build a killer Amp
Post by: stevenvalve on November 04, 2012, 12:09:52 AM
What beautiful amplifiers! ... Indeed, I recall seeing a pair of similar monoblocks at Lucas' place a few years ago (still being built at the time), and can't help wondering these might be the very same ones...?

- r.
They most likely are the same. He built them for peter.
Title: Re: How to Build a killer Amp
Post by: Peter A on November 04, 2012, 04:18:36 PM
These are the same amps.  It took about 10 years for Lucas to build the amps in his spare time.  Lucas said there was a lot of experimentation with getting the interstage and output transformers right. 

I sent two STC 4212E tubes to Lucas, but only one made it in tacked.  The insurance did not cover the tube because I packed it.   Lucas could not listen two them both in stereo.

Lucas did a fantastic job as he had to build them from scatch.  No web plans and previous circuits to copy from.  Lucas rang me indicating he was coming up to Brisbane and he dropped them off.  Not bad for service. 
Title: Re: How to Build a killer Amp
Post by: Pixelplay on September 09, 2017, 10:18:18 PM
Well I am 90% there to getting my ux250 killer amp bits together and feeling very excited.
Thanks Steve for all of your help and wisdom so far.

Title: Re: How to Build a killer Amp
Post by: stevenvalve on September 15, 2017, 07:01:09 PM
This circuit is for my 50 Amplifier. You guys can thank Pixelplay for drawing this. Zenelectro is also responsible for some of the circuit, it''s the best soundŪng amp i have heard, Magical indeed, but it is more than just the circuit, it's the wire, choice of parts, and then years of tuning. I do not run 400V into the rectifier, mine is around 300v at the Valve. I dont push the UX250 valves to run hard. Mine has about 2 to 2/5 watts, but with 450 volts you can get 4.6 watts. If you plush them they will not last as long, and can sound stressed, The circuit picture was not right, i will resubmit the correct revised picture soon
Title: Re: How to Build a killer Amp
Post by: stevenvalve on September 15, 2017, 07:13:42 PM
Some pictures of the amplifiers being made. The wood is Australian Cedar. Second amp has a copper top. The 5692 RCAs are replaced with ECC32 Mullard.
Title: Re: How to Build a killer Amp
Post by: stevenvalve on September 15, 2017, 07:33:40 PM
Here is a picture of the 50 amp underneath. I have made changes since this picture, i will take a new picture soon.
Title: Re: How to Build a killer Amp
Post by: rab on September 24, 2017, 10:37:51 PM
Curse you guys! Just when i thought i was nearly at the end game, I hear Pixelplay's incarnation of this damn amp -- not even tuned -- and can't stop thinking about it. 
Title: Re: How to Build a killer Amp
Post by: Pixelplay on September 25, 2017, 12:19:26 AM
Ha ha Rab, it is a fun journey. Perhaps we will have to build you one!
Steve has been such a great help, let alone a treasure trove of useful information.
I have updated the schematic and will post some images of the amplifier soon.
Title: Re: How to Build a killer Amp
Post by: stevenvalve on September 25, 2017, 12:54:46 AM
Ha ha Rab, it is a fun journey. Perhaps we will have to build you one!
Steve has been such a great help, let alone a treasure trove of useful information.
I have updated the schematic and will post some images of the amplifier soon.
Best to run around 300v/0/300v to the rectifier. 400V/0/400v will probably have to much voltage, especially if you run the 15uf cap on the voltage out of the rectifier. The 15 uf cap is needed to lower the noise floor but it is a case of diminishing returns, a bigger cap will probably not lower it much more anyway, but it will not hurt. The other advantage of the 15uf cap is you get a voltage increase and that will allow you to run a lower voltage mains transformer. The UX250 or type 50 is good for 450 volts, but dont run that because that will shorten the life of your hard to find UX250 globes and could make them sound stressed. I run 250v/0/250v and that gives me around 280v-300v at the valve. the B+ switch is used to let the valves warm up before adding the currant, helps the valves last a lot longer. I must say my UX250 globe amplifier running this circuit is so good it is the end game for me, it really does sound real, but to get it there you must use the right bits and tune it correctly. My PX/4 amplifier is running the same circuit and same parts combination.
Title: Re: How to Build a killer Amp
Post by: stevenvalve on September 25, 2017, 07:14:18 PM
I have replaced the Jensen 4 pole 385v- 470uf electrolytic with an 680uf to lower the noise floor, but the 680uf has a lower voltage, so check your voltages. Remember the rule is, doubling the cap size means lowering the noise floor by half, that is important because with no feedback and direct AC heaters you want to lower the noise floor. Its always a battle to work out how to do that without hurting the sound.
Title: Re: How to Build a killer Amp
Post by: kajak12 on September 25, 2017, 09:00:14 PM
I have replaced the Jensen 4 pole 385v- 470uf electrolytic with an 680uf to lower the noise floor, but the 680uf has a lower voltage, so check your voltages. Remember the rule is, doubling the cap size means lowering the noise floor by half, that is important because with no feedback and direct AC heaters you have to lower the noise floor without hurting the sound. Its always a battle the work out how to do that.
If i was anactive member on SNA i would post this and ask the almighty zb for advice :-*
Title: Re: How to Build a killer Amp
Post by: stevenvalve on November 02, 2017, 07:00:28 PM
Just taken this picture of the internals of the PX4 amplifier as you see mechanically its finished. But are they ever finished, as i type i will be trying a new main transformer, well not new, but very vintage.
Title: Re: How to Build a killer Amp
Post by: kajak12 on November 03, 2017, 08:26:04 PM
Just taken this picture of the internals of the PX4 amplifier as you see mechanically its finished. But are they ever finished, as i type i will be trying a new main transformer, well not new, but very vintage.
i feel so honoured you are looking after my future amplifier (put that in your will  :-* :-* :-* :-*)