The KillerDAC Audio forum
General HIFI => Amplification (Pre/Power) => Topic started by: gamve on October 15, 2010, 06:55:39 PM
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Have been struggling with the pre amp issue for more than a couple of years now. Have had some luck with passive pre amps but only when driven by a decent phono stage, CD always seemed dry and lacking drive without a good active preamp. Like most here have been looking at the optical light dependant resistor volume control type passive (well no gain anyways). Having some luck here but still have to build my Lighter Note kit. I am currently testing another unit, see http://killerdac.com/forum/index.php?topic=141.0. This unit is really starting to grab my attention.
The competition to the passive is this knock off of the Japanese Audio Note Kondo line stage. This thing sounds pretty good, bloody should as well the components cost a small fortune. Shinko resistors, Vcaps etc. My main problem is I have tons of records, CD's, R2R tapes, cassettes etc and I need a lot of inputs. I am destined to go the Killerdac route but this issue is giving me the shiezer!s. Anyone else in the same boat?
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/Layout.jpg)
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/5687DualTriode.jpg)
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/OutputVCaps.jpg)
Power supply
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/DSCF2733.jpg)
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/DSCF2731.jpg)
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That preamp does look good gamve. Such expensive caps there yet still using a alps blue volume pot (nothing wrong with them, but they are cheap compared to the rest of the components) ?
Dont worry, the killerDAC works great with passives :) Tested and proven so far!! In saying that, I guess it depends on the input stage of the power amp.. but so far, no complaints from any owners that I am aware of!
Here's a link to some internal shots of the KONDO M7 Line/Phono preamp
http://tubeguru.hu/audio_tube_amplifier_SE/KONDOs_M7_line_+Phono.html (http://tubeguru.hu/audio_tube_amplifier_SE/KONDOs_M7_line_+Phono.html)
And here's a link to TubeGuru.Hu's professional level preamp which he believes matches the performance of the Kondo. (he also has access to Kondo's Ongaku and Kondo Niero amplifiers and has made reissues of them. I find his work really impressive).
http://tubeguru.hu/audio_tube_amplifier_SE/Prof.preamp.html (http://tubeguru.hu/audio_tube_amplifier_SE/Prof.preamp.html)
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i use a alps blue in my amp and its a killer it all comes down to synergy in ones system everything plays a part its a matter of trying diffrent parts until magic happens
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The Alps Blue has no sonic signature in this pre. The volume is controlled by a shinkoh resister on the grid of the 5687. All of the signal goes through this resistor. The alps is paralleled across the shinkoh and changes the value of the shinkoh resistor changing the value hence the volume...very clever.
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Very true Mario. Your system definitely has the magic! And true the price of the component doesnt matter. Just like how I much prefer my stepped attenuator which uses $1 takman rex carbon resistors over the bloody expensive ($20 per resistor) vishay z-coil naked metals! (on my system).
Damnit, I don't understand the concept of how paralleling the shinkoh with the pot will make it so the signal doesnt go thru the alps pot!! Does the volume change in steps or is it gradual(ie. like turning the alps pot)? Is there any advantages (theoretical or practical) in this design over using a stepped attenuator with individual resistors for each level?
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Hey Tuyen,
My electronics knowledge is basic at best and I'm not exactly sure on the theory of this except to say it works just like a step less plastic pot and it works very well. The guy who built this amp for me said he had tried several volume control devices with this circuit including Siden stepped attenuators with shinkoh's, TVC's and everything in between. His comment was that this works best with this circuit bar none. Hey I have heard plenty of systems and this is amoung the very best active pre's I have ever heard at any cost. I was lucky to find someone building this circuit and even luckier to have a builder willing to modify it to my exact specification. I'm very lucky to own it. The original amp was a single box affair with ordinary switching and single outputs. I brought this one and was so impressed with it I went back to the builder and got him to build another one to my spec. Separate power supply, relay switching, dual outputs (the big VCaps go to dual sub woofer). Price was ridiculously cheap compared with Audio Note stuff and I reckon I got most of the important stuff being the SQ.
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sounds like a variable shunt setup, like this:
(http://photos.bravenet.com/415/566/861/2A870B08A8.gif)
so basically a voltage divider, with the pot varying the lower leg of the divider, and the signal only passing through the first (quality) resistor on the way to the tube grid.
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Hey Omodo,
That could well be the very setup. Works a treat at any rate.
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The Tin foil Teflon V-Caps were top of the pile way back when I brought this preamp. Was going over a few thoughts earlier tonight concerning Dueland caps and thought hang on a minute, those Dueland .47 400V I got for my killer amp build are the same value as the V-Cap output in this pre.....MMMMMM.
Just installed the caps and played 3 songs off SG's Gynt disc. OMG they already sound better than the V-Caps ever did. I'm in for a treat when these babies run in. Bugger I will have to buy some more.
Picys tomorrow.
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So what happened about the "Truth" and nothing but the ......... ?
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So what happened about the "Truth" and nothing but the ......... ?
I have too many bits and bobs. Decided to try a 15W SET again with the Ultras. A bit more drive was required
so I put the active pre amp back in. The Truth is still the best sounding unit I have but with no gain it needs to
be matched to an appropriate amplifier/speaker setup.
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OIC - you were driving them with a NAKSA IIRC - I gather the results are still good with the SET.
Just re-reading old stuff here and noting Tuyen's query re the shunt wired pot, I tried this in my amp with an Alps Blue and an AN tantalum load resistor, much better than the Alps Blue, but not as good as my Takman Metal film stepped attenuator.
Theoretically, the stepped attenuator provides greater accuracy WRT channel balance as the resistance of the tracks in a pot can vary quite a bit between one channel and the other.
Worth noting in this context, if the stepper is wired as a shunt type then different load resistors can be tried to vary the sound whilst retaining the accuracy of channel balance. I am presently using an AMRG 2 watt carbon as load resistor on my Takman metal film stepper.
All signal to the circuit passes only through the load resistor, the pot merely drains a variable amount to ground, so only 1 quality resistor is required and it is relatively cheap to try different types.
Apologies for the digression, although the content seemed appropriate here.
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OIC - you were driving them with a NAKSA IIRC - I gather the results are still good with the SET.
Just re-reading old stuff here and noting Tuyen's query re the shunt wired pot, I tried this in my amp with an Alps Blue and an AN tantalum load resistor, much better than the Alps Blue, but not as good as my Takman Metal film stepped attenuator.
Theoretically, the stepped attenuator provides greater accuracy WRT channel balance as the resistance of the tracks in a pot can vary quite a bit between one channel and the other.
Worth noting in this context, if the stepper is wired as a shunt type then different load resistors can be tried to vary the sound whilst retaining the accuracy of channel balance. I am presently using an AMRG 2 watt carbon as load resistor on my Takman metal film stepper.
All signal to the circuit passes only through the load resistor, the pot merely drains a variable amount to ground, so only 1 quality resistor is required and it is relatively cheap to try different types.
Apologies for the digression, although the content seemed appropriate here.
amrg? japanese made carbon resistors i must try one day (in flemo's amp)
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"OIC - you were driving them with a NAKSA"
No I had the truth driving a 35W push pull Modjeski RM10 valve amp. This has a bit more grunt than the SET amp
and worked well with the truth. The ultimate aim is to have the truth driving 180W transcendent audio OTL Beast
mono blocks (30db gain) with the Ultras. Pretty sure this setup will really sing.
Stepped attenuators are nice but I have had better results (read my limited experience) with the LED setup via the
Truth, and the volume control in this pre. Note that the pre amp builder tried most every method including TVC's and
stepped attenuators in both series (DACT) and Ladder type devices and the shunt method yielded the best results
in his opinion. It suits me as well. I have another passive here with 32 step Siden switches and dale close tolerance
resistors that sounds good with my analogue rig but washed out and lifeless with the digital setup. Volume control
seems to me to be one of the hardest things to do right. I'm starting to believe that SG has the right idea. No pre
amp no volume control and burn your CD's + or - dB to get the right listening level......mute switch would be a good
idea.
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I'm starting to believe that SG has the right idea. No pre
amp no volume control and burn your CD's + or - dB to get the right listening level......mute switch would be a good
idea.
Mute switch oh yes gamve its called the power switch at the amp doh i forgot steve doesnt have one he really runs a limited system :D
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I quite believe that the shunted arrangement you have there would be optimal, the signal effectively passes only through the Shinkoh which is only 1, very high quality, resistor.
I recall a discussion with AndyR from SNA about this some years back, it might have been in relation to an AKSA preamp and involved a TKD pot shunted with Vishay Z-foils.
I know what you mean about the Dales, my previous stepper was a ladder type with Dales and it did lean to the pale and washed out side of things.
My present arrangement is similar to your arrangement in that the signal passes through only 1 resistor on the way in.
You will need a clearance from DCA before you fire up those OTLs :o
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The Duelands installed in this pre are just plain scarry good. I can't believe the amount of difference
they make to this unit...Aw who am I kidding....I know what Duelands do, The ultras and the KD have
shown me this.
The King Is Dead
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/OutputVCaps.jpg)
Off With His Head
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/DSCF2750.jpg)
The True King Lives
(http://i480.photobucket.com/albums/rr165/gamve/GW%20Pre%20Amp/DSCF2749.jpg)
Now must tidy and shorten leads these are staying
Note to self Ring Mr. Lenehan
The 2.0uf caps can stay for the bass output
FOR SALE 2 x 0.47uf Tin foil Teflon V-Caps 300V
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gamve your in deep sh!t duelunds will hit your hifi budget very hard the only problem is once they are in their is no going back ;)
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gamve your in deep shiezer! duelunds will hit your hifi budget very hard the only problem is once they are in their is no going back ;)
Rang MikeL. Whaddya know he had 4 x 0.47uf's in stock and did them at a nice price for me.
2 will go into Garrys pre (Very similar to my pre discussed in this thread)
The other two I will put back into the KillerAmp parts bin (and try to leave them there) ::)
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I quite believe that the shunted arrangement you have there would be optimal, the signal effectively passes only through the Shinkoh which is only 1, very high quality, resistor.
I recall a discussion with AndyR from SNA about this some years back, it might have been in relation to an AKSA preamp and involved a TKD pot shunted with Vishay Z-foils.
I know what you mean about the Dales, my previous stepper was a ladder type with Dales and it did lean to the pale and washed out side of things.
My present arrangement is similar to your arrangement in that the signal passes through only 1 resistor on the way in.
You will need a clearance from DCA before you fire up those OTLs :o
Audiophool,
A point of clarification in regard the shunt style arrangement being discussed.
The leg to ground (the pot) as actually a very significant, and probably the most significant 'flavouring' component in this setup. The current path is from source thru the series resistor acting as a voltage divider thru the pot to ground. The voltage seen at the grid (which is a high input impedance) is the resultant I*R across the pot. Thus the signal that the grid is seeing is actually the vlotage appearing across the the pot from the current flow thru it.
I noted that GAMVE commented that the pot seemed to be paralleled across the tantalum resistor which suggests that the shunt arrangement drawn earlier is probably not how it is aranged.
Assuming that the pot is indeed parallelled across the tantalum, it is possible that the tantalum itself is the 'shunt' leg as you discussed above and there is another fixed series resistor, in which case the pot will act to vary the shunt leg to ground in a continuous manner. In this arrangement the sonic influence of the pot increases as volume increases.
Option B is that the series resistor is the tant and the pot is paralled across it using a fixed shunt to ground ie also a variable voltage divider. This is a less likely setup because it creates a greater variation in the input resistance. BUT the sonic flavour is more consistent with volume because the leg to ground is unchanging.
Stepped attenuators will provide lower noise injection than a carbon film pot. That is an additional attraction to the greater channel balance that you mention.
One also then has a defined sonic flavour from a particular style of resistor and have the ability to play.
A series shunt (switching both series and shunt) is the best way as there are only ever 2 resistors in the pathway at this position.
Food for contemplation,
Cheers
Rawl
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Your elaboration of the half baked theory I had gleaned from reading and asking the odd question is welcomed for the clarification and extension of understanding it brings me and hopefully others.
Thank you for taking the time.
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I quite believe that the shunted arrangement you have there would be optimal, the signal effectively passes only through the Shinkoh which is only 1, very high quality, resistor.
I recall a discussion with AndyR from SNA about this some years back, it might have been in relation to an AKSA preamp and involved a TKD pot shunted with Vishay Z-foils.
I know what you mean about the Dales, my previous stepper was a ladder type with Dales and it did lean to the pale and washed out side of things.
My present arrangement is similar to your arrangement in that the signal passes through only 1 resistor on the way in.
You will need a clearance from DCA before you fire up those OTLs :o
Audiophool,
A point of clarification in regard the shunt style arrangement being discussed.
The leg to ground (the pot) as actually a very significant, and probably the most significant 'flavouring' component in this setup. The current path is from source thru the series resistor acting as a voltage divider thru the pot to ground. The voltage seen at the grid (which is a high input impedance) is the resultant I*R across the pot. Thus the signal that the grid is seeing is actually the vlotage appearing across the the pot from the current flow thru it.
I noted that GAMVE commented that the pot seemed to be paralleled across the tantalum resistor which suggests that the shunt arrangement drawn earlier is probably not how it is aranged.
Assuming that the pot is indeed parallelled across the tantalum, it is possible that the tantalum itself is the 'shunt' leg as you discussed above and there is another fixed series resistor, in which case the pot will act to vary the shunt leg to ground in a continuous manner. In this arrangement the sonic influence of the pot increases as volume increases.
Option B is that the series resistor is the tant and the pot is paralled across it using a fixed shunt to ground ie also a variable voltage divider. This is a less likely setup because it creates a greater variation in the input resistance. BUT the sonic flavour is more consistent with volume because the leg to ground is unchanging.
Stepped attenuators will provide lower noise injection than a carbon film pot. That is an additional attraction to the greater channel balance that you mention.
One also then has a defined sonic flavour from a particular style of resistor and have the ability to play.
A series shunt (switching both series and shunt) is the best way as there are only ever 2 resistors in the pathway at this position.
Food for contemplation,
Cheers
Rawl
Right on the money, Rawl. This is a very good explanation of the issues with series shunt attenuators, not to mention the varying input impedance with this arrangement. The ladder type, or L Pad atenuator overcomes these problems as there are only ever two resistors in the circuit. The downside is cost and complexity, as one needs double the resistors, but there are some reasonably priced kits to make them. Michael Percy has some good ones for very reasonable prices. The only thing is that you need good soldering skills and lots of patience.
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Tripped over an interesting possible modification for this preamp while browsing yesterday. I noticed there are adaptor plugs available to change from a 5687 9 pin tube to an octal ECC32 :o
Steven and I had a bit of a discussion on the possibility of adding another gain stage to the killeramp while I was visiting in
Sydney and I guess this was still in the back of my mind. I guess that it would be possible to get this but from the preamp out instead of an extra stage in the killeramp?
Questions for the technically advanced (your there Zen? Rawl?)
1. How close are the 5687 and the ECC32 electrically in there characteristics, power supply requirements? heater voltage, current draw etc.
2. Hoping that they are similar, what needs to be done/changed to give this a try
I love the sound of the ECC32 and would dearly love to try one in my pre.....
Cheers
Graham
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http://www.r-type.org/exhib/aad0139.htm
http://www.r-type.org/exhib/aaa0436.htm
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http://www.r-type.org/exhib/aad0139.htm
http://www.r-type.org/exhib/aaa0436.htm
Thanks Mario
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Tripped over an interesting possible modification for this preamp while browsing yesterday. I noticed there are adaptor plugs available to change from a 5687 9 pin tube to an octal ECC32 :o
Steven and I had a bit of a discussion on the possibility of adding another gain stage to the killeramp while I was visiting in
Sydney and I guess this was still in the back of my mind. I guess that it would be possible to get this but from the preamp out instead of an extra stage in the killeramp?
Questions for the technically advanced (your there Zen? Rawl?)
1. How close are the 5687 and the ECC32 electrically in there characteristics, power supply requirements? heater voltage, current draw etc.
2. Hoping that they are similar, what needs to be done/changed to give this a try
I love the sound of the ECC32 and would dearly love to try one in my pre.....
Cheers
Graham
Hi guys
Adding a gain stage is not a bad idea because it can give a lot of advantages in one swoop
The trouble with 1 stage (tube) to drive OP tube is you need a lot of voltage gain, or a high u, so tube choice get
thin, hence ECC32 and equivalents. Also generally tubes with high u, don't have a lot of current drive.
Once you go to a 2 stage IP, you only need a gain of 20 per stage to get total of 400.
This opens up many more possibilities, especially some nice high current high drive tubes.
5687 and ECC32 are very different tubes. 5687 is like a 6DJ8 on steroids but with a bit lower gain.
Used in a lot of Audio Note stuff.
If you sub 5687 for ECC32 with same configuration it wont work. Less voltage gain, but will want to
run at much higher current. 5687 should work well in a 2 stage cascaded circuit. IOW 1 stage following
the next.
Another option is to try a cascode. This means one half of the tube on top of the other but different to
SRPP. This will give high voltage gain and still only 1 coupling cap. I don't know of any cascode
1 driver stage amps but 5687 should be suitable for cascode. Something like an ECC32 wouldn't work
very well as a cascode.
How much voltage have you got available at the HT? From memory it was 350 or so?
I'll do a bit of poking around the net and see what I can find but as you can see it's a can of worms.
PS cascade and cascode are 2 different things, cascade = 1 after the other, cascode = one on top of the other.
PSS I think I'm going to cascode the missus :)
cheers
T
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OK I had a bit of a look and before you know it I'm reading an article by John Broskie
on a circuit that he called 'ultra path'.
Its funny, this is exactly the same circuit I modded with Steven on his amplifier's OP stage.
In the Broskie article he ties a cascoded front end tube to the utrapath OP stage for a
2 stage high gain SE amp.
The only thing that worries me is cascodes sound different and it may take some tweaking
to get even close to original amp sound.
T
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Tripped over an interesting possible modification for this preamp while browsing yesterday. I noticed there are adaptor plugs available to change from a 5687 9 pin tube to an octal ECC32 :o
Steven and I had a bit of a discussion on the possibility of adding another gain stage to the killeramp while I was visiting in
Sydney and I guess this was still in the back of my mind. I guess that it would be possible to get this but from the preamp out instead of an extra stage in the killeramp?
Questions for the technically advanced (your there Zen? Rawl?)
1. How close are the 5687 and the ECC32 electrically in there characteristics, power supply requirements? heater voltage, current draw etc.
2. Hoping that they are similar, what needs to be done/changed to give this a try
I love the sound of the ECC32 and would dearly love to try one in my pre.....
Cheers
Graham
Hi guys
Adding a gain stage is not a bad idea because it can give a lot of advantages in one swoop
The trouble with 1 stage (tube) to drive OP tube is you need a lot of voltage gain, or a high u, so tube choice get
thin, hence ECC32 and equivalents. Also generally tubes with high u, don't have a lot of current drive.
Once you go to a 2 stage IP, you only need a gain of 20 per stage to get total of 400.
This opens up many more possibilities, especially some nice high current high drive tubes.
5687 and ECC32 are very different tubes. 5687 is like a 6DJ8 on steroids but with a bit lower gain.
Used in a lot of Audio Note stuff.
If you sub 5687 for ECC32 with same configuration it wont work. Less voltage gain, but will want to
run at much higher current. 5687 should work well in a 2 stage cascaded circuit. IOW 1 stage following
the next.
Another option is to try a cascode. This means one half of the tube on top of the other but different to
SRPP. This will give high voltage gain and still only 1 coupling cap. I don't know of any cascode
1 driver stage amps but 5687 should be suitable for cascode. Something like an ECC32 wouldn't work
very well as a cascode.
How much voltage have you got available at the HT? From memory it was 350 or so?
I'll do a bit of poking around the net and see what I can find but as you can see it's a can of worms.
PS cascade and cascode are 2 different things, cascade = 1 after the other, cascode = one on top of the other.
PSS I think I'm going to cascode the missus :)
cheers
T
Terry you should try push and pull on your missus :P
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Could not resist..............
Most of the fairer sex (who made that statement!) tend to push you into decisions that leave you pennyless, then they pull all your resources until sucked dry and then they discard you for a richer model..................ho hum and the laws are there to protect them, not us. Go figure. Of course there are some worth hanging onto but they are rear indeed.
Sorry for hijacking the thread.
V
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Thanks for your replies Terry. Looks like it is not a simple exercise to change from the 5687 to a ECC32. I would not bugger about going to a cascode stage with the 5687 tube cause it already sounds very good and works well with my other gear. I was basically just curious to see if a ECC32 could be swapped with a few basic changes in the same circuit.
Cheers
Graham
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I'm quite keen to get this one: http://www.transcendentsound.com/Transcendent/Velvetizer.html
His Groundid Grid Preamp (http://www.transcendentsound.com/Transcendent/Transcendent_Sound_Grounded_Grid_Preamp.html) seems popular and look at the cost compared to other preamps in the lists below:
For CD playback
1. Vacuum State RTP-3D
2. AcousticPlan Sarod
3. Silvaweld SWC 1000
4. Kondo KSL M7
5. Vacuum State FVP 5a
6. Wyetech labs Pearl
7. Silvaweld SWC 450
8. Transcendent Sound Grounded Grid
9. Sphinx Project 4 MkIII
10. Audible Illusions Modulus 3a
11. Sonic Euphoria PLC
12. Jolida JD 1000a
For LP Playback
1. Vacuum State RTP-3D
2. Kondo KSL M7 + KSL SFz transformer
3. Silvaweld SWC 1000 + Silva SWH 650
4. Vacuum State FVP 5a
5. Wyetech labs Pearl + Silva SWH 650
6. AcousticPlan Sarod
7. Silvaweld SWC 450 + PS Audio
8. Transcendent Sound Grounded Grid
9. Sphinx Project 4 MkIII
10. Audible Illusions Modulus M3a
11. Sonic Euphoria PLC
12. Jolida JD 1000a
Link: http://www.positive-feedback.com/Issue26/preamps.htm
Hmmm I wonder where the CAT preamp would be on that listing?
Price for the Velvetizer: http://tubehifi.websitetoolbox.com/post/show_single_post?pid=1282056157&postcount=1
Anyone got experience with his Groundid Grid preamp?
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A pair of 'good' sounding 300b tubes not cheap though? $1500 and over?? Unless think of using chinese or russian (eletroharmonics)?
The GG ive heard before. Very clean clear detailed and dynamic. Doesn't have richness or valve 'bloom'. Was only a stock unit though. Maybe with mods could of been different story!
Falls Audio maybe able to build a nice DHT pre using a less common tube thus making price vs sq better overall?
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I'm quite keen to get this one: http://www.transcendentsound.com/Transcendent/Velvetizer.html
His Groundid Grid Preamp (http://www.transcendentsound.com/Transcendent/Transcendent_Sound_Grounded_Grid_Preamp.html) seems popular and look at the cost compared to other preamps in the lists below:Link: http://www.positive-feedback.com/Issue26/preamps.htm
Hmmm I wonder where the CAT preamp would be on that listing?
Price for the Velvetizer: http://tubehifi.websitetoolbox.com/post/show_single_post?pid=1282056157&postcount=1
Anyone got experience with his Groundid Grid preamp?
William, Talk to Mark OTL. You have heard his grounded grid pre-amp
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How about a used Tram2 pre?
Bryan and rab seem to love theirs. Can use 45/2a3 tubes which are sometimes cheaper than 300b?
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A pair of 'good' sounding 300b tubes not cheap though? $1500 and over?? Unless think of using chinese or russian (eletroharmonics)?
The GG ive heard before. Very clean clear detailed and dynamic. Doesn't have richness or valve 'bloom'. Was only a stock unit though. Maybe with mods could of been different story!
Falls Audio maybe able to build a nice DHT pre using a less common tube thus making price vs sq better overall?
Thanks for sharing Tuyen. Paul Baker preamp is my dream preamp, but to build one is just too expensive for me. I am keen on Transcendent new 300B preamp because it's affordable, yes very true a great pair of 300B would be expensive but they are still more affordable than Western Electric 205D.
William, Talk to Mark OTL. You have heard his grounded grid pre-amp
Hi Graham, yes we heard them together at his place and I actually have a fond memory about his system. Fast, clean, neutral without sounding overly clinical. Perhaps with 300B, it would add texture, body, weight and liquidity? That's what I hope.
How about a used Tram2 pre?
Bryan and rab seem to love theirs. Can use 45/2a3 tubes which are sometimes cheaper than 300b?
I read people got so many problems with the Tram2 so that's why I'm not that keen. Plus, I've already got single ended parallel 45 amp so I think I would gain more by adding 300B sound? Not sure, but I guess I just have to buy and try it.
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Interesting idea of wanting to add the some of that '300b sound' to your system. I would of just thought that the price of a good pair of 300b tubes + price of the preamp, total will be over $2k? Then mods (at least Jensen/solen caps in power supply, Shinkoh resistors, duelund/mundorf coupling and output caps), $3-4k ? If just keep it stock with average parts/tubes, wouldn't it just bottleneck the rest of the system? All the beauty and magic of the killerdac and 45 amp will be washed away?
I thought the killerdac works best direct into the 45 amp with a volume pot? If not, couldn't Paul advise how make them work best together? After, then just tune the system (ie. just change parts on the Kdac/45amp) to give the system more of an overall '300b sound' that you are after?
Or am I missing something?
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I thought the killerdac works best direct into the 45 amp with a volume pot? If not, couldn't Paul advise how make them work best together? After, then just tune the system (ie. just change parts on the Kdac/45amp) to give the system more of an overall '300b sound' that you are after?
Or am I missing something?
Well, I have decided that the best thing in my case, was to run the system that way.
Ie: killerdac->pot->amp
I came to the conclusion that my tannoy system with Radford amp and killer front end had soo much engagement and beauty, that I didn't need my M3 preamp adding more colours to the mix. It was just in the way.
But that doesn't mean this is the right way for everyone.
Sometimes our gut tells us we need something extra.
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Well, I have decided that the best thing in my case, was to run the system that way.
Ie: killerdac->pot->amp
I came to the conclusion that my tannoy system with Radford amp and killer front end had soo much engagement and beauty, that I didn't need my M3 preamp adding more colours to the mix. It was just in the way.
But that doesn't mean this is the right way for everyone.
Sometimes our gut tells us we need something extra.
That is generally the best option IMO.
To run no pre amp there are 2 options:
a) Use a passive volume after the DAC
b) Use a volume control inside the DAC and connect the DAC directly to power amp.
There are advantages / disadvantages to both.
With a) the passive volume control loads the DAC down
With b) you can run the DAC 'open' or no load into the power amp, the power amp but the volume control must be inserted 'inside' the DAC
which will have it's own effect.
IMO, either is a better option than a pre amp, especially given the extra cost.
I already have a bunch of custom special low impedance volume controls for this very purpose but haven't yet tried it.
Z
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Hey Zen, the problem with a) is that it doesn't always work well. It's hit and miss, depending on the source(s) and connecting amp.
I totally understand why active preamps are preferred by many.
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Hey Zen, the problem with a) is that it doesn't always work well. It's hit and miss, depending on the source(s) and connecting amp.
I totally understand why active preamps are preferred by many.
If you understand the impedances and how they interact it's not a problem. The volume pot however, should ideally be inside amp or very close to it
otherwise you can easily pick up unwanted noise. Also a passive pot will not drive the interconnect that well.
But IMO, option B/ is the best way to go, coupled with a very high impedance input R in the amps valve #1. You can easily go to 470k or 1Meg, this will unload the
DAC beautifully and allow for the best dynamics and lowest bass. I am surprised no one has asked me to install one - it's a very cheap high performance
replacement for a pre amp.
When I get out of Hospital I'll install one in the Enterprise and see how it goes.
Z
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My passive is sounding very good, and gives me a switch, which I can't live without.
I don't think I'd ever be a single source guy.
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Or am I missing something?
I like to try new things in life and generally prefer the bang for the buck type of things :)
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I see I see. In which case, zenelectro's suggestion of his tweaked volume controller inside the dac would give you best bang for buck!? will give you best sound quality possible for dac into the power amp too! Or is that how you are currently using it now?
Ps. I know what you mean by liking to try new things in life. Lol
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Yes, in general volume pots sound better with the KillerDAC. But, it's just a volume pot. No valves.... :D Also, I would like to have a second (or even third) output to connect to the bass amp. My comment about bang for buck is for comparisons between different preamps ;)
I just realised the Velvetizer does not have valve regulated power supply, asked Bruce if it's possible to get a valve regulated power supply. Still waiting.
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Hey Will,
Any further thoughts on the 300B Velvetizer preamp by Bruce? Or has it been crossed off the list due to no valve rectification? :)
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Hi Tuyen,
It's still a prototype so not for sale yet (I think). But yeah, I kinda lost my interest because of the solid state rectifier.
Cheers,
Wil
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as far as just pre or no pre, I went thru a period where I experimented with and without preamps. I tried it without a preamp for a week, allowing me time to get used to the different sound. It could just very well be my ears are used to a certain sound which isn't actually that accurate as you would think adding a preamp is just adding more circuits for the signal to have to go thru etc, but for my earsI thought the preamp-less sound was 2 dimensional, it didn't have the layering, texturing etc that I was getting with a preamp.
Then I picked up a Conrad Johnson pv2ar preamp and it took my system to a whole new level and to be honest, I never thought I would own a system that sounded this good.
I have been to a persons house that had some really nice albeit vintage totl gear and he wasn't t using a preamp .Listening to it I was not really that impressed, was pretty much the same as my experience without a preamp, the music just sounded lifeless.
Don't see how a preamp does it (I am taking decent preamps of course) and I wouldn't consider my one small test indicative, but for me, besides the ability for more connections, I just really prefer the sound of a preamp.
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I think the drive preamps can give is a factor, needing to much of a step up in gain often means a preamp can be better. I have tried many preamps including my CAT (Convergent audio technology) and in all cases they take away from my (you are there focus and realism) and add a little smear and veil. Where the singer is like real, now there is a slight artificial haze, with a preamp my system it is just good HIFI. One caveat is, i do have valve output on my KDAC, you could say that is like a mini preamp.