Crack;Bottlehead OTL
Jul 9, 2013 at 5:03 PM Post #1,951 of 12,335
I couldn't agree more, I got mine off eBay for $165 shipped while biting my lip the entire time. I'm not much of a tube roller so I feel okay considering that is the only tube, excluding the stock GE tube, I own. Unfortunately, I am guessing that quality tubes will only go up in price since they aren't manufactured anymore.
 
Jul 9, 2013 at 5:10 PM Post #1,952 of 12,335
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So...  I've just ordered one of these adapters too.  Mine is the 6.3V version.  Did I order the right thing?
 

 
I have the 6.3V version and it works fine.  Somebody reported receiving the 12V version and it didn't work with the Crack.  I'm not sure why they even sell a 12V version that you plug a 6SN7 into that has a 6.3V heater filament.  Maybe someone else can explain this.
 
Jul 9, 2013 at 11:57 PM Post #1,953 of 12,335
6.3v is the right one.  Unfortunately, my experience with these adapters doesn't quite match bmwr's.  The first one I ordered had a horrible buzz in the left channel that increased in loudness as you turned up the volume.  The second one, from a different vendor, is arguably "listenable", but has a bit of audible noise in both channels.  (Also - from other posters here and on the bh boards, I know I'm not the only one who has dealt with QC issues, so caveat emptor when dealing with the overseas ebay sellers who make these things...)
 
 
The only thing my forray into adapters and 6sn7's really accomplished was to show me how very much I love my dead quiet, faultless tung sol 12bh7.  
 
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As an aside, in reference to the discussion of woo amps above - the transformer coupled amps in their lineup are actually faster and more dynamic sounding than their otl options.  So you definitely want to stick to the speedball crack, and stay away from the wa3 and wa2 if you found the wa6 and wa22 thick and slow sounding.  To my ears, a speedball crack (made even better with the upgrades recommended by beefy above) bests all of these amps by a significant margin, particularly with hd800's.
 
Jul 10, 2013 at 12:15 AM Post #1,954 of 12,335
Quote:
6.3v is the right one.  Unfortunately, my experience with these adapters doesn't quite match bmwr's.  The first one I ordered had a horrible buzz in the left channel that increased in loudness as you turned up the volume.  The second one, from a different vendor, is arguably "listenable", but has a bit of audible noise in both channels.  (Also - from other posters here and on the bh boards, I know I'm not the only one who has dealt with QC issues, so caveat emptor when dealing with the overseas ebay sellers who make these things...)
 
 
The only thing my forray into adapters and 6sn7's really accomplished was to show me how very much I love my dead quiet, faultless tung sol 12bh7.  
 
---
 
As an aside, in reference to the discussion of woo amps above - the transformer coupled amps in their lineup are actually faster and more dynamic sounding than their otl options.  So you definitely want to stick to the speedball crack, and stay away from the wa3 and wa2 if you found the wa6 and wa22 thick and slow sounding.  To my ears, a speedball crack (made even better with the upgrades recommended by beefy above) bests all of these amps by a significant margin, particularly with hd800's.

Add a Goldpoint stepped attenuator and it gets even better.
 
Jul 10, 2013 at 12:46 AM Post #1,955 of 12,335
Always wanted to try a goldpoint, but I'm very wary of steps on a hp amp.  I feel like I am making minute adjustments to my volume all the time - so I went with beefy's suggestion of a well regarded pot: http://www.partsconnexion.com/tkd_64186.html  No regrets here!
 
Jul 10, 2013 at 1:18 AM Post #1,956 of 12,335
I got the Mini-V Custom Goldpoint and populated it with Dale's, which was Doc's recommendation.  Very big sonic improvement.  I have heard good things about the TKD as well.  The steps on the Goldpoint, however, aren't drastic.
 
Jul 10, 2013 at 3:16 AM Post #1,957 of 12,335
The truth of the matter is, aside from the WA2 using paralleled sections on the output and thus having higher peak power output, the Crack is potentially a FAR better amp.

With a Speedball, you have a much better tube load than the resistors in the WA2. LED biasing should be superior. Bit hard to tell from the photos whether the WA2 is direct or AC coupled. Add a good pot and film caps on the output, and you are miles ahead for far lower cost.


Well, I've got the Speedball installed, and I also installed a TKD volume pot and 100uf ClarityCap ESA film caps on the output, plus I bypassed the last cap on the power supply, again with a ClarityCap ESA. As for output power, I actually installed a pair of in-line RCA signal attenuators on the inputs on my Crack, since I actually found it had too much gain...

Oh, and I'm using a GEC straight brown base 6AS7G and I've got a decent selection of driver tubes (12AU7, 12BH7 and E80CC).

Of all of my amps, the one I am least willing to part with is my Crack. Check my profile...

:D
Adam
 
Jul 10, 2013 at 3:25 AM Post #1,958 of 12,335
If I were doing it over again, I wouldn't have spent $100 on the TKD. I don't have any complaints about the TKD, I'm just not sure its the best use of money. I've built a Bottlehead Quickie with various upgrades, including a Vintage Audio Lab (VALab) ladder-style stepped attenuator. I think the VALab has the edge over the TKD, although it is difficult to really be sure about this kind of thing. But for $25, it seems like an absolute steal. After I finish building my balanced M^3, I will be building a Bottlehead Smack and a S.E.X. I will drop VALab attenuators into each of them. FYI, I found the steps in the VALab to be small enough to make it easy to find a comfortable volume level. I do recommend using a larger, heavier knob with a stepped attenuator, however. It improves the ergonomics in practice, since stepped attenuators are harder to turn than volume pots, and the larger knobs give greater leverage and grip.

Best regards,
Adam
 
Jul 10, 2013 at 6:46 AM Post #1,959 of 12,335
Quote:
If I were doing it over again, I wouldn't have spent $100 on the TKD. I don't have any complaints about the TKD, I'm just not sure its the best use of money. I've built a Bottlehead Quickie with various upgrades, including a Vintage Audio Lab (VALab) ladder-style stepped attenuator. I think the VALab has the edge over the TKD.....

 
It is entirely possible that the VALab has the edge, but there is no way I would ever trade out a 'proper' smooth pot like the TKD for a stepped attenuator. Not being able to find an exact volume level would drive me nuts.
 
Jul 10, 2013 at 8:03 AM Post #1,960 of 12,335
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It is entirely possible that the VALab has the edge, but there is no way I would ever trade out a 'proper' smooth pot like the TKD for a stepped attenuator. Not being able to find an exact volume level would drive me nuts.


Are there any disadvantages to making minute controls to volume via source - eg preamp or DAC with a volume control?
 
Jul 10, 2013 at 8:18 AM Post #1,961 of 12,335
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Are there any disadvantages to making minute controls to volume via source - eg preamp or DAC with a volume control?

 
I try to keep everything at max and use the volume control at the final step. You are less likely to throw out information that way, and get fewer surprises if you accidentally set something wrong. But it depends very heavily on the equipment, software, personal preference, etc.
 
Jul 10, 2013 at 2:24 PM Post #1,963 of 12,335
FWIW we spent a lot of time and money listening to all the attenuators we could lay hands on last year, for our BeePre preamp. The end result was our own stepped attenuator design, that we felt sounded better than anything we could buy. A spinoff kit from this work is our Submissive passive attenuator and source selector. It is a stand alone volume control that can be used ahead of pretty much any amp. One could use it in front of a Crack and probably hear an improvement over the stock control.
 
Jul 10, 2013 at 2:28 PM Post #1,964 of 12,335
Quote:
FWIW we spent a lot of time and money listening to all the attenuators we could lay hands on last year, for our BeePre preamp. The end result was our own stepped attenuator design, that we felt sounded better than anything we could buy. A spinoff kit from this work is our Submissive passive attenuator and source selector. It is a stand alone volume control that can be used ahead of pretty much any amp. One could use it in front of a Crack and probably hear an improvement over the stock control.

Is it better than a Goldpoint and are they on your website for sale.
 

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