SuperBAF Cheap Tube Amp Guide ~$1200 or less

Evonimos, not sure how much knowledge you have, but I was curious if you were familiar with the DarkVoice amp, and if so, were able to compare/contrast the Crack and it from a design perspective? I am not an EE, but would be interested to hear a technical description if you had the background to provide it.

 

Just ordered the Quicksilver Headphone Amp - $998

http://quicksilveraudio.com/products/headphone-amplifier/

Will let you know my thoughts after I get it.

 

That's the amp I've really had my eye on the past few months. If I hadn't ordered the SW51+ after reading about it here, that's the one I was going to buy. To be honest, I am very tempted still, so I look forward to your impressions. I think this amp has been flying under the radar in the <$1000 price bracket, but those that have it compare it favorably to more expensive amps.

@snatex What other amps do you have to compare to the Quicksilver? Also what headphones will you be using besides the Aeolus in your picture?

 

fwiw Mike Sanders of Quicksilver has been around the game forever, he doesn't do review units for the audio press so not much mainstream coverage of his products.

he winds his own transformers and in general it is difficult to screw up a single ended EL84 amp. I am sure it sounds good for $1000. let us know what you think

 

I've certainly been a victim of the HF hype train over the years. That's why I like this place. Everyone here seems to keep a level head. I've read impressions from a few Quicksilver amp owners that have directly compared it to the WA6-SE, and both heavily favored the Quicksilver. Again, who are "they"? It's hard to qualify opinions on the internet.

I have an SW51+ on order at the moment. I may bite the bullet and purchase the Quicksilver as well to satisfy my curiosity. If I do, I'll try to post some comparative impressions once I have them both.

 

Details on the Crack are proprietary I believe. So there isn't much to go there.
But i think (correct me if i'm wrong here) that both are basically iterations of the Aren van Waarde project (itself based on an older Rudy van Stratum schematic).

Basically 2 double triodes with a 6922 for input staged and a 6AS7G as a CF.
Simple as it can be, no feedback, single ended topology.
Power supply is also simple.

So i guess simplicity does the trick in that case and if this basic design is built with quality parts, it can really sing.
Now, if anyone has a detailed schematic of a Darkvoice, maybe we can look into it a bit more.

 

Not 100% confident I can confirm every detail, but this does look like a Darkvoice to me.

 

We see here the topology is indeed an iteration of the van Waarde project.
The differences are limited, mainly in the power supply (no choke) and a lower cathode bias value at the 6AS7G.

Also, B+ voltage seems quite lower.
Original schematic supplies 150V right at the anode of the CF tube.

The output caps are higher value, which in my opinion is a good move.
Especially if you are feeding sub-150Ω cans.
I also like the abundant shunt caps on the electrolytics.

The other difference to the original is the cathode bypass caps on the 6922 stage.
This is probably to increase gain which i find non-essential.
However, it might have a sonic benefit if implemented with good quality caps. Have not tried it though.

In the output caps, I'd add a small PIO bypass cap.
Not essential but i like ex-military soviet caps.

 

Oh and that schematic has an Octal tube at the input stage instead of the 6922.
Now I noticed.
That probably explains the cathod bypass caps, since 6922 has more gain than the Octal in this schematic.

Also, it doesn't show the filaments circuit.

I am using an LT1083 linear reg and it does a nice job, although heat must be dissipated accordingly.
Diodes must be high dissipation and the heatsink big enough.

Otherwise, a separate center tap transormer (3.15-0-3.15 volt 5A) elevated 50V or so is a very good alternative.
AC filaments save on parts, are simple to implement, sound good (or better according to the gurus), waste no power, and will be dead silent if implemented correctly.

One thing to note, is that this 10K to ground at the output might be a bit large for low impedance cans.
The reason is that as you go big (as recommended for low Z cans) on the output electrolytics, leakage current coupled with that high resistance might cause substantial DC voltage buildup. This is something I noticed and I didn't like the pop when I plugged my low impedance HD599 cans. I changed it to a 2K carbon composite and things were better.

 

Any opinions on the Elekit amps? Tempted to purchase one for all-in-one duty (speakers, dynamics/planars and electrostats)

 

https://www.superbestaudiofriends.o...ded-pentode-tube-amp-build-impressions.10100/
https://www.superbestaudiofriends.org/index.php?threads/elekit-tu8600.5132/

I think those are the two popular models right now. I'm not sure what kind of sound you're going for so I'd check out those two threads first

 

Elekit 8200r I think is the big value winner in my eyes. They also have lundahls developed to fit as well for future upgrade. If you know how to solder and want an amp under 1k, I bet it sounds great. Personally have an 8600s as I wanted to experience the 300b magic.

https://tubedepot.com/products/elekit-tu-8200-stereo-tube-amplifier-kit

 

There's a guy selling an Elekit TU8200 nearby, which makes it really really tempting to pull the trigger. Edit: Nevermind, found what I needed.

 

I’m typically just a one headphone type of guy. I only have two on hand when I am trying to unseat my current favorite. The last few I’ve had on hand were the Ananda, LCD4 and Verite. I’d like to bring in the Auteur to compare with my Aeolus.

I also ordered the Decware CSP3 OTL amp a few months ago. So I will have two in this category to compare. Not sure when that will arrive but I plan on testing it against the Quicksilver and possibly my V280. I think all 3 amps will be good but I will probably just stick with the one that pairs best with my ZMF.

 

It’s here...

 

This belongs in a status update, not a thread for discussion and impressions. Also however it sounds the font on the front makes me a little bit sick; it's such a weirdly balanced shaded script and the majuscules are.... off? No real consistency in the loops and it just looks sloppy. They also don't look to be on the same slant as the minuscules.

Eh ignore me. I hate the writing and typography on a lot of amps that people here love.

 

The text isn't the half of it, there's nothing on that faceplate which aesthetically makes sense. The plate itself is larger than the actual front of the chassis, it blocks the view of the tubes, the pot knob isn't centered, and wtf is the point of the cut for headphone jack, LED and power switch?

 

I think the designer admires the Audio Research design philosophy: