REVIEW: Audiotailor “Jade” Vacuum Tube Headphone Amplifier
Dec 9, 2008 at 3:34 PM Thread Starter Post #1 of 973


Reviewerus Prolificus
Apr 30, 2005
The Court of the Crimson King
I was approached by Audiotailor to review a new tube headphone amplifier with a unique circuit design. Of course I was immediately intrigued by the idea. I cannot reveal the details of the design, but it does result in their being two headphone outputs, with different sound signatures. This is the principle “feature” of this otherwise well built and attractive, but otherwise unassuming tube headphone amp. The Jade is made in China, and will sell in the USA for $350 shipped – an attractive price.




The Jade uses the current reigning king of headphone amp power tubes – the 6AS7G – as its output tube. The input tube is a 12AX7. The amp uses one of each tube, meaning that one channel rides on one section of each of these dual-triode tubes. I am a fan of the 6AS7G – it is a powerful, good sounding tube that offers a lot of inexpensive tube rolling options. And of course the 12AX7 may be the most popular 9-pin dual-triode ever. That does mean there are some expensive variants here, but there are also affordable options.

My Jade, which is an early production unit, did not come with any tubes, so I cannot comment on the stock tubes, but this is just as well – it surely would have come with Chinese tubes, and I wouldn’t even have used them. For the review I used primarily a GEC 6AS7G and a Sylvania 5751 – my experience is the 5751, which is the lower gain version of the 12AX7, sounds better and is quieter in headphone amplifier applications.

I mentioned mine was an early production review unit, and as such, there were two issues. One is that the 6AS7G’s tube socket was mounted too close to the PCB, and as such, the tube would not insert fully. I alerted Audiotailor, and they have assured me this will be fixed in the final production. It was OK for reviewing, but not acceptable for a buyer, so it’s good they will be correcting that. Also, the volume control was noisy when changing levels. No problem during listening, only when the volume was being changed.

Sonically, the Jade was terrific, but it’s a little hard to write the review since one really has to review the different outputs separately. One output is close to solid state – firm, detailed, deep bass, high resolution, very clear and transparent, and certainly not bright or edgy, but not lush or ripe, either. The soundstage was very well defined, but wider than it was deep. It was actually quite similar to the tube-hybrid Head Direct EF1 in sound, which is to say, excellent. Were this it’s only output, I would recommend the Jade, but not to people who were looking for a “tubey” sounding amp. Its sound is more “Yang” than “Yin”.

The other output was still very open and transparent sounding, but this time the sound was a little softer and sweeter on top, a little warmer throughout, and with just a little less deep bass, but with a little fatter mid-bass. Mids were on the lush side. The soundstage again was very good, but deeper than it was wide. In this case, were this the Jade’s only output, I would have happily recommended the Jade, but to people looking for a tube amp that was a little on the tubey side. So this output is the more “Yin” of the two.

What this does is make the Jade a terrific amp for people who own multiple headphones of different sound signatures. I preferred the “Yang” output with my JVC headphones, but I preferred the “Yin” output with my Beyer headphones. The differences are NOT night and day, but they are easily heard, and they do make headphone matching both easy and fun.

The overall quality of the sound from the Jade was very high for the price. The amp was very quiet. I enjoyed a very wide variety of music, and here again, sometimes I would prefer one kind of music on one or the other of the two outputs, although I normally cannot be bothered with such things. I like to set stuff like that and leave it, so once I identified which of the outputs was best on the specific headphones I was using, I would just leave them that way.

Being a tube amp, it’s possible to tune the amp with different tube choices. I briefly used a Tung-Sol 5998, and it was just slightly less warm. So of course I slightly preferred it with the warmer of the Jade’s outputs. I did not try rolling 5751’s much – I only have RCA’s, Sylvanias, and GE’s, and I do not hear a huge difference amongst these – and what I do hear makes me prefer the Sylvanias.

The Jade will be sold web direct, and at $350 shipped to the USA, I think it’s attractively priced. For me it was definitely better sounding than the Darkvoice 336SE. It certainly compares well with the Head Direct EF1, and does offer the option of the two sound signatures. The Jade had no trouble driving any of my headphones well, but the lowest impedance headphone I now own is 64 ohms, and so the EF1 might still be a better choice for very low impedance headphones like Grados or Denons. And it’s not a giant killer – both my Singlepower amps were better, as one would expect them to be for the price and topology.

In any case, assuming Audiotailor resolves the small early production issues my review sample had, it gets an enthusiastic recommendation from me as a flexible, good sounding tube amp at an affordable price.
Dec 9, 2008 at 6:13 PM Post #2 of 973
Thank you for the write up!
Dec 9, 2008 at 7:03 PM Post #6 of 973
Thanks for the kind comments, folks.


Originally Posted by sentinl /img/forum/go_quote.gif
Would you recommend this for someone with one headphone? Did you try these with any Senns? Thanks for the writeup

Sure - you can get 2 different sounds from your one headphone
Sorry though, I have no Senns to test it with.


Originally Posted by mr.khali /img/forum/go_quote.gif
Thanks for the great introduction to this amp, Skylab. Another good sub $400 amp?! Interesting concept with the two sound signatures. Does it have any output connectors as well?

No outputs other than the headphones, no.
Dec 9, 2008 at 7:13 PM Post #7 of 973
Excellent review, and what a cool find!

This comes as great news to a lot of tube holdouts, I'm certain.
Dec 9, 2008 at 8:49 PM Post #8 of 973
Would it be a good match with AKG K701?
Dec 9, 2008 at 9:48 PM Post #9 of 973
I think the lusher output would be, yes, but I have not owned the K701 in a while.
Dec 9, 2008 at 10:29 PM Post #10 of 973
thanks for the great review! I really like the idea of having two outputs with diff. sound signatures. Must be fun to play with.

did you compare it with your DV337? they used the same output tube.
Dec 9, 2008 at 10:36 PM Post #11 of 973
Yes, and while the Jade is surprisingly close, I slightly prefer the 337. But the Jade's "warm" output is definitely warmer than the 337 ever is - the 337 is not an overly romantic tube amp.
Dec 9, 2008 at 11:43 PM Post #12 of 973
Hrm what qualifies the 6AS7G to be "the current reigning king of headphone amp power tubes"

Also can you elaborate on what you mean by "yin" and "yang" when talking about the sound signature?
Dec 9, 2008 at 11:48 PM Post #13 of 973

Originally Posted by Icarium /img/forum/go_quote.gif
Hrm what qualifies the 6AS7G to be "the current reigning king of headphone amp power tubes"

Also can you elaborate on what you mean by "yin" and "yang" when talking about the sound signature?

There are the following amps using the 6AS7G, off the top of my head:

WooAudio 3
WooAudio 2
Darkvoice 336
Darkvoice 337
Singlepower Extreme

I'm sure I am forgetting some. Seems like a lot to me.

Generally, yin = darker, and in audio lusher, yang = brighter, and in audio leaner.
Dec 9, 2008 at 11:50 PM Post #14 of 973
Gotcha thanks for the clarification.

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