Tuesday, May 5, 2009

Audiotailor "Jade" Tube Headphone Amplifier.

Above: The Audiotailor "Jade" in it's present stage of evolution with a low and high impedance switch on the front panel, two headphone outputs with different sound signatures and green LED.


The Audiotailor "Jade" Tube Headphone Amplifier has come a long way since it's early beginnings, my present version is somewhat different in appearance from the original which "Skylab" had originally reviewed on Head-Fi. A photo of the original review version can be found below and you can see immediately the changes which are apparent.The Jade is made in China, and will sell for $250 – an attractive price. I have not mentioned shipping price since this was not incurred as "Audiotailor" - Mr. Joseph Lau arranged for His partner C.K. Lau of Antique Sound Lab to meet me at my local train station for pick up. Thanks Joseph and C.K. for your help.

The "Jade" Tube Headphone Amplifier is not available on the web and in shops and one must contact Audiotailor through Head Fi to arrange to get a set. The original set came with a Peking "Star" 6N5P and a Electro Harmonix 12AX7 which is used as the driver. These tubes were in fact well partnered as stock tubes. The 6n5P is the Chinese variant of the 6AS7. For my own listening preferences I rolled the Sylvania 6AS7 and the Siemens ECC83 (12AX7) as I like the synergy of these tubes partnered. Burning in is now approaching the 100 hour mark and I am sure once passed the 200 hour mark it will be a stunning amplifier since the performance now is already quite exceptional.
With the 6AS7G as it's output tube and 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.

There are two outputs for headphone, both with slightly different sound signatures, one on the left sounding a bit more like an SS amp and the the one on the right more tubey in character. Naturally I preferred the right hand output. On the left side,
the sound was solid, very detailed, with deep penetrating bass, of high resolve, very clear and transparent, and certainly not bright or edgy, but not lush or rich as expected from a tube sounding amp. The sound stage was very well defined, but wider than it was deep.

For the right side the amp displayed a more tubey signature with an open sound sweet highs, slightly richer mids and less deep bass. The sound stage was quite wide and the general sound being warm associated with a tube amp.

This feature is great especially if you have multiple headphones like me and it means that you can mix and match to obtain the best sounding combination for each respective headphone. And of course on the the front panel there is also a high and low impedance switch which will help with those hard to drive headphones, but in my initial listening test I have found that I have not been able to use the high impedance setting since I have been able to drive most of my headphones quite well, except maybe for the Bwyer's which are high impedance. In the original review sample which "Skylab" had, there was no high/low impedance switch on the front panel.

Below is a photo of the original version:

DAC of Choice:

Some of you are going to call me nuts when I tell you that I have taken the digital signal from the CDP to be processed by an old Micromega "Microdac" DAC before sending the analog to the "Jade". The Microdac is quite an old design, but after trying and listening to various DAC's and pairing them up with the Jade, the Microdac was the best combination, it was the most lively, involving and musical combination. Worried about resolution, need not be as there was ample resolve and the sound staging was also excellent adding some needed depth. The Jade already had plenty of width.

There are still many audiophiles out there searching for the Microdac today and it is indeed still held in high regard, fetching even 250 to 300 Euros on the second hand market. Why, because it is musical in nature and more akin to analogue sound then hard cold digital. The Microdac is a DAC using 1 bit PDM Bitstream technology with 256 times oversampling.
Sampling frequencies are 32, 44, 48 kHz. Frequency response is 2 Hz - 20 kHz + - 0.2db. Digital input is either via coaxial cable or Toslink, but I prefer coaxial. Oh I did forget to mention that my Microdac is not your run of the mill version since I have upgraded and modified the inside components using Panasonic "Pureism" ele. caps, Holco .1% tolerance resistors and other goodies.

The digital cable between the CDP and Microdac is the XLO HT-4 Silver clad 4N - 1M length (99.994% pure) with OFHC center conductor and features:

  • Symmetrical coaxial geometry
  • Silver-clad, 4N (99.994% pure) OFHC copper center conductor
  • Ultra-low capacitance LDPE dielectric insulation
  • Bi-metallic shielding (silver-clad 4N OFHC braid + aluminum Mylar® foil)
  • for maximum protection against EMI and RFI
  • Pressure extruded, high stability protective outer jacket
  • Terminated with XLO’s precision machined, 24K gold-plated 75 Ohm RCAs

Burn-in Tools:
For burning-in I used the "XLO" burn in CD and the "Ayre" Irrational, But Efficacious CD's.

Review CD's:

1. Audiophile "Timeless Best Collection" 24 bit / 96khz DSP Mastering URCD;
2. Wild Blue "Jeanne Newhall";
3. We Miss You, Leslie "Chris Babida";
4. Dark Side of the Moon "Pink Floyd";
5. Tubular Bells "Mike Oldfield";
6. Variations "Andrew Lloyd Webber";
7. Hotel California "Eagles" - Japanese CD pressing;
8. 2AM "Danny Summer" XRCD;
9. Natural Elements "Acoustic Alchemy";
10.Breakdown "Paulinho Da Costa";
11.Gold Lion KT88 Vacuum Tube Audiophile Recordings "HECM - Musical Fedelity Recording";
12.Eternity "Angella Christie";
13.Hi-End Audiophile Test Demo "HD Mastering - ABC Recordings";
14.The Tube Hi-Fi Saxaphone " High Resolution Tube Recording - ABC Recordings";
15.Headphone Test Disc "ABC Recordings";
16.Memorial Version 30 years - Tubes "ABC Recordings";
17.Luxman 2009 Demonstration Disc " DSD recording";
18.Blue Skies "Stan Getz";
19.vol.SOUND "S.E.N.S."

More Later!

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