[oghoter]

GK 1-J revisited

This is the small portable s-state version of the Jade. Not quite as refined as Jade, but better in some respects, especially bass on low impedance headphones, according to designer hz_joe.

Some years since I tested it, with AKG 701 headphones (62 ohm). Now I am testing with Audioquest Nightowl and Nighthawk (both 25 ohm). Joe was right. This sounds very good indeed. Better than my small battery driven Denon DA-10 headphone amp, and not much bigger, although it needs AC (no battery). GK has a more forceful, wider and deeper sound with less distortion. I am impressed.

The benefit of balanced cable is clearly heard, just like on Jade. The GK has two big jack contacts on the front (like Jade) for balanced cable, and a pair of rca contacts at the back, for input. I can insert it into my office system just like Jade. The power supply seems ok but it could maybe benefit from a linear supply.

The sound is clearly recognizable from the Jade sound. It is basically the same, although achieved with s-state components. I think it reflects what joe said about same topology.

However I note some variation in sonic quality.

1 Top of the list - Nightowl and Nighthawk. Great.
2 Akg 701 - also good.
3 As desktop speaker amp - Arche Fr2 single drivers - not so good. GK1 doesn't sound hard or shrill with the headphones, but here, it does. Jade sounds softer and better. But these speakers are quite bright anyway, and the gain matching maybe not be optimal.

The GK 1-J does what was claimed - it drives low impedance headphones very well.

 

[oghoter]

Audiotailor GK 1-J

 

[ShaolinGrump]

I am trying to find a wiring diagram for the Jade balanced cable. I have several adapters that I can modify. I just need to know which wires go where inside the left and right 1/4" plugs.

 

[MDR30]

It's not so easy to use existing adapters. You need a Y-split, or even better - and simpler - a braided balanced cable where you can just connect the four leads to a four-pin XLR (or whichever plug/jack you have, Pentaconn/TRRS 3,5mm etc) according to the sketch below.

Normal connection for four-pin XLR is:

Pin 1 - left+
Pin 2 - left-
Pin 3 - right+
Pin 4 - right-

 

[ShaolinGrump]

It's not so easy to use existing adapters. You need a Y-split, or even better - and simpler - a braided balanced cable where you can just connect the four leads to a four-pin XLR (or whichever plug/jack you have, Pentaconn/TRRS 3,5mm etc) according to the sketch below.

Normal connection for four-pin XLR is:

Pin 1 - left+
Pin 2 - left-
Pin 3 - right+
Pin 4 - right-

Thanks! I will study this. I PM'd you a different guess. Thanks for the quick info.

 

[oghoter]

I can add that a balanced cable is well worth it, for example the low cost twisted silver plated cable to ca 40 euro from amazon (link below).
To my surprise, this cable does not perform much worse than the stock Audioquest owl and hawk cables, instead, the sonics are quite even. And in addition, it is easy to handle, and gives a good 'panoramic' balanced effect.

https://www.amazon.se/HiFi-kabel-ba...30-af20-126b4d91bcf8&pd_rd_i=B07X6M5LXS&psc=1

 

[ShaolinGrump]

Okay, so a y-splitter for the Jade is two TRS 1/4" plugs to a female XLR4. Jade's left jack is cathode, and the right jack is anode.

XLR4 pinout to dual TRS 1/4" plugs:

Pin 1 cathode tip L+
Pin 2 anode tip L-
Pin 3 cathode ring R+
Pin 4 anode ring R-

Sleeve on both TRS is open?

 

[oghoter]

Why I like Jade
It has no AI
It has no DAC
It is not multipurpose
It does not try to achieve a lot of things at once
It has only one focus; the best possible gain stage, for analog sound
It does this in a minimalist way - just two tubes, no output transformer
It offers balanced (or similar to balanced) open sound
Jade is still an act that is hard to beat
I will test the solid state GK version more, this summer. My impression is that the small GK is remarkably like the Jade. Same OTL type of sound.

 

[MDR30]

Okay, so a y-splitter for the Jade is two TRS 1/4" plugs to a female XLR4. Jade's left jack is cathode, and the right jack is anode.

XLR4 pinout to dual TRS 1/4" plugs:

Pin 1 cathode tip L+
Pin 2 anode tip L-
Pin 3 cathode ring R+
Pin 4 anode ring R-

Sleeve on both TRS is open?

That's correct. And it doesn't matter in which jack you connect the TRS 1/4" plugs, the only thing is absolute phase changes when you switch output between them. Which might be interesting to check for those who are so inclined.

 

[ShaolinGrump]

@MDR30 Thank you, thank you! Those drawings are now filed away in my AT Jade note.

I have all the supplies to build the y-adapter, EXCEPT the XLR4 female. Just ordered a couple.

 

[oghoter]

Testing Audiotailor GK 1-J with balanced cable to Audioquest Nighthawk headphones (25 ohm).
This small portable s-state amp sounds remarkably similar to Jade, with more deep bass (on low ohm headphones), although not quite as delicate as Jade (with good tubes) in the higher frequency spectrum. Ideal in a situation where you can't bring Jade along, like now, in my cottage system.

 

[MDR30]

A NEW TAKE ON AUDIOTAILOR JADE

For quite a few years, I’ve had the idea of developing/modernising the original Audiotailor Jade circuit, just because it’s such a good and enjoyable amp. A deceptively simple yet very clever design making the most of the few components involved. The man behind the amp, Joseph Lau (Hz_joe), has hinted at updated and developed versions during the years, but so far nothing has surfaced.

So it was up to some of us, fans of AJ, to do something. What about constant current sources instead of energy devouring resistors, a highly regulated, stabilized PSU with top-notch topology instead of a choke and capacitors, and SMD components to substantially reduce space requirements? An assignment outside my competence but fortunately I have two friends who are up to standards. I approached them and they found the idea interesting enough to face the challenges. JoaMat did the design work in LTspice and MLA stood ready with components and tools to build the prototype.

JoaMat – mostly known as a contributor on the HC site – has extensive experience in modifying circuits and finding new solutions to awkward problems when building his amps, being involved in several electrostatic (and dynamic) projects. MLA has built most of those amps and knows both the pitfalls and possibilities of advanced DIY, which he regularly discuss on HC.

In a short time the circuit was developed and finalized, and boards ordered. The boards are compact, making maximum use of the limited space. How JoaMat managed to squeeze a Golden Reference High Voltage PSU on a 55 by 70mm board is somewhat of an enigma, but he did it. GRHV is probably the most accomplished high voltage supply out there, designed by Kevin Gilmore with help from Kerry Gerontianos and James Lin.

MLA quickly soldered, built and tested a prototype with parts and components readily available.

He took advantage of the small format and fit the whole thing in a foursquare 1U case, 230x230mm. Two transformers were used out of necessity, but a custom made transformer with “tailor made” specifications will improve layout and technical performance further.

The sounding result fulfilled all expectations. The heart and soul of the original AJ is there, the detailed, spacious and three-dimensional sound, supplemented with increased clarity, speed and dynamics. In one sense, it’s like a different amp, but a side-by-side comparison clearly shows the family ties. Subjectively I like both amps and their individual qualities, they certainly provide musical pleasure of distinction.

So, hats off to JoaMat and MLA for making this DIY experiment come alive, and also to Joseph Lau who started it all.

 

[Joe Lau]

Hi ! I be back now. I am Joseph Lau . I am designer of Jade. I will back to headphone design soon. Thank for your support very much.

 

[ShaolinGrump]

Welcome back, Mr Lau! @Joe Lau

My adapter cable is working great. Thanks to @MDR30 for the design schematics. More listening this evening and over the weekend.

 

[MDR30]

Hi ! I be back now. I am Joseph Lau . I am designer of Jade. I will back to headphone design soon. Thank for your support very much.

Hi Joe, good to have you back in this thread! We all look forward to your next projects, whether new creations or expanded versions of Audiotailor Jade. I know you have many exciting ideas that are waiting to be realized.

Welcome back, Mr Lau! @Joe Lau

My adapter cable is working great. Thanks to @MDR30 for the design schematics. More listening this evening and over the weekend.

If you pick good acoustic recordings of voices and instruments in any genre, the balanced Audiotailor Jade will show you its stunning capabilities. But it also shines in everything from jazz, rock and indie to current hits on the top lists.

That's one massive adapter cable by the way, no risk of losing any electrons on the way!