JDS was generous enough to send me their full EL Stack for review, and I've spent the past two-ish weeks with it. It's been a wonderful time.
Fit and Form
Both the DAC and amp are incredibly well built. Both are monolithic, matte-black, aluminum blocks. I will admit that they sit a little bit large on a desk, but I had a convenient spot for them, so it ended up being a non-issue for me. The knob up top is a definite high-point. Its actuation is smooth as could be and its just... oddly satisfying to use. I could spend a whole page talking about this knob, but I don't think that'd serve anyone too well. The copper accent ring is subtle and a nice design accent without disrupting the aesthetic they've created.
The back of the amp features RCA inputs and line outputs, a port for the 16VAC power in, and two buttons. One button controls power, the other controls high-/low-gain. This design, with the buttons placed on back, would have been an issue for me if this sat where I normally put amps/DACs, but as it sat on the edge of my desk, this was, again, a non-issue.
The 1/4" jack on the front is a slight gripe of mine. Once the jack is inserted beyond the entrance, it sits stably and inserts well, but before it gets in, you have to align the jack pretty put perfectly head-on to get it in. Not too much of a hassle, and definitely didn't impede use, but it was something that I noticed compared to other systems.
On the front of the DAC, there is a touch sensitive circle with an LED ring surrounding it that controls the input to the DAC. Red is TOSLINK, yellow is coaxial, and blue is USB. The device will only be recognized by the computer when it is in USB mode, which was appreciated. A long press of the circle turns off the DAC.
The amp is incredibly powerful. With a 32Ω load, it can push 1.5W. That was more than enough to handle anything and everything I threw at it. It responded in spades. Not only is it powerful, it's absolutely clean. Getting to listening levels, I experienced no distortion whatsoever, and that's partially a result of the cleanliness of the amplification in the DAC as well.
The DAC features a AK4490EQ chip, which was audibly transparent to me. Something that irks me about the review atmosphere today is that there is much too much talk of the sonic characteristics of DACs and amps, and how they change frequency response. The reality of these components is that the most they can do is minimize distortion, noise, and general disruptions to the transmission of the file from source to listener. This isn't to say at all that all DACs and amps sound the same, because they do not. However, it's just to say that no DAC or amp will take a neutral headphone and make it V-shaped or vice versa.
There are a plethora of things to consider when pairing an amp/DAC, and those are what I'll talk about in this review. The amp has an output impedance of 0.1 Ω. In use, this means that there pretty much isn't a headphone out there that these can't drive well. From 32 Ω to 600 Ω, there isn't a load that these won't be impedance matched for.
Both the amp and DAC have more-than-sufficiently low THD+Noise (.0009% and .0011% respectively). The DAC has a transformer isolated S/PDIF connection, which helps to eliminate the possibility of ground looping internally. I personally didn't use the S/PDIF connection, but for those that do, this is a good feature to have.
In summary, I found that this combination was pretty much sublime. The amp is suited to power any load with no issues, and the DAC introduced pretty much no noise or distortion to my ears. The amplification shared that. This stack faithfully communicated the music from my computer to my ears with as much clarity and dignity as I could expect from anything.
Minutia and Miscellaneous
The only issue I experienced during my use of this setup was that I experienced a bit of stuttering after about five hours of use one night. The DAC had gotten extremely warm, but I talked with John, the company's president and head of engineering, who assured me that the DAC had been tested extensively for heat issues, and ran exactly the same hot as it did dead-cold. I think that this issue may have been with my drivers, as afterwards, I uninstalled and reinstalled them, and the issue never recurred.
I love this setup. It fits well on my desk, can drive anything I could imagine to throw at it, and is pretty much completely audibly transparent. It introduced no distortion or noise that I could detect on any headphone at any volume level. The design is subtly stunning and it has more than enough I/O options to satisfy every use-case I could foresee. If you have the money and the inclination, I very highly recommend this setup.
This setup were provided to me for review by JDS Labs. I am not being paid by anyone to write this review, to endorse the product reviewed, or for the content that I put in the review.
I have had this setup for about two weeks, and I have put about 85 hours of analytical listening time through them during that period. I will continue to listen to this setup intermittently for the rest of the review period, and will update any opinions that change over that time.