ART DIO variability...AAARRRRGGGHHHHH!!!
One of the more frustrating things about the DIO is that a tweak that works for someone else may not be as good for you simply because of QC at ART. Someone at AA pointed out that two DIO's did not necessarily have the same sound. I'm up to three (one as external computer soundcard, second (will NOT call it ART2DIO2
) as DAC in headphone system, third as DAC for secondary CDP in main system).
I had ART2 setup in headphone system with Creek OBH-11se. This unit really played to the strengths of the Creek, great detail, dynamics and imaging. Unfortunately, I couldn't let well enough alone, and moved the Creek over to the computer DIO (which still does a great job with it), and put an X-Can V2 in the headphone system. I could hear a lot of what the X-Can was trying to do, but it never quite sounded right. At best, slightly veiled with a mildly diffuse image. Good detailing, nice tonality, but weak bass. Since the DIO had none of these weaknesses with the Creek, the natural suspect was the X-Can... at this point DIO3 had about 3 days of warm-up (the first two took at least ten days before their sound stabilized), so I simply inserted it in place of DIO2. Ummm....OK. Much more focussed image than previous DIO. Bass is back (not up to top flight amp, but quite tight and defined). Veiling is gone. The X-Can now sounds like an excellent headphone amp, which it did not do with DIO2.
A quick look inside each DIO when the tube was taken out showed that there were different types of spacers used to keep the boards from contacting the cover (in one, the a spacer held the tube against the resistors on the main board, while another omitted that spacer). I didn't spend a whole lot of time looking for other differences but in any event that's an indication to me that final assembly was likely done by different people, with whatever parts were at hand. The result? Two ART DIOs do NOT necessarily have the same sound, or synergize well with the same external components.
I wonder what other components might also display this unit to unit variability, but cost so much that it is impractical for people to buy more than one, so the variability remains concealed.......