Thanks-I'll be interested in your findings.
@HOWIE13
OK, did some combination testing to the point that I absolutely convinced myself (at least), about the Vali2 and background noise or hum. Of course, this is related to the headphone impedance.
Short answer is that the Vali2 is very quiet, to the point of no perceptible background noise or hum, IF the tubes are quiet. This confirmed my previous opinion but I wanted to revisit the issue to be certain, sometimes we can learn to ignore a little bit of background noise if the overall sound performance is good.
Headphones used for test (impedance noted):
Senn HD600 (300 Ohm), AKG K7XX (62 Ohm), Oppo PM3 (26 Ohm), GR07 (IEM) (50 Ohm).
All four HPs were used with the same set of (quiet) tubes on the Vali2 and the Lyr1. After that series, the HD600 and the AKG K7XX were used for another sequence on only the Vali2, with an additional 8 tubes of various brand and type, all of which were quiet with the exception of one tube with a borderline noise/hum.
Level for each HP was set at a typical dynamic range of 50-80 decibels with peaks at 85-90. Vali2 was always set to high gain. Background noise was checked by cutting the signal at this volume level. To help determine if the background was absolutely quiet, after background level was noted, volume level was turned down to zero, and/or hi gain was switched to low gain, to see if there was any perceptible background change. (Of course, if you open the volume all the way, some low level hiss or hum will be heard, but this testing was to determine background at typical listening levels.)
Results: HD600 completely quiet, also the AKG K7XX surprisingly, given the low impedance of 62 Ohm. The Oppo PM3 with the very low impedance of 26 Ohm, showed just a very small level of background, in the category of 'very, very slight', or 'almost imperceptible', not a level that I would actually notice if I wasn't looking for it, or anything that takes away from it's performance. The GR07 IEM had a background level that was noticeable but still suitable for quality listening.
With regard to background noise, performance was fairly consistent between the Vali2 and the Lyr1. Again the Vali2 was tested at high gain, the Lyr1 has only high gain mode. With the Vali2 on low gain, everything is quiet.
If interested, I can list the tubes used but since all the quiet tubes gave the same result, I thought it was of secondary importance. So, (HOWIE13) there is a disconnect between my experience with the Vali2 and your experience. Not sure what the answer is. This test was using the Gumby to feed the Vali2, both were powered from an isolation strip into a wall socket used only for audio.
Last points: I do like the Vali2 for it's performance and convenience. I use it often to evaluate new tubes, since you can evaluate the triodes separately (one for each channel). So, I have a good bit of experience with it. However, IMHO, it is not up to the level of the Lyr1, or the other Schiit tube amps, but a very impressive little tube amp for $169.