Alrighty there humans, here's the scoop on the Yulong vs. Metrum.
With the sharp filter on the Yulong, and the volume knocked down 1.5dB on the DAC (I decided to do it there instead of in JRiver... I somehow just trust Yulong to do less, if any, damage), there is an audible, and I believe significant, difference between the Yulong and the Metrum playing FLAC files. It is the same difference I heard between the Metrum and the other Indistinguishables -- the Metrum has more mid-range energy, more sustain, sounds warmer, more fluid, and brighter at the same time. Those who prefer faster, flatter sound will likely prefer the Yulong in this setting. Those pining for a more analog/vinyl sound will probably prefer the Metrum.
I then changed the Yulong filter to slow, re-set the Yulong volume level to -1.0dB, (which yields a close-but-not-perfect match... grumble) and guess what???... The Yulong now sounds almost identical to the Metrum. The Metrum still has a tiny bit more energy than the Yulong in part of the mid-range, but most of the time, and in most of the spectrum, the two are now pretty much indistinguishable, or at least close enough that the difference is not meaningful in regular listening (as opposed to what I've been doing for 3 weeks, which is NOT normal, even for an abnormal person like me).
The difference can be heard in the volume of some voices, particularly female voices: the Metrum seems just a tiny bit louder, which might actually be the 0.1-0.2dB difference in volume that I can't match out with 0.5dB steps. Or it could be in the equalization profile of the two. But I think it is volume, not grain, or etch, or any other quality measure. The quality of the voices sounds the same to me. Consonants like "s"s and "t"s sound the same, just sometimes a tiny bit louder with the Metrum (I did the slight delay setup in JRiver again, where I could listen to a word (or other sound) with the Yulong, switch, and immediately hear the same word (sound) on the Metrum). Instruments all sound the same on both DACs to me playing FLAC files.
In my view, any difference that I can only hear sometimes in certain parts of certain songs while doing level-matched A/B tests is not meaningful, even if it is primarily in voices, which are very important to me. Again, I believe there is a material/meaningful difference between the filters, but each of them aligns the Yulong with one of the major groupings of DACs in this test -- the sharp filter puts it in the Indistinguishables group, and the slow filter puts it with the Metrum. In effect, you get two DACs for the price of one, with two different headphone amps thrown in as well, since the filters really have a large impact on the headphone amp's sound. Given that (depending on Grant/Shenzen's sale price of the moment) the Yulong with upgraded power cord is ~$300-400 cheaper than the Metrum, which is a DAC only, that makes it a bargain.
And then throw in the real kicker. Ohhhhhh that DSD sound... The Metrum can't touch it. The other DSD DACs might be able to, but they are all significantly more expensive. The Chordette is $1800, $500-600 more than the Yulong, and is only a DAC. The Benchmark is great, and I have really taken advantage of its pre-amp capabilities over the past couple of days, but it is $2,000, and I don't need a pre-amp that badly. (Note: the Yulong is not a real pre-amp to me -- no analog inputs, no analog volume control).
If I decide I really need a pre-amp, I'll have Brunk or Potterma build me one of those LED ones... I bet I could bargain one of them down to less than the $700-800 price difference between the Yulong and the Benchmark. If not, I'll just do a pre-amp comparison test next year...
(NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!)
