Looking at the 'Stereophile' reviews and measurements for some DACs, and it looks pretty interesting. John Atkinson notes that the Weiss DAC202 is the best DAC he has yet to measure. To use that as the 'benchmark', I then compared this superficially to three other DACs, Bel Canto e.One DAC35vb, Musical Fidelity M1-DAC and Musical Hall PH25.2.
An interesting aspect is how close the Bel Canto and M1 comes to the 202's performance. The 50Hz sine wave spectrum for the Bel Canto looks really nice, with a nice decaying set of harmonics, with each higher harmonic less than the previous. But seems to be some weird left and right channel mis-match. But the best looking one would be the Musical Hall, with only a slight peaking on the 5th harmonic. Perhaps this is due to the tube output stage?
Secondly, the graphs on the jitter also presented some interesting issues. The Music Hall has a lot higher noise floor at around -125dB, but shows a relatively tight base, especially with over-sampling, and no side bands. Whereas all the other DAC had side banding at 16 bit, but none with 24 bit. The Weiss floor hovers below -145dB, whilst the Bel Canto just below 135dB and the Music Fidelity at -145dB.
What this very cursory and laymen's review of these measured performance is that the $550 Music Hall and Music Fidelity $750, compares very well to the $3,500 Bel Canto and the $6,500 Weiss. And it also seems that when the lesser ones are paired with a good digital input (that has itself good performance in terms of jitter, noise, etc) the DAC can perform at very high levels.