The only way to compare DACs accurately is using a really low jitter digital source IME. Otherwise, what you are hearing is the DACs ability to reduce jitter a little, not what the DAC can actually deliver.
Case in point:
A good friend of mine uses a modded NOS DAC based on the TDA1543. Drives it with I2S. With a typical CD player driving this DAC, almost any newer generation DAC will sound better. However, when you drive it with a really low jitter signal, such as a computer source, the NOS DAC takes the lead by a fair margin.
The point is that some DACs need a really low jitter digital signal to shine. If you dont have this, then the other DACs appear to be better. What you are hearing is just the jitter of the source.
Another case in point:
http://www.avguide.com/review/peachtree-audio-idac-tas-214
One of the conclusions here is that the digital source is actually more important than the DAC. I agree.
Steve N.
Empirical Audio
Case in point:
A good friend of mine uses a modded NOS DAC based on the TDA1543. Drives it with I2S. With a typical CD player driving this DAC, almost any newer generation DAC will sound better. However, when you drive it with a really low jitter signal, such as a computer source, the NOS DAC takes the lead by a fair margin.
The point is that some DACs need a really low jitter digital signal to shine. If you dont have this, then the other DACs appear to be better. What you are hearing is just the jitter of the source.
Another case in point:
http://www.avguide.com/review/peachtree-audio-idac-tas-214
One of the conclusions here is that the digital source is actually more important than the DAC. I agree.
Steve N.
Empirical Audio