I finally took the dive and bought a dAck! to mod. It is so popular at this price-point that I thought this has potential.
Initial impressions of the stock dAck!:
1) imaging appears very good but not excellent, likely due to lack of HF extension. Sounds appear to jump from a black background, but they are not in sharp focus and the HF reflections (air) that should accompany them are not there.
2) like most stock DAC's, lacks ultimate dynamics, particularly at the HF's
3) strange noises through my DC-coupled preamp at power-on - usually this only happens when there is some DC-offset. Volume control causes no noise, so it must not be too bad - need to measure this
4) some sibilance, but not too bad. Probably due to stock coupling caps
5) does not really keep me interested or start my toe tapping like my P-3A DAC, but very nice sound for the money. Piano is too warm to sound live.
6) prediction - should not take much to bring this one up to Turbomod status. Strategy is to make key mods that minimize the cost yet deliver the maximum improvement.
Planned mods:
1) replace the coupling capacitors
2) improve HF power delivery to analog section
3) add Black Gates where it makes sense
4) improve analog filtering
Results:
TBD