I bought this DAC used with the Pacific Valve mods having already been applied; their "mods" consisted of swapping a handful of caps. I added several, much more extensive and meaningful mods:
1) Sonicap output caps with gen 2 bypasses and Cardas RCAs
2) Re-built the output filter to decrease the load on the DAC chips (greatly decreasing load induced distortion) and applying a less aggressive filter to the signal. The filter is very similar to that used in the Hagerman DAC.
3) Implemented an LED bias on the tubes for increased stability and gain to partially make-up for the decrease gain induced by decreasing the load on the DAC chips
4) Upgraded the tube power supply diodes.
5) Upgraded the tube power supply filter caps to Mundorf MLytics
6) Changed the tube power supply filter to a CLC using a Hammond choke
7) Changed the digital filter chip to slow roll-off mode for smoother top end
Due to mods 2 and 3, the output level of the DAC is somewhat lower than stock, and will only output ~1.2V max RMS compared to the CD standard of 2V. This worked fine in my passively pre-amped system and shouldn't be a problem in most systems.
Included are matched pairs of EH 6922s and gold pin Tesla E88Cs and a pair of tube dampers. I would rate the condition of the DAC as 7/10 due to it having developed a few light scratches from being on my work bench several times.
Asking $
550 500 shipped.
