I just installed a Nixon Tube Dac+ in my system and would like to post a few comments for those interested in Nixon's products. To preface, I have been listening mostly to vinyl lately and I've been veering away from PC audio. My iMac G5->Firestone USB Dac sounds quite nice but there is a bit of a (digital) edge that gets to me during extended listening. My room is big, live and for the most part untreated. In this room I prefer a warm full sound which I get from vinyl and listen near field. My vinyl rig is relatively nice, nothing to write home about but serves it's purpose, it consists of Project Perspective TT w/ Grado Plat Ref cart-> Monolithic PS1-> Odyssey Candela->SS amps.....Selah 3-ways.
I recently picked up a new Oppo 980H and a used Scott Nixon TubeDac+ & 3ax power supply for kicks. The Nixon comes stock in a little plastic box which moved all about under the weight of my Zu Ash cable. I think the cable weighs more than the DAC. I decided to rebuild the DAC into a much more solid wooden enclosure and upgrade the signal path with Ridge Street's solid silver hook-up wire. I also switched out the IEC socket while I had the DAC apart. Unfortunately I did not have much more than a few minutes listening time on the DAC before I rebuilt the case and added the new wire so I am not able to give a direct comparison of the stock vs. slightly upgraded versions.
As for the sound I am very impressed with the Nixon DAC. Playing the same reference passage ("Zigeunerweisen" Uncommon Ritual/Sony Classic) on the Oppo without DAC, iMac & Oppo with DAC provided quite a difference to my ear. The digital edge or harshness which annoyed me previously is gone with the Nixon DAC, imaging improves slightly by becoming a bit more 3D and midrange/bass become slightly more prominent which is perhaps due to the smoothing of the highs. The Nixon DAC gives me a more relaxed, analog sound that I can listen to for extended periods without the "digital fatigue". As a side note, I hear no difference when the X-sinc filter is turned on or off and cannot comment on the effect of the Ridge Street wire upgrade. I truly encourage anyone who is interested in an inexpensive NOS dac to give this little guy a shot.
cg.
Edit: I am using an Adzam SQ E88CC tube
