“Nasal” Audio Note 3.1x Balanced.

Hello,

I had this Dac myself and sold it, without any doubts. An old DAC3 or a great DAC4 signature, are far better.
This 3.1x bal sound mechanic and crispy.

It seems that the new one is ok (MKII).

Ugo

Can other types of tubes be used in this dac? 12at7 ex.

I think you are hearing the combination of three "mellow"-sounding technical choices: non-oversampling DAC, 12au7 tubes plus paper-in-oil coupling caps.
These are all good choices and can sound awesome in the right system...however...if you have optimized your system for a previous, maybe brighter sounding DAC, your system may sound nasal with an AN DAC.
May I suggest the following "voicing" tweaks:
a-RCA clear top 12au7 tubes, very transparent and clear sound.
b- new coupling caps. The most transparent caps that I know are V-cap TFT, they sound like a clean window into the music.
Also, if by any chance your cables lean towards the mellow side, try Fusion Audio PCs (PCs DO make a huge contribution to system voicing) and Tara Labs Air 1 interconnects. These cables are not bright or tipped-up, they sound very transparent and neutral to my ears.
I hope this helps