Low gain dac!

OP,
You have made it abundantly clear that the addition of the Supratek improves the sound quality of your Audio system. Other alternatives you have tried were not as satisfying in your opinion. So you’re keeping the high gain Supratek. I understand that rationale. After all you wrote "it sounds bloody fantastic".

At this juncture since the Supratek is staying put, I do believe that acquiring a DAC with a lower output voltage (Probably 1.5 volt or less). I agree it would be nice if more amplifiers and preamplifiers had variable gain adjustment.
Charles

Don’t think I was talking to you.
But yes OP, just responding to your little digging slur. Just go with Charles he’ll give all the "correct" none technical answers

George,
 Sometimes you make no sense. OP has freely acknowledged he has too much system gain. He wants to address it by finding a suitable DAC with less output voltage.  This makes sense and is a reasonable solution. 

You like to frequently tout your tech expertise,  ok fine. Why so blatantly ignore his documenting  his'very' positive listening impressions with the Supratek?  You brush that aside because this result (Good sound, we are discussing audio) doesn't mesh with your version of tech dogma.

OP couldn't make it more clear that his audio system sounds better with the Supratek in the signal path. 
Charles 

Less source voltage will = even more hum/noise.
Inline attenuators to reduce the massive gain he has already will give impedance mismatch problems and more hum/noise.
Throwing a good dac aside for one with "at least" half if not less output to rectify this problem, is a sideways band aid fix with other problems that I've outlined.
As I said the amp with 0.7v for full output is the problem if the Supratek is to be kept

If you didn't know.

@charles1dad - Thanks, I don’t understand George either!

I am one that likes what tubes bring to a system, but have decided to have them in the pre amp as tube power amps would need more care and my speakers are 87db, so needs good power, not necessarily many watts, but a good power supply is a good thing, maybe some day I will have tube mono amps, Supratek makes a nice pair, so, maybe that would be a good pairing with my pre someday when I have gone on pension and have more time on my hands.
I made a post in the Supratek tread about when in Bangkok I was so lucky to hear a anniversary Supratek setup with Triangle speakers, the dealer had time for me, and we sat listening to music and talking about Hi-Fi, music and life in general, I think for 2 hours, as my wife was shopping, that was the best sound I have ever heard and today I can lister to even a better pre from Supratek.
Never expected to buy a pre amp all the way from a one man production shop in Australia, but it’s been totally worth it.