Berkeley DAC into preamp or amp ?

I've done some searching but don't see many comparisons of the sound of the BAD Alpha DAC fed through a preamp versus into the amp directly. I'm interested in the degree/range of digital attenuation needed with amps of various gain. At what attenuation level did sonic degradation (if any) become audible?
I have a berkley dac and am using it to drive a pair of ATC 50aslt's directly.
I tried using it through my pre-amp, but felt the compromise was too pronounced.
I use 54 attenuation on the DAC, this being the recommended.
I am not a fan of digital, and before I bought it was moving back to vinyl.
The berkley dac reversed that decision. It's that good.
Very few preamps can be better than no preamp.
I've tried many very expensive ones and always cable was better than preamp.
Except once: Tidal Preos.
So, if you want to put preamp, be ready to spend a lot of time and money.
But at the end you may get into Nirvana!
I am using a preamp with my Berkley only because I am using the DartZeel pre and power which sounds best only with the 50ohm Zeel cable... otherwise, I would ditch the preamp as well, assuming I have no analog source.
Pbrennan - Yes 54-55 is the recommended fixed setting on the DAC when feeding a preamp, but how far down do you have to attenuate with strong signal sources (e.g. CDs with high playback level) when feeding directly to your amp?
I run it through a JRDG Capri but am selling the pre and will run it direct to a pair of older Jeff Rowland model 7m's. The dac is in the middle of it's volume scale most of the time. I have tried it both ways and cant say that I can tell the difference. Which is either high praise for the capri or a poor review of my ears.
I honestly think that I EXPECTED degredation from a dac at lower volumes (throwing away bits and that sort of thing) but cant say that I heard any.
My Berkeley rarely gets out of the 30s feeding directly into the amp. Any comments?
I recently tried the Berkeley running directly into the amp. My experience has been that such a setup always flattens the depth dimension of the soundstage, and this was no exception. In my opinion, any minor improvements over an excellent preamp (immediacy and such) are not worth what I consider to be an unacceptable compromise. In my case, I need the preamp for vinyl in any event. The exercise simply proved what I had heard on numerous 'direct feed' systems previously.
Curriemt11 - that's been my experience too, at least with a couple of Wadia CDP's I used to own. As for the Berkeley direct, do you recall how far you had to attenuate with most music? (I.e. what was the LED readout, and did large attenuation seem to affect the sound?)

Rja - what amp are you using?
Ral - sorry, I should have mentioned that. Moderately high volumes were in the 50 range. I noticed no deterioration of the sound at lower levels, but then again, I rarely listen at those volumes.
I think the input impedance of the POWER amp side is a huge factor. Some amps will never work with a DAC directly.
Rja - the DNA225 has a very high gain (about 30dB -- I owned one long ago), which is probably why you have to attenuate the Berkeley so much. In fact this probably represents the extreme test case for the DAC's attenuation. But this amp also has a high input impedance (~100K). The benefits of a good preamp which Curriemt11 mentions (e.g., expanded soundstage, more 3D images) may involve factors beyond just impedance. I'm not sure what, exactly.