DAC/Pre's Digital attenuation vs. analog

Doh!!, just reread your OP and realised you're looking for specific advice, not general, sorry. My vote (of the 3 you mention) might be for the DAC2, provided you feel 16 db of attenuation is ok for you. This would inherently be a bit better (or at leat more direct in terms of transparency) than either the DAC One or the Bryston. However a quality active preamp usually works to 'improve' for lack of a better word the soundstaging of a well suited amp. An amp fed directly may offer a more live sound and an amp with an active pre in the price range of the Bry may have a wider or deeper stage (or both), but the degree to which that's true may vary depending on both the quality of that preamp (again, shouldn't be a real issue for the Bry) and how well it was impedance matched to its amp - like I say it all tends to come back to matching, but amps driven straight can (though not always) have slightly smaller stages (though no less coherent or 3D). If there's any way you can audition your amp temporarily, before you decide on anything, being fed directly from a CD source with 32-bit attenuation, then you can compare to your current pre if your using one, both in and out of the signal path, and get at least some impression of the general differences involved. The Bryston may end up being somewhat different in this regard than with your current pre, but this audition should show you the basics. I have actually valued transparancy more than soundstage in this circumstance with my own gear, but of course it may be the other way around for you.

I have done a few shootouts between setups using volume controls on the DAC, and uning preamps, and finally ended up settling for "DAC direct" (PS audio perfectwave MKII). Prior to the arrival of the MKII, I found a slight advantage in using an very expensive (tube) preamp. Based on my experience, I am quite confident concluding that for a given budget, and with no need for input switching, DAC direct will give you the best results - considering you can buy a better DAC with the money you save on the preamp. If you don't have the time/appetite to circulate different pieces of gear through your system and make the decision based on your own observations, I would have no problem recommending going the DAC2 route. You will also save cabling funds, which can all be applied towards better hardware elsewhere in the chain.

Hi guys. I should have mentioned that my main concern is at low volumes. I was thinking that maybe digital attenuation would be to my dis-advantage. I'll be playing .flac files through foobar2000 exclusively (which has a digital volume control itself). Would it be best to leave the foobar volume control all the way up?

I'm having a hard time agreeing with "32bit offers only 16dB of attenuation before eating into the 16bit resolution of Redbook".
As far as I know, every bit accounts for 6dB, thus 16x6 would mean that a DAC chip working internally on 32 bit will offer 96dB of digital attenuation of a redbook stream before loss of information occurs. And that's pretty much the entire dynamic range of redbook.
Attenuation in the digital domain is no longer the bad thing it used to be, with the advent of these 24-32 bit DAC chips. The myth, though, will continue, I'm sure.

Using digital volume exclusively for volume control will result in a significant reduction in detail and imaging. It's okay to do about -9dB, but not more. This requires that the DAC have some kind of gain control or a good volume of its own.

There are five types of volume control:

1) Digital volume control - reduces resolution as the volume is decreased

2) resistive attenuation - delivers detail, but kills dynamics with most amps

3) active gain control - adds distortion, noise and compression, but has good drive, so dynamics are good.

4) Transformer scaling attenuation - with strong DAC outputs and good transformer linestages, like Music First TVC, this is more transparent and preserves the dynamics. Easy to match to amps

5) D/A reference voltage control - This volume adds no noise, distortion or compression, in fact it actually improves S/N ratio as the volume is decreased. No loss of resolution. The best of all possible options.

Steve N.
Empirical Audio