Preamps built Into DACs

Here is one way of looking at it. All the available musical information is encoded in the digital signal. This includes all the timbre, body, spacial information, decay and what have you.

The DAC converts this digital information to an analog signal. Anything added to the analog signal after it leaves the DAC is by definition information that was not originally there.

In many instances what is added may make the sound more pleasing. It may compensate for something your DAC did not retrieve, or your speakers or amps do not reproduce naturally.

The better your system is capable of reproducing the sound encoded in the original digital signal, the less it will benefit from adding something in the chain that adds coloration. In a (hypothetical) "perfect" system a volume control that just controls volume will sound best.

A perfect source (say a live acoustic piano recital) will sound better live than running the same hypothetical perfect source signal into an (imperfect) preamp into hypothetical perfect (i.e. capable of perfect reproduction of the source signal) amps and speakers. QED

" All the available musical information is encoded in the digital signal. This includes all the timbre, body, spacial information, decay and what have you. "

I agree with this and part of why I think the potential for pure digital amps is huge even with audiophiles and that these will be the norm in 5-10 years perhaps.

"However for well-designed DACs with volume controls, even these will be crushed. There are only a couple out there that accomplish this BTW, so it is likely that you have not heard them."

Steve, please list or reference if you have already.

Thanks.

Keep in mind the VC is only part of the design. You never listen to just the VC. There are very good DACs with analog, digital and hybrid VCs. It is conceivable a very good dac that has a digital VC could be improved upon by making it hybrid or analog, but at the end of the day you are buying a DAC/VC package and system performance matters. Also keep in mind some DACs are now 64 bit, theoretically making it possible to control volume in the entire range digitally without any loss.

Some examples:
Hybrid: Weiss (and probably Steve's Overdrive)
Analog: Aesthetix, MSB, Theta
Digital: Bel Canto, PS audio, Berkeley, DCS

Mapman - there are only two DACs that I know of that use the reference voltage to control volume (which actually connects the DAC line-out directly to the amps):

Empirical Audio Overdrive SE

I believe the other is a dCS DAC that is out of production

Steve N.
Empirical Audio