dacs as preamps ?

Generally using a dac as a pre-amp is not a great idea. Using a separate pre-amp will sound much better.

Wyred4Sound DAC2 would has a built in volume control, as does the original Eastern Electric Minimax DAC.

Generally yes, a preamp in the chain is much better... but I am mightily impressed by the implementation in the Berkeley Alpha DAC.

I was discussing this in another recent thread regarding the Wadia 121 I just got. Here's a long excerpt:

There were some comments in another thread that using a dedicated preamp is preferable because digital volume controls degrade the sound, especially at low volumes. Wadia strongly disagrees with this. From the manual (which comes in pdf form on a flash drive):

"We strongly recommend that you use your Wadia 121Decoding Computer connected directly to your power amplifier. Even if you purchased your Wadia 121Decoding Computer with the intention of connecting it to your preamplifier, we suggest that you try direct connection to your amplifier. Many listeners are surprised by the improvement in performance over even the most expensive preamplifiers."

"Does the Wadia Volume Control compromise resolution?

The Wadia 121Decoding Computer uses the latest generation of Wadia’s proprietary digital volume control. The volume level can be varied in the digital domain by means of mathematical manipulation of the signal, eliminating the distortion and noise that are inevitable with even the best analog volume controls. While conventional thinking indicates that reducing the volume digitally can sacrifice low level resolution, Wadia has created an innovative solution. Wadia’s patented digital filtering algorithm produces a 32-bit output. This high-resolution signal is then used in the computations that in turn reduce the volume level. This new signal is fed directly to the DAC chips. Through this innovative method, the Wadia 121Decoding Computer maintains high resolution even at the lowest volume control settings."

"Can I bypass the Wadia Volume Control?

Because the Digital Volume control does not include any analog circuitry, there is none to be bypassed. Even the mathematical program step that performs the Digital Volume Control calculation is an integral part of the Wadia DigiMaster filter algorithm and therefore cannot be bypassed. If you do not need the Wadia Volume Control, set it to its maximum level on the LED display."

Your question is tough to answer because it's a matter of personal preference. Both my dacs have volume control, but I strongly prefer the sound when they run through my tube preamp. When I connect them directly to the amp, they have a lean midbass and sound kind of thin. Some people might like that, but I prefer a fuller and richer presence.

The Benchmark DAC 1-Pre has a lot of fans. It's generally describes as very transparent, though many listeners find it "lean" sounding. I used one for several years and I'd agree with both assessments. At the end of the day, it's probably a fair bit of personal taste and somewhat system dependent.

Marty

Depends on the voltage and output impedance of your DAC. If you use something like the MSB Platinum, which can output 7.5V rms into 50 Ohms and your amp has sensitivity of 1.5V or less and 45K ohm or higher, then it should not sound lean. In fact, with high voltage DAC's like MSB the preamp will distort when fed such a signal. Passive is the way to go for a DAC like MSB.