Can I use a udac->powered speakers. will it act only as a DAC or as a preamp?

I believe this was the design criteria of the udac - as a versatile pre-amp for Udacs desktop amplifiers.

The RCA output works as preamp. It would be double amping if you use the headphone out. That is not recommended, but if you can't hear any sound quality degradation, I suppose it doesn't really matter.

 

Perhaps you should invest in a source that has balanced output for your speaker setup if you really want to use the XLR input. The MR8 should also have RCA input for unbalanced signals.

Edited by transient orca - 6/15/10 at 6:36pm

Quote:

How is there a difference in sound quality between RCA out and headphone out?  They both have L and R channel, both volume output adjusted with the knob.  So, how is there a difference?
 

Well, according to my limited knowledge, whenever the line level signal from the source go through an amplifier, there is always some level of distortion (very little for a good amp, a lot for a lousy amp). When the amplified signal go through another amp down the chain, both the signal and the distortion are amplified. It is recommended to have as few amp as possible in the equipment chain to reduce the cumulative degradation.

The Udac is fundamentally a pre-amplifier, not dac, in design - it is OK to pipe them into an amplifier that does not have its own volume control.  There is only one output stage on the Udac - the pre-outs and headphone out is the same circuit with a different connector at the front and back.

Bumping this thread a bit to add a question:

How would one manage the volume with the UDAC and M-Audio AV40's connected through RCA jacks? Volume on PC at 100% I assume, then what? I'd also plan to use headphones on the UDAC's 3.5mm occasionally..

Sorry for the newb question, thanks!

Thats the problem I have with Udac - the name causes confusion and people don't understand that it is not actually a dac.  Its like calling my surround sound yamaha reciever the BiggyDac - its got a built in dac also.

 

For your case I think if you leave one volume at twelve oclock and adjust with the other should be OK.  Better still get a dac.

When you plug in the 3.5 mm jack on the Udac, the RCA pre-out is automatically disabled.

Actually, the Sabre DAC has a 2v line-output which is not amplified, which passes through the.volume pot on the way to the RCA outputs. Plugging a headphone into the front panel activates the headphone amp and disables the RCA line-out, and only the signal to the headphone jack is amplified.

Double amping, double attenuating - whatever, it's not ideal.  Until Nuforce by-passes the volume control in the way of it's lineout - it isn't a true one, and until then - ethically, should not call it a Udac - I'd have no problems with Udac Pre. 

 

A true dac it is not. 

 

Those that have two volume pots should turn the Udac up to maximum when used as a Dac - in light of the fact the control only attenuates and doesn't boost - any overloading of your inputs - take it up with Nuforce.

Edited by SP Wild - 8/10/10 at 4:52am