Dacs: voltage output affecting SQ?

[Ceko]

There are DACs with variable output levels, like the Chord Qutest and the RME ADI2. I’m under the impression that higher output voltages result in better quality sound. But is that true at all? So higher voltage dac with lower volume amp vs lower voltage dac with higher volume amp, which one wins?

 

[Nopiano]

I don’t think it’s as binary as you infer! Hifi rarely is that simple. The important thing is an adequate output from the DAC for the sensitivity of your amp. I’m not a DAC swapper, but most offer at least 2 volts which is plenty (and is equal to the standard CD player output which anything designed in the last thirty years should cope with ok).

Obviously, overdriving a low-powered amplifier with too much input voltage won’t make a good system!

 

[tuga]

There are DACs with variable output levels, like the Chord Qutest and the RME ADI2. I’m under the impression that higher output voltages result in better quality sound. But is that true at all? So higher voltage dac with lower volume amp vs lower voltage dac with higher volume amp, which one wins?

To the best of my knowledge the higher output will give higher S/N. The receiving end may prefer higher or lower voltage.
Generally I prefer to use lower gain into the amplifier and foruntately for me I can do that "transparently" with HQPlayer ≥64-bit processing.

 

[Strider]

Higher voltage output from the source can give the illusion of increased S/N resolution however it's more a case of 'I don't need to turn it up as much now to achieve the same volume level."
Most Chord* DAC's I've encountered output a 'hot' voltage exceeding 2v by +.5v or even +1v thus appearing more detailed than another DAC at the standard voltage however such voltages are sailing close to overloading the input of some amplifier inputs.
Many others here have a far better technological vocabulary than I and can put into words...

*Other voltage roasters are available.

 

[technobear]

The answer is it depends.

The RME has a nifty feature called Auto Ref Level which adjusts the gain of the analogue stage so that less digital attenuation is required. This maintains a high SNR at lower listening levels.

The Qutest I think also lowers its output in the analogue domain so should sound identical at 2V or 3V. It's a question of whether the amp is happy with 3V. Some are, some aren't.

A higher input voltage means the amp has to apply less gain but whether this results in better or worse sound is down to the design of the amp so it's a case of try it and see.

 

[uzzy]

I assume that you mean that the DAC has an output variable on the analogue out. If this is the case the thing to remember is, you are then feeding it into an analogue RCA or XLR connector on your preamp and that input will have a range of voltage it can handle without producing distortion.

So for example older amps are expecting to see an input value of less than 200 millivolts yet most CD players and DACs with no output attenuator will kick out 2 volts and so overload the input on the preamp.

 

[StingRay]

I assume that you mean that the DAC has an output variable on the analogue out. If this is the case the thing to remember is, you are then feeding it into an analogue RCA or XLR connector on your preamp and that input will have a range of voltage it can handle without producing distortion.

So for example older amps are expecting to see an input value of less than 200 millivolts yet most CD players and DACs with no output attenuator will kick out 2 volts and so overload the input on the preamp.

Yes some 70s amp sounded pretty bad with digital.

 

[uzzy]

Yes some 70s amp sounded pretty bad with digital.

The advantage of course of the attenuator is not just matching to the amp but matching to other kit so when you switch to say a turntable or FM Tuner the output is the same volume ..

 

[lazycat]

I had a 2Qute for a few months. It's output was 3v. It didn't overload my amp but it gave the volume control a lot less travel to use.

I used Rothwell attenuators and even knocked up some T atten's to try. I prefered the latter, just.

Quite honestly it was a PITA. I was glad to be rid of it.
I can't see any good reason for such an excessive voltage output.

 

[tuga]

I had a 2Qute for a few months. It's output was 3v. It didn't overload my amp but it gave the volume control a lot less travel to use.

I used Rothwell attenuators and even knocked up some T atten's to try. I prefered the latter, just.

Quite honestly it was a PITA. I was glad to be rid of it.
I can't see any good reason for such an excessive voltage output.

It's been said that Watts uses a DAC to drive his B&W 801s

 

[griffo104]

I had a 2Qute for a few months. It's output was 3v. It didn't overload my amp but it gave the volume control a lot less travel to use.

I used Rothwell attenuators and even knocked up some T atten's to try. I prefered the latter, just.

Quite honestly it was a PITA. I was glad to be rid of it.
I can't see any good reason for such an excessive voltage output.

The original Mojo also outputs 3V when you put in to line level mode. This doesn't overload my headphone amp but it does make the Mojo seem a little more impressive compared to other DACs until you adjust the levels to match.