DAC straight to amp

[Mnyb]

Exactly the reason I avoid running a volume-controlled DAC directly into a power amp. Put a simple Goldpoint analog attenuator between them. Set your digital front end to 100% volume and use the attenuator to adjust to the loudest you'd ever listen. Now you're protected against "runaway". Your speakers will thank you.

Yes you can even use more crude inline attenuators ( these are just plugs on the cable ) with fixed values .
It also improves the SNR as the DAC can run closer to the max output .

Attenuators are great in a hifi world where no one seem to able to agree on any kind of general gain scheme.
And most hifi power amps do not come with adjustable gain/sensitivity ( pro amps always have them ).

But as seen lately in all these Purifi and hypex variants adjustable gain may actually be more common in hifi .

 

[FrantzM]

Less is more I agree, but preamp often drives power amp better (lower output impedance), while preamp's volume control is likely better quality.
I use Benchmark DAC3 directly to AHB2, but somebody with exactly the same setup inserted high quality Benchmark's preamp and reported better sound.

If it was on Audiogon, I'll bet hat soon , someone would recommend your friend to use better or warmer speaker cable or a different power cord or perhaps to use a PS Audio AC conditionner...
Please stay here and learn, you'll end up, spending less for better sound.

 

[Holmz]

Exactly the reason I avoid running a volume-controlled DAC directly into a power amp. Put a simple Goldpoint analog attenuator between them. Set your digital front end to 100% volume and use the attenuator to adjust to the loudest you'd ever listen. Now you're protected against "runaway". Your speakers will thank you.

^This^ harkens back to my earlier post #10

True, so we need to know the output impedance of the DAC and the input impedance of the pre.
…

We take a DAC with maybe 1000 ohms output impedance, and put a 30dB attenuator on it.
What will be the impedance at the amp input?

And if the amp’s input impedance is low, then we a case where the interconnect capacitance might make a difference.

Passive pre amps look good until we think of impedances.

I would run the DAC straight in except where a volume knob is handy.
If one does not need a selector, and has some volume adjuster elsewhere, then just leave the preamp out.

 

[Neddy]

Ya that scares the hell out of me and my solution so far has been just using pro amps with level controls so I use them to set as my max volume in case JRiver does do anything weird!

So your post finally got me to rewire the system so I can use the OktoDAC8's remote control for volume.

(Which involved switching the Venu360 bi-amp mixer/controller from AES fixed level inputs to Analog, so all 7.1 channels are now controllabe via the OktoD's tiny apple remote.
I'd had the box of 'spare' canare xlr cables sitting up there for almost a year - can finally put them in storage!)

And yes, there are other ways to do this (or not), and my dac/preamp already has volume control but I just couldn't use it, so technically a bit off topic.

Anyway - yes, it works fine, and no, I can't really tell any huge difference in background noise or anything else, tho reconfiguring the Venu caused me to have to re-run the autoEQ function, so of course they 'sound better'.

However, now I face (temporarily?) the dilemma of 'which remote (Mouse or Tiny remote) to dive for' when I need to change volume or select different tracks on JRiver!! Oh dear.

So, while it's DEFINITELY an improvement of 'elapsed time to Mute' speed, it's offset a bit by 'choosing which to go for' - and more 'choice complexity' in everyday use (trackball for track change/selections vs. tiny remote for volume changes, tho I can still do that via the trackball).
Probably the biggest 'gain' (hah) is for Movie Night, when I don't have to have the PC display up and have to mess with the trackball to adjust volume levels when one of the movie goers complains about 'too loud' or 'too soft'.

So, to my point - having a 'ready to hand' volume/mute remote, while adding some mental task complexity, sure removes any concern about Windows/JRiver Slapping to Full gain risk.

(PS. Final thought. I've found there's a good 10-15db variation in volume levels across the 4Gb of music files I have, so setting the gains for 'worst case' will reduce my dynamic range - I think - too much. I am trying out JR's adaptive vol control, tho, and while I don't trust it all that much, for casual listening it seems to work fine.)

Jeeze, all this just b/c I can't trust the OS or app to not go batty on me!
Time was it was all just knobs and switches and dials, and stuff just Did What it Was Supposed to Do (until it Broke, of course).
I sometimes wonder if the 'advent' of software based "control apps" has reset kids' expectations about what 'reliable' means - with consesquent social implications?
"Sometimes the app just doesn't work" "Ok".
No. NOT OK.
Grumpy Out.

 

[Pdxwayne]

For the last two weeks, I have been trying to use my node2i to do volume control and all the chains I tried just didn't sound right to me.

Using Parasound A21 as amp, I have tried
Node2i to
E30
Gustard x16
Minidsp 2x4 HD
All directly from DAC/minidsp to amp.

Every single one seems a bit off.....

I went back to Node2i fixed volume to Gustard x16 full volume to Gustard H16 (as volume control) to amp and this one feels the best to me....

Gustard previously advised me to not using node2i and DAC to do volume control as digital volume control is not bit perfect. Gustard suggested I use H16 analog volume control instead. The advice still holds true after my latest experiments.

I am not sure if OP using computer software volume control has same not bit perfect issue or not....Since OP is happy, I guess OP can just skip considering preamp.....

 

[ex audiophile]

Less is more I agree, but preamp often drives power amp better (lower output impedance), while preamp's volume control is likely better quality.
I use Benchmark DAC3 directly to AHB2, but somebody with exactly the same setup inserted high quality Benchmark's preamp and reported better sound.

I inserted an LA4 in between a DAC3B and AHB2 not for better sound but to get the superb volume control and the mono output for my subs. I don't know how you would integrate a sub without the preamp, there may well be but it's above my pay grade/tolerance level!

 

[Kijanki]

I don't know how you would integrate a sub without the preamp

I don't have sub in my setup, but I imagine you can connect active sub to DAC3B RCA outputs.

 

[Plcamp]

I have some (possibly dumb) questions about direct DAC to power amp.

1) Do modern DACs have (essentially) zero output dc offset, such that a power amp with servo control could delete its input isolation capacitor? Is dc offset a design concern? Is it specified by any DAC makers?

2) Right now, my e30 is never used at volume greater than about -25 db … would I noticeably benefit by inserting 12db or higher attenuators so the DAC operates closer to full scale output?

3) Is DAC output impedance stable over entire output level/ frequency range? I think my app could use a passive line level cross, the power amps I use have high (100k) input impedance.

 

[SIY]

I have some (possibly dumb) questions about direct DAC to power amp.

1) Do modern DACs have (essentially) zero output dc offset, such that a power amp with servo control could delete its input isolation capacitor? Is dc offset a design concern? Is it specified by any DAC makers?

2) Right now, my e30 is never used at volume greater than about -25 db … would I noticeably benefit by inserting 12db or higher attenuators so the DAC operates closer to full scale output?

3) Is DAC output impedance stable over entire output level/ frequency range? I think my app could use a passive line level cross, the power amps I use have high (100k) input impedance.

1) In any of the units I've tested, DC offset is a non-issue. On the order of a few millivolts at most.

That said, I would still use an input cap in any power amp. Unexpected things happen, so why not spend a dime or two to minimize the damage?

2) If you're not hearing any noise from the gain structure, I wouldn't spend time, money, or worry on it.

3) Generally so. It might rise a bit at very low frequencies if the output is capacitor coupled, and may rise a bit at high frequencies because of falling open loop gain. But we're talking a change from really negligible to just negligible.

99.9% of the time, you can just hook up the components and go with no further fuss.