What volume level should a DAC be set to when feeding your Pre Amp

Thanks @dweller, much appreciated.

What volume level should a DAC be set to when feeding your Pre Amp
I have an Accuphase DAC (DC-901) with a digital volume control that feeds my Pre Amp/Accuphase integrated Amp.

Dacs volume up close to full, or you can run the risk of "bit stripping" if too low (below 75%), an can cause resolution reduction 14bit 12bit and so on the lower you go.

If then with the dacs volume up close to full, if you are below 10am on your preamp volume because it’s too loud, then think about a passive preamp or active preamp little or unity gain.

Quote from Nelson Pass

Nelson Pass,

"We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp."

Cheers George

Thank you George.

I had "randomly" picked -15db on the DAC (its range is -80db -through 0db.  The only reason being this resulted in my Integrated sitting between 9 and 11 oclock on the volume control for regular listening levels.  I may have blindly determined the correct setting with any rhyme or reason. I have tried 0db on the DAC (full volume) and had no discerning change in sound quality (my ears are not that young). I also wasnt keen un running the volume way up to between 12 and 3 oclock for low level listening when the DAC was set to lower levels. I may be mistaken but figured this was working the Amp harder.

Cheers

I may be mistaken but figured this was working the Amp harder.

No the same, just letting the same amount of input signal through the volume pot to the power amp section, instead of shunting it to ground when the dac's vc is higher.

Cheers George 

0dB FS (full scale) should correspond to 24dBu.  Since 24dBu is a level related to 0.775V (1mW over 600ohm) it will correspond to 12.3Vrms.  When you selected -15dB your DAC would output  24dBu-15dB=9dBu = 2.2Vrms.  I'm not sure what nominal level should be.  I looked at one of the power amps that outputs 125W at 8ohm and has gain of 26dB.  That would imply 1.6Vrms input.  My current power amp Benchmark AHB2 has high gain position of 8.2dBu=2Vrms.  You should be OK.  My previous DAC had jumper selections of 0dB, -10dB and -20dB.  The best position for driving power amp direct was -10dB. 

You might find this useful:
https://www.av-iq.com/avcat/images/documents/pdfs/measdigaudlvls.pdf