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

G'day All

I have an Accuphase DAC (DC-901) with a digital volume control that feeds my Pre Amp/Accuphase integrated Amp.  The DAC is fed via USB. It reports its volume level in db and altering the volume on the DAC impacts the volume level coming out of my Integrated.  I currently have the DAC set at 0.0db. This DAC level is purely a guess on my part not really understanding the technicalities of it all.  I'd like to understand better the implications of this DAC volume setting on my overall listening experience and whether or not the setting I have in place currently is correct.

Any advice appreciated.

Cheers
plb02

Showing 1 response by kijanki

kijanki's avatar
kijanki
4,410 posts
 
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 
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