How does digital music volume (in dB) affect my dac in terms of voltage/power?

Hi,
i've been diving into digital audio lately and came to this problem. All of my music is replaygained, meaning the RMS values are -18dB (foobar 2000). I have it set up in gain + clipping prevention mode. If i play a song thats louder without RG, well, it sounds louder. This means both my dac and my amp have to have some volume (voltage) overhead (at the same knob position in the amp case). My gear is Schiit Magni 2U and Modi 2U. The DAC can put out 1.5Vrms max. Amp can do 9.8Vrms max. The amp has LG 1.5 (3dB) and HG 6 (15.6dB), not listed if that is voltage or power gain though.
Is there any way to atleast approximately calculate what RMS voltage numbers should i expect from my dac and then from the amp with -18dB replaygained music?
Thanks a lot
Dave

 

Hi, Dave. There are kind of a lot of moving parts to this question, most of which relate to the ReplayGain specification, which evidently uses 83 dB SPL in some predefined audio system as the reference. For questions like this, I would probably try Computer Audiophile or hydrogenaudio instead of SBAF. Same for all of the computer-based upsampling stuff. Taking a quick peek, I think [this forum thread] and [this wiki article] would get you most of the way to your answer. Happy Turkey Day~

 

Thank you very much! I'll check out the threads. Happy thanksgiving to you too