I can't speak to the Oppo but I have a similar situation with an NAD C-658 DAC/preamp. I used to use it as both a DAC and premap with a set of Rogue M-180 monoblocks. I finally came up with some cash and bought a new Rogue RP-7 so now I use the NAD as a DAC only. What I found is if the NAD is set to higher than 70% output I can only go to 125 or so in volume on the RP-7 before I begin to hear some "noise" in the form of distortion. The NAD has a feature where I can set the output signal to a value and not worry about additional noise from my system. The "70" number mentioned for the Oppo seems to hold true for me too since after I set the NAD to 70% output fixed I no longer have the noise issue. It took a little trial and error but the 70% output set value seems to be te ticket for me.
Gain / Amplification
Ok, dumb question maybe….maybe the more troll-like members could chill on this one. I was just wondering, is there likely a quality-of-sound difference between utilizing maximum gain (say, out of a CD player, to keep it a simple scenario) and needing much less amplification from your amp, or is it in any way different to set your CD gain/output volume at a lower level and let your amp do its job? Let’s say balanced connections, so that’s added gain as well.
Question just kind of occurred to me when I fired up my Oppo for first time in awhile and it was **LOUD**. Which is not an issue, I was just wondering, circuit design-wise and engineering-wise, should one or the other provide a better sound ?
JH