Ah good the ADA1250 and 1500 have higher voltage. 2volt I think.
That was my concern when I purchased my 1250, not having enough power from my pre outs.
Over on HTF the moderator has an in depth article on setting gain connecting a Pro Amp. and all the tidbits that go with it. Quite lengthy but very informative.{Make sure the voltage is compatible crank AVR to clipping roll back to before clipping. Then set Amp. gain to just before it can start clipping} Very short hand. But the idea is that they can reach Max and clip together if point is reached.
