Please note that the "fixed volume" component only applies to the pre-outs; if you are only running a 5.1 setup and reassigning the two surr.back amps to power zone 2, then you can control the volume internally with the receiver. This is exactly how I have my 2113 setup, powering two speakers in the back yard with the surr.back amps and a 5.1 setup in main zone.
If you use the pre-outs, the volume control will either be supplied by the external amp itself, or by some other in-line volume control. Many dedicated 2ch amps don't have volume controls themselves, but if you wanted to go this route you could just an old stereo receiver and control the volume via the second receiver. Or you could feed Zone 2 pre-outs to an amp, and then run the speaker wire to the speakers, with some sort of wall-mounted volume control dial in-line between the amps and the speakers.
If you use the pre-outs, the volume control will either be supplied by the external amp itself, or by some other in-line volume control. Many dedicated 2ch amps don't have volume controls themselves, but if you wanted to go this route you could just an old stereo receiver and control the volume via the second receiver. Or you could feed Zone 2 pre-outs to an amp, and then run the speaker wire to the speakers, with some sort of wall-mounted volume control dial in-line between the amps and the speakers.

































I will call them today and raise a stink. I shouldn't have to deal with this crap as a replacement for a receiver that was just a couple of days old. It's not like the 3313 is an old discontinued model that they might have had difficulty finding around to send as replacement. They had this mangled turd around, and they just tossed it my way. By the way, it's not Denon US handling the repairs/replacement, but rather Panurgy - who Denon has outsourced all the repair work to.