So I know that you can use a receiver as a pre/pro only and use an external amp, but can you do the opposite? That is, can you use a a receiver as an amp only and an external pre/pro such as the 990?

The reason I ask is because I am thinking about using my current receiver as an amp for my rears when I switch over to a 990 and 3 channel amp for the fronts.

Thanks

only if your receiver has inputs for the amp channels. if your receiver has pre-outs, so it can be used as a pre/pro, each amp channel would be connected by a jumper to a set of corresponeding inputs (main out to main in, center out to center in, etc). to use the amp section of your receiver, you would remove the jumpers and run RCA connectors from your pre/pro to the receiver.

It's a bit tricky to do. As pcreel points out, some receivers have pre-outs and corresponding main-ins (the RR2150 does this, as seen in the bottom middle of this picture ). Most receivers do not have this. People have used receivers' 5.1 or 7.1 direct inputs in order to get access to the receivers' amps - in this scenario, you connect the processor's pre-amp outputs to the 5.1 or 7.1 analog input of the receiver, set the receiver to that input, set the receiver to some mid-level volume position (and then leave it that way forever - don't want an extra volume control messing things up), and then connect speakers to the outputs that correspond to whatever channels of the 5.1/7.1 input were used. I wouldn't recommend it as a long-term solution, but it's been done before as a stop-gap measure.

My NAD-T762 developed problems in the suround sound processing, so I converted it to an amp, and purchased an Outlaw 970.