If I add a power amp to my NAD receiver....

If the receiver has preamp-amp jumpers you can connect a power up. The receiver amplifier would be bypassed. If you don't have preamp out on the receiver there is no easy way to use an external amplifier.

Most NAD receivers I've seen have a "pre-out", so you should be able to add an external power amp. Doing so will bypass the internal amp, the external amp will be your power source. Make sure the external amp is at least twice as powerful or you won't hear any volume difference.

-RW-

Before adding a power amp, I would replace the ugly pins that come standard with NAD bridging the preamp out/power in with good quality jumpers. This will improve the unit substantially and you may find no need for a new power amp.