Processor direct to amp?

I’ve previously passed the output of my Bryston SP3 processor through a preamp. While my rack is being modified, I’m trying to use the SP3 to drive a NAD M-22 directly without success. I bought the NAD used several years ago with the idea of using it for cable, but have yet to do so. It may be defective or perhaps the SP3 may lack the voltage to drive an amp directly. I’m skeptical it’s the voltage because the SP3 drives a pair of NAD C-268 amps used for surround, on the other hand there is no audio from either channel.