rufustOn the back of the HCA750 you have level controls for each chanel, just try them first with your source plug directly into the 750 ()no preamp), as this will be the cleanest most uncolored sound you'll get. And if you like what you hear just get a passive preamp with remote.
to pair with a newly inherited Parasound HCA 750A Will be driving Spica TC 60
Cheers George