2X6 the 504 looks just like yours. But again i'm not willing to risk blowing it up. Basically with these old amps..you keep throwing them in protection...NOT good.

The QSC will work..or not..in any case will not blow up the QSC..which i can send back....if it dosen't work with the M80's..then there is a problem with the M80's and i can send them back.

Not real rocket science here...just strait logic. Just not willing to risk the 504, thats all.