Beveridge RM-1/RM-2 Self Mutes Repeatedly

I am currently running a Beveridge RM-1/RM-2 into a Cary V12 that powers a pair of Magnapan 17's. The system sounds terrific . . . except for the fact that the Beveridge seems to be going into "protective mute" mode all by itself repeatedly at irregular intervals not related to the signal strength. This system is for vinyl via a VPI Scout II with Sumiko Blackbird cartridge. The Cary and Beveridge have been completely re-tubed. Now I am suspecting a faulty IC in the RM-1 monitoring circuit. Should I just replace all the IC's? Any ideas would be greatly appreciated. There's nothing worse than having your Coltrane drop out unexpectedly . . .
Contact Roger Modjeski at Music Reference/Ram Labs. RM are his initials.