MC2300

Mcintosh MC 2300. It happens when you first turn on the amplifier. 

Are you turning you’re preamp on first? If so, let it warm up for a minute then mute before turning on your amp. Try that if you haven’t.

Power up the preamp first, mute, turn the volume down on the power amp then power up the power amp, volume up the power amp, volume up the preamp. If it pops then recap that puppy. :-) I've had a few MC2300 and 2500. "The Beast", broken they keep working.. Circuit breakers too. No BS fuses crap.. 

The only thing I've ever seen spin a meter faster were VTL 750 or 1250 watt MB valve amps.. They ALL could suck a Utility pole dry.. :-)

Happy New Year.

One of the all-time greats and possibly longest production super amp. They also hold their value: 

Thanks, will try the power up sequence. My MC2500 black face has the speaker switch. These are big amps when they are powering up.C46 is my pre-amp….Happy New Year everyone.