P12 Sends McIntosh Amp Into Sentry

Power Components
1

Gents, I am close to taking a loss and selling off some components of mine as my home theater is frustrating me right now.

I previously had a Marantz MM7055 A/B 5 Ch amp. I just upgraded to a McIntosh MI347 7 Ch class D amp. Within 2 weeks, I would notice my surround channels would ‘clip’…cut out sound, then come back. Sentry Monitor has been activated. My dealer swapped the unit, and within 2 weeks the problem is back.

I had the Marantz and now the McIntosh hooked up to a P12. Readings are 375 average and I see peaks at 500. I have been told by others it could be the P12 is not giving the unit enough power and that is causing the sentry activiation. But on just 1 or 2 channels? Wouldn’t the P12 shut down?

I have the McIntosh MI347 now plugged into a McIntosh MPC500 power controller. I will report back if that fixes things, but I am curious.

Could it be the MI347 doesn’t like the P12???
I also have a McIntosh MX160 plugged into the P12. Could it be that IT doesn’t like the P12 and is thus putting something in the outgoing XLR signal?? But why wouldn’t my Marantz or other 3 M1200s exhibit the same problem if it were from my processor?

List of components plugged into P12
65” Sony TV
McIntosh MX160
3x M1200
Panasonic UBDP9000 4K Player
McIntosh MI347 amp
Martin Logan Illusion Center Channel (woofer amp plus panel charge)
375-500 watts is all I have ever seen on screen.

I am about to either swap the McIntosh amp for 2 S300s or the P12 for just a regular Puritan Conditoner

2

It seems like you are on the right track, trying to find the source of the issue. Your first step is a smart first step. If it turns out to be the correct first step, the next one would be to unplug the woofer amp/panel charge from the P12 and see if that (woofer amp/panel charge) is somehow demanding too much energy.

3

Update:
Removed the MI347 from the P12 and the issue persists. So it it not because the P12 cannot deliver the power to it.

4

Next step is to check speaker cable and interconnect, by changing which speakers they go to, one at a time, to see if the issue remains with the same speakers with different connections to them, or whether the issue follows to different speakers as the connections change.

5

Did both. Issue is only when connected to the woofers of the speakers. Switched speakers to confirm. I’m thinking dual 8s is too much for this to drive without shorting