Amplifier Goes into Protect Mode Right Channel

Why do you think it's the preamp and not the amp?

I had something happen similar to this issue one year ago when I bought the Ray Samuels Nighthawk phono preamp. The amplifier would go into protect mode while playing music. Before I checked the phono stage with the multimeter for DC leakage, I sent the amplifier back for evaluation. They could not find anything wrong with the protection circuit or anything else for that matter. When I returned the Nighthawk and went with ClearAudio basic phono stage, the amplifier stopped going into protect mode. So, I'm making a big leap here and assuming there's a connection but I could be completely wrong on this. I did run the multimeter on the preamp right channel output jack - it did register something but it was always intermittent. Does that provide additional helpful information?

Same amp, same channel again???? W two different phono stages and two different line stages??? I'd be thinking its something w the amp that only happens after it warms up, and that when you sent the amp back, the tech did not let it run for a long period of time. I'd try swapping speaker cables, then the various interconnects, and work my backwards to isolate the component. It'll be a long haul if it takes 1-3 hours each time to get it to go into protect mode, but that seems to be the only certain way.