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Amplifier Goes into Protect Mode Right Channel

Wanted to hear your tech thoughts on this problem. After spinning vinyl for 1-3 hours, the right channel on my solid state amplifier goes into protect mode. This repeats itself multiple times each session. I have a tube preamp and tube phono stage. Only one source - turntable. I've swapped tubes in the linestage preamp which made no difference; swapped IC cables which made no difference. The linestage tube preamp is new (one month old) but I'm beginning to think it may be a leaking cap causing the trouble. Also looking at the speaker cables as a possibility. Would that matter? Any thoughts? At the point where I'm ready to RMA the preamp for bench test. Thanks in advance.
wescoman
wescoman OP
117 posts
 
Was on another website and got some great ideas. Need to check out speaker damping. My speakers sit directly on carpet. They come with spikes but I didn't install them. Maybe I need to use them or put some marble pavers underneath them. Secondly, recommendation to use turntable shelf instead of placing on butcher block and then on dedicated wood table. Third idea deals with tonearm/cartridge resonance issues. If indeed it is subsonic frequency issues, this could get complicated.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
You don't need to wait for your Acoustic Zen cable to come back to perform this testing. You can use Radio Shack speaker cable ($5-$10), or even some plain old lamp cord for the sake of trouble-shooting.

Why would you not install the speaker spikes??? Correct that wrong first, that should make as much of a difference as isolating your turntable. If the issue is feedback going through your system, fix the spike issue first, then if there is still excessive woofer excursion, look into a turntable wall mount.

If you are still having issues, then follow the switching cables path suggested above to trace down the guilty component.
pops
2,273 posts
 
Have had this problem before, with MIT SC and classe amp, would send the amp into oscillation, never figured out, MIT checked the cable and was stumped, the cable and amp would not match up. That was the solve, no other cable caused the problem.

Make sure your rca's to your amp if single ended....are installed properly, ie, tightened so the ground is making good contact. Had this problem with WBT's once and it always happened when the system had been playing and heated up. Pliers fixed that problem, a barrel on one cable was a little too big for the inputs.

Did you find out if your tube preamp was passing DC? Could also be a loose solder joint around the tube socket from swapping out tubes.....have had that happen also.

Double check cartridge clips and wire/solder connection to the clips - has not broken or been compromised....have had that happen also and ended up sending my phono pre back only to find out it was fine....

Stay in this hobby long enough and just about everything will happen eventually....you will find it, good luck!
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