Amp makes clapping noise


I had a Peachtree Preamp and Amp that worked perfectly well and recently sold them here. The buyer hears a clapping noise when connecting the amp to his speakers. The preamp or other sources are not connected. I did a FaceTime call and it does happen. Any ideas what the issue could be? He is connecting them to Snell speakers which he says works with his earlier integrated amp. Any input is appreciated. 
128x128rajivhifi
my amp gives me a standing O when i play vinyl

and it boos me out of the room when i stream spotify

sorry couldn’t resist :)

sounds like that class d amp in the peachtree has bit the dust and is oscillating ... just a guess
The amp or the speaker is clapping? There are cables between the units? There are cables from the preamp. I'd make sure EVERYTHING was hooked up, pre amp to amp amp to speakers, and nothing was touching or BACKWARDS.  Then test. Removing ONE cable at a time, and retest, if you don't see something.

Backwards or touching is my guess? Bad cables, jerked loose when pulled and put back into service, on the newer gear.. What did work great may have been manhandled and caused something to pull loose or cause a wire to touch somewhere..

Regards
Thanks oldhvymec. The sound comes from the speakers and not the amp itself. The pre-amp was not connected to it. Just the amp and the speakers.

I'm wondering the same as well if its an issue with the cables or the power outlet. Tried searching online but have not seen anything related to it. I'm confident about the amp and the shipping boxes themselves did not have any damage. 
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Well what's up OP? Get it solved?  I sure hope it's not a problem. Why would it develop a problem, from being shipped? That would be VERY rare, I would think, well actually, know.. If it's packed right, I've NEVER had a shipping problem, PACKING yes, shipping other than the wrong address or lost, no..

Regards