PSW125 heartbeat

Razorback1973

I have a PSW 125 with a heartbeat. The last amp stopped working, and had a very faint heartbeat, so was replaced with a new amp. This new amp has a very distinct heartbeat, which is soft when the amp is off, but quite noticeable when the amp is on, and even more so when playing sound through it. It also does this when disconnected form my AV receiver and even plugged in at my friends place (power only), several miles from mine. I've tried a different power lead as well, just in case that was causing the problem, but no luck.
A colleague at work, who dabbles in electronics, seems to think it could be either a cap charging and discharging, and/or a faulty earth somewhere. Or could I just be unlucky and have a lemon amp, requiring another new one to be sent out?
Thanks for any help or advice you can give.

[Deleted User]

Hello,
Thanks for posting on Polk's forum. That is certainly unusual, to say the least. I suspect a defective second amp, there's not much else that could cause that kind of problem and you've eliminated outside causes. Time for a call to Polk CS at 1-800-377-7655, I'm not sure what their schedule is this weekend, but they'll help solve the problem.
Cheers, Ken

Razorback1973

Thanks. I've been in contact with Kim Jasper (I think she's at Polk CS), and hopefully she has received my email covering this. She arranged for the last replacement, and on install it had this problem. So I've been working through it, testing different ideas, and failing each time. She ran through a few of the things I've tried, and I've had advice from a few friends & colleagues. All of which has lead me to the same conclusion you've reached. Hopefully another amp will fix the issue.