Hi guys, haven't been on this forum in years. I have a late 60s/ early 70s Magnavox astrosonic stereo that has this sound out of the left speaker that is kind of like moving a creaky door really slow. Has worked fine for a long time, the sound just started. Any ideas?

Are the electrolytics original? Some of those caps prevent oscillation or cause it when bad.

Are the electrolytics original? Some of those caps prevent oscillation or cause it when bad.

Im almost 100 percent sure they are. The sound corresponds with bass, whether from the record player or radio. It spends most of it's time sitting and was played a good chunk of this weekend. Usually on bad caps, I just get the typical death hum.

I'd bet on lytics too - maybe a "motorboat" oscillation when a push-pull stage draws increased current due to increased bass volume?

Ill see if I can make a video of it sometime, then it may be easier to help diagnose, it has some pretty dirty controls, I may give it a shot, but it probably is caps.

https://www.youtube.com/watch?v=_XRP-GAcLwc
Here is the video, it went away overnight, and then came back after about an hour. Sounds like popcorn. Doesn't get louder with volume, but does become more rapid.

Definitely bad capacitors Johnny you may want to change those a full recap is in order

After some diagnostics, turned out to be a capacitor on a small board for the output. Problem solved thank you all for your help.

Congratulations show me I'm fixing that I hope you enjoy your Magnavox I love that sound but Magnavox specially the tube type models solid state is okay but tubes are better going to stay in touch better