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An audio/video receiver (AVR or home audio receiver) is a consumer electronics component used in home theaters that convert signals into sound.

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A and B left speakers crackle

I have a rather old Sony receiver that claims it’s a STR AV-910. It has connections for four speakers, A and B with left and right options for both. For some reason, the left side speakers for both A and B connections make crackling noises whenever they’re plugged in. They will play music, but it is extremely staticky. I’ve removed the back and checked the wiring, but I can’t see anything obvious that might be causing the problem.

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Hi @pianomacpower ,

Do you hear the crackle when using headphones?

If not it may be dirty contacts in the A/B speaker selector switch or a dry joint left channel connection to the switch.

If so it may be dirty contacts in the protection relay (RY701) or a problem further back in the amp stage.

Here’s an image from the service manual that may help.

Block Image

(click on image to enlarge)

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I don’t have the kind of headphones that would work with the receiver… But I don’t think it has to do with the A/B selection; my current setup is just to use the Right speaker for both A and B, and twist the balance all the way to the right. When I removed the speaker wire connection parts, they looked as clean as the working ones.

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@pianomacpower

using the headphones would help to isolate where the problem is further.

I'm thinking about the switch contacts themselves which if the switch is in an enclosed case can't be seen.

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