marantz 4430

[Roger68]

left side of phono after a while becomes very fuzzy

 

[par4ken]

left side of phono after a while becomes very fuzzy

The first thing would be to swap the left and right phono inputs to prove that the problem is the amp not the cartridge.

You can download a service manual here for free.

https://www.hifiengine.com/manual_library/marantz/4430.shtml

 

[Roger68]

The first thing would be to swap the left and right phono inputs to prove that the problem is the amp not the cartridge.

You can download a service manual here for free.

https://www.hifiengine.com/manual_library/marantz/4430.shtml

I swaped the left and right phono inputs,same

 

[Roger68]

I swaped the left and right phono inputs,same

Thank you

 

[barfle]

I’m not familiar with this particular model, so any advice I can give would be generic.

Can you remove the cover and inspect the boards? Can younsee if anything in the phono stage is getting warm or hot compared to the other?

 

[Roger68]

I’m not familiar with this particular model, so any advice I can give would be generic.

Can you remove the cover and inspect the boards? Can younsee if anything in the phono stage is getting warm or hot compared to the other?

I ordered a rebuild kit for the 700 board.hope that works. thanks

 

[par4ken]

That circuit looks pretty basic. I would suspect C704 (22µF 25V) capacitor. You should also replace C703 (right channel), and C713 100µF 50V. Other than that it could be a noisy transistor, there are only 3 per side.

Before replacing any parts I would clean (DeOxit) the selector switch. Poor contact there could also cause a "fuzzy sound".

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