Help with Sony TA-AX295 distortion

Apr 07, 2008 3 Replies

I have aquired a Sony TA-AX295 integrated amplifier (circa 1990 I think) as part of a system. The amplifier distorts badly even at fairly low volumes on all input channels. The VU meters show that the signal is being overdriven at normal input levels. Even at very low input levels the audio is clipping although the VU is normal. I assume that this is happening in the pre-amp somewhere. Does anyone have any experience with these amps that will point me in the right direction. I have been unsuccessful in finding a service manual or schematic.



I'm pretty handy with a soldering iron although my expertise is in digital electronics and not audio. I am thinking of replacing all of the electrolytics, but I may be way off. Any help with advice or schematics etc. will be greatly appreciated.



Regards Kasper de Bruin


Does this happen on all inputs? This certainly sounds like you're hooking up a high level input to the phono input. Is the tape/rec out signal normal?

-- David Farber David Farber's Service Center L.A., CA

up

Yes it does happen on all inputs with their normal components connected ie. tuner on the tuner input, cd on the cd input tape on the tape input and phono on the phono input. With an external (not part of the component system) cd player the same thing happens on tape, tuner, cd and video (vcr) inputs.

Regards Kasper

From your description, the fault can possibly be many things.

The best approach would be to get the service manual. This can be ordered from a Sony parts distributor.

You will need a scope, DVM, and an audio generator to properly service this amp's audio path. Verify that the power supply is working properly, and that there are proper voltages from it.

If the power supply is working properly, connect the audio generator as recommended from the service manual, and take the measurements with the scope along the audio path, as shown in the schematics. Check for levels that are out of proper spec as indicated in the service manual. At least with this procedure you will be able to find the stage where the fault is occurring. Then you will be able to troubleshoot that area for the defective components.

--

JANA _____

I'm pretty handy with a soldering iron although my expertise is in digital electronics and not audio. I am thinking of replacing all of the electrolytics, but I may be way off. Any help with advice or schematics etc. will be greatly appreciated.

Regards Kasper de Bruin

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