Stereo Amplifier is in trouble- low volume

Thread Starter

Almu

Joined Nov 24, 2019
1
Sir/ madam good day,since we gathered all information from all of you there,i have a little question rgdg my stereo amplifier is in trouble rgdg VOLUME and i noticed that the 8 pin ic is not working part number AX358,i already change all posible electronic parts like capacitors,diodes,transistors,and some 2 ic but unfortunately its not working,i cannot make higher volume.since i suspect the ic ax358 was the defective parts although im not so sure but my problem is i cannot find ax358 ic in our area.so my question is,is there any subtitute,replacement or compatible with this kind of ic???pls let me know and what to do this things....thank you in advance for your BIG HELP!!!AND THANK YOU ADMIN,respectfully yours allan
 

Ylli

Joined Nov 13, 2015
851
Let's start out with the make and model of the amplifier.

The AX358 is a dual op-amp designed for single supply where the inputs can go a bit below ground. Seeing how it is being used would be very helpful in determining what a good replacement would be.

edit: it does looks like a LM358.
 

Audioguru again

Joined Oct 21, 2019
553
An LM358 and its Chinese copy are not used for audio because they have terrible crossover distortion, a poor slew rate that gives trouble to audio frequencies above 3kHz at high levels and they are noisy (hiss).
 

Ylli

Joined Nov 13, 2015
851
An LM358 and its Chinese copy are not used for audio because they have terrible crossover distortion, a poor slew rate that gives trouble to audio frequencies above 3kHz at high levels and they are noisy (hiss).
That's why I'd like to know make/model and perhaps find a schematic. Could be being used as a DC servo.
 

MisterBill2

Joined Jan 23, 2018
4,579
The best way to service almost all electronic things is not to just start replacing components, but to first locate the problem. So with an amplifier, is there any increase in distortion? Most failures that cause a drop in the output also increase the distortion level, or alter the frequency response. And the next question, doeas the problem exist on both channels of the stereo system, or just one side? If the problem is on both sides then it is more likely to be in the power supply.
If you are able to share a copy of the circuit schematic, and if you are able to accurately measure voltages at points in the circuit then probably the folks here can be able to point to the failed component. Otherwise you are just getting guesses, some much better than others, but still just guesses. Even my comment about the power supply is just a good guess, but based on almost no information.
 
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