Hi there
Total noob here.
I have been hanging on to learn more about diagnosing and fixing amps, and watching a lot of youtube.
This one is the Ariston Integrated Amplifier. There's no model number.
I didn't find many references online: https://www.worthpoint.com/worthoped...made-174132328.
I've owned this one for about 15 years. It was working fine, and was put away for a long time. Today the sound can be described as crunchy. You can clearly hear music, but it's very clipped and distorted.
When very low input volume it sounds better, but increasing up the amp volume soon reveals crunchy sound. When mid input volume, it's crunchy from the start.
Identical distortion on both output channels.
Same distortion listening to the headphone (bypass switch) or speakers.
Fuses are good. Two LEDs shine on the output stage.
Don't see any obvious caps bulging, but they'll all be 40 years old by now.
Doesn't matter what input (aux, tape, cd).
I'm guessing it's a problem at pre-amp stage? But why both channels together?
I'm looking for help with some diagnosis steps.
- thinking caps, awaiting delivery of an ESR tester before I start pulling them out.
- what drives the pre-output stages ? How to get an oscilloscope on ?
- it's a wonderfully crazy board. There are some labels but I'm not sure where the pre-amp caps are.
- output NPN and PNP transistors seem OK with a diode test.
Total noob here.
I have been hanging on to learn more about diagnosing and fixing amps, and watching a lot of youtube.
This one is the Ariston Integrated Amplifier. There's no model number.
I didn't find many references online: https://www.worthpoint.com/worthoped...made-174132328.
I've owned this one for about 15 years. It was working fine, and was put away for a long time. Today the sound can be described as crunchy. You can clearly hear music, but it's very clipped and distorted.
When very low input volume it sounds better, but increasing up the amp volume soon reveals crunchy sound. When mid input volume, it's crunchy from the start.
Identical distortion on both output channels.
Same distortion listening to the headphone (bypass switch) or speakers.
Fuses are good. Two LEDs shine on the output stage.
Don't see any obvious caps bulging, but they'll all be 40 years old by now.
Doesn't matter what input (aux, tape, cd).
I'm guessing it's a problem at pre-amp stage? But why both channels together?
I'm looking for help with some diagnosis steps.
- thinking caps, awaiting delivery of an ESR tester before I start pulling them out.
- what drives the pre-output stages ? How to get an oscilloscope on ?
- it's a wonderfully crazy board. There are some labels but I'm not sure where the pre-amp caps are.
- output NPN and PNP transistors seem OK with a diode test.
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