Hi I've been asked to look at a friends bass amp that has a intermittent issue. Sometimes it starts making a strange noise that is akin to a old zx spectrum loading but at a constant frequency. My friend says once it starts its won't stop even after resetting the amp.
It's uses two irs2092 in btl mode and has two pots to trim the oscillators and in the schematic the frequency is stated as 333khz. I've scoped the test point and one was set to nearly 400khz why the other was around 345khz.
I set the high one as close to 333khz as I could and started to bring the other one back into spec when they seemed to lock together. I've now got it running almost bang on 333khz and it all seems fine but as it was a intermittent problem I'm not sure if the issue will return.
My main question is this likely to cause such a issue and are the irs2092 suppose to be exactly in sync albeit with a slight phase shift.
Any advice much appreciated
It's uses two irs2092 in btl mode and has two pots to trim the oscillators and in the schematic the frequency is stated as 333khz. I've scoped the test point and one was set to nearly 400khz why the other was around 345khz.
I set the high one as close to 333khz as I could and started to bring the other one back into spec when they seemed to lock together. I've now got it running almost bang on 333khz and it all seems fine but as it was a intermittent problem I'm not sure if the issue will return.
My main question is this likely to cause such a issue and are the irs2092 suppose to be exactly in sync albeit with a slight phase shift.
Any advice much appreciated