Well Taj,
No luck with the new small triac or oc. I'm pretty sure the op-amp is not properly controlling the oc's diode but I can't verify the op-amp's output control voltage with invalid inputs from all 3 power supplies due to them not reaching operating voltages. I'll retest all passives in op-amp circuit and as a last resort replace 4558 again.
BTW the big caps are 10Kuf @ 100v.According to the schematic the high v rail is +/- 98v. Do all Carver amps specify cap's working voltage with no margin above amp's operating DCV? Which ps voltage is the regulator control pot adjustment supposed to be set for?
Best Wishes
No luck with the new small triac or oc. I'm pretty sure the op-amp is not properly controlling the oc's diode but I can't verify the op-amp's output control voltage with invalid inputs from all 3 power supplies due to them not reaching operating voltages. I'll retest all passives in op-amp circuit and as a last resort replace 4558 again.
BTW the big caps are 10Kuf @ 100v.According to the schematic the high v rail is +/- 98v. Do all Carver amps specify cap's working voltage with no margin above amp's operating DCV? Which ps voltage is the regulator control pot adjustment supposed to be set for?
Best Wishes
Uf......
Now it looks like it will take some time to repair.....
First. Yes in all carver amps.....at least those which I have, are caps somehow underrated....but Bob use hi quality parts. Sprague and phillips caps with much higher max voltage. I find defective cap only once in PT2400 or maybe PT1800......it is the same amp basically.
About the pot. It regulate triac firing angle and it affects on all voltages. It is like dimmer for regulate bulb......
I really try to remember.....I think that I replaced this 4558 at my amp but it wasn't the cause....there was dead diode after this ic. There are 2 diodes D10,D11. And because there is very few components from op amp to the oc it is worth to check them all. C5 for an example. It is also very possible that one of the resistors died. I have once a 33K 1W resistor in PM1.5 amp which was't burned at all but simple shows no resistance.....I'm afraid that you will be forced to check everything....
What about some small cap in the nearby of some hot resistor? I find some such stupid layouts in all my carver amps....?
I wish that you are somewhere closer.....it would take 2 coups of early grey and wo would repair it. I have nice basement workshop......with all materials needed for such operation.......Maybe you can teleport tfm and yourself here...?
Regards
Now it looks like it will take some time to repair.....
First. Yes in all carver amps.....at least those which I have, are caps somehow underrated....but Bob use hi quality parts. Sprague and phillips caps with much higher max voltage. I find defective cap only once in PT2400 or maybe PT1800......it is the same amp basically.
About the pot. It regulate triac firing angle and it affects on all voltages. It is like dimmer for regulate bulb......
I really try to remember.....I think that I replaced this 4558 at my amp but it wasn't the cause....there was dead diode after this ic. There are 2 diodes D10,D11. And because there is very few components from op amp to the oc it is worth to check them all. C5 for an example. It is also very possible that one of the resistors died. I have once a 33K 1W resistor in PM1.5 amp which was't burned at all but simple shows no resistance.....I'm afraid that you will be forced to check everything....
What about some small cap in the nearby of some hot resistor? I find some such stupid layouts in all my carver amps....?
I wish that you are somewhere closer.....it would take 2 coups of early grey and wo would repair it. I have nice basement workshop......with all materials needed for such operation.......Maybe you can teleport tfm and yourself here...?
Regards
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