Electrolytic is fine. Polyester would be better.
If I understand you right, yes.
Originally posted by Dan2
R39 (temperature sensor) is not on the board, and the wire link from T13 to the relay is missing. so the components for the thermal protection are on board, but not being used
( i see now the protection circuit was only used for power-on delay, am i right? but then how did the relay switch on and off after it was powered up?)
D14 (LED) was never connected (also part of thermal protection)
How odd! Omitting the thermal protection isn't too bad as it appears that whoever built it has made alternate arrangements for this - those look like thermal breakers on the top of the heatsink and they probably cut the power in the case of an overheat
No, these are part of the voltage amplifier stage, however if the VI limiter circuit (T4 and T5) have been activating a lot due to abuse, then these parts will have been damaged.
"AC" should have a raw AC connection from the transformer secondary. This is used for "Loss of AC" muting. The amp will work without it.
Clip should have an LED connected to ground. This lights when the amp is driven into clipping.
Yes, just the electrolytics. Replacing the main power supply capacitors will most likely fix the lack of bass issue.
termal element?? there are 2 sensors on top of the heatsink that regulate the fan, the one that is in the schematic was never put in
kay well i have bought replacement parts, gonna start replacing tomorrow. the website for the amp says i need 4 10000uF caps for the PSU. i could only get 2 - i hope that will be enough.
kay well i have bought replacement parts, gonna start replacing tomorrow. the website for the amp says i need 4 10000uF caps for the PSU. i could only get 2 - i hope that will be enough.
ok so now i want to add 2 things to this amp - an audio limiter and an active crossover. both circuits are from Rod Elliott's site.
both circuits need a -15 0 +15 v supply (about) so i was wondering if i can use the supply from the amp which is used for its op-amps ?? or will it not be able to supply the current??
the +- 15v are set up using 3k3 resistors and zener diodes. the resisters look quite big - 5watt i think.
both circuits need a -15 0 +15 v supply (about) so i was wondering if i can use the supply from the amp which is used for its op-amps ?? or will it not be able to supply the current??
the +- 15v are set up using 3k3 resistors and zener diodes. the resisters look quite big - 5watt i think.
thanks for the info - but i am going to keep the power transistors that are there.
i still want to test this amp at high power for a while to make sure it doesn't cut out, so what is the best way of doing this?? i was thinking of hookin up the speakers and running a low frequency (abt 10hz) for a while. the amp will be working hard and it will be fairly quiet (the speakers i have can't produce really low bass). the only thing i am worried about is burning the speaker's voice coil
i still want to test this amp at high power for a while to make sure it doesn't cut out, so what is the best way of doing this?? i was thinking of hookin up the speakers and running a low frequency (abt 10hz) for a while. the amp will be working hard and it will be fairly quiet (the speakers i have can't produce really low bass). the only thing i am worried about is burning the speaker's voice coil
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