Hi and thanks for your help. I want to start building an amp but i figure if i cant fix one then i shouldnt build one. I have an amplifier running 2sa1943 power transisters, when listening to loud music the amp stopped. The unit still powers up and i can hear the music at line volume but not amplified. The power transisters seem to be ok from basic multimeter testing and im not sure what i should be checking next. I have attached a photo of the amp. I would appreciate any ideas. Thanks
Attachments
Both channel of power amp stopped?
Possible power fault, but most probably DC Protector fault. Whatever operates that relay in the lower left corner there is either working or not. If the DC detector is working, there's a problem with the amp. If the DC detector is not working then the fault is in the DC detector circuit itself.
To discover the difference, measure your speaker output. It won't be at the speaker jack. Speaker output will now be at the pins of the relay that isn't on. See if there is DC offset.
So, of there isn't DC offset, fix the DC detector or just supplant it with a kit. But, if there IS DC offset you'll need to fix the amp.
P.S.
That isn't a chip amp. The item pictured is a discrete solid state amp.
A chip amp is much easier to build or repair but not as strong unless paralleled.
Possible power fault, but most probably DC Protector fault. Whatever operates that relay in the lower left corner there is either working or not. If the DC detector is working, there's a problem with the amp. If the DC detector is not working then the fault is in the DC detector circuit itself.
To discover the difference, measure your speaker output. It won't be at the speaker jack. Speaker output will now be at the pins of the relay that isn't on. See if there is DC offset.
So, of there isn't DC offset, fix the DC detector or just supplant it with a kit. But, if there IS DC offset you'll need to fix the amp.
P.S.
That isn't a chip amp. The item pictured is a discrete solid state amp.
A chip amp is much easier to build or repair but not as strong unless paralleled.
Last edited:
Hi, thanks so much for your response. Yes both channels stopped at same time. I remember that relay still clicking on and of as normal but i certainly value your ideas and they have given me a new direction to head in. Ill continue trying to find the fault and post my findings tomorrow. Again thanks and i look forward to being part of this community in the future 🙂
- Status
- Not open for further replies.