general amp voltage question?

safeshow

Member
2019-12-22 2:17 pm
I am working on a c-300 chiro audio amp, I noticed one of the channels made a really loud strange noise from the speaker (like a cap discharging),, I turned it off asap, I put a meter on the rail voltage on the output pcb + an - ,,,, Im pretty sure I was missing the - voltage,,, I pushed on the pcb an it came back, dont know for sure if my meter connection was bad or what,,,, just wondering what would be the effect if I was missing a - rail voltage to the outputs (in general)
 
I am working on a c-300 chiro audio amp, I noticed one of the channels made a really loud strange noise from the speaker (like a cap discharging),, I turned it off asap, I put a meter on the rail voltage on the output pcb + an - ,,,, Im pretty sure I was missing the - voltage,,, I pushed on the pcb an it came back, dont know for sure if my meter connection was bad or what,,,, just wondering what would be the effect if I was missing a - rail voltage to the outputs (in general)

Disconnect all inputs and speakers ... put your meter on the speaker connectors and take a reading ... I'm betting you will find a very large DC voltage on one of them. From you're description you've blown an output transistor.
 

oiphy

Member
2011-09-01 10:08 pm
norway
I am working on a c-300 chiro audio amp, I noticed one of the channels made a really loud strange noise from the speaker (like a cap discharging),, I turned it off asap, I put a meter on the rail voltage on the output pcb + an - ,,,, Im pretty sure I was missing the - voltage,,, I pushed on the pcb an it came back, dont know for sure if my meter connection was bad or what,,,, just wondering what would be the effect if I was to the outputs (in general)

missing a - rail voltage will prolly give you a big fat + dc out