hi everyone,
I need some expert help. Problem is that whenever I connect RCA to any device the buzzing, noise starts coming from speakers. There is less noise when only one input is attached. If there is no connection, it almost does not exist.
I disconnected the input ground and negative path with a 10 ohm resistor. But there was no change. TL082 replacement to OPA2134; no changing.
What solution do you think I should find?
Thank you in advance for your help
I need some expert help. Problem is that whenever I connect RCA to any device the buzzing, noise starts coming from speakers. There is less noise when only one input is attached. If there is no connection, it almost does not exist.
I disconnected the input ground and negative path with a 10 ohm resistor. But there was no change. TL082 replacement to OPA2134; no changing.
What solution do you think I should find?
Thank you in advance for your help
Attachments
You probably have multiple problems here.
1. With both input channels connected, the input cable + source complete e ground loop. Trace the signal ground of one channel through the central star ground to the other channel, back out and to the source and back, and you should see it. This ground loop is picking up magnetic fields from the mains transformer.
This problem is not new and has e.g. been sighted in the Quad 405 as well. Power amps with the input jacks spaced far apart are very susceptible to it.
FIX: Relocate one input jack so that both are right next to each other, and route input audio cables such that loop area is minimized. E.g. both in parallel to the input of the nearest channel, then the remaining one over the big capacitor ground over to the other side.
2. The noise with one channel connection might be an external ground loop. Please show your input RCA jacks (especially whether they are insulated) and the mains wiring (especially PE hookup).
1. With both input channels connected, the input cable + source complete e ground loop. Trace the signal ground of one channel through the central star ground to the other channel, back out and to the source and back, and you should see it. This ground loop is picking up magnetic fields from the mains transformer.
This problem is not new and has e.g. been sighted in the Quad 405 as well. Power amps with the input jacks spaced far apart are very susceptible to it.
FIX: Relocate one input jack so that both are right next to each other, and route input audio cables such that loop area is minimized. E.g. both in parallel to the input of the nearest channel, then the remaining one over the big capacitor ground over to the other side.
2. The noise with one channel connection might be an external ground loop. Please show your input RCA jacks (especially whether they are insulated) and the mains wiring (especially PE hookup).
I shortened the signal line and only got gnd from a single pcb and i brought it closer the rca sockets. The noise is less now, but there is some hum sound.better than before.