Good possibility. Put a shorted plug in the second input jack and see what happens. And remember your ears can get really sensitive if the environment is quiet for a while. A better question is how many dB down is the crosstalk? (Test with a steady tone - near clipping at the 3.5mm output jack - from your signal generator.) Also, the budget stereo amplifier implementation might not be as good as we'd like, and it may have some inherent crosstalk.-does this happen because the "empty" channel, since it's not connected to anything is picking up all kind of crap (the "active" channel being the nearest).
How do you mean shorted? T and R together?Put a shorted plug in the second input jack and see what happens.
No. Moving the other channel controls doesn't change anything.Does the crosstalk change depending on what the other output on the B box is doing e.g. its volume setting or which channel it's switched to?
T and R and S. That connection scheme grounds all inputs so noise pickup is eliminated (assuming ground is noise-free).How do you mean shorted? T and R together?
If this is 4V DC from the amplifier then there is a problem with the amplifier. A proper bridge amplifier should not have more than a few millivolts of DC between the outputs. Please remind us of what IC is used on the amplifier board. (Also, I'm not sure what pins 2 and 3 are. I would use the terms Input / CW - clockwise, Output / Arm, and Common / CCW - counterclockwise.)I measured voltage at the pots pins and I read 4 volts between pins 2 and 3 when the pot is fully cranked.
Possibly, but the entire bridge-tied output / RJ-45 scheme needs to be ungrounded except for a shield on the cable.maybe I'm just missing some grounding in the A-Box?
I measured voltage at the pots pins and I read 4 volts
TDA7297Please remind us of what IC is used on the amplifier board.
(Also, I'm not sure what pins 2 and 3 are. I would use the terms Input / CW - clockwise, Output / Arm, and Common / CCW - counterclockwise.)
Check the amplifier with out anything connected to the outputs - although your schematic looks basically good.
Your thinking is right since that would be a balanced signal coming out of a proper aux bus, but my friend is going to use 2 headphone outputs on a cheap Zoom podcast console to send both Channels A and B to Box-A.A note on the input jacks: If you are being fed from a professional audio console the output is on tip and ring, so they should not be shorted together. Use just tip and sleeve for an unbalanced connection, with ring floating.
A note on the input jacks: If you are being fed from a professional audio console the output is on tip and ring, so they should not be shorted together.
my friend is going to use 2 headphone outputs on a cheap Zoom podcast console
Ok. So I guess I should return it asap.Hope everyone had a good Christmas!
4.3v dc between L+ and L- is definitely wrong. Assuming you've connected the power supply correctly the only reasonable explanation is that the amp module is defective.
Take the sum off the junction of the two resistors, with sleeve as common.
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