dalmaproductions
Well-known member
Hi! Recently one channel of a API312 preamp is having trouble. When the input is something very loud, it eventually just drops out, about 20dB in volume. And stays that way for a while. The preamp has 2 channels, and this is the strange thing I measure:
I put a 0.05V signal, sine wave, into both channels. But right after the xlr in, I'm getting only 0.02V on the broken channel, and the correct 0.05V on the good channel. The Xlr's are fine.
The only thing that changes this, is the pad switch. With the pad switched ON, the signal voltage goes back to normal, same on both channels: 0.05V. The pad is AFTER where I'm taking the measurements (XLR IN pins2 and 3).
Could this switch be dying? How could it affect the signal that comes before it in the signal chain?
I put a 0.05V signal, sine wave, into both channels. But right after the xlr in, I'm getting only 0.02V on the broken channel, and the correct 0.05V on the good channel. The Xlr's are fine.
The only thing that changes this, is the pad switch. With the pad switched ON, the signal voltage goes back to normal, same on both channels: 0.05V. The pad is AFTER where I'm taking the measurements (XLR IN pins2 and 3).
Could this switch be dying? How could it affect the signal that comes before it in the signal chain?
