I just purchased the entire PSM in ear monitor system. My first time using it, 3 songs into the gig the PSM mixer stopped working and was sent a continuous loud hissing sound to the transmitter and I could no longer use the system. I was running the individual bass, guitar, keyboard, line outs from each of the 3 amps into each channel of the PSM mixer. For the fourth channel, the sound guy unplugged the 1/4 cable from the wedge monitor and plugged it into the PSM mixer. What went wrong? In the future, under the above scenario of "guitar, bass, keyboard, vocals" how should I set up the PSM mixer?
"For the fourth channel, the sound guy unplugged the 1/4 cable from the wedge monitor and plugged it into the PSM mixer. What went wrong?"
* Impossible to tell by email, but the signal designed to drive the wedge monitor was far too strong to for the P4M mixer. This may have damaged the P4M inputs.
The P4M can handle any signal directly from a mic (mic level), from a guitar or keyboard (aux level), or from the output of a mixer (line level). The P4M cannot handle the signal level from the output of a power amplifier (speaker level).
To keep your P4M safe in the future, never connect a signal that can drive a loudspeaker!