Precis DSP 18x18 - Loud Pop on Power Cycle

Jim-H

My first time working with a Precis switcher and whenever I switch the power off/on or the system loses power, there is a loud pop through the speakers when going off and again when turning the switcher back on.

Is this normal behavior?

Thanks,
Jim

vining

Yep. I no longer put it on with other devices that i like to power cycle to force a reboot.

ericmedley

I would put the switcher on an UPS and put a power controller on the amps. Amps are always last on -first off. For power cycles, make sure to wait until the amps are dead befor cycling the switch.

Auser

Sounds like a large DC offset on the outputs of the switcher and slow (or no) mains fail/collapsing rail detection on the amps.

Easiest to resolve by having the amps on a separate switched power channel so that they can be shut down first as previously mentioned.

There are separate issues here with the switcher and amps. In general the following options are available in order of preference:

- Choose amps with mains fail detection that shut off the outputs as soon as the mains power is cut
- Put the amps on a separate switched power channel and shut them down before the equipment feeding them
- Use a line isolation transformer at the inputs to the amp