Levinson 432/436 turn on 'pop'

Hello,

I purchased a few Levinson 432 stereo and 436 mono amplifiers. All of them seem to have the same 'pop' when I switch the amps on/off. It's especially bad when turning the amps on, my woofers extend outward fully for a few seconds, I'm worried it could be damaging my speakers so I just keep the amps on all the time for now.

Does anyone know if this is normal for Levinson amps or what the issue could be? I wouldn't think all 6 amps would have the same problem. Maybe some issue elsewhere in my system could cause this? I'm also using a PS Audio Premiere power conditioner.

I really don't want to lug all six 100+ lbs amps to the repair shop...

Thanks,
Chris