M700s when not in use

I had a question about my M700 amps. I’ve noticed when you plug them in and turn the power switch on in the back that I hear something, a relay?, click after a few seconds. I have both amps plugged into an Adcom ACE-515 power filter. If I use that, when it’s switched off all power going to the amps is removed. When I turn the filter on, I will hear the relay click in both amps after a short period of time. My question is, is there some circuit within the M700s that benefits from having power at all times to reduce warm up time? My Mark Levinson No. 28 preamp is like that. It’s always partially powered so I plug that into the unswitched outlet on the filter. Just curious. It’s only slightly easier to switch the system off with the ACE-515. I could easily leave that on at all times if there was some sonic benefit. If there is, it’s nothing I’ve been able to hear yet.

Thanks in advance,


Yup. It is a relay that protects the outputs from the turn on thump. It is perfectly normal and expected.

Thanks Paul but what I’m really asking is, is there a sonic benefit to leaving power supplied to the amps, but not switched on, at all times? It’s quick and easy to throw one switch on the ACE-515 to power the system down. The exception is the No. 28 preamp which is plugged into an unswitched outlet. Levinson tells you in the manual to leave it powered on like that at all times to reduce warm up time. It’s in a sort of sleep mode keeping some components, but not all, powered. Turning the volume knob brings it out of sleep mode. I was wondering if the M700s were similar in that regard or not.

By the way, thanks for a great product. I’m happier with them daily.

They are meant to be left powered on at the back for reasons I imagine are similar to the Levinsons. Put them in standby (front panel logo button) when not in use. So using an unswitched outlet would be a good idea,

Indeed. They are meant to be left on and happiest when they are.