Is it OK to externally cut the power on an audio interface (and what about more amps)?

[sep]

I have a setup where I may want to have the computer going out to an audio interface with 8 outputs, and putting these outputs into amps. Since it's for an installation that needs to be easy to power on-off for the staff, it'd be ideal to be able to have one power breaker for everything except the computer.

Now I've read that some amps you need to turn the power switch off before cutting the power or your risk damaging it, though I wouldn't imagine that applies to amps with no power switch like this little one. Are there any rules of thumb for knowing what kind of amp it's OK to cut the power on externally? Just whether or not there's a power switch?

As for the interface... many 2ch amps use USB power so they'd just get powered down with the computer, but I imagine most 8ch interfaces need an external power source, like the MOTSU UltraLite mk3 Hybrid. Is it fine to cut their power externally? A problem for us with the Motu is that it needs to have its power button pressed to turn it on. Any recommendations for an interface with 6 to 8 audio outputs that can be powered on and off only via its power supply?

 

[rollmottle]

Yes. A switch is a switch.

 

[sep]

Yes. A switch is a switch.

Thanks. There are some articles about the correct way to turn off an amp, but I guess that's for guitar tube amps and not for speaker power amps?

Also, updated my post to highlight that I need an audio interface that doesn't need to have its own power button pressed. I guess if I can't find a 6-8ch one like that I could use multiple 2ch ones... though that creates complications with certain softwares.

 

[rollmottle]

Depending on your setup, the order in which you turn things on might matter...turn your amps on before your speakers (edit: which i guess in a passive speaker setup doesn't happen...turn DOWN the volume on your amps before turning them on or off) so you don't risk big pops hurting your speakers (or ears). These days, lots of modern gear has soft start so this isn't a problem. Some people have power sequencers to handle that. Powered speakers don't have this problem. I have my mastering rig on two switches that turn on and off about 15 things.

 

[sep]

Depending on your setup, the order in which you turn things on might matter...turn your amps on before your speakers (edit: which i guess in a passive speaker setup doesn't happen...turn DOWN the volume on your amps before turning them on or off) so you don't risk big pops hurting your speakers (or ears). These days, lots of modern gear has soft start so this isn't a problem. Some people have power sequencers to handle that. Powered speakers don't have this problem. I have my mastering rig on two switches that turn on and off about 15 things.

I see... I'm thinking of using the JBL Control 65P/T passive speakers, so I'll ask the sales rep about whether the not turning down the volume of the amp before turning it on can damage the speakers. The pop to the ears doesn't matter as much as the risk of damaging the speakers.

 

[Chrispy]

The 8150 amp can perform in a few different ways,, and depends on the stage before the amps to an extent. Can't imagine a left/right shift in audio below the speakers being that particularly interesting in a general use of a bar. Maybe just for experimental audio use, but that's pretty limited. I wouldn't worry about amp thump particularly doing damage so far....

 

[Speedskater]

In pro-audio analog systems, the standard turn om/off procedures are:

Turn-on = sources>>control units>>power amps
Turn-off = power amps>>control units>> sources

This is because some sources and control units can generate a loud pop at turn on/off. This happens when their + and - DC supplies ramp up or down at different rates.

 

[abdo123]

Now I've read that some amps you need to turn the power switch off before cutting the power or your risk damaging it

That's true.

 

[sep]

The 8150 amp can perform in a few different ways,, and depends on the stage before the amps to an extent. Can't imagine a left/right shift in audio below the speakers being that particularly interesting in a general use of a bar. Maybe just for experimental audio use, but that's pretty limited. I wouldn't worry about amp thump particularly doing damage so far....

The sales rep today said that with the 8150 there's no such danger