Powering on/off amps with preamp trigger

Obey the golden rule

"Amps on last and off first"

Thank you oneobgyn. Can you please explain what the reasoning behind the golden rule is?

The reason that folks like to power on and off as you have mentioned is that a a pre-amp can do some nasty stuff during warm up if it doesn't have a mute circuit and you can also experience rude noises from the preamp when its shut down. Some amps and speakers have no problem dealing with these noises, you just hear some pop's or noise, however some amps do have problems and their problems can be conveyed to and be damaging to speakers. DC offset comes to mind for some reason.

If you have a good mute circuit in your pre-amp it shouldn't make a difference so long as the mute is engaged. If it is not an 'auto' mute circuit during warm up you want to be sure its ingaged.

Why not leave the amps on all the time (assuming they are not tube)? There are a number of threads here on Audiogon on the issue.

Thanks Newbee for your detailed response. I think I can have my classe cp-700 preamp startup either in mute or with 0 volume. Is 0 volume the same as mute? In other words will it prevent any sound or signal from being passed to the amps?

Arni, unfortunately for me, my amps idle at 550W!! so leaving them on all the time is not an option!!!!!

Tbooze, Zero volume is not mute.

I really am not familar with your pre-amp. Most pre-amps have the volume contols before the amplifing stage so the amp is always seeing the full output of the pre-amps line stage. The volume control only lowers the signal from the source coming into the pre-amp, it doesn't lower the signal from the pre-amplifiers amplifing stage.

A mute circuit typically cuts off the signal after the amplifing stage and is the best way to insure that 'no' signal passes from your pre-amp to the amp. Without a mute engaged your amp is totally exposed to warm up irregularities and shut off issues.

Hope that helps a bit.

whenever I turn off my amps I always turn volume to zero as well as mute the preamp,

When I turn on my preamp it always comes on at zero volume (ARC Ref3)

The potential for blwing a driver exists if you turn off your preamp before your amp. Good speakers will blow a resistor before the friver but the transient to the speaker can be excessive.

As been stated...
Pre on first, amps second. Amps off first, pre second. Zero volume and mute. I don't have a 12v trigger on my pre, but do on my monoblocks. I wired one amp to trigger the other amp (one less button to push), and the JC-1's have a timer delay. So, one amp powers up nice and slow, then triggers the other amp, which powers up nice and slow.

Thanks everyone. I will heed the advice and do what everyone says. Here is how I will accomplsh this using my pre which has 2 output triggers (by the way, my pre allows me to assign the triggers to my remote so I can manually turn on or off the trigger):

One solution is to use a normally open 12v relay. I can use trigger #2 to actuate the relay. I can then wire trigger #1 to this relay. So when the cp is powered up, trigger #1 will output 12v (assuming normal logic). I can then assign one of the remote function keys to toggle the relay. After the cp is turned on, I can then use trigger #2 to open the relay allowing trigger #1 to power up my amps. Before powering down the cp, I will toggle trigger #2 so that the relay is open, essentially cutting power from trigger #1 that my amps see.

What does everyone think?

Tboooe,
There may not be enough current available in the trigger circuit to close a relay that switches 120v. You should look at the specifications on available relays and check with the preamp manufacturer. I tried this once and it didn't work.

Oh yeah, before any one says it, I am an indeed too lazy to take the extra step of turning on and off my monoblocks. Yes, this is purely a matter of convenience for me.

Why did you buy monoblocks then?

One solution is to use a normally open 12v relay. I can use trigger #2 to actuate the relay. I can then wire trigger #1 to this relay. So when the cp is powered up, trigger #1 will output 12v (assuming normal logic). I can then assign one of the remote function keys to toggle the relay. After the cp is turned on, I can then use trigger #2 to open the relay allowing trigger #1 to power up my amps. Before powering down the cp, I will toggle trigger #2 so that the relay is open, essentially cutting power from trigger #1 that my amps see.

Reading that makes me glad I sold all of my seperates and went back to an integrated amp.

Have fun, :-)

John