Order to powering on/off

[rolyasm]

Hey all,
I have a friend with a HT. His setup guy told him to always turn on his receiver first(P. Elite 54tx) and then his amp (Adcom). Both are connected to a Richard Gray power box. When he turns off his HT, he is supposed to turn off his Amp first, and then his Receiver. Does this matter? Both have seperate power. One is not connected into the back of the other. Anyway, thought I would ask. He wouldn't let me near it until I promised to do it in that order. One day I did it anyway, not on purpose, and nothing happened. Hmm. Puzzling. Thanks for the reply.
Roly

 

[jcPanny]

Receiver / Amp power sequence

Turning the receiver on before the amp is intended to prevent any noise or static from reaching the speakers during the first couple seconds that the receiver powers up. Most prople have their receiver connected directly to their speakers without a seperate amp without any problems when the receiver powers up. Thus, the receiver amp sequence is a good idea, but probably not necessary. Also, the power down sequence is not as critical.

 

[MDS]

The reasoning behind turning on the receiver first and then the amp is that if the amp is turned on first there is no signal for it to amplify and you sometimes get a loud thump in the speakers. Turning on the receiver first ensures that there is a signal for the amp by the time it is up and running.

Many receivers delay turn on or slowly ramp up the volume when they are first powered on (that tell-tale 'click' sound a few seconds after powering on). Some amps do as well. If you don't have a problem with feedback in the speakers when the amp is turned on first, then you don't have to follow the rule.

Edit: Typing at the same time as jcPanny.

 

[rolyasm]

Thanks. I appreciate it. I will forward this to him.
Roly

 

[markw]

Power up sequence: Source > Preamp > Power amp

Power down sequence: Power amp > Preamp > Source

As others said, this prevents any unwanted power up/down pops, thumps and whatnots from being amplified and reaching the speakers.

 

[brisrascal]

So what happens if you get a very weak thump sound both ways? I mean if I tried both the sequences during shut down and still get the thump sound. How bad is this for the speakers, wharfdales diamonds.

 

[ParadigmDawg]

It's not going to hurt anything; just annoying.

So what happens if you get a very weak thump sound both ways? I mean if I tried both the sequences during shut down and still get the thump sound. How bad is this for the speakers, wharfdales diamonds.

 

[Audioholics]

If you still get a thump it's actually the amplifier doing the thumping.

Whenever I explin this I simply ask people to remember this:

"Your amplifier AMPLIFIES stuff. You don't want it to AMPLIFY other things being turned on. So Make sure it's off until everything else is powered up. You also don't want it to AMPLIFY things being turned off, so turn it off first."

 

[calif.bob]

Outstanding information!

 

[mtrycrafts]

The reasoning behind turning on the receiver first and then the amp is that if the amp is turned on first there is no signal for it to amplify and you sometimes get a loud thump in the speakers. Turning on the receiver first ensures that there is a signal for the amp by the time it is up and running.

Many receivers delay turn on or slowly ramp up the volume when they are first powered on (that tell-tale 'click' sound a few seconds after powering on). Some amps do as well. If you don't have a problem with feedback in the speakers when the amp is turned on first, then you don't have to follow the rule.

Edit: Typing at the same time as jcPanny.

I need to disagree with this premise.
Even some stand alone amps have a delay in them before the output stage is switched on. This is so you don't get the thump from the caps receiving the inrush current causing a spike output, not that there is no signal to amplify.
If an external amp is connected to the preamp out on a receiver, that preamp doesn't have a delay and could send that spike signal to an amp that has its output stage switched on already, hence, amps are off first and on last.

 

[mtrycrafts]

"Your amplifier AMPLIFIES stuff. You don't want it to AMPLIFY other things being turned on. So Make sure it's off until everything else is powered up. You also don't want it to AMPLIFY things being turned off, so turn it off first."

Precisely, thanks. With turn on, lots of stuff happens, like inrush current to the caps, etc. Big thump; good test for the sub

 

[no. 5]

Whenever I explin this I simply ask people to remember this:

"Your amplifier AMPLIFIES stuff. You don't want it to AMPLIFY other things being turned on. So Make sure it's off until everything else is powered up. You also don't want it to AMPLIFY things being turned off, so turn it off first."

That's what has always been said on the pro sound crews I have worked with (well, not those exact words...), it is several thousand watts different, but it's the same principal.