order of turning on/off pre, power, etc

[pyonc]

Hi, friends,

I currently listen to 4343 in a biamp mode.
What bothers me, though, is that I hear a thumping sound when I turn on or off Crown DC300A, which I use for the bass. Is this thumping sound inevitable, and doing any harm to the speakers? Your idea or suggestion would be welcome.
And The way I do in terms of the order of turning or or off the system:
Turning on I go XOVER (JBL M552), preamp, amp, amp,
Off I reverse the process. Is this the right way to turn on and off?

Another question is whether it's wise to keep the switch of this XOVER, preamp, and the two amp on all the time, rather than turn on and off every time you want to listen to the speakers, which is the way I do now. Any good suggestions?
Thanks a lot for your kind suggestions and advice in advance.

[grumpy]

A crown expert will have to comment on the thump.
You have the order right, where it matters: amps on
last and off first (so they don't amplify any line level
switching transients or DC-like pre or post operational
signals that might linger).

I'd suggest turning off equipment between listening
sessions, certainly overnight. If worried about changes
in sound character, turn them on 15min (plenty for
most gear) to an hour ahead (or don't be immediately
critical). ... my personal take on it anyway.

[pyonc]

A crown expert will have to comment on the thump.
You have the order right, where it matters: amps on
last and off first (so they don't amplify any line level
switching transients or DC-like pre or post operational
signals that might linger).

I'd suggest turning off equipment between listening
sessions, certainly overnight. If worried about changes
in sound character, turn them on 15min (plenty for
most gear) to an hour ahead (or don't be immediately
critical). ... my personal take on it anyway.

Thanks, grumpy. I'm relieved the order is right.
By the way, when you don't listen to music, you suggest turning off the equipment, right? That's what I do.
Actually all the power cords of the equipment' stay hooked into the multi-outlet power strips that're ON anyway.

[opimax]

Thanks, grumpy. I'm relieved the order is right.
By the way, when you don't listen to music, you suggest turning off the equipment, right? That's what I do.
Actually all the power cords of the equipment' stay hooked into the multi-outlet power strips that're ON anyway.

I leave my amps on 24x7, turn off/on my receiver head unit when I use it or not. My 1986 Perreaux pro amps have an unbelievable thump when ever they go off, both of these model do this so I assume normal for them. I also have heard that a lot of "wear" is caused by cycles of heat and then cooling and therefor last alot longer. After having 1 of these reapired I would rather pay for electricity then go through that hassle again.

Chang has borrowed my home ver perreaux amp I just received and we were discussing this last night. I have not turned off the one he borrowed so i don'tr know if it pops as the pro versions do. this came up because I asked him not to use the onboard switch which is suspect in all these big old amps i have and use the surge protector switch when possible

Also these old big amps store so much juice ,they just keep playing after power has turned off

Mark

[grumpy]

Hi Mark,

yes, but those older Perreaux amps are -known- to do that (previously owned a PMF2150B ...
Perreaux sent me a new switch to replace a blown one... and a PMF 3150)...
my lights used to dim briefly when I'd turn one on. It was a design decision (almost no
protective circuits in the attempt to keep the audio path simpler and perhaps "better"),
and a bit of a special case.

If the receiver doesn't pop, then that joyfully works for your case :) (I -knew- there would
be a 24/7 proponent in the crowd).

(... and still have a 5000B around somewhere :))

[opimax]

Hi Mark,

yes, but those older Perreaux amps are -known- to do that (previously owned a PMF2150B ...
Perreaux sent me a new switch to replace a blown one... and a PMF 3150)...
my lights used to dim briefly when I'd turn one on. It was a design decision (almost no
protective circuits in the attempt to keep the audio path simpler and perhaps "better"),
and a bit of a special case.

If the receiver doesn't pop, then that joyfully works for your case :) (I -knew- there would
be a 24/7 proponent in the crowd).

(... and still have a 5000B around somewhere :))

I just bought a 3150 , he is playing with it, I really want a 9000.....to match the 6000s, like the level controls...and to relavant I wouild leave it on 24/7 too

[Rolf]

As said in an above post, older Perreaux Power Amps do this. They have no protection circuits. Therefor it is very important to switch them on last and off first. I can recommend installing a circuit that cut of power to the speaker if DC is detected, and a"soft on" "quick off" relay. I did this at the time I owned the PMF2150B, after the amp and speakers was blown up. It cost me some $$ to get it fixed.

Today I have two Perreaux 350 Power Amps and a Perreaux SM6MK2 Pre, and switch everything on or off from the remote control, as the Power Amps are turned on/off by a 12V from the Pre to the Power. No bumps.