In which order do you turn on/off your equipment?

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In which order do you turn on/off your equipment?

Post by admin »

I was wondering if people had a certain order in which they turn on and off their stereo equipment. I worry that there may be small current/voltage spikes as my equipment powers off an on and I don't want to damage anything.

I have been turning my components on from speaker to source, and in reverse when turning them on. In other words, I turn on the amp, preamp, DAC, and then the CD transport. When time to go off, I go in the opposite direction with my amplifier the last to be turned off.

Does anybody have any words of wisdom on this, or it simply does not matter?
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Re: In which order do you turn on/off your equipment?

Post by jeffreybehr »

It does indeed matter, for the worse, if you have a preamp with a turn-on pulse and your poweramps are already on...as in...POP! goes a speaker!

Starting with everything turned off, I turn on the preamp--which starts its maybe-one-minute-warm-up-before-the-output-shorting-relay opens--and then walk about the front wall turning on powerconditioners for the V-steen woofers and main poweramps (which turns on one of the '750s because it has a bad--permanently on--powerswitch) and then switching on the other '750 and also the 'HT5 poweramps. Then the Crown SuperSubs poweramp.

Turning off the sytem goes in reverse--all the poweramps off first and then the preamp--in case it has a turn-off surge. I leave the Oppo '95 on all the time.

BTW the MET1 preamp does NOT have turn-on or turn-off surges or pops, but this is the process I learned decades ago when I had less-sophisticated preamps.

-----------------------------------------

More based on Admin's comment about his c-j poweramp's turn-on delay: 5 of my poweramps--2 McC '750s, a McC 'HT5, and 2 V-steen 5A woofer amps--are connected and are conducting 'instantly' on turn-on. The Crown has a few-seconds delay, and for all I know, it won't start conducting if there's a pulse on its inputs.
Last edited by jeffreybehr on Thu Jan 10, 2013 3:00 pm, edited 1 time in total.
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Re: In which order do you turn on/off your equipment?

Post by Ray »

I've typically always turned power amps on last, and off first, to as already mentioned eliminate the possibility of a device upstream of a power amp, causing a turn-on THUMP.
If all of the gear in a given setup is well-behaved with power-up and power-down transients, then obviously it may not make any difference.

I have owned in the past a very "minimalist" preamp that had no muting. If it was powered on, or off, with power amps on, there was a very good chance of a massive THUMP hitting the speakers. I still typically do the Amps on last, off First just out of habit.
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Re: In which order do you turn on/off your equipment?

Post by admin »

Interesting to hear. It seems like everybody is doing the opposite of my procedure. I should note that I don't have to worry about any "thump" hitting the speakers as my CJ Evolution 2000 amp has a delayed activation (allowing time for the tubes to warm) so buy the time it kicks on, my other equipment is already on (and also warming up). I have never heard a "thump" signal to the speakers in my system. I think the the prevailing consensus is to power up from source to amp and vice versa for the power down. I think I will adopt this new method. Thanks for all the input and help guys!
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Re: In which order do you turn on/off your equipment?

Post by Ray »

funny story, or maybe not so funny...but on the ET5, if AC power was removed for a minute or so, and then re-applied. The first preamp turn-on, would on occasion THUMP. I noticed this only once or twice, it usually would occur if I'd removed AC power to swap a tube, then re-apply AC power to the preamp and then power up...having forgotten to power down the power amps! Whoops! I remember calling Ed at the time telling him that all muting circuits need to absolutely be 100% fool proof all of the time and that at least on the ET-5 there was a way to make the muting circuit fail. Looking back, as I should have expected, he informed me of the proper turn-on, turn-off sequencing. The discussion went no where beyond that.

After that I was more careful, and actually stopped remo0ving A.C. Power to the preamp when changing tubes...and continued with power amps on-last, off-first.
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Re: In which order do you turn on/off your equipment?

Post by aldinohiend »

Ignition sequence:
cd --> pre --> amp

Shutdown sequence:
amp --> pre --> cd
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Re: In which order do you turn on/off your equipment?

Post by Bluesbob »

aldinohiend wrote:Ignition sequence:
cd --> pre --> amp

Shutdown sequence:
amp --> pre --> cd
Same here, although I usually leave the CD on. But no matter what, the amp is the last on, first off. I'm old, and I remember the days of turn-on transients.
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Re: In which order do you turn on/off your equipment?

Post by Ray »

If you have absolute bullet-proof muting in each piece of gear, then in the end it probably doesn't make any difference.
...but, I've seen (and own now by the way) gear that has muting, which doesn't mute 100% reliably.

...thus power amps on last, off first is safe way to go.

I had a home-made preamp back in the day, (Tube) one of the biggest struggles was getting a muting circuit that could not be fooled from time to time.
In the end I got it done, such that no matter what would happen with quick power on/off, power glitches and power going off and right back on, no thumps ever!
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Re: In which order do you turn on/off your equipment?

Post by Ian Millar »

The following is my opinion only:

...

And if you happen to be unlucky enough to own a C-J mono power amp pair such as Premier Eight monstrosities, don't turn one off before the other, else "other" may blow its polystyrene feedback cap which is rated just at the 500V voltage it sees with no margin whatsoever even for mains voltage fluctuations. The slightest transient may cause it to explode.

I turn all off together* and of course turn on in signal path order. You can buy power sequencers or build them from kits. This is basic and fundamental.

Solid state C-J amplifiers have no loss of AC detection to release the speakers, no speaker protection (apart from fuses), no ground loop breakers, no soft starters which they need badly and very little of anything else in the "safety department". My MF2500 for example needs an external soft starter. My Premier Eights have extremely dangerous ground lift tabs at the rear which if lifted render the amplifiers potential death traps.

I am not at all impressed with C-J gear any more. It is highly priced and poorly engineered junk in fancy casework in my opinion.

For example I see very little point in mounting expensive and marginally-rated bulk metal foil plate resistors directly alongside a valve and then boxing them in without so much as raising them off the PCB for cooling. The use of such components gains a marketing advantage to the very great detriment of the owner who must deal with it soon after the warranty expires.

Any DIYer worth his salt can build better amplifiers than those of C-J at a small fraction of the cost. I have done so as a rank amateur and my amps have all the features listed above and were built at less than a 10th of C-J prices and I would challenge anyone to double blind comparisons to prove it.

Actually mine would fail double blind because of the loss of AC detection which shorts the speaker wires to prevent turn-off thumps which all CJ power amps (even tube) so graciously provide. Connect a C-J amp to a tweeter in an active system at your peril!


*edit. I need to clarify about the "loss of AC" detection. It is a simple circuit built ino a speaker protection module of some good power amps to control speaker muting relays which disconnect output of the amp from the speakers terminals (and places a short across the terminals) upon detection of DC (amplifier fault) or excessive low unwanted frequency, or loss of one or two AC cycles at the mains. In my own DIY system, power can be removed from the whole system at one switch and the speakers will not receive any turn-off thump from the power amp or anything else up front. C-J and other so-called high-end amplifiers don't bother AFAIK with any speaker protection other than fast blow rail fuses and in my own C-J system the power amps must be turned off first (and they will thump the speakers because they are unsophistcated). Then the line level components can be turned off together at their own switch. No doubt some might argue that a relay is an unwanted component in the audio path, but this would of course be nonsense since the contact resistance of a good high-current hermetically sealed relay is negligible - like that of banana plugs, spade lugs or Neutrik Speakon connections and can be ignored.
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Re: In which order do you turn on/off your equipment?

Post by Good Dog Jocko »

I generally turn on my equipment before I start drinking. I generally turn off my gear after I have finished drinking. If I have been drinking a lot, I sometimes turn off my gear the next morning.

My old Vandersteen speakers have rattling woofers where I drank too much Scotch and fell asleep in front of them with the music blasting all night on repeat at a high volume. I have since switched to VMPS speakers with dual woofers and more voice coil heat sinking area and higher efficiency, and so far my turnoff protocol has suffered no further problems.
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