[goingsolo]

I was told the correct way to turn off audio equipments is turning off the amps first and then the preamp.
But if I were keep the amps on 24/7, it is safe to just turn off the preamp especially a tube preamp?

Thanks for your recommendations.

[Pars]

I used to do this when I had a Counterpoint tube pre, but it had a manual mute switch. Turn vloume all the way down, mute it , then turn it off worked fine. I do the same thing now with my SS pre, but its mute works well.

In general though, you are correct in the turn on/turn off order.

[BobC]

I leave my amps on all the time and switch the pre on/off.  Always with the music stopped.  No issues, so far.

[TJHUB]

I leave my amps on all the time and switch the pre on/off.  Always with the music stopped.  No issues, so far.

Same for me.  If the music is stopped or if I shut my DAC off first, my Rogue Audio Perseus doesn't even cause a little snap when powering down.  If my DAC is on and no music is playing, I get a very soft snap. 

[Mitsuman]

For 35+ years, always turn the power amp on first, then preamp, then sources. Turn off in reverse order. 

[mark funk]

Thats not right. Always turn the amp off first and the amp on last




                                                                                       

[Mitsuman]

Thats not right. Always turn the amp off first and the amp on last




                                                                                       

I guess that's why all of my 30+ year old power amps still function like new.    To think I've been doing it wrong for over 30 years. 

[stereo5]

I am using a tube preamp with my Stratos amp.  I leave the amp on all the time and turn off the preamp when I am done listening for the day.  I mute the pre, then turn it off.  No issues, ever.

[goingsolo]

Thanks for sharing your experience.
I am a newbie and just started to moving toward a separate-components system.  I always turn off my equipments before going to bed.
But according to Klaus, Odyssey amps should be left on 24/7.  I was trying to find out how most Odyssey owners turn off their preamp without shutting down the amps.
I like the preamp with mute function mentioned by Pars.  Would muting the preamp prevent any signal going to the amps or there is still a chance something could damage the speakers?
Do most preamp have this mute switch?   

[jimdgoulding]

I am using a tube preamp with my Stratos amp.  I leave the amp on all the time and turn off the preamp when I am done listening for the day.  I mute the pre, then turn it off.  No issues, ever.

That's what I do, too, with no issues.

[James Romeyn]

Every owner manual and common sense prohibits such action, likely tubes more dangerous than SS.  In the words of James Bongiorno, even if the preamp has a circuit to eliminate thumps on power up/down, "Why tempt fate?"  You risk blowing the amp and driver voice coil(s) for minimal gain (IOW, high risk to reward ratio). 

You'd have to remember to insure the amp is off whenever powering the preamp up/down, easily forgotten when you power up the preamp while the amp is still on.  Plus a lot of unnecessary wear on the power amp switch and its PS.   

I powered up a processor in front of a receiver, then before it stabilized I powered up the receiver, followed by a white flash of light from the receiver power supply signifying "DRT" like we used to say in the firehouse (dead right there).   

No amp maker including Klaus and no speaker maker warrants a blown amp or speakers used in such fashion.  It's flat wrong from every imaginable angle.

Risk is much lower with the preamp muted IF the mute shorts the outputs, but I'd still not risk it.  Turning down the volume is pretty useless because it's usually up closer to the input/not the output.  You're concerned with the output.   

Ask anyone who recommends it to confirm if the owner manual prohibits it. Why would amp and speaker makers prohibit something safe? 

Sole/exclusive power up/down procedure: Up: start from the source, in sequence with amps last, wait for each component to stabilize before proceeding to the next component (take my advice, I don't).  Down: reverse of above. 

Don't tempt fate.     

[James Romeyn]

For 35+ years, always turn the power amp on first, then preamp, then sources. Turn off in reverse order. 

I respectfully suggest you might want to peruse the owner manual and reverse this procedure. 

[Mitsuman]

Thank you to all for your concern.

[Afterimage]

Goodness, I have a Cary SA 200.2 power amp and a Cary SLP 03 preamp.  I leave the power amp on 24/7 and turn the pre on and off all the time.  No issues, but I guess I am gambling here.

[Wayner]

Thats not right. Always turn the amp off first and the amp on last




                                                                                       

This is a good practice. It allows the preamp to stabilize before initialing the amp. If the preamp starts to go into some kind of failure mode, the amp will not be on to reproduce it.

As far as leaving amps or preamps on all the time, there simply isn't a good reason to do it and lots of good reasons not to do it, like shortening component life.

Wayner

[kalel]

First of all, I am not an expert. 

Many moons ago, I had an Adcom ACE-515 Power Enhancer.  Everything was plugged into it.  When turning it on, it would sequentially turn each piece of equipment on.  It started by turning on the
source (analog/CD), then the preamp, and then to the amp.  It went in the reverse order when I turned it off.  I have made the error of not going in the proper order, on my own, and blown a speaker.

The fact that something has worked consistently does not make it correct.  Then again, it doesn't mean that one should change what is working and has been for so long.  However, I believe that there is science behind the reasoning for a particular correct sequence.

My understanding is that by turning on equipment prior to the amp being turned on prevents any aberrant signals from being magnified needlessly, which can damage your equipment.  The same goes for powering down.  Turning off sources and preamps may not be audible to us unless the amp is still on.  Why amplify the "pop", which can be damaging, when turning your equipment off?  At least, that is how is has been explained to me.

Chacun a son gout!

[avahifi]

If you are going to leave your power amplifier on all the time, you definitely need a preamp with output protection circuits.  These will provide a time delay to allow the internal preamp circuits to stabilize and come up to full working voltage before it's outputs are connected to the amplifier input circuits.

At turn off, the preamp output protect circuit instantly disconnects the preamp output from the power amp, so that any preamp off pulses or DC drift does not get to the speakers.

The need for this is because amplifiers are really stupid.  They will amplify anything that reaches their inputs.  A preamp, especially a vacuum tube preamp, may generate speaker and or amplifier damaging transient pulses if turned on or off into an energized power amplifier.

All new AVA equipment built within the last ten years has output on and off protection circuits standard, as do our DACs.

Caution is the word to keep your system alive.

Regards,

Frank Van Alstine

[AlexG]

A properly designed vacuum tube preamp should have a protection circuit providing a time delay to the outputs. This protection circuit will work both when you turn the unit on or off.

In general, vacuum tube preamps generate some DC voltage at the outputs before they fully stabilize - not good for amplifiers and speakers. It also a good idea to turn the volume down all the way before turning the preamp off, if you decide not to turn off your amplifier.

In the case of Odyssey and SL equipment, all vacuum tube preamps have a protection circuit built in.

It is always a good idea to use caution with your system.

Alex

[lazydays]

my amps have been shut down three times in the time that I've owned them. I have used them with four different preamps, and have never heard a pop, boom or anything similar. I don't even turn the volume down, and they just seem to work. On the otherhand I had an Adcom setup that would sound like a hand grenade going off if I didn't turn the volume down all the way. I have heard a slight bit of a boom when I turn on my phono preamp, but even then it's very slight.
gary

[soundbitten1]

I am using a tube preamp with my Stratos amp.  I leave the amp on all the time and turn off the preamp when I am done listening for the day.  I mute the pre, then turn it off.  No issues, ever.

ditto