STANDBY SWITCH - Clarification

[chamelious]

I've read many things online and am more confused than ever.

My amp has an "on" switch, and a "standby", which one of these goes on first?

 

[M1Fanatic]

When the amp is off, the standby switch should be engaged. Turn on the amp, let the tubes warm up for short while then take it out of standby.

Turning it off is the opposite. Place the amp in standby for a few minutes, and then turn of the mains.

 

[chamelious]

Is this right? I thought the whole idea of standby was to warm the tubes before turning the amp on and activating a large current across them. I also thought it made no difference when turning off.

 

[stevieb]

I have read and heard so much conflicting advice about the standby switch- from amp makers, from players, from electronics techs and engineers- that I truly wish no one had ever invented the darn thing. But here's what I believe to be the essence:

The standby switch (SS) sends SOME current to the tubes, to warm them up slowly and gently. Sort of like idling your car in the driveway for a few minutes before you drive off, so that the oil is warm and circulating.

M1F got it right- when you first approach your gear, turn on the SS before you do ANYTHING else- before you pick up your guitar, before you plug anything in, before you do anything. If you look at the tubes at this point, you will see a faint glow. Then, strap on your guitar, tune it up, etc.- go thru the ritual you always do. By the end of that, your tubes should be ready- hit the "on" switch and play. At the end of the session, turn off the "Power" switch, but LEAVE THE "STANDBY" SWITCH IN IT'S ON POSITION, while you unplug your guitar from the amp, put it in the case, etc. Turn off the SS right before you are ready to put the cover over the amp, or whatever it is you do to put it away.

If you remember only one of those procedures, make it the start-up one. Shut down is less critical.

But...

Opinions differ as to what to do DURING BREAKS. Some say turn the power "off" but leave the "Standby" switch on- that this lets the tubes loaf while they are doing nothing, but keeps them ready. Some say leave them both on- that the "hot/warm/hot" cycling of the tubes is almost as bad as "hot/cooling/hot" cycling. I tend to go with the "leave it on" camp, but I can't say it's really better, or even as good. If I am being OCD about it, I leave both switches on, and turn the volume to "0".

Some amps have a circuit that is quite different. My Fender Champ 25SE, for instance, has this procedure:
Both SS and PS off- amp cold.
Turn PS on, leave SS off- amp in standby mode (LED at switches flashes to indicate standby mode), all tubes (pre and power) show faint red glow.
Turn SS on- amp in ready mode, power tubes glow brighter orange, and show fluorsecent (and very cool-looking) blue glow at base. LED glows steady, to indicate "ready to play." Play, boys, play.Chamelious, this demonstrates that your "large (sic) current across (the tubes)" is incorrect- if there WAS a higher current across the tubes, they would glow much brighter in standby mode than they actually do.

Whereas, my vintage Fender Deluxe Reverb likes this:
Both SS and PS off- amp cold.
Turn SS on, leave PS off- amp in standby mode, all tubes (pre and power) show faint red glow.
Turn PS on- amp powered up fully and ready to play. Tubes glow brighter orange.

Like I said, I wish no one had ever thought of the standby switch, or that someone would build a circuit that did it for you- you see ONE switch. You turn it on. The amp sits in standby as long as it needs to, and when it knows it is ready, automatically switches it's self to full on. When you are done for the evening, you just turn the switch to off. The amp idles along in self-induced standby for as long as it needs to, then turns it's self all the way off.

 

[slowmotion]

At the end of the session, turn off the "Power" switch, but LEAVE THE "STANDBY" SWITCH IN IT'S ON POSITION, while you unplug your guitar from the amp, put it in the case, etc. Turn off the SS right before you are ready to put the cover over the amp, or whatever it is you do to put it away.

You seem to know a lot about amps so please clarify this for me because it makes no sense to me. Why would you not just turn them both off at once?

I understand the standby is there to warm the filaments before playing. But what's the logic behind turning the amp OFF and then standby off a bit later?

 

[M1Fanatic]

I place the amp in standby for a few minutes before turning it off. If you place the amp in standby before shutting off the mains, you don't have to remember if the amp is in standby the next time you power it up.

 

[slowmotion]

I place the amp in standby for a few minutes before turning it off. If you place the amp in standby before shutting off the mains, you don't have to remember if the amp is in standby the next time you power it up.

? Same as if you turn them both off at once.

Seems to me that the only thing you're doing if you set an amp to standby for a few minutes before turning it off is slowing the cool down process?

 

[M1Fanatic]

Yes.

I play about two hours a day at moderate to high volume levels and I still have the original VOX branded tubes in this amp after four years. I don't gig with it so that has helped their life as well.

I'd rather not thermal shock the tubes upon turning it off.

 

[slowmotion]

Yes.

I play about two hours a day at moderate to high volume levels and I still have the original VOX branded tubes in this amp after four years. I don't gig with it so that has helped their life as well.

I'd rather not thermal shock the tubes upon turning it off.

Well that's not something to be proud of. After 4 years with regular use your power tubes could definitely do with being replaced. Treat yourself.

There is no such thing as thermal shock when cooling tubes unless your amp is chock full of snow. Where did you get that information? Just don't move your amp straight away; give it a moment to cool and it'll be fine.

 

[M1Fanatic]

There hasn't been any sound degradation from the set. They sound very nice actually. I have a set in reserve for when that day comes. I thought it would be a couple of years ago, but they are doing fine.

Only a theory. Didn't read it or hear about it anywhere. I've worked as an electronics tech and heat is usually the number one enemy of electronics. I just try to treat them gentle is all. Or what I consider gentle.

 

[Lt. Bob]

Well that's not something to be proud of. After 4 years with regular use your power tubes could definitely do with being replaced. Treat yourself.

There is no such thing as thermal shock when cooling tubes unless your amp is chock full of snow. Where did you get that information? Just don't move your amp straight away; give it a moment to cool and it'll be fine.

yeah ..... you can just turn it off and it won't hurt anything as long as you don't vibrate the cooling tubes by banging the amp into something.

Personally I use the standby almost religiously but I come from the old days when amps were mysterious things and we were trained to do it that way.
Actually nowadays there are amps with no standby switch at all and I've read several articles saying they didn't do much.
In answer to the OP, flipping the standby doesn't do anything if the power is off ...... no lights ..... no warm tubes ..... nothing.
So the power switch goes on first.
Let the tubes warm up and then switch it out of standby. Reverse the process to shut it down.

 

[slowmotion]

Gentle can never be a bad thing I must admit. I am keen to hear the theory behind shutting an amp off and then turning the standby off later though.

Oh and hey, if you've got a spare set of new tubes kicking around, give them a whirl. If you can't hear a difference, put the old ones back in and keep rocking. I'm always blown away by the difference some fresh power tubes can make.

 

[chamelious]

In answer to the OP, flipping the standby doesn't do anything if the power is off ...... no lights ..... no warm tubes ..... nothing.
So the power switch goes on first.
Let the tubes warm up and then switch it out of standby. Reverse the process to shut it down.

Now im confused again. You're saying power first and not standby, surely to "switch it out of standby" i have to turn the standby switch on as well as the power?

 

[Lt. Bob]

Gentle can never be a bad thing I must admit. I am keen to hear the theory behind shutting an amp off and then turning the standby off later though.

Yeah, that's why I use them ..... safe rather than sorry.
But it's definitely standby first and then power off.
One thing that gets confusing is does on mean 'in standby' or does it mean on as in it's ready to play?
Amp makers can use that 'on' term either way as applied to the standby switch.
Sometimes they'll label it 'on' meaning that the standby switch is engaged putting it into standby. But others will label it 'on' meaning that it's not in standby and ready to play.
But being in standby means no sound even with the power on.

 

[chamelious]

Hmm, ive used a tube amp for a year and ive always had the standby switch *on* when im playing, are you saying it shouldn't be?

 

[Lt. Bob]

Hmm, ive used a tube amp for a year and ive always had the standby switch *on* when im playing, are you saying it shouldn't be?

I specifically said that manufacturers use the word 'on' either way.
If your amp makes sound when the standby switch says 'on' ...... then it is not in standby when the standby switch is 'on'. It's out of standby and in playing mode.

As I said above ..... some manufacturers label the standby switch as 'on' when it's in standby ....... others use the word "on" to mean the amp's on and ready to play ..... i.e. ..... NOT in standby.
Yeah, it can get confusing I suppose but this isn't difficult ...... regardless of how it's labeled, if it's in standby there will be no sound ....... if there is sound it's not in standby.
You want the amp in standby when you power it up and then switch it out of standby when you're ready to play. To power down you switch it to standby and then turn the power off second.

Obviously you want to use the one where the amp makes sound regardless of how the manufacturer labels it ...... well, I say that but I haven't heard you play.

 

[ZoSo58LP]

wow what a thread lol....

with my JCM2000, when i turn it on, i turn on POWER first...let it warm up, then hit standby so that the sound comes out of it. then when i turn it off, i flick standby with power still on, let it cool a bit, then flick power off. my friend did this since he got it in '03, and i've done it ever since i bought it from him in '08....hmmm

 

[dementedchord]

for the record... stand by switch lets the heater voltages get to the tube WithouT the ht or B+ voltage being applied... it's a good idea to use the standby but rarely will it kill anything... good idea to use it on breaks as well...

 

[ggunn]

I've been playing on tube amps for... OMG is it over 40 years already? Anyway, I've been flipping the power and standby switches off and on together for all that time except for breaks that might end abruptly, when I want my amp to not make any annoying noises while I'm offstage but I don't want to have to wait for it to warm up. I've noticed no ill effects from this practice and my tubes last as long as anyone's. YMMV.

 

[lpdeluxe]

I've only been playing tube amps for 36d years, and I have always religiously kept the standby switch off until the tubes warmed up, then flipped it off a few minutes before I shut off the power amp.

I ran into this exact discussion on another forum a couple of months ago -- the consensus was...

there was no consensus.

I just got a Fender Deluxe Reverb Reissue that makes a loud pop when I turn off the standby with the power switch on, so I have a new way of doing things.