Tube amp warm up/ cool down

I usually give my tube amps about 4 to 5 minutes to warm up. This could be wrong, but when I was a kid 50 years ago I as told not to let them warm up for an extended period of time, nor to leave them on during a break. I'm sure there are people here with a lot more info than I have who will prove me wrong.

 

I don't usually let my 400+ warm up for any real appreciable amount of time, and I don't do any standby/cooldown time. Usually I turn it on and go about my business of grabbing my bass, etc. then plug n' play...no more than 3 minutes, I guess.

If it's been cold out and my amp has been transported in the cold, I do let the amp spend some time warming to room temperature before turning it on, and I may let it standby for a few extra minutes...the same thing I do with my solid state amp too.

 

Let it sit in standby long enough for the tubes to conduct current and then flick it on. 30s is plenty for most amps.

You don't need to put it back into standby before you shut it off. Just hitting the main power switch is fine

You're better off not leaving an amp in standby for long periods of time.

I'm not even sure standby is all that necessary. Our amp (hifi) doesn't have a standby switch at all.

 

I give mine 3-5 minutes at start up and shut down.

TD

 

Good evening to all: Here's a statement which I've heard from time to time over the past 35 years, and, with no disrespect intended to the writer, I'd like to know, if this is correct, why is it "so", and what's the purpose of the "standby" switch on my M/B 400+

Can anyone explain this for me? Seriously, I've been wondering about this for years...

all my best to all concerned...

RC a/k/a "notrt"

...everything is, but some things are more than others...

 

FWIW:

asked the same question before and got similar response. I just go by manufacturer recs assuming they know their amps. For my Thd it's 5 minutes warm/cool down. The explanation for the cool down was in part to prevent arcing from just switching off. To me cool down made sense from a reverse prespective of warm up, a more gradual decline but there seems to be more concensus that the extending period for cool down is not necessary.

Sometimes emails aren't a great way to communicate with manufacturers cuase you can't clarify misunderstanding but an email from Thd stated they were no issues with leaving it in standby for 30 or 45 minutes. What I was really asking was if it was better to leave it in standby for that period rather than shut it off.

Maybe I'm goofy, but seems to me the tone changes noticeably in the THD post warm up to somewhere around 20 minutes of play.

 

I usually let my Mesa 400+ warm up to room temperature turned off, after hauling it inside (it's Winter here in Ohio!), then after it is room temperature, turn it on standbye for 5-10 minutes before I power it up. I usually put it on standby for breaks, and then on standy at the end of the night for 10 minutes or so (usually the amount of time it takes me to put my basses away, roll up cords, and put my pedalboard away), before completely shutting off the power.

 

I usually leave my 400+ on a minute or 2 before playing. There is no need for cooldown whatsoever, just shut the thing off.

 

There is usually a noticeable difference in sound (usually an improvement) within the first 30 mins of playing, once the tubes get nice and hot they tend to sound better...

 

I give mine 20 - 30 seconds no matter what temperature it is...never had any problems. Once the plate voltage is up, that's about it, correct Mark?

 

My amp tech suggested that with the amount of power going through my amp i should give it about 5 minutes to heat up, but not to worry about a cool down

He said once finished playing, just turn it to standby, and when it goes from the green light to the red, hit a few notes and when thiers silence turn it off (basically getting rid of the power thats in the caps i think)

Heat up is important, cool down isnt

 

FWIW
The Ampeg V4BH manual has the following information:

" STANDBY: The Standby mode allows the tubes to warm up or remain warm without high voltage being applied to them. This extends tube life. This switch should be OFF when first turning the amplifier on. Allow the unit to warm up for 20 seconds before switching to the on position. During short periods of non-use, the amp should be put into Standby mode."

All it says about power is the following:

"POWER: This supplies AC power to the unit. Turn this switch on before turning on the Standy switch, as explained above."

No mention of a shut down sequence or duration so...

Warm up in Standby for 20 seconds and engage, when you're done turn it off.

Putting the unit into Standby before is not mentioned but I usually wait for the status light to turn from green to red, signal and energy storage discharges and signal input and speaker cables being disconnected makes no noise. If Standby mode reduces the high voltage it seems to make sense that the gradual heat reduction could be easier on tube life as well.

 

Are you saying you switch to standby then after the discharge of stored energy you unplug the instrument and speaker cables?!

 

i was told by a very reputable bass player in a local punk band that if you dont let your amp warm up for at least 45-60 minutes your'e in SERIOUS damage of causing an unbalanced load and risking blowing your speakers and cliping the tubes. im pretty sure he knows what he's talking about so i've always followed his advice. just kidding.

 

Thats only for the pre gig food . . . if you dont have access to a cooker

 

Only problem I have with this is..... if I don't switch it back to standby before I shut it *off*, then it's not gonna be in standby the next time I switch it *on*.....

Even if it's completely unnecessary to switch to standby before powering down (which it may well be), it sets me up for the "next use"......

 

Trace Elliot owners manual advises a minimum of 1 minute warm up (power on, standby on) and cool down. They also recommend using standby during 'breaks'. I choose to follow the advice rather than having to retube any more often than necessary.

 

Exactly!
If one were to leave a note or chord ringing and switch to standby you can hear the power die off, so I wait those few seconds for the standby, already set up for the next power up, to turn red. Then I start unplugging cables, just me probably but that's who it works for.

 

Taking a tangent, never done it but was wondering if there is any potential damage to the amp in plugging/unplugging into the input jack with the amp on standby.

I have occassion to do it periodically so it's of interest?