Tube Warm-up Time

pachius · #1 03-26-2010, 01:27 PM

so you power up you amp and leave it in stand-by.
how much time is necessary for the tubes to warm up?
does it vary on how many tubes it has?

anonymous02282011 · #2 03-26-2010, 01:28 PM

not much, like 30 seconds. should be enough for any amp.

If you search you will find a few threads asking the same question.

Gearhead43 · #3 03-26-2010, 01:31 PM

I warm mine up under my armpits.

MarcusPocus · #4 03-26-2010, 01:40 PM

I have been told that when the amp is powered on, and the amp is on standby, the tubes only receive a small percentage of the total power. The tubes obviously won't start warming up totally on standby. Best practice, turn amp on in standby, take out of standby after about 30 seconds. There is no need to flip to standby when changing basses or whatever, just turn down or stomp on your tuner, if you have one. Oh, play the crap out of it. My V4 has this old ozone-y smell. When I dig into it the smell permeates through the room. That is the smell of tone.

johnk_10 · #5 03-26-2010, 01:43 PM

the the power switch supplies the filament (heater) voltage to all of the tubes. once they're warmed up (after approx 20 -30 seconds), the standby switch supplies the high tension (plate) voltage.

pachius · #6 03-26-2010, 04:55 PM

thanks a lot for the info.
I was waiting like 3 minutes for the tubes to warm up.

jimbilly · #7 03-26-2010, 05:34 PM

My tech tells me 2 minutes, maybe he figures that if he tells me 2 minutes I'll actually wait 30-60 seconds.

johnk_10 · #8 03-26-2010, 06:08 PM

Quote:

Originally Posted by jimbilly

My tech tells me 2 minutes, maybe he figures that if he tells me 2 minutes I'll actually wait 30-60 seconds.

JimmyM · #9 03-26-2010, 10:39 PM

i don't think there's an amp with tubes out there anymore that will let you play it before it's warmed up. they used to, though. got a little airline guitar amp from 62 that will. but it's a terrible tube killing thing to play too soon, so i don't.

pachius · #10 03-27-2010, 02:24 PM

Quote:

Originally Posted by JimmyM

i don't think there's an amp with tubes out there anymore that will let you play it before it's warmed up.

how does that work?
does the standby switch not work while the tubes are still warming up?

BassmanPaul · #11 03-27-2010, 03:46 PM

Back in the day when tubes were the only option, many many amps did not even have a standby switch (VOX, Selmer, Watkins etc). Hi Fi amps from that era also didn't have standby switches. Most had tube rectifiers that applied the high voltage power after the rest of the tubes had warmed up. They wouldn't supply current until they had warmed up too. The tubes in those amps lasted almost forever. Granted the tubes then were better but the number of times I had to replace an output tube were few and far between.

Paul

Tajue17 · #12 03-27-2010, 08:37 PM

nahhhh tunrn it on and do it!! by the time your fingers are warmed up that head will be warmed up..

Flipper43 · #13 04-03-2010, 12:31 PM

When my friend had an SVT, he used to plug in his bass, turn the volume down, turn on the head (not in standby), and turn the gain and master to 10 and wait a minute or so depending on the weather condition. By that time the tubes were all nice and hot and ready to go. To this day both him and I aren't sure that this was the best idea, but it seemed to work well.

tony_clifton · #14 04-03-2010, 01:00 PM

My standby switches are always on. If I flick the mains switch I'll have sound as soon as possible.
Playing my (guitar) tube amp for 6 years now and never had any tube troubles. Tubes installed are Groove Tubes (which are considered inferior compared to JJ etc.) and are often pushed to their limits (not totally cranked, but on the edge of breakup).

Nightlyraider · #15 04-03-2010, 06:14 PM

How about when you have 12 of them to warm up? I've read about blowing fuses trying to heat up a big poweramp in a hurry.

JimmyM · #16 04-03-2010, 06:35 PM

Quote:

Originally Posted by Flipper43

When my friend had an SVT, he used to plug in his bass, turn the volume down, turn on the head (not in standby), and turn the gain and master to 10 and wait a minute or so depending on the weather condition. By that time the tubes were all nice and hot and ready to go. To this day both him and I aren't sure that this was the best idea, but it seemed to work well.

really doesn't make a diference if you've got no signal going through it. but if you did, you're lucky if you didn't blow some cabs.

**B-string** · #17 04-03-2010, 09:48 PM

Don't even use the standby switch I have toys to buy

Been repairing tube equipment for over 40 years, if it has SS rectifiers.....warm those output tubes for 30 seconds to 1 minute (thinking 6550C's, slow to reach temp).

James Judson · #18 04-03-2010, 10:27 PM

A tube needs two things to work. The cathode needs to be heated and the anode needs a high voltage. The standby switch simply cuts off the high voltage making the tube inoperable. Why do you need a standby switch? It kills the amp while the cathode heater warms up. Also kills the amp while keeping the cathode warm. Two really handy reasons (no noise during warm up and no noise during break). At least one of my tube books says the heater will stablize in about 15 minutes. I leave the on switch on all night and use the stanby as needed. That way my amp is always ready to go. Just flick standby on. Any combination will not harm your amp but it will sound funny as the heaters are warming up (or cooling off, keep playing after you switch that amp off).

YMMV

JJ

Sartori · #19 04-03-2010, 10:30 PM

Quote:

Originally Posted by MarcusPocus

I have been told that when the amp is powered on, and the amp is on standby, the tubes only receive a small percentage of the total power. The tubes obviously won't start warming up totally on standby. Best practice, turn amp on in standby, take out of standby after about 30 seconds. There is no need to flip to standby when changing basses or whatever, just turn down or stomp on your tuner, if you have one. Oh, play the crap out of it. My V4 has this old ozone-y smell. When I dig into it the smell permeates through the room. That is the smell of tone.

Well, no, it's not necessary put it on standby to switch basses. I just do because it's the easiest way to mute things.

Eight_Stringer · #20 04-04-2010, 03:31 PM

FWIW, a well designed standby switch circuitry not only switches the screen voltage off (dependent on tube type ), it also reduces the plate voltage. Powering up a cold amp with standby activated saves the HT capies from inrush current and allows a gradual rise in HT voltage. Sometimes this inrush is controlled by thermistors on the primary side. Care needs to taken with that approach as the very critical to tube life bias supply needs to be hard before HT is available, as can happen if a power cord is kicked while amp is hot or playing and suddenly plugged back in again. HTH