And there were no standby switches on most amps until fairly recently. When they were provided it was only a way to silence the amp and had nothing to do with "protecting" the tubes.
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Warming Up Tubes
- Thread starter trevschultz
- Start date
And there were no standby switches on most amps until fairly recently. When they were provided it was only a way to silence the amp and had nothing to do with "protecting" the tubes.
It is best to let tubes cool of before moving an amp. The temperature alone does not hurt tubes but the tubes components are much more vulnerable with dynamic movement while hot.Alex1984 said:
Huh i thought that was an issue. There sure is a lot of tube related misinformation out there!
Applying voltage to cold power tubes is a minor problem. Most bass amp power tubes have 350V to 700V plate voltage running through 'em. repeated thermal shock on the metal components will cause extra wear and shorten power tube life. At the low voltage through pre-amp tubes, this is not a concern.okcrum said:
Tubes were cheap and more sturdy back when radios and TVs had 'em. I'm not sure how much voltage was hitting those at start up.
Leaving the amp in standby with the heaters on will not help cool down the tubes.Mr. Foxen said:
For a short break between gig sets or short break while practicing/jamming/whatever, it's good practice to leave the amp in standby so that the tubes are still warm for the next set. The up and down heating and cooling cycles gradually add wear to the tubes, so it's best to minimize thermal cycles.
Per my Ampeg owners manual;
Survival Tips For Tube Amplifiers:
To prolong tube life, observe these tips and recommendations:
* After playing the amplifier, allow sufficient time to properly cool down before moving it. A properly cooled amplifier prolongs tube life due to the internal components being less susceptible to the damage caused by vibration.
* Allow the amplifier to warm up to room temperature before turning it on. The heat generated by the tube elements can crack a cold glass housing.
Survival Tips For Tube Amplifiers:
To prolong tube life, observe these tips and recommendations:
* After playing the amplifier, allow sufficient time to properly cool down before moving it. A properly cooled amplifier prolongs tube life due to the internal components being less susceptible to the damage caused by vibration.
* Allow the amplifier to warm up to room temperature before turning it on. The heat generated by the tube elements can crack a cold glass housing.
okcrum
in your chest
"Dynamic movement"? Really?
Alrighty then, this has officially become a cargo cult thread.
ok fine....dynamic forces induced by movement
Inside vacuum tubes, there are oxide coatings and welds that are very sensitive to movement while at high temperature.
Inside vacuum tubes, there are oxide coatings and welds that are very sensitive to movement while at high temperature.
When practicing or rehearsing, usually I turn the amp on (on standby) before I do anything else. Then I plug in pedals and tune my bass. When I'm done with that, the amp's been on for a minute or so, and it's ready to go.
After I'm done, I turn off the amp, and then proceed to put everything else away. Simple.
After I'm done, I turn off the amp, and then proceed to put everything else away. Simple.
Mr. Foxen
Commercial User
I mean as it is cooling. If you play through it, it distorts the same as playing through it right when you turn it on, but obviously fading out rather than coming up to full sound.
Newbie question, but just to be sure.
When the amp is warming up, the bass doesn't need to be plugged in, right?
With the rig set up at practice location I can just arrive turn on the power (still in standby) and get all the other stuff ready before plugging in, right?
Please feel free to flame if the question is too dumb xD
When the amp is warming up, the bass doesn't need to be plugged in, right?
With the rig set up at practice location I can just arrive turn on the power (still in standby) and get all the other stuff ready before plugging in, right?
Please feel free to flame if the question is too dumb xD
I don't know about the more sturdy part, but certainly cheaper.
There was very little plate voltage during warm-up in many designs. The heavy rectifier filament was the last one to heat up.
I have many tube radios from the '30s to '50s. I use one from 1947 quite often. There is nothing in it to control what tube conducts when, and every tube but one is original. They do their thing when they're warm enough to do it.
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There isnt! What intelligent tube amp engineers do is leave it to take the chill off in standby mode for about a minute (of course if the amp is full of condensation, a bit longer to dry the valve bases)
Then using bias probes in circuit, snap the standby off with a screw driver in the skeleton pot/pots at the ready, just incase a new power tube set requires a very different bias setting, or the amp has previously been fiddled with by a snugglemuffin.
You check it again after a few mins of Ted Nugent like full power amp clipping violence to see if anything drifted.
Sometimes we even use a variac to slowly reform the capacitors if we suspect the amp has not been used for a while.
If I put a new set of tubes in one of those amps full of vintage? electrolytic capacitors, I would want to
check it again after its been used for a week or two.
Those intelligent techs also say that standby switch in guitar amps is to prolong tube lifeThere isnt! What intelligent tube amp engineers do is leave it to take the chill off in standby mode for about a minute (of course if the amp is full of condensation, a bit longer to dry the valve bases)
Then using bias probes in circuit, snap the standby off with a screw driver in the skeleton pot/pots at the ready, just incase a new power tube set requires a very different bias setting, or the amp has previously been fiddled with by a snugglemuffin.
You check it again after a few mins of Ted Nugent like full power amp clipping violence to see if anything drifted.
Sometimes we even use a variac to slowly reform the capacitors if we suspect the amp has not been used for a while.
If I put a new set of tubes in one of those amps full of vintage? electrolytic capacitors, I would want to
check it again after its been used for a week or two.
Again no damage. All that happens is that the tubes conduct as long as electrons are being sent out by the cathodes. When that stops - no sound.
okcrum
in your chest
You wait with SS amps too. This is to make sure the circuit has stabilized from an ambient start. All electronic parts (including transistors) drift with temperature change. Once power flows in any circuit, it will warm itself up since any energy loss is converted to heat.
