One of the distinct characteristics of tube amplifiers is that they get better when the tubes are warmer.
When the tubes are warmer, tube amps tend to sound better. They introduce saturation which makes tones deeper and adds a little compression to the overall tone. Tube amp tones also deliver sweet overdriven sounds you can’t quickly get with a solid-state amplifier.
While tube modeling has become a thing now for many guitar players, nothing beats the warmth of a real tube amp. Sure, tube modeling negates the need to warm up the amp, and they are easier to transport, but tube amps are still the real deal, given the sound quality you can get from them.
Make no mistake; while there are good tube amp modelers in the market, both in hardware and VST format, a tube amp is a good choice, as there’s not much of a learning curve. But there is still that disadvantage of dealing with warming up the tubes.
Should you think that tube amps are still the way to go, consider the need to warm up when you use one.
How Long Should Preamp Tubes Warm Up?
Warming up tube amps can take 15 – 30 minutes, depending on the manufacturer of the amp and the tubes used. Before this time, your amp will produce sound, although it may or may not have the best sound it can make. You may play or keep the amp on standby to warm up.
Warming up is an essential thing to do when using a tube amp. It allows you to get the best tones from your amp, enabling you to take advantage of tube saturation in your tone.
What is tube saturation?
Tube saturation refers to the abundance of a signal that gives your tone more body and a little compression. Saturation happens when your tubes receive more than enough signal, which can add a slight overdrive to overtones. You may also experience some warmth in the signal, making it more natural.
Sometimes, the saturation also provides for sweeter overdrive tones when your amp reaches the breakup point. It’s this kind of tone that many effects processors try to emulate.
How long does it take for a tube amp to produce sound?
Unlike a solid-state amp that produces sound the moment you turn it on, a tube amp takes a few seconds before it makes any sound. This is usually attributed to the load on the tubes, which play a role in the overall sound of an amp. Once sound starts coming through, your tubes are also warming up.
When a tube amp is turned on, it begins warming up the tubes. You can play your guitar when the sound comes out, which would be an excellent time to get warmed up for your gig.
Why should you warm up your tubes?
Not allowing your tubes to warm up properly can make your guitar sound more restricted and may give you a tone you’ve tweaked during rehearsals. You’d want to get a consistent sound out of your instruments so that you can sound your best during a gig or recording.
Warming the tubes in your amp is all about getting good tones from your instrument and the amp, so you must allot time for your amp’s tubes to warm up. While warming up the tubes may take half an hour, allocating such a period can help capture your best performance.
Sure, it may take some time, and your amp may already be making sound, but it’s still not at its best. Waiting periods depend per amp, but perhaps you can use that time to warm up your fingers for a gig or recording.
Do power amp tubes need to warm up?
Power amp tubes also need to warm up like your preamp tubes. The good news is that they warm up with your preamp, so there’s no special process. Power amp tubes also add that warmth to your overall sound before it hits the speaker section and is responsible for power amp distortion.
But before you warm up those tubes, ensure that the tubes you use are matched; otherwise, the excess power driven can ruin your amp. And in the case of underpowered tubes, you might not be able to warm up the tubes properly, resulting in poor tone.
How do you warm up tube amps?
Warming up your amp is as easy as turning it on, switching it to standby mode, and letting the tubes warm up without making any noise. Many tube amps in the market have standby switches that allow you to disconnect the speaker output so that it doesn’t make any noise.
The time it takes to warm up tubes depends on each amp and tube, so it’s best to consult the user manual. If your amp does not have a standby switch, then turn on the amp and have a load box connected to a speaker output to prevent noise or damage. Not having a proper load box or speaker connection can cause the tube plates to melt.
Can tubes get too hot?
Tubes can get too hot, which can be dangerous to your amp. Under normal circumstances, the tube heats up to around 325 degrees Fahrenheit, usually with a power amp and rectifier tubes. Preamp tubes don’t heat up as much as the power amp and rectifier.
While it is normal for tubes to glow when heated, it should only be the filament that should glow inside the tube. If the plate in the center of the tube is also glowing, it means the tube is overheating. Overheating can cause damage to the tubes themselves and other components of the amp, including the transformer.
That’s why some tube amps have vents or open-back designs, which allow air to circulate to keep the tubes at an optimal temperature. You can have fans installed to cool the tubes, but if they still overheat, it’s time to have a guitar amp tech inspect your amp.
Heating tube amps is an essential routine when using any tube amp. It allows you to get better tones from your guitar and amp, which can inspire any player to play better and have more people enjoy your gig or songs. It shouldn’t take long to warm up, depending on your amp.
However, be cautious also of how hot your tube can get. Now and then, observe how the tubes glow on your amp so that you can ensure the amp still performs as expected. And if the center plate of the tube starts glowing, then it’s time to take it to a repair center.
And if you don’t have the luxury of time to warm up the tubes in your amp, such as quick gigs, consider switching to tube amp modeling, which can perform exceptionally well, depending on how you tweak the settings.
John Narciso is a guitar player and music technology hobbyist. He loves exploring guitar effects processors in pedal and plugin format and free music applications. His music preferences tend to be diverse, listening to genres spanning from metal to alternative rock and a little hip-hop.