Whether you’ve locked your tube amp in your car over the course of a cold winter night, found an old amp in a relative’s garage, or you’re planning on storing a tube amp in an unheated space for a period of time, you’ve likely wondered, “Can a tube amp be stored in the cold?” Tube amps are delicate and costly pieces of equipment, so we want to make sure you get the right advice.
It turns out that tube amps can be stored at reasonably cold temperatures without any issues. While temperatures of -40 degree Fahrenheit and beyond can be damaging to some electrical components, the biggest problem that results from storing tube amps in the cold is temperature fluctuation. There are several things to consider when storing your tube amp in the cold, including:
- The temperature consistency over a period of storage.
- The expansion and contraction of the materials of the amp components when you get a tube amp out of long term or short term storage.
- The development of condensation inside of the amp.
Some things do last longer when stored at cold temperatures, while other items require specific temperatures and humidity to keep their integrity intact. There’s all sorts of information comparing the storage of tube amps to storing light bulbs and batteries, but tube amps are a little more complicated, not to mention more expensive. Read on to learn more about how to properly care for tube amplifiers that have been stored in the cold.
As I mentioned above, temperature fluctuation is your biggest enemy when storing your tube amp for any period of time.
Some parts, like the tube sockets, can become very brittle when exposed to the cold, but for the most part, tube amps are pretty resilient when it comes to tolerating extreme temperatures alone. Humidity and temperature change are what cause the most problems when storing an amp.
Major changes in temperature can cause damage to a tube amp in several ways:
- The tube glass can fracture, or the seal between the glass and metal elements of the tube can break, compromising the tube’s vacuum.
- The filament inside of the tube is more susceptible to breaking.
- The formation of condensation can cause the amp to short circuit, and other components of the amplifier can be damaged by the moisture, as well.
The best way to protect a tube amp when dealing with cold storage is to make sure you aren’t continuously exposing your equipment to large fluctuations in temperature. Cold storage is fine, as long as it stays that way.
If you live in a climate with drastic temperature swings, such as the Midwest, where it can be below freezing one day and warm enough to wear a t-shirt outside the next, finding storage that is climate controlled is going to be your best bet.
If you aren’t storing your amp for long periods of time, try to avoid dragging it back and forth between the heat and cold all the time. This can be more damaging than moving an amp that has been in storage long term one time, because the materials are weakened by the constant adjustments they have to make to changing temps.
Obey The Laws (Of Science)
Anytime matter is heated, the molecules that make up that matter respond to the thermal energy with movement. The more heat that is applied to a substance, the faster the particles of that substance move, just as steam rises from a pot of boiling water and spreads out.
How Contraction And Expansion Wrecks Tube Amps
Tubes are constructed of rigid glass, which is delicate enough on its own. Take a tube that has been out in the cold and bring it into a hot environment and you risk cracking the glass without ever dropping or bumping into anything.
Cold glass can suddenly fracture when it is exposed to heat, because the inrush of thermal energy that the glass receives causes the molecules of the glass to move apart too quickly. The only way for this energy to spread out is by blowing apart the glass. Kind of cool, right? But not so good for your amp.
Even if the fracture isn’t a big, obvious blowout, the sudden expansion or contraction of the tube’s glass neck and the metal base can break the seal. This ruins the tube’s vacuum, and causes the tube to fail.
One way you can easily tell if a tube’s vacuum has been compromised by examining the getter, which is a gray, silver, or black coating on the top and/or sides of the tube. Once the tube sustains an air leak, the getter will turn ghost white. Another sign that there is leakage in a tube is if you see a purple glow around elements within the tube.
The glass isn’t the only part of the tube that can blow, and it isn’t even the most likely part to be affected by a sudden change in temperature. The most delicate part of a tube is the filament inside of it. Tubes with busted filaments will not glow, and they will not heat up.
While a healthy filament is unlikely to break when brought in from the cold, if you fire your amp up right away when it’s chilled, the inrush of electrical current will produce too much heat, too quickly. The brittle filament will not be able to adjust to this temperature fluctuation fast enough, and it will blow.
What You Can Do About It
If you’ve just taken a tube amp out of a cold spot, whether it was only there for a short time, or it has been tucked away for several years, you should always allow the amp to slowly come to room temperature to prevent damage from temperature shock.
When moving from excessively cold areas into heated rooms, try to find a middle ground to bring the tube amp into, first.
For example, if the amp has been out in the car in subzero temperatures, set it in the garage for a while before bringing it into the house. If your amp has been stored in a case, crack the case open for a bit before taking the amp out.
Allowing a tube amp to slowly acclimate to warmer temperatures when it first comes out of storage will reduce the risk of it sustaining damage when you power the thing on.
Another general issue with amp storage is exposure to moisture. Always make sure the area you store your amp in is dry.
This sounds obvious, but an unknown leak in the roof, or ice that isn’t noticed at the time of storage that melts later on can destroy an amp. It’s a good idea to get a cover or a case to help keep dust and moisture out of your amp.
You don’t usually have to worry about humidity in very cold environments, but it can cause issues when you bring a cold amp into a heated space. Any moisture in the air will condense onto a cold surface, like how a glass of cold water sweats on a hot day.
Condensation can damage the electrical components of the amp and cause it to short circuit when you turn it on. Never power on a tube amp if you notice any condensation on any parts of the amp.
Some people argue that you should turn a tube amp on right away when you bring it in from the cold. Their reasoning is that this will get the amp warm faster, and prevent excessive condensation. While this might be true, there is still the issue of damage from temperature shock that I mentioned above.
To avoid damage from condensation, let the amp dry out. The condensation will evaporate pretty quickly, and then you will be able to safely turn your amp on. At that point, the amp will have come to room temperature, too, so waiting to power it on is the best option.
So, can a tube amp be stored in the cold? Absolutely, as long as the cold is relatively consistent. The major concern is with temperature fluctuations, which can occur in unstable climates, but mostly happen when the amp comes out of cold storage and is brought into the heat.
Sudden temperature shock can cause fragile materials, namely the elements of the tubes, to crack and break. Further, condensation can accumulate on the components of the amp, and we all know that water and electricity don’t mix.
To prevent damage, store your amp somewhere dry, which you know will not be subject to sudden major temperature shifts. Use a cover or a case for added protection, especially when storing an amp over a longer period of time.
When you bring a tube amp out of cold storage, give it time to come to room temperature and let any condensation evaporate from the amp before you even think about turning it on. Taking these simple precautions will prevent unnecessary damage to your amp.