The technology that has led to the birth of tube amplifiers has been with us since 1906. However, a little percentage of musicians seems to have any knowledge of this low-tech but powerful device. These small mercury filled amps are not cheap, and the overall maintenance doesn’t come as cheap as that of solid state amplifiers, they are also quite heavy, but the sound they produce is unmatched. You are going to learn more in this post about tube amps, so read on.
An amplifier is a device that increases the sound produced by another device e.g. a guitar or any other audio device. Tubes, which are also known as valves in other areas of the world, are categorized in to three: preamp, power amp and rectifier. Each category has tube models with different specifications of performance.
The preamp tubes function to shape and boost the incoming signal. They are the smallest and the first ones that the signal encounters in an amplifier. Here, the signal acquires the desired amount of gain. Some popular preamp tubes are 12AX7 and ECC83.
The power amp tubes, also known as output tubes, aid to boost the signal on its way out of the preamp tube. They transmit signals from the amp’s speaker. Power amps can easily produce sound distortion if tuned to their maximum potential. This is a desirable tone determined by the tube’s special attributes. Some examples of common output tubes are: EL34, EL84, 6L6, 6V6 and 5881 to mention but a few.
The work of rectifier tubes is simply to convert alternating current (AC) to direct current (DC). These tubes aren’t as popular since most modern amps have incorporated solid-state rectifiers. None is superior to the other though, it is more of a personal choice and taste. Some rectifier tubes include, GZ34, 5AR4 and 5U4.
Diagnosing tube amps
When there are inconsistencies in the sound produced by the amp, it is important to check where the problem might be. You can easily do this by yourself.
The fuse– first you should check the fuse and see if it might have blown. This is usually near the power cord at the back of the amp. Make sure there are no burn marks. If there are, it means the tube has blown and this shows that the tube is dead therefore the amp is taking in more power overworking the fuse.
The tube– check out the tube and see if it is broken. If it is, it will have whitish or black powder on its interior, though it rarely burns out.
Turning on the amp– you need to listen to the sound coming from the amp. Usually, the sound coming from the rubes is dull. If they are completely dead, the sound won’t go away.
All tubes should be replaced if they are bad. This will ensure balanced power distribution in all the tubes. These are some of the most important points to note for tube amp owners.