In the shop here at Main Street Music Lessons, we have a tube tester!
Why are tube testers so important?
First, here's what tubes do: A vacuum tube is somewhat like a light bulb - it operates on the principle of thermionic emission - when voltage is applied, a metal filament coated with electrons, known as the cathode, is heated and emits some of those electrons. The electrons hit the plate and become a moving electric current in a wire. This current can do useful things, such as push a speaker cone to make sound. The tube tester tests the tubes to make sure that they are doing this job correctly and safely.
Once the tubes are tested as “good,” it is important that the power tubes are matched and biased.
When biasing tubes, you're regulating the amount of electrons hitting the plate. The tubes can be biased too hot (too many electrons) or too cold (not enough electrons). If the tubes are biased too hot, they will have a very short life. There are many electrons moving through the tube, hitting the plate and causing it to heat up when the amp is on and being played. If there are enough electrons heating it up, it will turn red-hot, melt the tube’s glass, and the tube will be destroyed. The tubes can also be biased too “cold,” although the tubes will have a very long life biased this way, the tone of the amp will be unpleasant and sterile. There is a happy medium to get the best of both worlds.
So if you bought an amp new and haven't had any maintenance done in a while, or you recently acquired that old tube amp from your uncle, play it safe and bring the amp to Main Street Music Lessons so that we can test those tubes and make sure everything is working right for your dream amp tone!!
(We got our information from http://www.premierguitar.com/articles/7525, where you can also find steps to extending your tube life in your amplifier without sacrificing tone)
Why are tube testers so important?
First, here's what tubes do: A vacuum tube is somewhat like a light bulb - it operates on the principle of thermionic emission - when voltage is applied, a metal filament coated with electrons, known as the cathode, is heated and emits some of those electrons. The electrons hit the plate and become a moving electric current in a wire. This current can do useful things, such as push a speaker cone to make sound. The tube tester tests the tubes to make sure that they are doing this job correctly and safely.
Once the tubes are tested as “good,” it is important that the power tubes are matched and biased.
When biasing tubes, you're regulating the amount of electrons hitting the plate. The tubes can be biased too hot (too many electrons) or too cold (not enough electrons). If the tubes are biased too hot, they will have a very short life. There are many electrons moving through the tube, hitting the plate and causing it to heat up when the amp is on and being played. If there are enough electrons heating it up, it will turn red-hot, melt the tube’s glass, and the tube will be destroyed. The tubes can also be biased too “cold,” although the tubes will have a very long life biased this way, the tone of the amp will be unpleasant and sterile. There is a happy medium to get the best of both worlds.
So if you bought an amp new and haven't had any maintenance done in a while, or you recently acquired that old tube amp from your uncle, play it safe and bring the amp to Main Street Music Lessons so that we can test those tubes and make sure everything is working right for your dream amp tone!!
(We got our information from http://www.premierguitar.com/articles/7525, where you can also find steps to extending your tube life in your amplifier without sacrificing tone)