1.
Contact the owner’s manual or a technician to determine which type of pipe is best for your manufacturer and model of amp. Buy a set of matched tubes and replace all the tubes at once, even if only one tube is bad. Just inserting a new pipe, among other things, which has experienced great use, reduces the life cycle of the new pipe. Mixing more than one pipe model can also cause poor performance or malfunction.
2.
Remove the panel that covers the preamplifier and power amplifier tubes. Identify preamplifiers and power amplification tubes. The pre-tube tubes are smaller and smaller than the number of power-enhancing tubes, and are often enclosed in the housing. Remove the cover from the pre-reinforcement tubes by pressing down on the cover, turning it counterclockwise and lifting up. Grasp the sides of the tube tubes and pull them straight out of their sockets. Insert the new preamplifier gently into the empty sockets with the pins or plugs facing down. Replace the cover. Replace the booster tubes as usual.
3.
Change all pipes at least once a year. If you play regular gigs or play for several hours every day, replace the tubes every four to eight weeks or when you notice reduced volume or tonal quality. An amplifier with function or overuse tubes gives less volume and poor overall sound, while even an old amplifier with a new set of tubes can sound completely new. An amplifier with new tubes will emit bright, full tones on the clean channel and allow greater manipulation of heights, mids and lows for a more nuanced sound. New tubes also allow for a greater number of tone options when playing with distortion.
Tips and warnings
Replacing tubes is an important part of proper maintenance of a guitar amp. Amplifiers contain both pre-amplification tubes and power amplification tubes. Gain relay sounds and amplifies the signal from the instrument as it enters the amplifier. Power-amp tubes actually produce the sound we hear by converting heat into electricity to amplify the electrical signal.
Source:danspela.com