2C45 tubes are a type of medium-mu triodes manufactured by Mullard, a British subsidiary of Philips. They feature an internal structure consisting of a heating element and three electrodes, a cathode, grid, and plate. The 2C45 is a high-gain, medium-mu triode designed for use in pre-amplifier and output stages on guitar amplifiers. It is capable of producing exceptional gain, clarity and tone when pushed to its limits. Despite its many benefits, the 2C45 is not as popular as other triodes like the EL34, 6L6, or 6V6. Its output, whilst high, is relatively low for a triode, requiring more amplification to reach desirable levels.It is also not as rugged and reliable as other triode tubes, and is more prone to high microphonics which can cause unwanted noise.