But since power tubes are a consumable part that needs to be replaced regularly, we need a way to adjust the bias voltage that governs how much current the tube draws. Most components in a guitar amplifier don't need bias adjustment the circuit is designed to provide the correct voltage in the right places. It could also provide just enough information to get through a tube failure in a pinch.Įlectronic components like tubes in circuits need specific voltages at their terminals in order to work properly. Still, having a grasp of the general concept can give you more options in fine-tuning your amp's performance. You could play a tube amp all your life without knowing or caring about the reasons, especially if you have a great tech to maintain it. But the reasons why always seem just a bit mysterious because the related folklore among musicians clouds the issue. For example, these days most players with tube amps know that we have to get our power tubes biased when we replace them. Sometimes we learn to do something without understanding why it is important.

Tube bias guitar amp