What common issues come up when building a valve guitar amp?

As Lamington amp builders progress through the construction of their amplifiers, some common questions arise. I thought it might be helpful to discuss some of these questions to assist other diy amp builders.

The first issue that often comes up is identification of the components. For a newcomer, it can be confusing to identify capacitors, resistors, diodes …… picofarads, microfarads, megohms etc!

The first step is to identify the resistors. They look like this:


You can see that most resistors have their value marked with a colour code. To “read” the value of a resistor, here is a colour code chart: