Standby Switch

Bryan Bradfield · Post by **Bryan Bradfield** » 23 Oct 2004 7:35 am

Ricky Davis, in a thread about noise in an amp, described the positive features of the standby switch, and concluded by saying that the lack of a standby switch could be a sign of poor amp design.

I have 2 questions.

1) Is the standby switch a feature that was added to tube amps at a certain point in history after tube amps had been around for awhile, or is it a feature that is (and was) added only to high end amps?

2) Is it possible to retrofit a standby switch, or is it a complicated, expensive proposition?

John Daugherty · Post by **John Daugherty** » 23 Oct 2004 7:52 am

The standby switch is common in tube amps. It is in series with the B+ plate supply voltage. In the standby position, the filaments are on and the B+ voltage is off. This is an easy modification but be sure you have a good switch that will not arc with 500 volts on it....JD