To check, remove the power from the amplifier and see whether the problem goes away. There are three types of amplifier – masthead, set-back and distribution. All these need a power supply to work.

which can involve large amounts of power, but both of these types of tubes are designed to achieve this effect with only 2.2 volts provided to the heaters. [J.G.] is powering this amplifier with a ...

The dedicated headphone amp is a completely new addition with a current-feedback design and high slew rate to ensure it works with all types of headphones. The original 303 stereo power amplifier ...