A reader asked why the power transformer isn’t mounted at 90° to the output transformers in my 1955 build, and whether that close spacing causes induced hum. Here’s why the layout works in practice.
Transformer Orientation and Hum: Why the 1955 Layout Works Read More »
Some individuals aspire to build the 1955 Model tube amplifier themselves. However, they often encounter challenges when attempting to recreate its retro, point-to-point assembly.
Mullard 3-3 Printed Circuit Board Read More »
This document aims to serve as a guide for building the 1955 Gen2 vacuum tube amplifier. It can also be used for assembling the simplified wiring version, the 1955 Gen1.
Model 1955 Gen2 Assembly Instructions Read More »
In the original Mullard 3-3 design the operating point of the EL84 tube is highly dependent of the amplification factor of the EF86 valve.
EL84 bias issue on Mullard 3-3 tube amplifier Read More »
How to calculate a voltage divider to reduce the input to the valve amplifier
How to reduce the input sensitivity of the tube amplifier Read More »
It’s been over a year and a half using the first built 1955 model tube audio amp I have in my living room. The tube amp has been running two to three hours a day to listen to jazz or classical music.
One year of operation of the 1955 Tube Amp with no breakdowns. Read More »
New performance measurements have been made over the 1955 (Mullard 3-3) tube amplifier. You can see it on the 1955 tube amp measurements page.
Performance measurements on the Model 1955 (Mullard 3-3) tube amp Read More »