Brian May’s Deacy Amp

This is a little amp made by Queen bassist John Deacon in 1972 that Brian used for studio recording on songs such as “Killer Queen”, “Procession”, “Wedding March”, and “Good Company”.

For those orchestral things, I’ve usually used a Vox AC-30 as well as a small amplifier which was made by John Deacon. This has a little hi-fi speaker cabinet which is about a foot by six inches, and John put a little transistor amplifier inside it. I use it with a treble booster which overloads it. It just makes a good noise; I don’t know why.

Interview with Brian May “Guitar Player” magazine – January 1983

John, who at that time was an electronics engineering student, apparently found pieces in a trash bin of what was eventually discovered to be a Supersonic PR80 portable radio. He made a small speaker box for it and connected it to a 9-volt battery, and the famous Deacy amp was born.


Greg Fryer, who worked on a number of Brian’s amps and guitars, at one point in the late 90s attempted to produce a replica of the Deacy amp, with the help of UK amplifier specialist Dave Petersen. However, this version ended up not meeting the expectations, and the idea to produce it in larger numbers was quickly abandoned.

In 2003, Nigel Knight of Knight Audio Technologies got involved in the story, and worked for 7 years, together with Celestion, on making an exact replica. Finally, in 2010, the Deacy Amp replica was given the official approval and blessing of both Brian May and John Deacon. For a short while these amps were available for purchase under the KAT brand, but as of 2022, this no longer seems to be the case, as they are nowhere to be found on the KAT website.


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