1950s Gibson GA-40 Les Paul Amplifier

Here is an old and beat up Gibson GA-40 Les Paul amplifier that we had the pleasure of working on.

Gibson GA-40 Les Paul amp front

The amp belongs to a well known NYC Jazz guitar player who bought it in this condition and brought in for repair and restoration.

Upon inspection it was found that the power transformer was burned up.

The amp also needed new filter caps and some resistors, mostly in the power supply, as well as a few other components that had to be replaced.

The speaker was a reissue Jensen Alnico in perfect shape.

Gibson GA-40 Les Paul amp front

A dead transformer could be rewound and restored but it’s often cheaper and easier to just use a brand new replacement unit, if and when available.

We used a Mercury Magnetics exact replacement transformer that physically fit perfectly in the original mounting holes and yielded the correct voltages.

With that in place and all the other issues taken care of, the amp is working perfectly and sounds fantastic.

A very classic 50’s sound that is similar to the smaller Fender tweed amps from that time period. Cool!