Below a few photos of a couple of guitar amplifiers I built. They are copies of a Jansen 4/Twelve valve amp from the late sixties I believe. They comprise two pre-amp valves and two EL84s in the power amp section.

A mate lent me his original 4/Twelve and I ‘reverse engineered’ it and the made the chassis and cabinet just like the original. I then decided to make another copy and put it in a combo.

I changed the original circuit a little bit by using the spare valve triode for extra gain and also added a master volume. Both copies sound like the original with the added bonus of dialling in distortion at low volume.

Below a couple of videos of trialling out the head version of the amp. This was recorded just prior to finalising the head with a new faceplate and logo.

And here the finished head on the left being put through its paces.