Tweed Amp conversions

Can't afford a new amp build in a fancy chassis or combo cabinet. Want to try an amp but don't really know if you should spend big dollars to see if you like it. Me too. That's why I started taking perfectly servicable older amps- maybe an old PA or mono tube amp. Perhaps a power amp from an old organ.

These old amps were built with some really great transformers that lend themselves to great sounding guitar amps. Its important to know the details of the amp you start with- what power tubes can it drive, are the voltages correct for the circuit your building, etc. Frankly its not a simple rewiring job when I build one of these. I strip out all the old components. Clean or refit new tube sockets. Drill the chassis for the new controls, inputs, power switches adn pilot light. I usually repaint or reface the amp for a clean look. I build a completely new point to point circuit or use a custom amp board to mount the components. I like to isolate my input jacks and keep preamp and power amp grounding separate. Its really much the same a building a new amp- I just can save the customer money by reusing the chassis and transformer set- a big savings sometimes.

Here are some Tweed amp conversions I have done.

How cool is this. Its a 50's Thordardson PA amp I transformed into a Tweed Deluxe circuit. It really sounds great and I wish I had kept it for myself, it was just the coolest art deco piece. The new owner loved it and when he moved to England I converted the power transformer to a 220 volt model so it could go with him.

 

 

 

 

 

 

This amp was a late 50's or early 60's Bogen integrated Mono amp. I built a Deluxe tweed circuit inside this as well. I took off the front faceplate and turned it over then hand polished the brass until it was like a mirror. I installed an LED power light in the original housing and installed the power switches and input jacks on the back panel. It still has the original tube socket covers although one of the 3 preamp tube sockets is not wired as the Deluxe only needs two preamp tubes. It really sang.

 

 

 

 

Here is a major piece of coolness. I scored an old Ampro movie projector speaker cabinet. Very solid with a removeable back cover. I took out the old 16 ohm Jensen speaker (too frail) and mounted a Tweed Princeton circuit amp and a new Jensen speaker. Sounded very good.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Here is a '61 Stromberg Carlson Signet amp I made into a tweed deluxe. These amps have some great quality transformers- some of the the very best of their day. A super sounding amp.

 

 

 

 

An early '60's Hammond Organ amp converted to a 5E7 Bandmaster. I altered the chassis to mount it in a combo with the tubes hanging down. You can see the chrome plugs I used to cover the old tube sockets. This amp was a lot of work as I painted the whole chassis after stripping it and removing all the parts. I also mounted a choke as the circuit calls for.

 

 

 

 

 

Here is the inside of the amp. I even was able to reuse the tag board Hammond used to mount their components. A bit of a pain having to clean them all out, but it fit perfectly and the amp sounds great.

 

 

 

 

This small 9" by 5" Hammond Organ amp is converted into a Tweed Champ circuit. I use the rather large output transformer as what is usually found on a Champ and this give it a great bottom end. These will drive a big 15" speaker no problem. I built these as a standard offering at $225