Guitar Tube Amplifier

"Modified" Fender CHAMP-AMP - MODEL 5F1, electric guitar tube amp from old radio housing.

The amplifier is based on Fender model 5F1 with EL34 instead of 6V6 output tube, so the most important for the quality of the sound and the most expensive parts needed in this project are:

Power transformer with secundary voltage:

• 250V / 200mA
• 6,3V / 3 - 4A

Output transformer:

• primary impedance around 5k (depending of speaker impedance), capable of aprox. 8W

Tubes:

• preamp tube 12AX7 + base
• output tube EL 34 + base

Speaker:

•  My choice: Jensen CH6/15 6'' 15W

Other parts needed are some capacitors, resistors, jacks, fuse, etc...

Try to find old radio. Thoroug exam of the housing. Disassemble the interior of the radio, maybe you will find some still usefull parts (tube socket, power transformer, output transformer,...), but it depends of the radio type you find.

Firmly clean the housing. Use very fine sand paper. Repair all damages (glue them). Make new parts (back plate, front plate). Change the speaker cloth. Paint all parts.

Take your time, to do it right.

The amplifier is based on Fender, model 5F1. I used an aluminium sheet and craft it to fit it in the old radio housing.

Drill or punch all the holes needed (for transformers, tube base, wires,...)

Take care of positioning the power transformer and the preamp tube. Place them as far as possible.

Grind all holes and paint the framework.

I used point to point technique. So acording to plan, wire (solder) all parts together.

... and at the end, try if it works.

Before fitting all together inside the housing, wire the volume potetiometer, input socket, power light, speaker, then fix the framework inside the housing, and close the back.

Leave some openings that the heat from the tubes (lamps) can "escape".

Put all together, test it,...

... plug in the guitar, invite your friends and enjoy your work.