Vintage Fender Bassman restoration, part V

Continued from part I, part II, part III and part IV.

I plugged the current limiter into the wall, and the now-complete Bassman into the current limiter.  There were no tubes in the amp on this first run, I just wanted to make sure there were no shorts.  I made sure the switch on the limiter was set to the limit position, and I hit the power switch on the amp.  The pilot lamp on the amp burned bright red, and the current limiter bulb flashed brightly and quickly faded to a very dim glow, as the filter capacitors charged.  Success!  I switched the amp off, and inserted the four preamp and phase inverter tubes.  I switched the amp on again, this time with the limiter set to full power.  The filaments of the four tubes came to a dull orange glow in their sockets.  I switched the amp off again, and inserted the power tubes and connected a speaker.  I mentally prepared myself for the final test.  Continue reading

Vintage Fender Bassman restoration, part IV

Continued from part I, part II and part III.

Once I finished populating the main eyelet board and mounting/wiring the tube sockets, I got to work on the power filter board.  This is the part of the amp that filters out the ripples in the DC power and can kill you if you are not careful.  These capacitors are about the size of my thumb, and they can hold enough of a charge to stop your heart, even after years of disuse.  Of course, since these were new capacitors and had never been charged, they were harmless.  Below is the fully assembled filter board, with color coded wires running through the grommets to the other side of the chassis. Continue reading

Vintage Fender Bassman restoration, part III

Continued from part I and part II.

The parts arrived while I was on tour.  As soon as I got home I opened up the box and took stock of my purchase.  I had ordered the kit minus the cabinet, which turned out to be a big mistake, because I ended up having to order one separately anyway, and I could have saved on shipping had I ordered it at the same time as the rest of the kit.  The box from Mojotone contained everything as promised: the passive components along with all of the sockets, jacks, pots and bolts/fasteners sorted and stored in marked hobby cases, coils of wire with color coded push-back cloth covering, brand new eyelet boards, a brand new (and now redundant) chassis, Blackface-style face- and backplates, and the transformers packed in separate boxes.  The next morning I got down to the real work. Continue reading

Vintage Fender Bassman restoration, part I

As some of you may know, I dabble in electronics.  I got into it several years ago when I happened to be browsing the Internet under the influence of some delicious (and apparently potent) local IPA, and before I knew it I had ordered a DIY guitar pedal kit from Build Your Own Clone.  I eventually sobered up and built the pedal, and I found–much to my surprise and delight–that it sounded great!  I later got into circuit bending children’s toys from Goodwill, building more basic (and also esoteric) guitar pedals, and microphones out of old rotary phones. Continue reading