Davidson Amp Repair: Custom Audio: Model B
I actually started building amplifiers in about 1982. I think most tube amp repairmen of my generation got started the same way, tinkering with their own gear trying to perfect their own amp tone for their own music. I had lots of fun getting electrocuted, burned, and pissing off the neighbors. I even had a nightmare with Orange Drop capacitors lined up like an army and attacking me! I woke and grabbed the soldering iron. I was 21 and really into it. When I wasn't ruining my Fender Vibrolux I played hundreds of gigs..... in the street.
Unfortunately, what's fun or even beautiful is not always practical. Even the most artistic people sometimes need to eat. In the mid 1980's I began to seriously study lutherie, and after about five years I started to get paying customers. I had to put the amp experiments aside in 1986 after getting a 700 volt shock from one of my "projects", but my guitar repair customers loved the sound of my "Davidson Special" so much that I started repairing their amplifiers as well as their guitars in about 1990. When I moved to Nashville in 1993 I decided to drop the guitar repairs and stick to amplifiers only. I have occasionally built custom projects over the years, including guitar amps, mic preamps, and various custom power supplies, but 99% of my work has always been always straight-up amp repair, both tube and solid state. In the Spring of 2008, I dropped my exotic tube compressor project after wasting hundreds of hours and started fresh designing a plain old tube guitar amp. The object was to design a guitar amp that was as repair friendly and reliable as possible, based on my long experience seeing what's right and what's wrong with thousands of guitar amplifiers.
Some people claim to have invented the Holy Grail of Tone. I do not. I believe that really beautiful music is born in your heart and travels through your brain into your fingers. Of course some guitars and amplifiers obviously sound better than others, but they are still just tools that help you connect with the hearts, minds and bodies of others and leave them feeling better than they did before they heard you. Or in simple terms, the tone's in your fingers, and the feedback's in their feet! Any plain old Fender amp from the 60's or 70's sounds golden when it's properly serviced and used by the right hands.
I have invented nothing. I have just borrowed all the good ideas and filtered out the bad ones, and tried to do something good for the people around me by designing a high value, classic tone product using as many American made parts as possible. The Peavey Butcher conversion and Blues Deluxe conversion are also part of this project.
The amp was sold to a local studio. Only one copy of the Model B, or Raunchette, was ever made.
Interior shot showing the Keystone U.S. turret board, U.S. Sprague 716 Orange Drop Capacitors, U.S. IRC and Dale resistors, Piher Spain bias pot, Sprague Atom cathode capacitors, Cornell Dubilier U.S. Extended Life electrolytic filter capacitors and Cornell Dubilier Mexico silver mica 250 pfd. All jacks are Switchcraft U.S. . The potentiometers, (controls), are Bourns U.S and the switches are Carling Mexico, (Fender OEM since the 60's).
Hammond Canada parts: Aluminum front rack panel, grey steel chassis box, and 272FX power transformer. The output transformer is by Thordarson-Meissner U.S. . The blue filter cap is by Cornell Dubiler U.S. All Photos and Video Copyright Jon Davidson 2011