I've wanted to flip an amp ever since seeing what
people were doing with the Epiphone Valve Jr. So I set my sights on doing
something unique with a SS Vox Pathfinder. I figured the 8" speaker
and 16"x14.5"x8" cab would be perfect for a small amp such as the Firefly
from AX84.com.So, I picked up a working
Pathfinder on eBay for $42.00, promptly gutted it and began work on a layout
plan for a Firefly. Looks like it will all fit in the original chassis. Then
one night while taking a break from the layout work, I decided to plug my
November Project head (ax84.com's 18
watt Plexi) into the Vox speaker. I was impressed! I got a good
crunchy sound and when I backed off the Strat volume, I had a nice chimey
sound too. All at bedroom volume! I immediately scratched the Firefly plans
and proceeded to figure out how to stuff a November chassis in this cab.
It wasn't long before I realized I would have to use a
separate chassis for the preamp and power amp. I just used the original chassis
to house the preamp. Had lot's of room especially since I would get B+ and
filament voltages from the power amp. The power amp chassis layout was a bit of
a challenge, not because it was too small, but because the iron and tube layout
had to also fit around the speaker in that small box. After working out the
major layout of the power amp, I proceeded to layout the boards.
With board layout and assembly done, it was just a matter
of final assembly. I used the same assembly techniques and grounding scheme that
I've used on my other amps. The preamp umbilical cord used separate STP cables
for the B+ and filament, and teflon insulated coax for the signal. The cord was
hard wired to the preamp and connected to the power amp via an octal plug and
socket. There were no surprises during construction or startup. I even got the
feedback polarity correct the first time!
