ONBOARD EQ, BUFFER, AND especially boost
circuits for guitar
have seen plenty of action over
the years, and several popular
models are available from EMG,
Seymour Duncan (the Pickup
Booster or Firestorm), Wald,
Walker, CAE, and Alembic (the
still-kicking and easy-to-install
Stratoblaster). There was a time
when lots of guitars came with
onboard effects like fuzz or
phaser (Gretsch Chet Atkins
Super Axe, anyone?). An extreme
recent example is Matt Bellamy
of Muse building a Korg Kaoss
pad into his guitar. I am not suggesting
you build your entire
pedalboard into your guitar, but
if you have a favorite booster,
distortion, or even reverb pedal,
it might be cool to have it as a
little onboard secret weapon.
Back in the day there were
popular books by Craig Anderton,
Electronic Projects for Musicians
and Do-It-Yourself Projects
for Guitarists. The latter encouraged
intrepid guitarists to take
the soldering gun into their own
hands and start building some
of their own electronics. There
are also a couple of popular FET
and op-amp buffer circuits online,
but you can just as easily buy
one preassembled and save your
skills for the installation.
The main reason you may
want a buffer in your guitar is
that the lower impedance output
from the guitar will be less susceptible
to high-end loss from
cable and pedal capacitance and
give you a more consistent tone.
Jerry Garcia was known for the
unity-gain buffer preamp in his
guitar. If you have the option,
some buffers work best with a
25k volume control.
From there you can step it
up and add a boost circuit.
Recently I was asked to build an
Xotic EP Booster into a guitar.
Onboard boosters can be a great
way to raise your level for a solo
or get more gain out of your
amp’s front end. It can also help
you match levels if you’re switching
between, say, a high-output
humbucker guitar and a loweroutput
A Seymour Duncan Pickup booster install before and after. In place of the two tone controls there is a push-pull pot in the neck tone control that acts as a master tone (down) and Pickup booster engage (pulled). The treble tone pot is the variable boost knob. The 9-volt battery fits neatly inside.
If you’re on the go and don’t
want to hassle with pedals, you
can build many effects right into
your guitar. I have a customer who
brings a travel guitar on trips. He
likes the convenience but hates
the dry tone in his headphones. I
installed the circuit of a greatsounding
Wet Reverb pedal into his travel
guitar, making for a much more
enjoyable listening experience.
A few considerations when
planning your install: The big
challenge is usually real estate.
Some circuits have potentiometers
soldered directly to the circuit
board. If you are in luck you
can find a way to keep the pots
on the board and mount that
as-is to the guitar. More likely
you will have to remove the pots
from the board and remotely
wire them back up, same with
switches. To consolidate,
consider using push/pull pots
to add switches and concentric
controls for more knobs. Is there
space for a battery? If not, you’ll
need to rout for a battery cavity.
If you can’t fit a battery in your
guitar you can build an external
battery box that can go on the
floor, your strap, or the back of
the guitar. You can even buy
these boxes premade from
B-Band, Highlander, and EMG.
If you are looking for a jumping-
off point, stompthatbox.com/byo.html
has compiled a
large group of links that can help
you through your project.
Gary Brawer runs Stringed
Instrument Repair in San Francisco.
His many clients include Joe Satriani,
Metallica, and Neal Schon.