With so many cool and interesting pedals readily available to the modern
musician, you will inevitably
come to the point where you
need to build a pedalboard
(especially if you’re a gear junkie
like me). You’ll need to decide
which kind of board to buy or
build, which pedals will actually make it on your board, the
optimum order of the effects,
cable lengths, and whether or
not you will buy pre-made
cabling or wire your own. But
probably the single most critical decision you’ll make is how
to power all of the pedals on
your new board. There are three
major issues to consider when
thinking about powering your
pedalboard: voltage, current,
and isolation.
Luckily for us, the early popularity of Boss pedals helped to
establish an unofficial standard
when it comes to the voltage
level and DC (direct current)
jack used in powering pedals.
The simple fact that most pedals could be powered by a 9V
battery was the logical starting
point that led to the inclusion
of 9V DC power inputs. These
DC inputs were useful when
players didn’t want to hassle
with batteries, and instead
wanted to be able to power
their pedals from standard AC
wall outlets. Boss chose to use
a 2.1mm DC power input jack
with a center negative polarity
and because of this, the majority of pedals on the market
today also use this “standard.”
Take a look at the labeling next
to the input on your pedals
and chances are it will say 9V
DC, center negative (an icon
symbolizing a jack with a negative sign pointing to the center
symbolizes this).
Of course, not all pedals
are powered with 9V, so make
sure to take note if there is
one in your collection with
MIX DECAY
PRE-DELAY
BYPASS FAVORITE
HIGHDAMP LOWDAMP
MIX TIME
REPEATS
BYPASS TAP
WOW&FLUTTER TAPEAGE
DRIVE OUTPUT
TONE
special voltage requirements.
Some devices out there even
use 9V AC (alternating current)
power. Be very careful not to
accidentally plug an AC power
source into a pedal designed to
be powered with DC. Chances
are that if a pedal needs 18V or
24V DC, the manufacturer will
have supplied a special power
adapter anyway. Be sure not to
hook your pedal up to a higher
voltage source than it calls
for—no one likes ending their
pedalboard project with a puff
of smoke!
Current is the next thing
you will need to think about.
The current that a given effect
consumes is not likely listed on
the pedal itself. For that you
will need to look in the manual.
Assuming they’re analog devices,
a distortion, overdrive, fuzz,
compressor, or wah will in almost
all cases have a very low current
requirement (less than 20 mA or
so). This is because these classic
analog effects use only a handful
of transistors and op-amps with
low power requirements.
A digital effect, on the other
hand, will contain a micropro-
cessor or DSP, probably some
memory, logic chips, A/D and
D/A converters, as well as sup-
porting analog components. In
this case, you will literally be
powering millions of miniatur-
ized transistors inside of these
digital chips, so the pedal will be
a bit hungrier for power. Digital
and DSP-based pedals typically
consume more than 150 or 200
mA, and modern power supply
manufacturers have taken this
into consideration.
TERRY BURTON is an
engineer at—and the
founder of—Strymon.
