Not far from the same Boston Harbor
where the American Revolution was
born, there’s a small warehouse complex
that houses Source Audio—a band of sonic
inventors who’ve embarked on a unique
musical mission they feel is also pretty revolutionary.
The Woburn, Massachusetts, company
sprang onto the effects scene in 2005
with pedals unlike any the world had seen. In
contrast to the vintage reimaginings you see
from a lot of stompbox makers, they came
out with the Hot Hand wah and Hot Hand
phaser/flanger—thoroughly modern designs
in molded-plastic casings that spoke more to
the computer age than the Woodstock era.
But looks were only the beginning: These
effects enabled a guitarist to control parameters
by waving around a ring attached to
their finger. But, as it goes for many new kids
on the block, Source Audio found that the
road forward wasn’t easy.
Source Audio president
Roger Smith was formerly a
“system on chip” designer at
Analog Devices, Inc. (ADI).
Jesse Remignanti, Source
Audio VP of engineering,
works on hardware and
user-interface design.
Source Audio videographer
Jeff McAlack says guitarists
are coming around to digital
pedal technology.
Bob Chidlaw, a former
designer at Kurzweil, works
with the actual sound elements
at Source Audio.
The Human League
It all began at Analog Devices, Inc. (ADI),
a designer and manufacturer of analog
and digital signal processing (DSP) semiconductors
(chips) based in Norwood,
Massachusetts. ADI is one of the world’s
largest producers of mixed signal “system on
chip” designs that have an entire analog and
digital signal path on a single silicon chip.
While working in a chip development
group at ADI, future Source Audio president
Roger K. Smith met Bob Adams, a
legend in the world of analog-to-digital and
digital-to-analog converter development.
“Bob recognized unique opportunities to
put more and more smarts onto the converters,”
says Smith. “This is what ultimately
formed the chip we use: analog in
and analog out, with an enormous amount
of processing power in-between.”
ADI’s high-performance SigmaDSP
audio processor is at the heart of the
SA601 chip used in Source Audio pedals.
While some competitive digital devices
use 16- or 24-bit audio processing, the
SigmaDSP uses a 56-bit processing path,
ensuring less digital distortion.
An inside look at “system on chip” technology.
But Source Audio’s story is as much
about people as technology: As any guitarist
or bassist can attest, it doesn’t matter how
fancy the hardware or software is if effects
designers don’t know how to make them
sound good. While at ADI, Smith met
Bob Chidlaw, a former designer at the
Kurzweil—a huge name in the keyboard,
sampling, and effects market. “Roger and
Jesse [Remignanti, Source Audio’s vice
president of engineering] were getting
itchy to start an effects company and
needed a DSP engineer,” says Chidlaw. “I
thought it sounded like fun, and it was
something I was well suited for.” Chidlaw
turned out to be a perfect fit, because his
experience playing with guitar, keyboards,
and wind instruments gave him a keen
sense of how musicians might use the
DSP processing in the real world. This
technical trio, combined with the business
acumen of C. Hunter Boll, became
the founding fathers of Source Audio.
Remignanti says it was his interaction
with Chidlaw that created the company’s
unique take on effects. “I usually come
up with the effect idea, then Bob will
figure out the algorithms that will make
it work. But in some cases he will say,
‘Here’s this algorithm I came up with.
How can we make this into a viable
product?’ Then I will have to design
some sort of interface.” For the most
part, Chidlaw works more with the actual
sound, while Remignanti works on the
hardware and user-interface design. “The
best example is the Envelope Filter: Bob
will fill it up with as much potential as
possible,” says Remignanti. “My job is to
simplify the interaction.”
Pedals to Taste
While still at ADI, Remignanti started
working on the software that plays a large
part in Source Audio’s newest concept, the
Flexbox. This pedal depends on the fact
that chips used by Source Audio are manufactured
with the potential to create any
number of different effects, based on the
algorithm supplied to the chip. “At ADI,
we were trying to make it so that people
who didn’t know how to do hardcore coding
for the chips could still use them for
signal processing,” explains Remignanti.
“I started designing Sigma Studio—dragand
drop programming software that lets
me add waveforms and tone modules and
assign them to outputs.”
This software allowed automobile
sound-system designers, for example, to
tweak the chips in their systems without
having to be full-on programmers. “Being
a guitar player, I started thinking, ‘What
if the waveforms and tone modules were
effects instead?,’” he says. “I had experience
in hardware and software, so I had the full
gamut of skills to do it.” This grabbing of
effect algorithms and dropping them into
a program along with parameter controls
became the Flexbox concept.
Chidlaw writes the algorithm that tells
the chip how to affect the input signal.
Depending on the code he writes, the end
result will be a filter, distortion, or reverb
pedal. This flexibility, combined with a
layer of the code developed at Analog
Devices, is what allows the Flexbox to do
more than merely become whatever effect
the user desires. “A program running on
your PC lets you determine which knob
controls which parameter for a specified
range from here to there,” explains Chidlaw.
“An easy, intuitive display interface for
all this stuff gets folded in with my code
and downloaded over a USB port to the
Flexbox. If you have a basic knowledge
of effects, this will allow you to do some
unique things on your own—without
having a Source Audio engineer standing
beside you. We would like to get it to
where, in the simplest version, you can
just download an effect chosen from a list,
with all the knobs preprogrammed for you.
If you are dissatisfied with that version
because you think, ‘I don’t really use that
knob, but there is another thing I would
like to control,’ you will be able to reassign
some of the controls. Some people won’t
want to deal with it, some will, and others
will want to go even further.”

The Source Audio MIDI interface (prototype pictured) allows you to run MIDI through the
expression pedal port and daisy-chain it so you can set up scenes with a MIDI controller.
Remignanti elaborates. “Let’s say Bob
comes up with an algorithm that could
potentially have 20 parameters, but there
are only five knobs. In one version of the
software, you can download the effect with
five preselected parameters, but in another
version you will be able to assign your
choice of any five parameters out of the 20.
You will be able to buy the effect online,
tweak it, and download it as a preset into
the Flexbox. You can share those presets,
but not the effect itself, with your friends.”
The Doors of Perception
Since the company’s inception, the folks
at Source Audio say there have been very
few complaints about the sound their pedals—
though they have had to contend
with a fairly significant prejudice against
pedals that aren’t entirely analog. “There
is that huge wall against digital,” says
Source Audio guitar guru/videographer Jeff
McAlack. “Unlike Line 6 or DigiTech,
we are in a more boutique realm where
it is all about analog—sounding like
Hendrix, or the Stooges, or whoever.”
Again, Remignanti weighs in. “You
design it and think it is a cool thing that
people will be into—we think of musicians
as artists, and artists are usually
forward thinking and experimental—but
it initially proved to be just the opposite.
Guitarists tend to be very conservative
and take a long time to come around to
an idea like this.”
The company has also struggled with
issues once faced by Electro-Harmonix:
Some customers have expressed a concern
that the units were too big and that the
housings didn’t appear to be roadworthy.
The first quibble was hard to argue with.
Players who wanted to add the original
Hot Hands to their pedalboard would
have to lose three or four smaller ones to
do so. Even the smaller Soundblox series
requires a hefty chunk o f real estate. But
the second concern about toughness was
purely one of semantics. Though the
housings are plastic, there is nothing delicate
about the type Source Audio uses—
they say they’ve literally driven a car over
these cases to no ill effects.
Even so, with the Soundblox 2 series,
the company has addressed both issues:
They now have metal cases that are half
the size—and yet they still somehow fit
more controls and switches than previous
models. “A lot of it is fashion,” says
Remignanti, “just changing the knobs to
black makes it look more traditional.”
The company has had to accede to
the demands of the market in other
areas, too. For all its brilliance, the original
Hot Hand was tethered to the pedals
by wires, restricting hand and arm movement
and limiting the ability to control
the effect from a distance. So, they quickly
moved to make it wireless.

Source Audio pedal prototypes at their headquarters in Woburn, Massachusetts.
A New Fan Bass
While Source Audio is doing its best to
meet the needs and wants of pedal fans,
at the same time the market is evolving to
meet the company’s concept. Even before
Soundblox 2, an unlikely group of allies—
bassists—showed signs of catching up with
the Source Audio vision. Once known
for owning but a single instrument and
plugging straight into the amp, in recent
years bassists have been building pedalboards
that sometimes rival guitarists’. The
company’s pedals started showing up on
more and more of these boards as bassists
became early adopters of the Envelope
Filter, Multiwave Distortion, and Hot
Hand controller.
Berklee College of Music graduate
Will Cady—whose multitasking at Source
Audio includes bass product line management,
marketing, shipping, and customer
relations—has some ideas as to why the
company’s surge of popularity is being
spearheaded by bass players. “First, they
are great pedals. Second, we marketed
directly to bass players. And third, we
got them in front of players a lot of bassists
admire,” he explains. “We started
with Victor Wooten, then moved on to
[Phish’s] Mike Gordon.”
The rise of dubstep also helped.
Almost 5 million YouTube views of
Nathan Navarro creating wobbling
dubstep bass parts using the Hot Hand
has sent the remote controllers flying
off the shelves. “Nathan is a bass player
on the rise,” says Cady. “When his
Skrillex cover video went viral, the Hot
Hand-controlled Envelope Filter and
Wave Distortion became go-to products
for a whole new way of playing the
bass. We are now tied in with a new
genre of music.”

The original circuitry for Source Audio’s Hot Hand Wah Filter.
Through the process of video production,
Cady has figured out that you can
create the dubstep wobble with just the
Multiwave Distortion. “You don’t necessarily
need the Envelope Filter pedal,” he
explains. “The foldback part of the distortion
tends to sound like an envelope
filter, so if you set the expression pedal
[or Hot Hand] to the distortion mix and
set it somewhere in the middle, you can
control how it comes in, so it feels like a
filter or 8-bit synth.”
Of course, Cady’s own expertise as
a bassist helps guide the company’s
vision, too. “I play out a lot, so I throw
our pedals on my ’board and gig with
them,” he says. “I can tell Jesse if an idea
is good in theory but might need to be
tweaked to be practical in real-world
situations. I explained to him that a tap
tempo on the LFO of the filter pedal
would allow me to play better with a
drummer—because I couldn’t quite lock
in using the knob. Now the Bass Envelope
Filter Pro has a preset switch that can be
changed into a tap tempo.”
Guitarists are coming around as well.
“Bass players are maybe talking to their
guitar players,” posits McAlack. “The
Multiwave Distortion is doing better and
better. Session guitarist Pete Thorn’s terrific
video explained how it is a useful studio
tool when you need a melodic line that
sounds completely different. Pete had used
it on his last record, and he highlighted
what’s great about that pedal. The EQ
pedal is selling very well, also.”
“One of the reasons players shied away
from digital before is that you didn’t have
as much control as with analog,” adds
Cady. “Now you have the control to get
those in-between quirks that you get from
analog effects.”
DragonForce’s Herman Li is another big
name who’s helped raise the Hot Hand’s
profile among guitarists. However, before
his and others’ enthusiasm had helped
spur a recent surge in sales, orders to the
overseas manufacturers of the Hot Hand
had temporarily slowed to the point that
the factory had destroyed the molds. Since
they had to be manufactured again from
scratch, Source Audio decided it would be
a great time for a redesign.
Will Cady is a jack of all trades for
Source Audio, handling bass product
line management, marketing,
shipping, and customer relations.
“The ring will look the same,” says
Remignanti, “but we added a third [parameter]
axis to give you more options. The
biggest difference is the receiver. It will no
longer plug into the back of the pedal [the
old ones will still work—everything is backward
compatible]. It will now be a separate
module that connects by cable. It will give
you the ability to tweak some parameters
right on the module, like depth and filtering—
similar to the Source Audio MIDIEXP
pedal. It will also have an expression
output, so you can use the Hot Hand with
third-party pedals.”
For those who want to control effect
parameters in real-time in a more traditional
manner than the Hot Hand, the original
Source Audio pedals and the Soundblox Pro
series offer inputs for any standard expression
pedal. The Soundblox and Soundblox
2 series work with the company’s own
model, which uses a pair of TRS expression
outputs to control two effects units
simultaneously. Unique to this pedal is a
special Sensor Output that connects directly
to any Source Audio Hot Hand input,
allowing real-time foot control over filter
sweeps, effect modulation, LFO speeds,
wet/dry mixes, drive levels, etc. “You can
use the expression pedal to control many of
the parameters, and you can daisy-chain a
number of Source Audio pedals so you can
use one expression pedal for all of them,”
says Remignanti. “With the advent of the
Source Audio MIDI interface, you will also
be able to run MIDI through the expression
pedal port and daisy-chain it so you
can set up scenes with a MIDI controller.”
In It for the Long Haul
It has been a long, slow climb for the team
at Source Audio, but a stream of innovative
ideas and quality execution seems to be
leading to a bright future. “Sometimes, [for
a pedal to be accepted] all it takes it one
person doing something really cool with
it,” say Remignanti. “Eventually, you can
win over the more traditional guys, but you
have to be around long enough that they
realize you are not another pedal company
that is here today, gone tomorrow.”
With a new generation of guitarists and
bassists who’ve grown up perfectly at home
with smartphones, deep recording software,
and a broader range of musical tastes than
ever before, it’s a safe bet that Source Audio
will find a spot on many of their pedalboards
and be a company to watch as the
future of effects pedals unfolds.