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Stone Deaf FX PDF-1 Parametric Distortion Filter Pedal Review

Stone Deaf FX PDF-1 Parametric Distortion Filter Pedal Review

The PDF-1 pays tribute to the Mastro Parametric Filter

Download Example 1
Height at 50%, Freq at 50%, Bandwidth at Fat, Switched to Dirty. Fano JM6 through Fender '63 Reissue Vibroverb.
Download Example 2
Clean Boost, Freq at 2 o'clock, Height at Maximum, Bandwidth at Thin. Fender Jaguar with Seymour Duncan Hot Jaguar pickups through Fender Pro Jr.
Whether crusty, rich, brittle, or big as a brick house, fuzz and distortion are heavenly sounds to many ears. But from the day Keith Richards kicked on his Maestro Fuzz Tone for the first blast of “Satisfaction,” guitarists have looked for ways to shape raunchy sonics into something more individual, musical, and malleable. Roger Mayer’s Octavia was among the first to expand what a single fuzz box could do by putting a little octave brawn behind the buzz. And by the ’70s, more adventurous manufacturers were giving players even greater power to shape their distortion. One of the cooler efforts of the era came from Maestro in the form of their Maestro Parametric Filter (MPF), a clever, clunky filter pedal that a resourceful player could use for everything from simple EQ to total fuzzification of their signal. It wasn’t the nastiest distortion or fuzz around, but it gave guitarists a lot of ways to manipulate their sound.

In the years since the MPF first hit music store shelves, 6-string adventurers, including Alex Lifeson and Josh Homme, have used the Maestro to sculpt their tones. Now, Stone Deaf FX of Manchester, England, has created a sturdier and more versatile evolution of the Maestro circuit. Despite its formidable-sounding moniker, the Stone Deaf PDF-1 Parametric Distortion Filter proves to be a pedal of myriad applications beyond heavy and blazing riff-rock. Like its inspiration, the PDF-1 is not the most out-there fuzz or fattest distortion. But it gives you access to sounds that most run-of-the-mill pedals can’t deliver.

English Kraftwerk
Though we’re in a Golden Age for stompboxes, a lot of great pedals suffer from looking and feeling like everything else behind the counter. Not the Stone Deaf PDF-1. The custom- machined aluminum casing, top-notch pots and switches, and stylishly engraved 3-ply plastic control panel are simultaneously reminiscent of an Apollo capsule control panel and the dash of a late ’60s BMW—elegant, easy to navigate, and perceptibly well made. If you love the way a good switch feels, you’ll dig tinkering with the PDF-1.

For all the obvious quality, the PDF-1 is an exceptionally light pedal. The 9-volt battery is brilliantly stashed on the side of the enclosure in a sliding access compartment that will have you setting records for fast, onstage battery changes. It’s a very cool-looking pedal too, with a compact but distinctive ’70s-inspired elevated profile that makes it easy to find on a crowded pedalboard.

In terms of operation, the controls are simple, if not completely intuitive at first. The Height knob (each of the curious control names are identical to those on the Maestro MPF that inspired the PDF-1) drops or boosts a given frequency by up to 20 dB. The Freq knob selects the frequency between 65 Hz and 3 kHz that you want to boost or cut. The 5-position Bandwidth switch moves from Thin to Fat settings and reduces or widens the signal’s bandwidth as a whole. Then there’s the Clean/Dirty switch, which effectively changes the Stone Deaf from a boost/parametric EQ to a distortion/parametric EQ unit.

If your amp and guitar were feeling like a cramped cottage,
the Stone Deaf’s clean boost function is like adding
a sunroom on the back.

Shape Shifter
If the Stone Deaf were only a boost pedal, it would still be an impressive and useful addition to a pedalboard. And my first experiments with the PDF-1, in the context of a pretty boisterous band jam, involved heavy use of the remarkably transparent clean circuit. Running the pedal after a TS-9 Tube Screamer and a Pro Co Rat, and into a blackface Fender Tremolux, a Music Man HD212, and a Fender Vibroverb demonstrated not only how much character this pedal can lend to your signal on its own, but how much it can help you tailor otherwise ordinary overdrive and distortion signals.

With the Stone Deaf set to clean, the Height to approximately +5 dB, the bandwidth to Fat, and the frequency to about 3 o’clock, the signal from both a toaster pickup-equipped Rickenbacker 330 and an E-series Fender Stratocaster took on a wide, lively, full-spectrum character. The tones displayed a sort of natural compression more akin to the output of an outboard studio compressor than a comp pedal—a pretty delicious addition to an already lovely single-coil and 6L6 tone recipe.

Sweeping the Frequency knob up to maximum gave individual notes and arpeggios a bright, but not-quite-spiky presence—especially nice for bridge pickup work—that also left a lot of room for shaping sound with a guitar’s volume or tone knob. If your amp and guitar were feeling like a cramped canyon cottage, the Stone Deaf’s clean boost function is a little like adding a sunroom on the back—it creates a lot of bright, airy space. It can also take the sound of a very aggressive distortion like the Rat and add even a touch more girth or snarling focus, depending on where you set the Bandwidth and Frequency knobs.

The dirty circuit is where a lot of rock players will live with this pedal. It’s certainly not a high-gain distortion path, nor does it crank out the most hornet-buzzing fuzz. But switch the Bandwidth all the way to fat and the Height and Frequency knobs all the way clockwise, and a humbucker-equipped Les Paul will turn into a throaty, roaring monster that makes chords thick and wooly, and leads simultaneously warm, rotund, and defined. It’s no wonder that Josh Homme has taken to this pedal as well its inspiration.

The Dirty switch isn’t just about fat and furry stoner-rock tones. Moving the Frequency knob to 3 o’clock, the Height all the way clockwise, and Bandwidth to any of the three thinnest settings produced a cool sound in between a cocked wah and an envelope filter, and—depending on the input from your guitar or additional pedals—a fuzz that ranged from quacky and prickly to muscular and super-focused in the high-mid zone. Try this setting with some P-90s and a cranked Champ or Pro Junior, and you’re neck-deep in Texas boogie mud.

The Verdict
Where simpler or more radical distortion circuits transform your tone entirely, the Stone Deaf PDF-1 is really best at lending more color and control to your existing rig. And if you’re more-or-less content with sounds you get, but just need a little more breathing room, command over equalization, or a stretch of sonic two lane where you can open up the throttle a little, this Stone Deaf is an elegant and very capable tool.
Buy if...
you want to expand your range of color and command with a tried-and-trusted rig.
Skip if...
you’re looking for over-the-top or high-gain distortion and fuzz.

Street $225 - Stone Deaf FX -