The Stone Deaf FX PDF-1 is a parametric distortion filter pedal from Stone Deaf FX of Manchester, England. It is a sturdier and more versatile evolution of the Maestro Parametric Filter (MPF) circuit, and Premier Guitar called it "a pedal of myriad applications beyond heavy and blazing riffage"1. In practice it works as a boost, overdrive, distortion and all-around tone shaper in one box2.
The core idea is a parametric filter: you pick a frequency, then cut or boost it, and the pedal can add gain on top. That makes it useful both as a standalone distortion pedal and as a shaping tool placed around other drives on your board.
A parametric filter that boosts, cuts and drives
A parametric filter lets you choose which part of the tonal spectrum to cut or boost, and by how much. On the PDF-1, the Freq knob selects the frequency, ranging from 65Hz to 3kHz, and the Height knob drops or boosts that frequency by up to 20dB2. The Bandwidth selector then narrows or widens the affected signal across five settings2.
With Frequency at 3 o'clock, Height clockwise and Bandwidth on the three thinnest settings, Premier Guitar's reviewer got "a cool sound in between a cocked wah and an envelope filter", with fuzz character ranging from quacky and prickly to muscular and super-focused in the high-mid zone1. The control names are identical to those on the Maestro MPF that inspired the pedal1.
The controls
| Control | What it does |
|---|---|
| Freq | Selects the filter frequency, from 65Hz to 3kHz2 |
| Height | Drops or boosts the selected frequency by up to 20dB2 |
| Bandwidth | Five settings that reduce or widen the signal's bandwidth2 |
| Clean/Dirty switch | Switches between a boost-type setting and a crunchier gain mode2 |
In the Clean setting, the PDF-1 works as an all-around tone and pedal shaper, pairing well with other overdrives and distortions to help tame and shape their sound2. Premier Guitar's reviewer found the clean circuit remarkably transparent, noting that the clean boost creates bright, airy space and lends character to overdrive and distortion signals1.
Dirty mode adds gain. Pedal of the Day described it as producing stoner rock inspired sounds without too much grit and grime2, while Guitar.com's review of the PDF-2's gain channel noted a range "from beefy medium-gain overdrive to something not far short of full-on fuzz"34.
Build and power
The PDF-1 is built in a custom-machined aluminum casing with top-notch pots and switches and a stylishly engraved 3-ply plastic control panel, and Premier Guitar noted it is an exceptionally light pedal for all its obvious quality1. Power comes from a 9-volt battery, which Premier Guitar described as "brilliantly stashed on the side of the enclosure in a sliding access compartment"1.
The PDF-1's successors
Stone Deaf has since released the PDF-2, which the maker calls "a successor to the legendary PDF-1", offering parametric EQ, overdrive, distortion and fuzz for guitars, basses, drums, synths and more5. The PDF-2 also runs on a 9V battery or DC adaptor, though Guitar.com noted there is no side-mounted battery compartment; you have to unscrew the base instead43.
In 2019 Stone Deaf issued the PDF-1X, a special edition of 200 units that includes the PDF-1 and PDF-2 sets of features6. On That Pedal Show, Mick and Daniel described the run: "these are special edition there's 200 of these right"7.
Stone Deaf has marked both the PDF-2 and the PDF-1X Ghost as the last batch before discontinuation58. The PDF-1 itself has been superseded, so remaining stock is what is available.
The maker positions the PDF-1X as a tone shaper and sweetener at the end of a pedal chain: "Place it after any overdrive or fuzz and before modulation and it will enhance your tone as a boost, EQ and Distortion device"8.
Stone Deaf FX has released a newer version of the PDF-1, the PDF-25.
Videos
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Iga Massardi
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Questions
Does the Stone Deaf PDF-1 take a battery?
Yes. The PDF-1 runs on a 9-volt battery housed in a sliding access compartment on the side of the enclosure, which Premier Guitar's reviewer called a clever touch. Its successor, the PDF-2, also supports a 9V battery, though there you have to unscrew the base to reach it.
What does the Clean/Dirty switch do on the PDF-1?
It switches between two modes. Clean mode works as a transparent tone and pedal shaper that pairs well with other overdrives and distortions, while Dirty mode adds gain, producing stoner rock inspired sounds without excessive grit. Premier Guitar found the clean circuit remarkably transparent and characterful with driven signals.
What is the difference between the PDF-1 and the PDF-2?
The PDF-2 is Stone Deaf's successor to the PDF-1, offering parametric EQ, overdrive, distortion and fuzz in one unit. Its gain control ranges from beefy medium-gain overdrive to something not far short of full-on fuzz, according to Guitar.com's reviewer. The PDF-1X limited edition combined the feature sets of both pedals.
What frequency range does the PDF-1 cover?
The Freq knob selects the center frequency of the parametric filter, ranging from 65Hz to 3kHz. The Height knob then drops or boosts that frequency by up to 20dB, and the Bandwidth selector narrows or widens the affected signal across five settings.
What is the PDF-1X limited edition?
A special edition of 200 units that includes the combined feature sets of the PDF-1 and PDF-2. On That Pedal Show, Mick and Daniel described it as a special edition run of 200. Stone Deaf has since marked its remaining stock as the last batch before discontinuation.
How much does the Stone Deaf PDF-1 cost?
Premier Guitar listed the PDF-1 at a street price of $225 in its review. The pedal has since been superseded by the PDF-2, which Stone Deaf has also marked as being in its last production batch before discontinuation.
Sources (8)
- Stone Deaf FX PDF-1 Pedal Review: Ultimate Guide, Premier Guitar, 2011-02-15
- Stone Deaf FX PDF-1 Parametric Distortion Filter, Pedal of the Day, 2016-05-30
- Stone Deaf PDF-2 & EP-1 Expression Pedal Review, Guitar.com, 2018-10-15
- Stone Deaf Kliptonite, Fig Fumb, PDF-2 & Trashy Blonde pedal review, Guitar.com, 2016-07-06
- PDF-2 - Stone Deaf, Stone Deaf (stonedeaffx.com)
- Stone Deaf PDF-1X Limited Edition, Delicious Audio, 2019-12-23
- Boss MD-200, Stone Deaf PDF-1X, GCP Comfortably Plum, TC Flashback II x4, That Pedal Show (YouTube), 2019-11-05
- PDF-1X GHOST, Stone Deaf
