The Free The Tone Iron Forest IF-1D is an analog distortion stompbox from Japanese maker Free The Tone, designed by Yuki Hayashi1. It pairs a wide gain range with a two-band EQ, treble and bass, which Free The Tone says allows a wide range of sound shaping2. MusicRadar reviewed it as an edgy, aggressive distortion that stays clear of fizz, aimed squarely at rock players1.
The pedal is discontinued: Free The Tone's product page marks it as out of production, at a Japanese retail price of 25,300 yen including tax2. When MusicRadar first covered it in November 2012, UK retail was £2223.
An aggressive distortion with bass and treble
The IF-1D sits in the distortion category, which MusicRadar describes as a harder edge than overdrive, the ground between Sabbath, Angus Young, the Foos and QOTSA1. Its tone shaping comes from a two-band EQ: Free The Tone specifies a wide gain range and a two-tone type EQ (treble and bass) that enables varied sound making2.
MusicRadar found those tone controls to be the heart of the pedal's flexibility132:
"The bass and treble pots are very powerful, enabling you to create a metal-type, mid-scooped sound by boosting both"1
Backing both controls toward 12 o'clock returns a more mid-rich sound, so the same pedal covers scooped metal rhythms and mid-forward lead tones without a mid knob1.
On overall character, MusicRadar's verdict was direct:
"Edgy, aggressive distortion that avoids ever getting fizzy."1
The review described the sound as aggressive and grin-inducing, getting fuzzy at the upper extremes of the gain range, and definitely rock. The reviewers preferred it with humbuckers and Marshall-derived amps over single coils and blackface Fender-type circuits1. RockBoard's PedalPedia entry describes a strong attack at the moment a string is plucked, followed by a smooth distortion sound with rich overtones, crispness in riff playing and the long sustain lead solos need4.
The controls
The control set is deliberately simple: four knobs, no switches, no extra options. MusicRadar framed this as the pedal's design philosophy, choosing four basic rotaries instead of extra switches and options1.
| Control | What it does |
|---|---|
| GAIN | Sets the amount of distortion, with a wide range2 |
| TREBLE | Boosts or cuts high frequencies; powerful enough to shape the mid balance21 |
| BASS | Boosts or cuts low frequencies; boosting both tone knobs scoops the mids21 |
| LEVEL | Sets the output volume2 |
The HTS circuit
The Iron Forest is built on Free The Tone's HTS (Holistic Tonal Solution) circuit, the same circuit MusicRadar noted in the Gigs Boson overdrive1. MusicRadar's 2012 coverage credited the HTS circuit with pure tones and silent on/off switching3.
MusicRadar also reported on the thinking behind it:
"which designer Yuki Hayashi maintains addresses the inherent flaws in both true bypass and buffered pedal circuits"1
For a player, that means the pedal's switching is silent rather than producing the click or pop some bypass arrangements give, and the signal path is designed to avoid the tonal trade-offs between true bypass and buffered designs31.
Power and connections
The IF-1D runs on DC9V, from either a 9V 006P-type battery or an AC adapter connected through a DC9V input jack on the pedal2. Current draw is about 9mA2, low enough that a battery is a practical option. The power input is center negative4.
The pedal is discontinued, so it is found on the secondhand market rather than from retailers. Its 9mA draw is gentle on a pedalboard power supply, and the center-negative 9V DC requirement matches common daisy-chain supplies4.
Connections are two 1/4-inch standard phone jacks, one input and one output, alongside the DC9V adapter jack5. The output expects a load impedance of 10kΩ or higher2, which standard amp and pedal inputs meet.
The pedal comes in a matt navy colored metal case, visually similar to the Gigs Boson except for the color3.
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Questions
Is the Free The Tone Iron Forest IF-1D still made?
No. Free The Tone lists the IF-1D as discontinued on its product page, alongside its Japanese retail price of 25,300 yen including tax. It is now a secondhand-market pedal rather than a current product2.
Does the Iron Forest IF-1D run on a 9V battery?
Yes. Free The Tone specifies DC9V power from either a 9V 006P-type battery or an AC adapter, with a DC9V input jack on the pedal for the adapter. Current draw is about 9mA, so a battery lasts a long time2.
What is the HTS circuit in the Iron Forest?
HTS stands for Holistic Tonal Solution, a Free The Tone circuit also used in the Gigs Boson overdrive. MusicRadar reports that designer Yuki Hayashi maintains it addresses the inherent flaws in both true bypass and buffered pedal circuits, and it provides silent on/off switching13.
Who designed the Free The Tone Iron Forest?
Yuki Hayashi, Free The Tone's designer, is named by MusicRadar in connection with the pedal's HTS circuit, which he maintains addresses the inherent flaws in both true bypass and buffered pedal circuits1.
Is the Iron Forest IF-1D analog?
Yes. The IF-1D is listed as an analog distortion pedal, with a two-band EQ covering treble and bass alongside its gain and level controls4.
Does the Iron Forest have a mid control?
No. The four controls are gain, treble, bass and level. There is no mid knob, but MusicRadar found the bass and treble pots are powerful enough to create a mid-scooped metal sound by boosting both, or a mid-rich sound by backing them toward 12 o'clock1.
Sources (5)
- Free The Tone Iron Forest Distortion IF-1D review, MusicRadar, 2013-03-04
- IRON FOREST / IF-1D｜Products 商品紹介｜Free The Tone, Free The Tone
- Hands on with the Free The Tone Gigs Boson Overdrive and Iron Forest Distortion pedals, MusicRadar, 2012-11-30
- IF-1D Iron Forest Distortion by Free The Tone, RockBoard PedalPedia, 2026
- IRON FOREST / IF-1D｜Products 商品紹介｜Free The Tone, Free The Tone
