Pedals / Graphic EQ

Graphic G

Graphic EQ · play-tested

seth — fish 
seth@ninevolt:~$
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Knobs

In the TUI each knob runs from low (left / 0%) to high (right / 100%). Start near noon, then nudge while you play.

100

Low bass band (~100 Hz) — boom and body.

  • Turn up More low thump.
  • Turn down Less boom; tighter bottom.

200

Upper bass (~200 Hz).

  • Turn up Warmer low-mids.
  • Turn down Leaner low-mids.

400

Low midrange (~400 Hz) — boxiness / warmth.

  • Turn up Thicker, sometimes boxier.
  • Turn down Clearer, less muddy.

800

Core midrange (~800 Hz) — presence in a band mix.

  • Turn up More mid punch; cuts through.
  • Turn down Scooped mids; sits back.

1.6k

Upper mids (~1.6 kHz) — attack and definition.

  • Turn up More pick definition and “honk.”
  • Turn down Softer attack.

3.2k

Presence band (~3.2 kHz).

  • Turn up More cut and edge.
  • Turn down Smoother, less harsh.

6.4k

Highs / air (~6.4 kHz).

  • Turn up Brighter sparkle.
  • Turn down Darker top end.

Level

Overall EQ output volume.

  • Turn up Louder after shaping.
  • Turn down Quieter after shaping.

Inspired by

Boss GE-7 Equalizer (1987–present) — seven gyrator peaking bands plus a 6.4 kHz shelf, ±15 dB per slider, Level master. Nirvana, Metallica, and other profiles use it for mid scoop or V-shaped rhythm tones.

Signal path

StepWhat it does
100 Hz peakGyrator band 1 — 100 slider (±12 dB).
200 Hz peakGyrator band 2 — 200 slider.
400 Hz peakGyrator band 3 — 400 slider.
800 Hz peakGyrator band 4 — 800 slider.
1.6 kHz peakGyrator band 5 — 1.6k slider.
3.2 kHz peakGyrator band 6 — 3.2k slider.
6.4 kHz shelfTop band shelf — 6.4k slider.
LevelMaster output slider (±12 dB in software; ±15 dB on hardware).

How we modeled it

Full GE-7 panel in series: 100 → 200 → 400 → 800 → 1.6k → 3.2k peaking → 6.4k shelf → Level. Each slider is independent — scoop 800 Hz while boosting 3.2 kHz, same as the real pedal.

Simplifications

- Fixed Q vs proportional Q gyrator behavior - Digital biquads vs op-amp gyrator topology - No buffered-bypass pop or slider noise