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Fuzz1973· Tycobrahe Engineering (USA)

Tycobrahe Octavia

Full-wave rectified octave-up fuzz — Hendrix's 'Purple Haze' solo in a box.

⏳
Schematic pending verification

We don't ship reference schematics until they've been hand-authored against authoritative sources (manufacturer service docs, ElectroSmash analyses, GEOFEX writeups) and reviewed in the simulator. Until then, the BOM, signal chain, controls and mod notes below are accurate, and you can still add this pedal to a project — it just won't include a circuit yet.

About

An input transistor stage drives a centre-tapped transformer; two diodes full-wave rectify the secondary, doubling the fundamental frequency to produce an upper-octave 'ghost' note above the dry signal. Sounds most octave-like on the neck pickup, above the 12th fret.

Signal chain preview

4 stages
Input
Input boost transistor stage
Drive transistor into 1:1 centre-tapped transformer primary
Secondary feeds two diodes (full-wave rectifier) → output cap
No tone control — just a Volume pot at the output
Output

Quick facts

  • The octave-up is loudest with single-note lines around the neck pickup — chords sound chaotic.
  • Originally built by Tycobrahe for Hendrix's tech; Roger Mayer's 'Octavia' is a separate parallel design.
  • Modern clones (Foxrox Octron, Prescription Electronics Experience) refine the same core trick.

Controls

  • Volume (100k log)
  • Boost (1k linear in some versions)

Mod recipes Pro

2 mods
  • Germanium rectifier

    Softer, smoother octave with less crackle on chords.

    How: Replace D1/D2 (1N4148) with germanium OA91 or 1N34A. Lower forward voltage = the octave 'kicks in' earlier and feels more musical.

  • Octave defeat switch

    Bypass the rectifier to use the pedal as a straight fuzz.

    How: Wire an SPDT to bypass the transformer + rectifier section, routing the input fuzz stage directly to the volume pot.