Chela Overdrive Drill Template
PedalPCB · 125B
Template details
- Circuit
- Chela Overdrive
- Vendor
- PedalPCB
- Enclosure
- Hammond 125B
- Dimensions
- 63.6 × 119.3 × 35.8 mm
- Layout
- 125B 6-Knob (Type 1)
- Category
- Overdrive
Export formats
- PDF: print at 1:1 scale
- SVG: vector graphic
About this drill template
Drill template for the PedalPCB Chela Overdrive, sized for a Hammond 125B enclosure (63.6 × 119.3 × 35.8 mm). The pre-positioned holes match the PCB's pot footprint exactly, with the footswitch centred below the 6-knob layout. Print at 1:1 scale, tape to the enclosure face, centre-punch, and drill. PCB and parts not included.
PedalPCB description: “Compare to EQD Talons”
Compared to the EarthQuaker Devices Talons, a high-gain overdrive with a full amp-style EQ: Treble, Mid, Bass and Presence alongside Level and Drive. Six knobs make for a denser drill layout than the typical three-knob drive.
Covers gritty boost through full-on distortion, with enough EQ range to re-voice the pedal entirely.
Build notes
Six knobs is the practical limit for a single-row layout, used for complex circuits where the extra parameters genuinely change the sound rather than just trimming it.
The Hammond 125B is one of the most common DIY pedal enclosures: a touch larger than a 1590B, slightly smaller than a 1590BB, with room for almost any single-effect PCB plus 9V supply.
Vendor specs: Designed for a 125B enclosure with top-mounted jacks
Controls
- Level: Controls the overall output volume
- Drive: Controls the amount of overdrive
- Treble: Adjusts the level of high frequencies
- Mid: Adjusts the level of midrange frequencies
- Bass: Adjusts the level of low frequencies
- Presence: Adjusts the level of upper mid frequencies
Drill measurements
Hole centres for the 125B 6-Knob (Type 1) layout. X runs left to right from the centre of the face being drilled. On the enclosure face, Y is measured from the centre, positive towards the top. For holes on a side, Y is the distance down the wall, measured from the face edge. Export the PDF for a 1:1 printable version with a scale check.
| Hole | Face | X (mm) | Y (mm) | Diameter |
|---|---|---|---|---|
| Pot | Enclosure face | -20.3 | 38.1 | 7 mm (0.28 in) |
| Pot | Enclosure face | 0 | 38.1 | 7 mm (0.28 in) |
| Pot | Enclosure face | 20.3 | 38.1 | 7 mm (0.28 in) |
| Pot | Enclosure face | -20.3 | 12.7 | 7 mm (0.28 in) |
| Pot | Enclosure face | 0 | 12.7 | 7 mm (0.28 in) |
| Pot | Enclosure face | 20.3 | 12.7 | 7 mm (0.28 in) |
| LED | Enclosure face | 0 | -27.3 | 6.4 mm (0.25 in) |
| Footswitch | Enclosure face | 0 | -45 | 12 mm (0.47 in) |
| DC Jack | Top side | 0 | 14.2 | 8 mm (0.31 in) |
| Jack | Top side | -15.2 | 24.3 | 9.5 mm (0.37 in) |
| Jack | Top side | 15.3 | 24.3 | 9.5 mm (0.37 in) |
Jig B covers 125B 6-Knob (Type 1)
Drop it over the enclosure, punch a mark through the holes this build uses, then lift it off and drill. It wraps onto the sides too, so the jacks and DC socket are covered.
Both jigs, $12 →