125B · 3 knobs
WarpfieldResonant Drive
Based on the Pearl Warp Sound
- Category
- Overdrive· Resonant filter overdrive
- Controls
- Distortion · Envelope · Output
- Difficulty
- Easy
- Price
- $12.50in stock
From the vendor
A rare effect from the 1970s combining a distortion circuit with an adjustable-frequency resonant low-pass filter. Most notably used by Kevin Shields of My Bloody Valentine.
The Warpfield Resonant Drive is an adaptation the incredibly rare Pearl Warp Sound, also sold under the Vorg brand name.
The Warp Sound was a generally unnoticed pedal when it came out in the mid-1970s. A few decades later, though, Kevin Shields of My Bloody Valentine was seen with one on his pedalboard that he had marked “Sometimes” (the eighth track on their classic album Loveless), and the MBV association has since caused them to sell for upwards of $500—if you can find one.
At its heart, the Warp Sound is a static resonant low-pass filter with adjustable frequency, sort of like a cocked wah. This is combined with a fuzzy, rough-around-the-edges distortion to create some really interesting textures. It’s not going to be your main drive pedal, but it’s a great tool to have in your arsenal.
The original Warp Sound only had two knobs on the outside, with the distortion trimmer set internally. The Warpfield puts the distortion control as an external knob. Many people like to leave the distortion all the way up, but you can be the judge.
The Warpfield is a direct adaptation of the Warp Sound. Other than the relocation of the Distortion control, the only other change was to make it true bypass (the original was buffered). You’ll notice a vestigial resistor and capacitor coming off of IC1. These were part of the buffer circuit, but since the signal does pass through them in effect mode forming a very slight filter, they were left in.
Note: This project uses a type of capacitor that has been temporarily discontinued by WIMA. Please see our news article about the issue and the substitution spreadsheet for project-specific recommendations. We are stocking a limited supply in the mean time. The build document has not yet been updated to reflect this.
Schematic
The schematic is in the vendor's build document, page 6. Open the build document. No KiCad fragment has been drawn for this circuit yet.
Parts list 40 rows
Report a wrong parse| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 16 | ||||
| R1 | 10k | 10k | Metal film resistor, 1/4W | |
| R2 | 220k | 220k | Metal film resistor, 1/4W | |
| R3 | 220k | 220k | Metal film resistor, 1/4W | |
| R4 | 47k | 47k | Metal film resistor, 1/4W | |
| R5 | 10k | 10k | Metal film resistor, 1/4W | |
| R6 | 330k | 330k | Metal film resistor, 1/4W | |
| R7 | 270R | 270 | Metal film resistor, 1/4W | |
| R8 | 10k | 10k | Metal film resistor, 1/4W | |
| R9 | 100k | 100k | Metal film resistor, 1/4W | |
| R10 | 10k | 10k | Metal film resistor, 1/4W | |
| R11 | 220k | 220k | Metal film resistor, 1/4W | |
| R12 | 47k | 47k | Metal film resistor, 1/4W | |
| R13 | 100R | 100 | Metal film resistor, 1/4W | |
| R14 | 10k | 10k | Metal film resistor, 1/4W | |
| R15 | 10k | 10k | Metal film resistor, 1/4W | |
| LEDR | 10k | 10k | Metal film resistor, 1/4W | LED current-limiting resistor. Adjust value to change LED brightness. |
| Capacitors 8 | ||||
| C1 | 47n | 47n | Film capacitor, 7.2 x 2.5mm | |
| C2 | 47n | 47n | Film capacitor, 7.2 x 2.5mm | |
| C3 | 22n | 22n | Film capacitor, 7.2 x 2.5mm | |
| C4 | 22n | 22n | Film capacitor, 7.2 x 2.5mm | |
| C5 | 1uF | 1u | Film capacitor, 7.2 x 3.5mm | |
| C6 | 100uF | 100u | Electrolytic capacitor, 6.3mm | Power supply filter capacitor. |
| C7 | 47uF | 47u | Electrolytic capacitor, 5mm | Reference voltage filter capacitor. |
| C8 | 100n | 100n | MLCC capacitor, X7R | Power supply filter capacitor. |
| Diodes 3 | ||||
| D1 | 1N5817 | 1N5817 | Schottky diode, DO-41 | |
| D2 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| D3 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| ICs 2 | ||||
| IC1 | LM1458 | LM1458 | Operational amplifier, dual, DIP8 | |
| IC2 | LM1458 | LM1458 | Operational amplifier, dual, DIP8 | |
| Potentiometers 3 | ||||
| DIST. | 100kB | B100k | 16mm right-angle PCB mount pot | Linear taper. |
| ENV. | 10kB | B10k | 16mm right-angle PCB mount pot | Linear taper. |
| OUTPUT | 50kA | A50k | 16mm right-angle PCB mount pot | Audio (log) taper. |
| Switches 1 | ||||
| FSW | 3PDT | 3PDT | Stomp switch, 3PDT | |
| Jacks & sockets 5 | ||||
| IC1-S | DIP-8 socket | DIP-8 SOCKET | IC socket, DIP-8 | |
| IC2-S | DIP-8 socket | DIP-8 SOCKET | IC socket, DIP-8 | |
| IN | 1/4" stereo | 1/4" STEREO | 1/4" phone jack, closed frame | Switchcraft 112BX or equivalent. |
| OUT | 1/4" mono | 1/4" MONO | 1/4" phone jack, closed frame | Switchcraft 111X or equivalent. |
| DC | 2.1mm | 2.1MM | DC jack, 2.1mm panel mount | Mouser 163-4302-E or equivalent. |
| Hardware 2 | ||||
| BATT | Battery snap | BATTERY SNAP | 9V battery snap | Optional. Use the soft plastic type—the hard-shell type will not fit. |
| ENC | 125B | 125B | Enclosure, die-cast aluminum | Can also use a Hammond 1590N1. |