Enclosure not stated · 2 knobs
Vsex Pedals Proximity Sensor (Zvex Probe controller)
Based on the Z.Vex Wah Probe
- Category
- Utility
- Controls
- Sensitivity · Intensity
- Price
- see vendor
- Tags
- freestompboxes.org trace
From the vendor
A redrawn version of the proximity controller in Zvex's Probe pedals, as revealed by freestompboxes.org members (~arph and others): an antenna plate feeds a 2N3906 oscillator built around 4093 NAND gates, whose output drives a 2N3904 LED driver lighting a vactrol. The vactrol's LDR then controls a parameter of an effect, here the Colorsound wah.
A copper board blank used for etching PCBs works as the antenna; try different sized plates. Use the 250KA pot to tune the sensitivity to a given antenna size and shoe thickness; the 10KA sets the starting intensity of the LED. When first tuning the circuit, use a visible LED in place of the vactrol to see how it reacts, then change to the vactrol.
Schematic
The schematic is in the post. Open it at Revolution Deux. No KiCad fragment has been drawn for this circuit yet.
Parts list 14 rows
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Fixes to the schematic, from the post
- The capacitor at the base of the second transistor (the 2N3904 LED driver) has no value on the drawing; it is 22nF.
Check before you build · 1 value the reader of this schematic was not sure of
- The panel names of the two pots are not given; they are named here from the drawing's notes.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 3 | ||||
| R1 | 10K | 10k | read from the schematic by eye | |
| R2 | 3.9K | 3.9k | read from the schematic by eye | |
| R3 | 1K | 1k | regulator; read from the schematic by eye | |
| Capacitors 4 | ||||
| C1 | 1n | 1n | antenna input; read from the schematic by eye | |
| C2 | 47p | 47p | read from the schematic by eye | |
| C3 | 22n | 22n | missing on the drawing; the post gives 22nF; read from the schematic by eye | |
| C4 | 1u | 1u | electrolytic; read from the schematic by eye | |
| Diodes 1 | ||||
| D1 | 5.1V zener | 5V1 | regulator; read from the schematic by eye | |
| Transistors 2 | ||||
| Q1 | 2N3906 | 2N3906 | read from the schematic by eye | |
| Q2 | 2N3904 | 2N3904 | LED driver; read from the schematic by eye | |
| ICs 1 | ||||
| IC1 | 4093N | 4093N | quad NAND; read from the schematic by eye | |
| Potentiometers 2 | ||||
| Sensitivity | A250K | A250k | Potentiometer | read from the schematic by eye |
| Intensity | A10K | A10k | Potentiometer | starting LED intensity; read from the schematic by eye |
| Other 1 | ||||
| OPT1 | VTL5C9 | VTL5C9 | vactrol; its LDR goes to the effect; read from the schematic by eye | |