Enclosure not stated · 1 knob
ISP Decimator Noise Reduction
Based on the ISP Decimator
- Category
- Noise Gate
- Controls
- Threshold
- Price
- see vendor
From the vendor
ISP's Decimator, a noise reduction pedal that uses a THAT 2181 VCA as a downward expander, steered by an envelope detector with ISP's 'Time Vector Processing' release, which reacts fast to staccato notes and slowly on long sustained ones. The post presents it as a transparent alternative to a classic noise gate, without the tone suck and note cut-off. Reverse engineered from an original on DIYStompboxes.com; Joao Galego drew the schematic and a PCB layout.
Schematic
The schematic is in the post. Open it at Revolution Deux. No KiCad fragment has been drawn for this circuit yet.
Parts list 73 rows
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Check before you build · 2 values the reader of this schematic was not sure of
- The quad op-amps U7 and U9 have no type on the drawing.
- Images 4 and 5 are further PCB artwork (a second layout view and the traces).
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 36 | ||||
| R1 | 1K | 1k | read from the schematic by eye | |
| R2 | 1M | 1M | read from the schematic by eye | |
| R3 | 20K | 20k | read from the schematic by eye | |
| R4 | 5.1K | 5.1k | read from the schematic by eye | |
| R5 | 22M | 22M | read from the schematic by eye | |
| R6 | 10K | 10k | read from the schematic by eye | |
| R7 | 10K | 10k | read from the schematic by eye | |
| R8 | 1M | 1M | read from the schematic by eye | |
| R9 | 27K | 27k | read from the schematic by eye | |
| R10 | 100K | 100k | read from the schematic by eye | |
| R11 | 5.1K | 5.1k | read from the schematic by eye | |
| R12 | 10M | 10M | read from the schematic by eye | |
| R13 | 20K | 20k | read from the schematic by eye | |
| R14 | 20K | 20k | read from the schematic by eye | |
| R15 | 20K | 20k | read from the schematic by eye | |
| R16 | 20K | 20k | read from the schematic by eye | |
| R17 | 100K | 100k | read from the schematic by eye | |
| R18 | 2.2K | 2.2k | LED resistor; read from the schematic by eye | |
| R19 | 10K | 10k | read from the schematic by eye | |
| R20 | 200K | 200k | read from the schematic by eye | |
| R21 | 68K | 68k | read from the schematic by eye | |
| R22 | 47K | 47k | read from the schematic by eye | |
| R23 | 1M | 1M | read from the schematic by eye | |
| R24 | 20K | 20k | read from the schematic by eye | |
| R25 | 100 | 100 | read from the schematic by eye | |
| R26 | 100K | 100k | read from the schematic by eye | |
| R27 | 10K | 10k | read from the schematic by eye | |
| R28 | 20K | 20k | read from the schematic by eye | |
| R29 | 20K | 20k | read from the schematic by eye | |
| R30 | 10K | 10k | read from the schematic by eye | |
| R31 | 750 | 750 | read from the schematic by eye | |
| R35 | 270K | 270k | read from the schematic by eye | |
| R36 | 1K | 1k | read from the schematic by eye | |
| R37 | 620 | 620 | read from the schematic by eye | |
| R38 | 100K | 100k | read from the schematic by eye | |
| R39 | 100K | 100k | read from the schematic by eye | |
| Capacitors 16 | ||||
| C1 | 470n | 470n | read from the schematic by eye | |
| C2 | 100p | 100p | read from the schematic by eye | |
| C3 | 10u | 10u | electrolytic; read from the schematic by eye | |
| C4 | 330n | 330n | read from the schematic by eye | |
| C5 | 100n | 100n | read from the schematic by eye | |
| C6 | 330n | 330n | read from the schematic by eye | |
| C7 | 1u | 1u | electrolytic; read from the schematic by eye | |
| C8 | 22p | 22p | read from the schematic by eye | |
| C9 | 10u | 10u | electrolytic; read from the schematic by eye | |
| C10 | 22u | 22u | electrolytic; read from the schematic by eye | |
| C11 | 100u | 100u | electrolytic, power filter; read from the schematic by eye | |
| C12 | 100n | 100n | power filter; read from the schematic by eye | |
| C13 | 100n | 100n | power filter; read from the schematic by eye | |
| C14 | 100n | 100n | power filter; read from the schematic by eye | |
| C15 | 22u | 22u | electrolytic; read from the schematic by eye | |
| C18 | 10u | 10u | electrolytic, power filter; read from the schematic by eye | |
| Diodes 12 | ||||
| D1 | 1N914 | 1N914 | read from the schematic by eye | |
| D2 | 1N914 | 1N914 | read from the schematic by eye | |
| D3 | 1N914 | 1N914 | read from the schematic by eye | |
| D4 | 1N914 | 1N914 | read from the schematic by eye | |
| D5 | 1N914 | 1N914 | read from the schematic by eye | |
| D6 | 1N914 | 1N914 | read from the schematic by eye | |
| D9 | 1N914 | 1N914 | read from the schematic by eye | |
| D10 | 1N914 | 1N914 | read from the schematic by eye | |
| D11 | 1N914 | 1N914 | read from the schematic by eye | |
| D12 | 1N5819 | 1N5819 | read from the schematic by eye | |
| D14 | 1N914 | 1N914 | read from the schematic by eye | |
| D15 | 1N914 | 1N914 | read from the schematic by eye | |
| Transistors 2 | ||||
| Q1 | 2N5551 | 2N5551 | read from the schematic by eye | |
| Q4 | MPS2222A | MPS2222A | read from the schematic by eye | |
| ICs 4 | ||||
| U5 | LF353N | LF353N | read from the schematic by eye | |
| U7 | ? | ? | quad op-amp, type not given; read from the schematic by eye | |
| U8 | THAT2181C | THAT2181C | VCA; read from the schematic by eye | |
| U9 | ? | ? | quad op-amp, type not given; read from the schematic by eye | |
| Potentiometers 2 | ||||
| Threshold | B10K | B10k | Potentiometer | drawn as POT; read from the schematic by eye |
| R180 | 1M | 1M | Potentiometer | trimmer (VCA symmetry); read from the schematic by eye |
| LEDs 1 | ||||
| D8 | LED | LED | read from the schematic by eye | |