PoliKick is an analog Eurorack kick drum inspired by the legendary TR-808. Based on the EDU DIY Kick Drum by Erica Synths, it adds a selectable distortion stage and an extended note range.
Key Features • List of Components • How To Use • Credits • License
- Eurorack Standard: Designed for standard +12V/-12V Eurorack power rails with a 10-pin power header.
- Trigger and CV Control: Accepts standard modular trigger pulses (5V-10V) and Control Voltage inputs for dynamic parameter modulation.
- Authentic Circuitry: Faithful reproduction of the original analog synthesis paths using modern, easily sourced equivalent components.
- Expanded Sound Design: Additional parameters exposed on the front panel compared to the original desktop unit.
!!!!!! Work In Progress
All the components listed below can be easily found and purchased on major electronic component distributors such as Mouser and DigiKey.
All resistors are through-hole Metal Film (Part Number: MFR-25FRF52)
| Resistor | Value |
|---|---|
| R1 | 470k |
| R2 | 4.7k |
| R3 | 47k |
| R4 | 1M |
| R5 | 100k |
| R6 | 14k |
| R7 | 33k |
| R8 | 100k |
| R9 | 100k |
| R10 | 22k |
| R11 | 120k |
| R12 | 39k |
| R13 | 100k |
| R14 | 1k |
| R15 | 1k |
| R16 | 1k |
| R17 | 18k |
| R18 | 1M |
| R19 | 100k |
| R20 | 10k |
| R21 | 2k |
| R22 | 330 |
| R23 | 10 |
| R24 | 10 |
| Capacitor | Value | Part Number |
|---|---|---|
| C1 | 15 nF | MMK5153K50 |
| C2 | 15 nF | MMK5153K50 |
| C3 | 10 nF | C430C106K3R |
| C4 | 68 nF | C320C683J5R |
| C5 | 5.6 nF | MMK5332K50 |
| C6 | 220 nF | MMK5224J50 |
| C7 | 47 µF | ESH476M050AG3KA |
| C8 | 100 nF | K104K15X7RF53L2 |
| C9 | 47 µF | ESH476M050AG3KA |
| C10 | 100 nF | K104K15X7RF53L2 |
| Diode | Characteristics | Part Number |
|---|---|---|
| D1 - D7 | Small Signal | 1N4148 |
| D8 - D9 | Schottky Barrier | 1N5819 |
| DS1 | Through Hole LED | LTL-1CHYE |
| Component | Characteristics | Part Number |
|---|---|---|
| U1 | Quad Low-Noise OP Amp | TL074CN |
| Q1, Q3, Q4 | NPN Transistor | BC548B |
| Q2, Q5 | PNP Transistor | BC558B |
| Designator | Name | Value | Part Number |
|---|---|---|---|
| A1 | AmpDeca | 50k, log | PTV09A-5025F-A503 |
| A2 | Distortior | 100k, log | PTV09A-4030F-A104 |
| B1 | Pitch | 100k | PTV09A-4025F-B104 |
| B2 | Tone | 50k | PTV09A-4025F-B503 |
| B3 | TuneDeca | 100k | PTV09A-4025F-B104 |
| B4 | TuneDept | 10k | PTV09A-4025F-B103 |
| B5 | PitchAmo | 100k | PTV09A-4025F-B104 |
| Component | Description | Part Number |
|---|---|---|
| Connector | Power Header | TSW-105-07-T |
| Connector | IC soket | 1-2199298-3 |
| IN1-Gate | 3.5 mm Stereo Jack | SJ3-35052B |
| IN2-AccentCV | 3.5 mm Stereo Jack | SJ3-35052B |
| IN3-PitchCV | 3.5 mm Stereo Jack | SJ3-35052B |
| OUT1 | 3.5 mm Stereo Jack | SJ3-35052B |
| SW1 | Toggle Switch | MN12SS4G03 |
| Component | Description | Size / Value |
|---|---|---|
| Screws | Machine Screws | M3 |
| Standoffs | Hex Standoffs / Spacers | M3, 1.5cm |
To install the module in your Eurorack system:
- Ensure your Eurorack case is completely powered off.
- Connect the 10-pin end of the ribbon cable to the header on the module's PCB. Pay strict attention to the orientation: the red stripe on the cable must align with the - marking on the PCB.
- Connect the 16-pin end of the cable to the bus board of your case (red stripe matching -12V).
- Secure the module to the rails using M3 screws before powering on the case.
To simulate the analog behavior of the circuitry, we used LTspice.
- Inside the
Simulationfolder, you will find thePoliKick.ascfiles containing the core voice circuits. - The trigger inputs in the simulation are modeled using a
PULSEvoltage source configured to mimick a standard sequencer trigger. - Run the
.trancommand to observe the envelope generation and the audio output transient response. - You can adjust the
.step paramcommands on the simulated potentiometers to test the range of the front panel controls.
Circuit analysis and schematic references based on the EDU DIY Kick Drum by Erica Synths, which originates from the classic Roland TR-808 service manual.