This repository contains schematics, PCB layout files and front panel for an analog, semi modular, patchable synthesizer. It is an interface that works in conjunction with my voice card https://github.com/polykit/polykit-x-voice-card
Specs of the voice card:
- a VCO with saw, pulse and triangle signal
- an envelope generator
- a multimode filter with 8 different filter responses
- an external input
- and a panning stereo output
See voice card repository for a full feature list.
Specs of the semi modular interface:
- a LFO where the waveform can be blended between triangle and pulse signal
- a wave folder
- a two channel mixer where one input can be attenuated
- an additional attenuator
- a buffered multiple
- different offset voltages
- and a power supply
- 3D printable case
Video playlist on its functionality and design process: https://www.youtube.com/watch?v=2grRbG7IwDw&list=PLUKLEU8jmlbHH4_13YZM0MI6ez4gYQPfy
Gerber files can be found here, front panel files are located here.
| Ref | Qnty | Value | Name | Description |
|---|---|---|---|---|
| C1, C2 | 2 | 1000uF | C_Polarized | Electrolytic capacitor |
| C3, C4 | 2 | 100uF | C_Polarized | Electrolytic capacitor |
| C5, C6 | 2 | 10uF | C_Polarized | Electrolytic capacitor |
| C7, C8 | 2 | 1uF | C_Polarized | Electrolytic capacitor |
| C9 | 1 | 2u2 non-polarized | C | Film or ceramic capacitor |
| C10, C11, C12, C13, C14 | 5 | 100n | C | Ceramic capacitor |
| D1 | 1 | LED | LED | Light emitting diode |
| D2, D3 | 2 | US1G | US1G | 400V, 1A, General Purpose Rectifier Diode, SMA(DO-214AC) |
| D4, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15 | 11 | BAS85 | D_Schottky | Schottky diode |
| D5 | 1 | Dual LED | LED_Dual_Bidirectional | Dual LED, bidirectional |
| J1 | 1 | OUT LEFT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J2 | 1 | OUT RIGHT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J3 | 1 | ADSR_OUT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J4 | 1 | GATE | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J5 | 1 | TRIGGER | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J6 | 1 | Conn_01x36 | Conn_01x36 | Pinheader, 01x36 |
| J7 | 1 | 12V AC | Jack-DC | Barrel Jack Socket, 12V AC/AC 1A wall wart power supply is needed |
| J8 | 1 | LFO | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J9 | 1 | PAN_CV | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J10 | 1 | PWM CV | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J11 | 1 | RES CV | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J12 | 1 | FREQ CV | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J13 | 1 | PITCH CV 1V/OCT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J14 | 1 | EXT IN | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J15 | 1 | VCA CV | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J16 | 1 | HARD SYNC | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J17 | 1 | SOFT SYNC | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J18 | 1 | FM | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J19 | 1 | MULT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J20 | 1 | WAVE IN | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J21 | 1 | ATT IN (+5V) | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J22 | 1 | MULT1 | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J23 | 1 | MULT2 | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J24 | 1 | ATT OUT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J25 | 1 | MIX IN2 | Can be used as default input for MIX2 when not patched | |
| J26 | 1 | MIX IN1 (-5V) | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J27 | 1 | MIX IN2 | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J28 | 1 | WAVE OUT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| J29 | 1 | MIX OUT | AudioJack2_SwitchT | Audio Jack, 2 Poles (Mono / TS), https://www.thonk.co.uk/shop/thonkiconn |
| Q1, Q3 | 2 | BC847 | BC847 | 0.1A Ic, 45V Vce, NPN Transistor, SOT-23 |
| Q2 | 1 | BC857 | BC857 | 0.1A Ic, 45V Vce, PNP Transistor, SOT-23 |
| R1, R18, R19, R47, R50 | 5 | 10k | R | Resistor |
| R2, R3, R4, R5, R20, R21, R45, R46, R54, R58 | 10 | 1k | R | Resistor |
| R10 | 1 | 100 | R | Resistor |
| R11, R12, R13, R15, R22, R23, R24, R25, R27, R28, R29, R30, R31, R32, R33, R34, R35, R36, R37, R38, R39, R40, R41, R43, R44, R51, R52, R53, R55, R56, R57 | 31 | 100k | R | Resistor |
| R14 | 1 | 220k | R | Resistor |
| R16 | 1 | 15k | R | Resistor |
| R17, R48, R49 | 3 | 12k | R | Resistor |
| R26 | 1 | 47k | R | Resistor |
| R42 | 1 | 470k | R | Resistor |
| RV1 | 1 | B100k LEVEL1 | R_POT-Device | Potentiometer RK097 Vertical |
| RV2 | 1 | B100k LEVEL2 | R_POT-Device | Potentiometer RK097 Vertical |
| RV3 | 1 | 10k LFO TRIM | R_Potentiometer_Trim | Trim-potentiometer |
| RV4 | 1 | B1M LFO RATE | R_POT-Device | Potentiometer RK097 Vertical |
| RV5 | 1 | B100k LFO WAVE | R_POT-Device | Potentiometer RK097 Vertical |
| RV6 | 1 | B100k PANNING | R_POT-Device | Potentiometer RK097 Vertical |
| RV7 | 1 | B100k A | R_POT-Device | Potentiometer RK097 Vertical |
| RV8 | 1 | B100k D | R_POT-Device | Potentiometer RK097 Vertical |
| RV9 | 1 | B100k S | R_POT-Device | Potentiometer RK097 Vertical |
| RV10 | 1 | B100k R | R_POT-Device | Potentiometer RK097 Vertical |
| RV11 | 1 | B100k RES | R_POT-Device | Potentiometer RK097 Vertical |
| RV12 | 1 | B100k FREQ | R_POT-Device | Potentiometer RK097 Vertical |
| RV13 | 1 | B100k PWM | R_POT-Device | Potentiometer RK097 Vertical |
| RV14 | 1 | B100k TUNE | R_POT-Device | Potentiometer RK097 Vertical |
| RV15 | 1 | B100k ATT | R_POT-Device | Potentiometer RK097 Vertical |
| RV16 | 1 | B100k MIX IN1 LEVEL | R_POT-Device | Potentiometer RK097 Vertical |
| SW1 | 1 | EXT_ON | SW_SPDT | Switch, single pole double throw |
| SW2 | 1 | FILTER_A | SW_SPDT | Switch, single pole double throw |
| SW3 | 1 | FILTER_B | SW_SPDT | Switch, single pole double throw |
| SW4 | 1 | FILTER_C | SW_SPDT | Switch, single pole double throw |
| SW5 | 1 | RES_MODE | SW_SPDT_MSM | Switch, single pole double throw, center OFF position |
| SW6 | 1 | FREQ_MODE | SW_SPDT_MSM | Switch, single pole double throw, center OFF position |
| SW7 | 1 | SAW_TRIANGLE | SW_SPDT | Switch, single pole double throw |
| U1 | 1 | MC78M12_TO252 | 78M12 TO-252 | Positive 500mA 35V Linear Regulator, Fixed Output 5V, TO-252 (D-PAK) |
| U2 | 1 | MC79M12_TO252 | 79M12 TO-252 | Negative 500mA 35V Linear Regulator, Fixed Output -12V, TO-252 (D-PAK) |
| U3 | 1 | L78L05_SO8 | 78L05 SO-8 | Positive 100mA 30V Linear Regulator, Fixed Output 5V, SO-8 |
| U4 | 1 | L79L05_SO8 | 79L05 SO-8 | Negative 100mA -30V Linear Regulator, Fixed Output -5V, SO-8 |
| U5, U6, U7, U8 | 4 | TL074 | TL074 | Quad Low-Noise JFET-Input Operational Amplifiers, DIP-14/SOIC-14 |
| U9 | 1 | TL072 | TL072 | Dual Low-Noise JFET-Input Operational Amplifiers, DIP-8/SOIC-8 |
See voice card repository for details on tuning. Additional male/female dupont cables are needed in order to get access to the trimpots. Minimal set of connections are ground, all four voltages, PITCH, PWM, ADSR_*, GATE, LVL2, FREQ_CV and outputs.
SAW output of the oscillator can be added to MIX IN2 default input via a 1k resistor, eg. by tapping into the signal between R1 and U6 pin 8 on the voice card.
Voice Card: https://github.com/polykit/polykit-x-voice-card
Footprints: https://github.com/polykit/kicad
Wavefolder: https://www.elby-designs.com/webtek/cgs/cgs52/cgs52_folder.html