Land Boards Synth Components

Synth Modules

• Synthesizer interfaces and modules
  • MIDI-IN-OUT - MIDI In/Out
  • SCF-2 - Dual 3.5mm Audio Jacks (Scale, Clip, Filter_
  • SYNTH-VCO-01 - Synth Voltage Controlled Oscillator
  • SYNTH-MIDI-CTL-01 - Synth MIDI Controller
  • SYNTH-MIDI-CV4-01 - 4 Output MIDI to CV controller

MIDI-IN-OUT

• MIDI-IN-OUT - MIDI In/Out
• MIDI In/Out Jacks
• 5V MIDI
• 3.3V or 5V Serial connections
• MIDI In is opto-isolated
• (2) 4-40 Mounting holes

SCF-2

• SCF-2 - Dual 3.5mm Audio Jacks (Scale, Clip, Filter)

• Digital Inputs or Outputs
• (2) 3.5mm Jacks
• Scaling resistors
• Schottky Clamping Diodes
• Filter cap
• Ring pin brought to connector
  • Ring pin is not used in Synth applications
  • Card can be used as a 3.5mm breakout
• (2) 4-40 mounting holes

SYNTH-VCO-01

• SYNTH-VCO-01 - Synth Voltage Controlled Oscillator

• Build of Pico VCO by HAGIWO
• Digital Voltage Controlled Oscillator (VCO)
• Three modes: Wavefold, FM and AM
• PWM output with 2 pole low pass filter
• Each mode has eight built-in waveforms
• XIAO RP2040 CPU
• (5) Pushbuttons
  • Octave Up/Down
  • Mode Up/Down (Wavefold, FM and AM)
  • Push Timbre switches between 8 waveforms
• (2) Knobs
  • Freq fine adjust
  • Mod adjust
• Standard EuroRack 16 pin header
  • Supports 12V in with on-board 5V regulator
  • 5V regulator can be not installed if 5V is available on EuroRack connection
• Card is not a Eurorack card
  • Probably too deep, needs cabling
• (4) 6-32 mounting holes
  • Stacks with SYNTH-MIDI-CTL-01 card

SYNTH-MIDI-CTL-01

• SYNTH-MIDI-CTL-01 - Synth MIDI Controller

• Adapted from HAGIWO's MIDI to CV module
  • Translate from Japanese to English using browser
• XAIO RP2040 CPU
  • Arduino MIDI library has not yet been ported to Pico so will need to use CircuitPython
• MIDI In/Out
  • Standard MIDI Jacks
  • MIDI out jack for future functionality
• (2) 0-5V Analog CV outs
  • MCP4822 12-bit D/A - SPI Interface
    • MCP4822 Datasheet
  • Use with SYNTH-VCO-01
    • CV1 = V/OCT
    • CV2 = MOD
• (2) Digital Outs, eX:
  • Gate
  • Clock
• Pot supports setting Clock rate
• Standard EuroRack 16 pin header
  • Supports 12V in with on-board 5V regulator
  • 5V regulator can be not installed if 5V is available on EuroRack connection
• Card is not a Eurorack card
  • Probably too deep, needs cabling
• (6) 6-32 Mounting holes
  • Stacks with SYNTH-VCO-01 card

SYNTH-MIDI-CV4-01

• SYNTH-MIDI-CV4-01 - 4 Output MIDI to CV controller

• Adapted from HAGIWO's MIDI to CV module
  • Translate from Japanese to English using browser
  • Removes Digital Outputs
  • Has 4 Analog Outputs instead of 2
• XAIO RP2040 CPU
  • Arduino MIDI library has not yet been ported to Pico so will need to use CircuitPython
• MIDI In
  • Standard MIDI Jacks
  • MIDI out jack for future functionality
• (4) 0-5V Analog CV outs
  • MCP4822 12-bit D/A - SPI Interface
    • MCP4822 Datasheet
  • Use with SYNTH-VCO-01
    • CV_1 = V/OCT
    • CV_2 = MOD
• Standard EuroRack 16 pin header
  • Supports 12V in with on-board 5V regulator
  • 5V regulator can be not installed if 5V is available on EuroRack connection
• Card is not a Eurorack card
  • Probably too deep, needs cabling
• (6) 6-32 Mounting holes
  • Stacks with SYNTH-VCO-01 card

Eurorack 4 Channel Mixer

• SYNTH-MIXER4-01
• Eurorack 6HP
• Adapted from HAGIWO's 5 Channel Mixer Module
• Views: Front (controls), Parts side, Front Panel

Eurorack 5 Channel Mixer

• SYNTH-MIXER5-01
• Eurorack 6HP
• Adapted from HAGIWO's 5 Channel Mixer Module
• Views: Front (controls), Parts side, Front Panel

Eurorack 6 Channel Mixer

• SYNTH-MIXER6-01
• Rear card is too tall to fit in rack between rail
  • Try tilting it in?
• Eurorack 6HP
• Adapted from HAGIWO's 5 Channel Mixer Module
• Views: Front (controls), Parts side, Front Panel

Eurorack RP2040 VCO

• SYNTH-VCO-03
• Eurorack 6HP
• (3) Card set
• Views: Control Panel rear side, Control Panel controls side, Logic card component side, Logic card rear side, Front Panel

Eurorack +/- 12V Power Supply

• 115VAC in, 24V CT, 24 VA Transformer
  • 12*1.414 = ~17V
    • Leaves 5V for regulator headroom and ripple
• L7812CV, +12V, 1.5A Regulator
• L7912CV, -12V, 1.5A Regulator

Eurorack DIY Panel

• Front/Back View
• Left = top

• Based on HAGIWO design

• 6HP wide
• 3U tall
• Power and Ground bus on either side of the card
• Reduces wiring
• Slotted mounting holes
• 5mm Grid on rear side makes it easier to locate connectors for drilling

MOD-SCF-JACKS

MOD-CF-JACKS

MOD-DIY

MOD-DIY

MOD-MIDI-THRU

MOD-MIDI-THRU

• DIN-5 in
• (4) TRS Type A outs

MOD-NANO-CPU

MOD-NANO-CPU

• Arduino NANO
• Runs MOZZI Arduino library
  • MOZZI audio output
  • Standard or HiFi
• MIDI In on TRS Type A
• Remove J4 (EN_MIDI) when USB is plugged into NANO CPU

MOD-POTS

MOD-POTS

MOD-XIAO-RP2040-CPU

Reference Docs

• Doepfer Eurocard inventor/specs
  • Principles of Voltage Control
• MIDI Communication
• Creative Control Strategies: MIDI to CV
• EuroPi
• Eurorack Beginners Guide
• Eurorack Wiki page
• KiCad Audio Jack Symbols
• MidiSoft
  • EuroRack Dimensions
  • Panel Holes
• A simplified guide to TRS MIDI
• How to Make Your Own 3.5mm mini stereo TRS-to-MIDI 5 pin DIN cables
• Eurorack Power Connectors
• MIDI Electrical spec

Projects

• elkayem midi2cv GitHub page - Nano based project
  • Arduino MIDI library has not yet been ported to Pico so will need to use Python
  • Drives 4 CV outputs: Pitch Blend, Control, Note, Velocity
  • This card only drives Note (Voltes/Oct, Mod)
• PicoPicoSynth
• Deftaudio GitHub - KiCad footprints
• graybloomfield - Very nice Arduino based designs
• Turing Machine
• DIY Hackable Arduino Drum Machine
  • vIDEO
• Build the Auduino Granular Synth

Other Notes

Daughterboard Heights

• From notes on How to Make Great Looking Modular Front Panels - Part 3 Module Circuit Board Layout
  • The absolute maximum of other boards I've seen is 111,5 mm and the TipTop Happy Ending Kit offers a space of 112,5 mm
• 114.8mm measured on 3U Synthrotek rails
  • 128.5mm - 114.8mm = 13.7mm both sides, 6.875mm per side
  • 111.5mm daughtercard, leaves 8.5mm clearances top/bottom

Part Orientations

• For pots with built-in pointers, pot pins go down for pointer to go up at center point

Module Kits

• Erica Synths
  • Erica Synths DIY GitHub
• SyntherJack - DIY Synths
• BEFACO - Kits
• Kassutronics DIY Store
  • Kassutronics DIY GitHub
• Music From Outer Space
• Thonk Shop - in UK
• synthrotek
• TuringMachine Mark 2

Software

• adafruit_midi CircuitPython API
  • Example code
• MIDI Controller in Python
• USB to Serial MIDI
• MidiEditor
• Convert binary files to C data arrays (Arduino) - In Japanese
• Binary to C Array
• Arduino Mozzi Library
• esp32_basic_synth
• esp32_usb_midi
• arduino_midi_library
• Pico MIDI Host to MIDI UART Adapter

Hardware/Parts

• Synthrotek Store
• THONKICONN – 3.5MM JACK SOCKETS
• Potentiometers are usually marked with an "A" for logarithmic taper or a "B" for linear taper;

Samples

• Drum Samples

HAGIWO Builds

• HAGIWO on Reddit

FUNCTION	3.5MM	POTS	TOGG	PBS	ROT	DIN5	CPU	LINK
MIDI-IN-OUT	0	0	0	0	0	2	NONE
SCF-2	2	0	0	0	0	0	NONE
SYNTH-MIDI-CTL-01	4	0	0	0	0	2	XAIO RP2040
SYNTH-MIDI-CV4-01	4	0	0	0	0	2	XAIO RP2040
SYNTH-MIXER6-01	7	7	0	0	0	0	NONE	https://note.com/solder_state/n/nffc1a33053be
SYNTH-VCO-01	4	2	2	1	0	0	XAIO RP2040	https://note.com/solder_state/n/nca6a1dec3921
SYNTH-VCO-03	4	2	2	1	0	0	XAIO RP2040	https://note.com/solder_state/n/nca6a1dec3921
No.56 Sample Drum	3	1	1	0	0	0	ESP32C3	https://note.com/solder_state/n/n950ed088c3cb
No.55 V2164 Dual VCA	6	6	0	0	0	0	NONE	https://note.com/solder_state/n/nd82c027d0597
No.54 PT2399 clock sync delay	4	3	1	0	0	0	NANO	https://note.com/solder_state/n/nf6dc0a61e26d
No.52 Reverse step sequencer	4	8	2	0	0	0	CDT7350	https://note.com/solder_state/n/n13c49f08ca1f
No.50 LFO/VCO rebuild	2	3	1	0	0	0	NANO/AD9833	https://note.com/solder_state/n/nd2c22a73e8fe
No.49 Clock Divider	11	0	0	0	0	0	TC4040BP	https://note.com/solder_state/n/n7979cda44dcb
No. 47 Sample & hold	3	2	1	0	0	0	LF398	https://note.com/solder_state/n/n29b52f4f01f1
No.46 Dual Envelope generator	4	8	0	0	0	0	NANO	https://note.com/solder_state/n/n6fb73eb1d8b8
No.45 Diode clip Distortion	2	3	0	0	0	0	NONE	https://note.com/solder_state/n/n5f35e2e84a3e
No.44 Wave shaper & VCA	2	1	0	0	0	0	NONE	https://note.com/solder_state/n/nfdc2e198255a
No.43 Envelope Follower	4	3	0	0	0	0	NONE	https://note.com/solder_state/n/n110e9ba066b3
No.42 PCM drum	6	4	2	1	0	0	NSX-1/SAMD	https://note.com/solder_state/n/neabe7e014c11
No.40 Voltage controlled switch	8	1	0	1	0	0	NJU211	https://note.com/solder_state/n/n98883e71f814
No.39 Diode ladder VCF	3	3	0	0	0	0	NONE	https://note.com/solder_state/n/n598f23105ec4
No.38 Touch controller	5	1	1	4*	0	0	NANO/MPR121	https://note.com/solder_state/n/ncd42925f726b
No.37 Overflow folding VCO	4	3	0	1	0	0	XIAO	https://note.com/solder_state/n/nf01e7c92b010
No.36 LM13700 Dual VCA	6	2	0	0	0	0	LM13700	https://note.com/solder_state/n/n3357199504d8
No.35 CV to MIDI	6	1	0	0	0	1	NANO/SSD1306	https://note.com/solder_state/n/nb618127f37c9
No.33 Dual Quantizer	7	1	0	0	1	0	SAMD/SSD1306	https://note.com/solder_state/n/nb8b9a2f212a2
No.32 Spin FV-1 multi FX	5	5	0	0	0	0	NANO/FV-1	https://note.com/solder_state/n/n1c402a78a0fe
No.31 Ring modulator & wavefold	4	3	0	0	0	0	AD633	https://note.com/solder_state/n/n9d138d74b39d
No.30 Euclidean rhythm sequencer	7	0	0	1	1	0	NANO/SSD1306	https://note.com/solder_state/n/n433b32ea6dbc
No.29 SH-101 type sequencer	7	1 TRIM	0	1	1	0	SAMD/SSD1306	https://note.com/solder_state/n/n80f4baf81226
No.28 DSP multi effector	2	0	0	0	0	0	DSP	https://note.com/solder_state/n/nd9c984a9ab7a
No.27 5ch mixer	6	6	0	0	0	0	NONE	https://note.com/solder_state/n/nffc1a33053be
No.26 V2044 VCF	3	3	0	0	0	0	V2044 VCF	https://note.com/solder_state/n/n0fabdc23fe1e
No.25 Oscillo scope & Spectrum analyzer	3	1	1	0	1	0	NANO/SSD1306	https://note.com/solder_state/n/n6b4cc8d1c6b9
No.24 V2164 Dual VCA	6	2	0	0	0	0	V2164	https://note.com/solder_state/n/n14a8be5f7118
No.23 CHORD VCO	4	3	0	0	0	0	NANO	https://note.com/solder_state/n/n681d2e07e324
No.22 Additive VCO	4	3	0	0	0	0	NANO	https://note.com/solder_state/n/n30b3a8737b1e
No.20 CV/GATE 8step sequencer	3	8	1	0	0	0	CD4022BE /NE555	https://note.com/solder_state/n/n4da93d157f26
No.19 FM VCO	4	3	0	0	0	0	NANO	https://note.com/solder_state/n/n88317851a4c7
No.18 2OSC VCO	3	3	1	0	0	0	NANO	https://note.com/solder_state/n/n71c67b5aaeca
No.17 Multi mode Envelope generator	2	4	1	0	0	0	NANO	https://note.com/solder_state/n/n69643b792274
No.16 CV/Gate sequencer & Arpeggiator	5	0	0	1	1	0	NANO/SSD1306	https://note.com/solder_state/n/n7c2809976698
No.15 TR-808/909 sample player drum	5	0	0	1	0	0	SAMD/SSD1306	https://note.com/solder_state/n/n0209d16d0d08
No.14 KICK	3	4	0	0	0	0	NANO	https://note.com/solder_state/n/ne33e32660d50
No.13 Noise & Hi-hat	4	3	0	0	0	0	NANO	https://note.com/solder_state/n/nf65437f12790
No.12 Clock SYNC LFO	2	4	0	0	0	0	NANO	https://note.com/solder_state/n/n4c600f2431c3
No.11 MIDI to CV	4	1	0	0	0	1	NANO	https://note.com/solder_state/n/n17e028497eba
No.10 Gate Burst/Delay	4	2	1	1	0	0	NANO	https://note.com/solder_state/n/n28b5c43229af
No.9 6ch trigger sequencer	7	0	0	1	1	0	NANO/SSD1306	https://note.com/solder_state/n/n17c69afd484d
No.8 SX150 VCF	3	2	1	0	0	0	NANO/MCP4726	https://note.com/solder_state/n/n5136d98930a8
No.7 Quantizer	4	2	1	0	1	0	NANO/MCP4726	https://note.com/solder_state/n/nde97a0516f03
No.6 Clock multi divide	4	2	1	0	0	0	NANO	https://note.com/solder_state/n/n8907f2f6e8f5
No.5 Generative sequencer	3	2	1	0	0	0	NANO/MCP4911	https://note.com/solder_state/n/n8a489f0b857a
No.4 samplar	3	1	1	0	1	0	NANO/TF PLAYER	https://note.com/solder_state/n/n6057a5256042

Videos

• Hooking together modules