DEMO VIDEO: https://youtu.be/1z2SvzbiTAY fn_blocks by ellitone - an affordable, minimal approach to the modular synthesizer system. fn_blocks (pronounced “function blocks”) are self-contained synthesizer function modules, designed to be used with other fn_blocks AND compatible with a wide range of external audio gear. fn_block #01 is the first entry into a series of electronic musical devices that share a common form factor. a common size​/​shape allows for multiple fn_blocks to be connected together both physically and electrically. combining modules together creates a larger, more powerful, customizable musical instrument system. fn_block #01: lofi digital 4-voice 8-bit polyphonic (4-voice) digital synthesizer sound module, controlled externally via TRS MIDI or Control Voltage (CV) (0-5V) ⁃ 25 waveforms ⁃ 6 preset envelopes (amplitude) ⁃ octave control ⁃ 3.5mm (1​/​8 inch) audio output ⁃ usb-c powered * fn_blocks are not kits, but they do require 5 minutes of finish assembly work by the user. a small philips-head screwdriver is the only tool you will need! watch this assembly video to see how quick and easy the finish assembly process is: https://youtu.be/ODOepVro3rA fn_block #01: operating instructions - ⁃power using usb-c cable and power supply. ⁃connect audio cable into the audio out jack (3.5mm) then connect cable into mixer, headphones, or powered speaker. ⁃connect a TRS MIDI (type A) output signal cable from an external device into the ‘midi in’ input. older gear outputting midi via 5-pin DIN is compatible! you simply need a DIN 5-pin to TRS 3.5mm MIDI (type A) adapter cable. ⁃fn_block #01 can also be controlled externally via analog control voltages. connect control voltages (cv) from an external device to the (11) cv input pegs using crocodile clip patch wires (2 wires included) a full set of 10 wires can be purchased separately here: https://t.ly/MVtDl (or search amazon for "crocodile clip test leads") ⁃pitch a,b,c,d input cv pegs respond to 1V per octave (0-5V range). pitch inputs are quantized! this means that incoming control voltages will ‘step’ between the 12 notes of the chromatic scale. pitch voltages that exist in-between half step​/​whole step note values will be ignored. ⁃trig a,b,c,d input cv pegs respond to trigger and gate signals above +2 Volts ⁃waveform, envelope, octave input cv pegs respond to voltages (0-5V) ⁃use touch pad buttons to change waveform (1-25), envelope (1-6), and octave (1-6) ⁃6 preset amplitude envelope shapes consist of (4) ‘fast attack’ envelopes and (2) ‘long attack’ envelopes. ⁃audio and midi can also be accessed through the metal pegs provided (use crocodile clip patching wires) these access points can work as either inputs or outputs. Included audio waveforms: 1- sine1 2- fmsynth1 3- electric piano1 4- triangle1 5- fmsynth2 6- square1 7- saw1 8- fmsynth3 9- distorted1 10- distorted2 11- human voice1 12- human voice2 13- blended1 14- human voice3 15- overtone1 16- fmsynth4 17- fmsynth5 18- overtone2 19- overtone3 20- blended2 21- blended3 22- blended4 23- blended5 24- blended6 25- blended7 *Special Functions* ⁃Round Robbin MIDI ​/​ Selective MIDI: hold down ‘waveform’ touch pad button for 5 seconds (until lights flash) to toggle midi input mode between ROUND ROBBIN (default) (incoming midi notes override held notes) and SELECTIVE (incoming midi notes are ignored if all notes are being held in sustain) 
 ⁃4 Volt​/​5 Volt Selection: hold down 'envelope' touch pad button for 5 seconds (until lights flash) to toggle between 4 Volt and 5 Volt input mode. by default, all control voltage input pegs are set to respond to input voltages ranging from 0-4V. this is the fn_block standard. however, certain external gear may output voltage signal levels between 0-5V. change the input voltage range from 0-4v to 0-5v by holding down the ‘envelope’ button for 5 seconds. the two lights on the right will flash 5 times when switching over to 0-5V mode. The two lights on the left will flash 4 times when switching back into 0-4V mode. changing this setting will be saved to EEPROM memory and will remain after power is turned off, this means you won’t have to keep changing this setting every time you power up the device. ⁃8 Voice (dual-unit) Mode: achieve 8 voice polyphony using two #01 units connected together! hold down ‘octave’ touch pad button for 5 seconds (until lights flash) to toggle between 4 and 8 voice (dual-unit) mode. in 8-voice mode, every other incoming midi note is ignored. when two #01 fn_block units are sharing a midi signal, BOTH units are set to 8-voice mode, AND units are staggered (let one unit be triggered by a midi note while the other is disconnected. THEN connect both units to the same midi signal) the two units will operate as a single 8-voice unit for double polyphony. *stay tuned for these new fn_block modules coming in 2025: #02: polyphonic touch keyboard #03: 4-channel generative sequencer #04: 4-channel mod