PCBs and FR4 front panel (only) for a voltage controlled oscillator synth module. This module is in LMNC's Kosmo format (20 cm high) and is 10 cm wide. Depth is 4 cm.

The Hero is built around a 3340 VCO chip. There are separate output jacks for each waveform: The standard triangle, ramp, and pulse, and also sine. Two V/oct pitch CV inputs, one exponential pitch CV input, PWM CV input, and linear FM CV input — the latter three with attenuators. Separate from the PWM CV attenuator is a knob for setting the initial pulse width, which can go from near zero to near 100%. There is a sync input jack and a switch to select hard, soft, or no sync. There’s a fine tuning knob and an octave switch with 11 positions. Why? Not just Spinal Tap fan service. It’s pretty nearly as easy to make an 11 position octave switch as a five position one, and the 3340 can track that whole range pretty well. So, y’know, why not? At the low end it’s into LFO territory, and at the high end the central pitch is up around C8, the top of the piano keyboard.

Also on the front panel there are holes for access to four trimmers, for adjusting tracking, high frequency tracking compensation, center frequency, and pulse width range.

Under the hood there are fixes for the 3340’s less welcome attributes. There’s regulated -5 V power which eliminates the infamous pulse width frequency shift, and an added resistor that gets rid of the ringing on the falling edge of the pulse wave at low frequencies. All the waveforms are scaled and shifted to make them ±5 V.

But the Hero's most unique feature is that it need not be a lone Hero. A header on the PCB allows it to be connected to one or more Sidekick VCOs. These are smaller, subsidiary VCOs also available on this site. The Hero sends summed pitch, pulse width, and linear FM control voltages to the Sidekicks; it also sends its ramp waveform which the Sidekicks can sync to. This allows easy creation and maintenance of multi-oscillator synth voices; it's a variant on the idea pioneered by the Moog 921a and 921b modules.

The user needs to source parts and assemble them. (Photo of my own assembled module for illustrative purposes only.) Easy through-hole construction.

Available as PCBs only, or PCB and panel sets with choice of white or black panel.

Be sure to see the Github repository (linked below) for BOM, build notes, and other information.