VCOFan1f manual and assembling

last update: 25 Aug 2025

This VCOFan uses the reflection of light that shines from a 3mm red LED onto the blades of a fan to generate sound.

Specifications:
• Toggle switch for volume: Right is always on, middle is active when gated, left is always off.
• Yellow knob: Fan speed, is connected to the LEFT cv input.
• Orange knob: Fan speed cv input attenuator, is connected to the LEFT cv input.
• Red Gray knob: Decay is connected to the middle two jack inputs, sets the decay time.
• Red Black knob: Sets output volume.
• Left jack socket: CV input speed.
• Second from left jack socket: CV input for volume.
• Second from right jack socket: GATE input to start a decay cycle for volume.
• Richt jack socket: audio out.
• Power: +12v, 30 to 150mA.
• Width: 10HP.
• Depth: 25mm.

Assembling:

Instructions for helping the assembly process.

Solder the LDR onto the top panel, and the 2 pin header also.
You can slide the 4.5mm shrink tube over the LDR then when you solder it to the PCB it will shrink because the LDR warms up from soldering its pins to the PCB front panel.

Screw the fan to the front pannel with the bolts, see picture above for how to. Dont forget to put the fans cable thru the big hole in the front pannel under the fan.

Fan cable going thru hole.

Solder the power connector for the FAN to the PCB. It can also be on the other side of the PCB.

Solder the VACTROL, the power connector and the 910k resistor (910k resistor is on the right of the VACTROL).

Solder the Capacitors and the Trimmer pots.
Then cut off the small flaps on the front side of the pots and put all components into the PCB, but dont solder them. Only solder them after you mounted the front pannel. (see also next image before soldering the pots jack and LED's switches.)

To solder the 5mm LED flat to the top pannel you can put painting tape over the hole for it, and stick the LED to it.

Make sure the 3mm LED is into its hole and the 2 pin header connections are in place.
Now solder it all.