Have you ever wanted to add control voltage to a parameter on your synth or circuit bent toy? Now you can!

The Vac Pak is a vactrol-based control voltage to variable resistance circuit.

• Connect your CV source to the input jack.
• Set the Scale and Offset trim pots to dial in your optimal resistance, with a range between ~300 ohms to ~10M (all vactrols are a little different in range).
• Connect the wires from J4 to your circuit to make a variable resistor.
• Daisy-chain multiple Vac Paks to the same power source using the remaining connector (either J2 OR J3).
• Power the Vac Pak with a 9V battery clip (wired to J2 or J3) or with your circuit's on-board voltage source (wired to J2 or J3).
• An onboard 5V regulator allows the Vac Pak to be powered with 6-18V DC.

Caution: Do not exceed +10V DC on the CV input, more may burn up your vactrol!