• A single vactrol for use in amplifiers or analogue synthesisers
• Uses an LED and LDR to control the resistance in a circuit
• 75 dB dynamic range and high dark resistance
• Fast response time – typically 2.5 msWhat is a vactrol?
A vactrol (or resistive opto-isolator) is an electrical component that consists of a light emitting diode (LED) and a light dependant resistor (LDR or photoresistor). When the voltage passes across the LED, the resistance of the LDR changes. This means that you can control the resistance in a circuit by altering the voltage to your vactrol’s LED.
What can I use this vactrol for?
Vactrols can be used in guitar amplifiers, analogue synthesisers and amateur (HAM) radio systems. As the input current increases, the output resistance decreases. The VTL5C3 has a good 75dB dynamic range and a low temperature coefficient of resistance. The VTL5C3 has a fast response time typically 2.5ms (maximum 35ms) with a small light history memory.