Item Tag: Opto-Isolator

Reproduction Sylvania LDR500 (PL8224) incandescent lamp-type optocoupler for vintage Gibson amplifiers including the Minuteman GA20-RVT and others (see below). These amps will not work with the Fender-type opto-isolators because they are neon lamp-type. The Neon types operate on about a 90V drop. At standard operating current in the Gibson 12AU7 vibrato circuit (~9.5mA), our custom-built tremolo bugs drop ~5V. We reproduce these optocouplers using modern components to be as close to the originals in look and function as possible. They are made with stainless steel tubing and are inserted in modern PVC covering. The red leads connect to the lamp. The green leads connect to the LDR. There is no polarity. We produce these parts in-house for our own repairs. They are designed for the Gibson-type tremolo circuit, but may work in others. Max Lamp Current: 14mAVoltage drop at max lamp current: 10VOff resistance (LDR): >100k (500k-10M typical)On resistance (LDR) at max lamp current: <10k (1-2k typical)Compatibility: GA-20RVT, GA-300RVT, GA-30RVT, GA-35RVT, GA-40T Crestline, GA-45RVT, GA-55RVT, GA77-RET, GA77-RVT Crestline It may also work in other circuits. Just send us a schematic and we can evaluate it!