Vactrol VTL5C1, VTL5C2, VTL5C3, VTL5C4, VTL5C9 replacement PCB
This PCB is an adapter to allow replacement of two stacked Vactrols with a single SSR chip. Please note that the SSR is not included.
Many guitar amp manufacturers use Vactrols (by VACTEC, Perkin Elmer, Excelitas) such as the VTL5C1, VTL5C2 and VTL5C9, as single throw switches or for FX purposes inside a guitar amp. Unfortunately these parts fail quite frequently. Due to advancements in technology and RoHS requirements, these parts are difficult to find and very expensive. For this reason I’ve designed a replacement PCB that allows a repair tech to drop in an DIP SSR (solid state relay) switch in place of the vactrols. As SSRs are non mechanical switches, they have the same bounce free quiet switching operation as Vactrols, but they are significantly more reliable.
Mesa Engineering made the dubious design decision in several products to stack multiple Vactrols vertically. For this reason, the PCB allows for replacement of two stacked Vactrols with a single DIP IC. You can see this implementation in the photos above, I’ve replaced a double stack Vactrol with this PCB in a Mesa V twin pedal (photo taken before soldering).
When the need next arises in my repair shop, I will make a new PCB to replace one of their crazy 3 or 4 high Vactrol stacks from the Dual Rectifier. I can also design this to order for a surcharge, just email me through Contact.
If you’re not repairing a Mesa (lucky you) then you can run flying leads to use the two single throw switches, or just use two PCBs.
Installation is simple. One end of the PCB is marked with LED symbols. This end matches the + – LED from the old Vactrol. The other end replaces the ‘Cell’ and isn’t polarised. Use a small amount of RTV to secure the PCB.
PLEASE NOTE: This product is ONLY suitable for replacing Vactrols in their use as switching devices. It is NOT suitable for replacing vactrols in applications where their variable resistive properties are used in FX circuits (tremelo, vibrato etc)