Parts List

We created two file formats for you, Excel and PDF. We created PDF versions for those of you that can't open Excel spreadsheets. Although, the spreadsheet contains hyperlinks to make ordering the parts a snap. Plexi SE PCB (Epiphone Valve Junior Conversion) This includes almost everything you'll need to assemble the Plexi SE PCB and install it into your existing Epiphone Valve Junior chassis / cabinet. You will need some 600V rated hookup wire and solder:


It does not include non essential items like tube retainers, faceplates or knobs. We leave these as optional items since the look and appearance of the amp varies from the builder's taste. However, we do offer a faceplate design that can be purchased from BNP Lasers. Refer to the faceplate section below for more information.

Chassis Layouts

These chassis layouts demonstrate how the Plexi SE PCB can be configured to have a Plexi style or Cascade (JCM800) style preamp.


Drill Plan

Drill plan for version 2 and 3 of the Valve Junior chassis.


Build Manual

This manual details how to convert your existing Epiphone Valve Junior into a 5 Watt Single Ended guitar amplifier using the Plexi SE PCB. Build Manual for the Plexi SE PCB Valve Junior Conversion



V.V.R. stands for Variable Voltage Regulation. It is a circuit that controls the voltage supply to the B+ and has the effect of being a master volume control. The idea being that the amp can go into full overdrive/saturation/distortion as it would normally do, but the overall output volume is lowered by lowering the B+ voltage. More information can be found over on the Wattkins VVR forum (login required).



We have created two faceplate styles similar to the format used in the Marshall 1959 Super Lead (Plexi). These faceplates are designed to work with the drill plan and chassis layouts. One permits the use of the stock power switch and the other is equipped with an indicator light, standby and power switches. We recommend BNP Lasers for a high quality laser engraved finish. We partnered with BNP Lasers to create high quality artwork for these faceplates. When placing an order, refer to BNP Lasers already has this artwork in their computers ready to make your faceplates. We recommend the Gloss Gold (922710) plate material, Reverse Etched, with a Black backfill.

Just in case, here are the raw files.
Plexi-SE-PCB-Faceplate-v2.eps (EPS)
Plexi-SE-PCB-Faceplate-v2.pdf (PDF)
Plexi-SE-PCB-Faceplate-Stock-Switch-v1.eps (EPS)
Plexi-SE-PCB-Faceplate-Stock-Switch-v1.pdf (PDF)

Another option is to take the electronic PDF file(s) to a printing company, like Kinkos, and have them print your faceplate on the card stock of your choice. Make certain the faceplate is printed to scale. The image can not be scaled or "fit to size" for the graphics to align with the component holes in the chassis layout. Of course you can print these out yourself with your own printer. Beware! Most printers do not generate prints exactly to scale. Test your printer by printing a layout drawing and checking the scale of the layout with a ruler. If the scale is OK, then you can print with assurance that your holes will line up with the faceplate.

Discussion Forum

The official online discussion forum for the Plexi SE PCB is hosted by Wattkins Amp Forums on


You can buy the Plexi SE PCB here.