Jam Box

This is my latest project. I call it "Double Trouble" - it is a two guitar input cross-switch with optional buffering and a switchable FX loop for each channel.

The purpose is to be able to connect two guitars to two amps and to cross-switch the guitars between the amps by pushing one button.

The top-right switch engages the buffer. There are two independent single JFET buffer circuits inside, one for each channel. The buffers are true by-pass using relais. This means that if the power goes out, the pedal switches itself to true by-pass and keeps operating (un-buffered).

The bottom-right switch switches the channels.

The bottom-left switch engages FX loop 1,

the top-left switch engages FX loop 2.

The following picture shows the circuit board with the components:

This is the schematic:

The following pictures show the strip-board layout, the templates for the cuts and jumpers, followed by illustrations of the work in progress and a couple of files for download.

DIY layout (http://bancika.github.io/diy-layout-creator/)

Position of strip cuts (copper side)

Jumper layout (component side)

Cutting the strip cuts

Running the jumpers

Resources:

• The LTSpice layout file: schematic
• The DIY routing and component layout file: layout