Fuzz Pedal Remote Footswitch

At least one Zaardvark tune requires Andy to operate his fuzz pedal at more or less the same time as playing the bass pedals. The positioning of the two - about a metre apart - makes this difficult to pull off. What is needed is a remote footswitch for the fuzz pedal that can be placed very close to the bass pedals, making it much easier.

The pedal is a Boss FZ-5 and, like most Boss pedals, uses a momentary footswitch. This makes it simple to bring out the switch's contacts to a socket, allowing a remote footswitch to be connected in parallel. But it also seems useful to have an LED on the remote that confirms the pedal's on/off state. This is more difficult to achieve as you can't just connect an external LED in parallel with the internal one. A buffer circuit is needed:

LED_IN connects to the FZ-5's LED anode. When it is off, no current flows into the base of Q1, so R4 pulls the base of the U$1 to 9V, turning it off, so no current is supplied to the external led via LED_OUT. When the internal LED is on, Q1 and U$1 are turned on, supplying current to the external LED via R3.

This circuit could have been fitted on Veroboard quite easily, but I wanted to get more experience with assembling surface mounted components, and fancied the challenge of making the board as small as possible. The final layout is 17.5mm x 3.5mm:

It's double-sided and will fit inside the pedal easily, enclosed in heatshrink.

Assembly:

Connecting to the 9V supply at the power socket:

Connecting it up inside:

The remote footswitch is connected through a stereo mini-jack socket:

Done:

The remote footswitch:

Demo: