Out of the box, the Danelectro BLT slap-echo pedal has two control knobs. One for echo volume and the other for the number of subsequent echoes. I was very pleased with this pedal but the more I played with it, the more I realized that I couldn’t get the effects I really wanted. Most expensive high-end pedals have another knob or button for adjustable tempo but my cheaper pedal lacked this feature. This was why I looked for ways hack into the main circuit to create new effects.
Standard Echo Pedal With Fixed Echo Rate
Because this is a digital pedal, I knew there was probably way to adjust circuit’s clock in order to make weird, wacky sounds. I searched online for any others who were able to do this and I found others who were able to create a variable delay time by replacing a resistor on pin 5 of the pt2399 Echo Processor IC with a potentiometer on the main clock output of the circuit. I unsoldered the 6.8 kΩ resistor that was labeled “682” and soldered on two wires on to legs 2 and 3 of my 100 kΩ potentiometer. This allowed me to vary the resistance instead of it just being constant. While fiddling around with it, I learned that raising the resistance adjusts the delay times between each echo. It took me a while to solder the whole circuit because I have never had any experience with on-board soldering.
When I finished soldering the whole thing, I was so excited to use it with my guitar but as I closed the housing, my guitar input bypassed the entire pedal. This confused me because when the pedal housing was open it worked. I found out the legs of my potentiometer were touching the bottom of the pedal’s metal housing, which means that the circuit basically bypassed the part of the potentiometer that had the variable resistance. I remedied this by placing electrical tape on the legs of the potentiometer.
Modified Pedal With Variable Delay Duration
