Boop
Components Needed
Components Needed
A fun way to add some tactile control to your eurorack. This simple module produces a gate when you boop the piezo disc. The potentiometer determines the length of the gate. Patch it to a sequencer for manual melodies or patch it to your drum modules for fully analog finger drums! There are four identical circuits in each module.
A fun way to add some tactile control to your eurorack. This simple module produces a gate when you boop the piezo disc. The potentiometer determines the length of the gate. Patch it to a sequencer for manual melodies or patch it to your drum modules for fully analog finger drums! There are four identical circuits in each module.
The build is very straightforward and should not be very time consuming. Start with the lowest components such as the resistors, capacitors, ICs, then diodes. When all of the SMD components are soldered, place the jacks, pots and LEDs in their homes and put the faceplate and nuts on before soldering them. The LED symbol indicates which direction the LEDs should be installed - in this case long leg up, short leg down. Solder one leg on each and then check they are positioned nicely before finishing soldering. Remove the faceplate, thread the piezo wires through the holes and affix the discs to the faceplate. You will need something soft to put under the piezo. We use 'X-protector' rubber sheet and a dab of glue. A dab of silicone caulk will also work, or many other things. Allow any adhesives to cure before attempting to continue. Finally solder the piezo wires to the pads on the PCB. The red wire goes to the pad labeled 'P#' and the black wire goes to the pad with the ground symbol. If the leads that come with your piezos are very long you can trim them but we recommend leaving them fairly long to avoid assembly headaches.
The build is very straightforward and should not be very time consuming. Start with the lowest components such as the resistors, capacitors, ICs, then diodes. When all of the SMD components are soldered, place the jacks, pots and LEDs in their homes and put the faceplate and nuts on before soldering them. The LED symbol indicates which direction the LEDs should be installed - in this case long leg up, short leg down. Solder one leg on each and then check they are positioned nicely before finishing soldering. Remove the faceplate, thread the piezo wires through the holes and affix the discs to the faceplate. You will need something soft to put under the piezo. We use 'X-protector' rubber sheet and a dab of glue. A dab of silicone caulk will also work, or many other things. Allow any adhesives to cure before attempting to continue. Finally solder the piezo wires to the pads on the PCB. The red wire goes to the pad labeled 'P#' and the black wire goes to the pad with the ground symbol. If the leads that come with your piezos are very long you can trim them but we recommend leaving them fairly long to avoid assembly headaches.
If you find the gates are not short enough at the shortest setting you can change the 220r resistors to 100r but we do not recommend going lower to protect the TL074. The trigger point for the module is set by a resistor divider made from the 10k and 100k resistors close to the main decoupling capacitors. If you want the module to be more sensitive you can reduce the 10k as low as 1k. Or you can make it less sensitive by increasing the 10k up to 100k.
If you find the gates are not short enough at the shortest setting you can change the 220r resistors to 100r but we do not recommend going lower to protect the TL074. The trigger point for the module is set by a resistor divider made from the 10k and 100k resistors close to the main decoupling capacitors. If you want the module to be more sensitive you can reduce the 10k as low as 1k. Or you can make it less sensitive by increasing the 10k up to 100k.
We use standard brightness LEDs and 4k7 current limiting resistors in our builds. Always choose current limiting resistors to suit your desired brightness and LED type.
We use standard brightness LEDs and 4k7 current limiting resistors in our builds. Always choose current limiting resistors to suit your desired brightness and LED type.
