LFO4 solderpads and hacks



The LFO4 quad LFO has some solderpads that you can use to change some functions on it.

Disable the 1K output resistor

On the bottom side of the PCB there are 8 solder-switches near the jacks.
By soldering a short for any of these solder pads, you can eliminate the 1K output resistor for that jack.
The OP’s used for this module is TL074 that has built in short-circuit protection on the outputs.
Therefore, it is possible to do this hack if you need, but it is still better to leave the 1K resistors working as default for extra protection.

  • SJ2 – Triangle LFO1
  • SJ3 – Square LFO1
  • SJ1 – Triangle LFO2
  • SJ8 – Square LFO2
  • SJ13 – Triangle LFO3
  • SJ14 – Square LFO3
  • SJ5 – Triangle LFO4
  • SJ7 – Square LFO4

Rate capacitors

On the bottom side of the PCB there are 8 solder-switches that adds capacitors to the rate timing.
With these you can change the frequency range for each LFO individually.
By soldering or unsoldering a short for any of these solder pads, you add or remove a capacitor to the LFO.

The smallest capacitor is always connected and does not have any solder jumper.
You can add a medium capacitor and a big capacitor.
You can also combine them. The more capacitors, the slower the LFO will be.
If you remove both solder jumpers, you will remove all extra capacitors and the LFO will be configured for its fastest mode (max approx. 850Hz).
By soldering both jumpers, you will add all extra capacitors and the LFO will be configured for its slowest mode (max approx. 1Hz).
If you solder only the jumper for the medium capacitor, you will get a maximum frequency of about 80Hz.

  • SJ4 – Medium capacitor LFO1
  • SJ6 – Big capacitor LFO1
  • SJ10 – Medium capacitor LFO2
  • SJ9 – Big capacitor LFO2
  • SJ15 – Medium capacitor LFO3
  • SJ16 – Big capacitor LFO3
  • SJ11 – Medium capacitor LFO4
  • SJ12 – Big capacitor LFO4