AR3 solderpads and hacks

The AR3 triple AR envelope generator 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 4 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 LM358 and 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 – AR1
  • SJ1 – AR2
  • SJ5 – AR3 pos
  • SJ3 – AR3 neg

Negative output pins – JP3

On the bottom side of the PCB there is also place for a 2×3 pin connector.
Here you will get negative outputs for all 3 envelope generators.
These outputs are NOT protected with any output resistors. You need to add a 1k resistor on the connector from this pinstrip to the jack.
One side of the connector are the 3 negative signals, and the other side are 3 GND pins.
You need to mount and solder the connector from the backside. That can be a bit tricky and you need to solder it a bit higher so that you can manage to solder under the plastic frame of the pinstrip connector.