The Teensy++ comes with two 10-pin strips of male headers. We'll need to make one modification before soldering them to the board.
To ensure pin 30 of the Teensy++ does not connect to the Prophet's PCB, we'll need to remove the tenth pin from one of the strips. An easy way to do this is to simply pull the pin from the header strip before soldering.
Locate the tenth pin of one of the header strips by counting pins inward from one side.
Use a pair of needle nose pliers to remove the pin from one of the strips, as seen on the images to the left.
Insert the header strips into a solderless breadboard to keep them stable while soldering.
Mount the Teensy++ on top and ensure you have it oriented correctly with pin 30 empty. Pin 30 is the unlabelled pad between the pads labelled "E6" & "R" (see image).
Solder all pins, taking care not to let any solder bits stray onto the Teensy++.
Next up, we'll solder some connections on the Teensy++ using jumper wire. Cut 3 pieces of ~4.5cm and one of ~10cm length and strip the ends as seen below.
We'll use the shorter jumper wires to connect the following pads on the Teensy:
- GND to R
- E0 to 5V
- E4 to C4
The remaining long wire will be used to connect the E5 pad to a socket contact on the Prophet 600's PCB.
Solder the short wire connections listed above, then solder the longer wire to E5.
Note that connecting to the E4 and E5 pads will require turning the board over and soldering to pads on the underside.
After soldering, trim any excess wire leads to keep things nice and tidy.
Finally, we'll need to cut the tiny trace connecting to 5V on the underside of the board.
Locate the 5V trace and carefully cut it using an x-acto or razor blade.
You can check to ensure the cut is successful using a multimeter's continuity mode or simply examine it using a magnifier loupe.