ProPulse Release Notes: Rev 0 PCB

Note the following:

• The board has holes for both a large 7805 and a small 78L05. Do not install both: install one or the other.
• Capacitors C1, C3, C7 should be non-polarized or bipolar capacitors.
• Please use a shrouded header for the Eurorack power connector. This will prevent you from attaching the power ribbon cable the wrong way. The slot should be facing outward. (To double check: the red edge of the ribbon cable will be on the same end as the word “Red” on the PCB.)

The following four small changes are mandatory:

• The negative power supply is not connected to the op-amps. Run a snipped resistor lead on the back of the board from the Eurorack power connecter vegative (pins next to word “Red”) to U4 Pin4.
• The decoupling capacitors C10, C11, C13, C14 are not connected to ground. Run a small snipped resistor lead on the back of the board from U2 pin1 to C11 inside (next to C12).
• C34 is not used. Run a small snipped resistor lead between the two holes (i.e. short).
• The LED functionality is upside down. Do not install R18 normally: instead mount it upright into the top hole of R18, and run the lead to solder to the top end of R34 which is immediately next to it.

Also please note the following:

• The board has holes for an MOTM style power connecter, which overlaps the Eurorack connector. It is not relevent for Eurorack constructors.
• If you prefer, you can use a 10-pin power header instead of the 16-pin given in the BoM. (The ProPulse module generates its own 5V supply and does not used the bus CV or Gate signals.) Align this smaller power header to the side marked with the word “Red” on the back of the PCB.
• The text labels on the PCB rear naming the sockets are wrong. Please ignore them.

There is no known problem with the panel.

Hints:

• The 6HP panel is large enough to use, e.g., a Davies knob for the Fraction control, but I recommend using a micro-knob (available Thonk) for the Threshold control.
• I suggest a green LED, meaning “go”.

Non-Eurorack Builders

The board has only been tested with Eurorack but should also work with +/-15V systems. It has minimal features for this:

• You can install an MOTM power connecter instead of the Eurorack connecter.
• The PCB has various mounting holes.