Pittsbirgh Modular MIDI
MIDI to CV converter module
• Dual Buffered CV Outputs
• Dual Buffered Gate Outputs
• Dual Buffered CC Outputs
• Midi Note/Gate Channel Learn Function by Button Press
• Midi Note/Gate and Midi CC Set Independently
• Midi CC Channel Learn Function by Button Press
• Midi CC Controller Number Learn
• All Settings Saved to EEprom and Loaded on Next Startup
• V/Oct (Linear) and Hz/Volt (Logarithmic) CV Output Available
• V/Oct (Linear) Mode Range: 8 Octaves
• Hz/Volt (Logarithmic) Mode Range: 3.5 Octaves
The purpose of a CV/gate converter is to transform incoming midi-note messages into control voltage for eurorack modular synthesizers and other monophonic synths featuring a CV/Gate input, like Minimoog, Roland System 100, SH101, Korg Monopoly etc. Furthermore, a logarithmic lookup table has been implemented for those synthesizers which require a Hz/Volt scaling rather than linear scale as a control voltage such as a Korg MS-10 or MS-20. In addition to CV and Gage Outputs, Midi CC control messages are available.
During normal operation, a new midi channel can be learned by pushing the Learn/Mode button once. The indicator LED will light up and remain lit until a midi note or Control CC has been received.
Midi Messages: Note on, Note off, CC
The channel of that incoming midi note will then be stored in EEprom memory. The LED will strobe for 1 second to indicate the storing operation.
Same function for CC Messages, CC midi channel will be stored in EEprom memory as well as the CC controller identifier number.
Note that the midi channel for CC Messages is allowed to differ from the Key On/Off midi channel. This allows to receive Key and CC messages from two separate sources for both control and key On/Off.
This also means that in order to configure the device, the learn function has to be operated twice, once for Key and once for CC messages.
At next power cycle, the last stored Midi channel will be retrieved from the EEprom memory. Successful loading of the midi channel will be shown by a LED strobe at startup.
Logarithmic CV scale mode also known as V/Hz mode (as can be found on KORG MS10, MS20) is accessed by holding the Learn/Mode button pressed at power up. This will toggle the CV mode. At button release, the LED will blink 4 times to show that we’re in V/Hz mode or blink 2 times long to display V/Oct mode. The CV mode is stored into EEprom memory as well and will be loaded at startup if no button is held.
You will notice that for the logarithmic mode, some rounding to the midi values had to be done to fit the 8bit max resolution of the DAC. This has as a side-effect that the range in log mode is severely restricted (to 3.5 octaves) and the precision is not too good, especially on the lower notes. Logarithmic mode is not recommend if very accurate tuning is required, but for general playing with these kinds of synths it should be good enough.