MIDI Hardware MINICV

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MIDI Hardware MINICV

 

MIDI Hardware MINICV

 

Some time ago I've made what seemed to be the world's smallest MIDI-2-CV converter, you can see it here. The idea behind it was to have something that you could mount inside toy synthesizers like Monotron, but probably because of affordable price and really good specs, people used it everywhere, including famous and expensive vintage synths like minimoog or VCS3. It didn't feel right, as it was really simple converter, yet more precise than many opensource coverters circulating around. Components placed on both sides of PCB helped a lot to achieve small size, but made assembly more complex. And finally, it was not too easy to install because of soldering pads in 2mm distances. So after very long time when it was not available any more I finally created its successor, redesigned from scratch, sharing only the name with its grandpa.

This new MINICV version 2 may be small, but don't let the size fool you. This is well grown serious converter, precise and packed with features. This is what it can do at the moment:

  • tuning errors smaller than 1 cent at 1V/oct
  • keyboard range adjustable to any size from 1 to 61 notes
  • user tunable V/oct scale from below 0.3 to over 2V/oct in really tiny steps
  • Hz/V scale with top note being always at 5V (*)
  • fast response, CV is settled 0.2ms after end of MIDI message
  • fast MIDI clock response on dedicated output, 45us delay on average with +/-16us jitter
  • MIDI clock divider is user adjustable from 1 to 128
  • constant rate portamento applied to CV output, adjustable by CC for time and on/off
  • CCs recognized as portamento controls are user assignable, default are 5 and 65
  • adjustable smoothing of CC and PitchBend messages
  • CV offset trim available via SysEx in range +/-10mV
  • all user settings via MIDI System Exclusive messages
  • Starting note and MIDI channel adjustable with MIDI-learn button
  • 16 scenes of user settings may be recalled by Program Change
  • individually assignable ID to access many MINICVs on shared MIDI line
  • gate output of V-trigger type. Gate ON selectable 5V or 0V (reversed)
  • possibility to reverse CV also (like 0V is top note, 5V is lowest note)
  • gate optionally retriggers with short Gate off pulse, adjustable from 0.1 to 5ms
  • PitchBend optionally added to note pitch CV
  • PitchBend range adjustable in semitone steps from +/-1 to 24e
  • CV may respond to:
  • MIDI notes (+ PitchBend if you want it)
  • MIDI PitchBend only, with full 14-bit resolution
  • any of 120 MIDI Continuous Controller, e.g. volume, modulation, etc.
  • firmware upgradeable via MIDI SysEx
  • dimensions: 21x12mm

MINICV comes with factory preadjusted scale and offset settings to best match 1V/oct at 100k load. Those settings are also recalled after factory reset command. Below is example graph of MINICV tuning errors measured in 26 randomly selected MINICV units. Horizontal axis range spans over 5 octaves, vertical one is scaled in milivolts of error from perfect 1V/oct scale. Full scale is +/-0.8mV, wchich is very close to +/1 cent of pitch errors if it was used as VCO driver. As you might expect, there's one marketing trick applied - the range in this graph includes only 60 notes, without top one. This is because MINICV top limit is about 4.985V so it cannot reproduce top note correctly in pure 1V/oct scale. One way to overcome this limitation is to scale it lower, like 0.997V/oct and instead of typical 100k resistor going to VCO summing node, use 99.7k. Or better 0.976V/oct with 97.6k which is more likely to be found value.

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  • Views: 1533
  • Brand: MIDI Hardware
  • Product Code: PCBARSMINICV1
  • Availability: 15
  • $30.00
  • Ex Tax: $30.00

Tags: midi, hardware, minicv, interface, pcbarsminicv1