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MIDI-Retrofit-16 Module
based on t
he MIDI2SDS
Reproduced with permission from Paul Maddox

Let's Go Shopping

MIDI-Retrofit-16

The MIDI-Retrofit-16 expands the 8 outputs of the MIDI-Retrofit-8 to 16 outputs
so providing control for most larger drum machines on the market.

PCB V1.5 onwards includes a new feature - MODWHEEL. Sending MIDI Control Modulation messages (B1, 01, xx & B1 21, xx) to the MIDI-Retrofit-16 will generate an anlaogue output voltage proportional to the modulation value. In the example below, the output voltage has been connected to the HiHat control on an SDSV (scope image at back of video shows the MODWHEEL output). The ModWheel feature is not included as part of the standard kit or build and must be selected as an add-on.

MIDI-Retrofit-16 requires a single-rail supply ranging from 12V to 15V providing for a maximum
TRIGGER output voltage of between ~8V (12V supply) and ~10V (15V supply).

MIDI-Retrofit-16 supports 2 'trigger modes':-

  1. PULSE Mode where the TRIGGER output is a pulse generated on receipt of a valid NOTE ON message
    and having a pulsewidth defined by the onboard trimpot (from around 2mS to 120mS),
  2. GATE Mode where the TRIGGER output is controlled by the receipt of valid NOTE ON/NOTE OFF messages.

The logic polarity of the TRIGGER outputs is also selectable:-

  • POSTIVE - the TRIGGER output swings from the low voltage (normally 0V) to the high voltage (usually 5V)
  • NEGATIVE - the TRIGGER output swings from the high voltage to the low voltage

In both cases the maximum amplitude of the TRIGGER output is determined by the VELOCITY value of the respective NOTE ON message as a proportion of the maximum set output voltage.

Settings are common to all outputs.

The MODWHEEL output applied to a Simmons SDSV HiHat courtesy of The SImmons Guy

Current Firmware (V1.4)

Build Guide

User Guide


Email:  elby-designs@bigpond.com
© Copyright 2000. All rights reserved.     Revised: February 3, 2024