Doepfer MTC64 Midi to Gate Interface (main board) - Manual (Page 4)

Page 4 MTC64 V2 User’s Guide
Introduction
• MTC64 is an universal MIDI interface that converts up to 64 succeeding MIDI note
on/off or program change messages into 64 TTL voltages (0/+5V).
• The outputs of the MTC64 can be used to control different switching functions. With
suitable drivers (e.g. switching transistors) relays, lamps, motors, electromagnets,
magnetic valves and so on can be controlled. A transistor driver board with 16 drivers is
planned for end of 2001 (4 of these boards are required if drivers for all 64 outputs are
necessary).
• For small loads (e.g.LEDs or high-impedance reed relays) the additional drivers may not
be necessary.
• The MTC64 is the counterpart to CTM64 that generates up to 64 MIDI note on/off or
program change messages with free contacts connected to CTM64 (for details please
refer to the CTM64 product information or CTM64 manual)
MTC64 has two different modes:
• note on/off mode (without velocity) or
• program change mode
In the first case (note mode) incoming MIDI note on/off messages control the 64 outputs
provided that the MIDI channel and note range correspond to the settings of the
MTC64. A note on message will set the corresponding TTL output to a high level (+5V),
the note off message will reset the output to a low level (0V). With an additional jumper
this behaviour can be set to the other way round (note on = low, note off = high) if
reversed outputs are required.
The note offset (i.e. the MIDI note number assigned to the first output) can be set to 0 or
36 with another jumper. With two more jumpers one can transpose up/down one octave,
i.e. +12/-12 semitones. Instead of these jumpers a three-position octave selection
switch may be used. Thus the note offsets 0, 12, 24, 36 and 48 are obtainable. If
another note offset is required the unused outputs remain unconnected.
In the second case (program change mode) MIDI program change messages are used
to control the 64 outputs. In this mode only one of the 64 outputs is activated. The
number of the activated output is identical to the program change number received at the
MIDI input provided that the MIDI channel corresponds to the setting of the MTC64.
In the program change mode the offset can be set to 1 or 64, i.e. setting the program
number range to 1-64 or 65-128 (0-63 or 64-127 in MIDI code). With two daisy-chained
MTC64 the whole program number range 1-128 is covered. Alternatively a range switch
can be used instead of the range jumper.
The MIDI channel for all messages processed by the MTC64 is set with 4 jumpers.
The outputs are available as four double row pin headers with 16 pins each. 16 pin
socket-connectors with flat cable can be connected to these pin headers (not included with
the MTC64, we offer a suitable cable set that contains all required connectors and cables).
Additionally there are some GND pins available (as solder pins and as additional pin header
with 10 pins) as a GND reference level is required for the devices controlled by the MTC64
outputs.
Pay attention that only voltage-free high impedance inputs ( > 1 kOhm) are allowed to be
controlled by the MTC64 outputs. The inputs must not have any active voltage, i.e. they are
not allowed to have a certain voltage level (e.g. GND). Otherwise the MTC64 and/or the
device controlled by the MTC64 may be destroyed. Ignoring any of these items will cause
warranty loss !