Introduction. DOEPFER CTM64 Contact to Midi Interface

Introduction

CTM64 is an universal MIDI Out kit. Up to 64 free contacts can be connected to generate MIDI note on/off or program change messages. CTM is suitable to retrofit keyboards, switch panels, button

arrangements or any other contacts so that they are able to transmit MIDI data. Up to 4

potentiometers can be connected to generate common MIDI controllers, pitch bend and after

touch. Additionally a 1/4 jack socket is available for connecting a sustain pedal.

Two different modes are selected with the first of 8 jumpers: note on/off or program change. In the note mode closing of a contact generates the corresponding MIDI note on message, opening generates note off - both without velocity (velocity is fixed to 100). In the program change mode closing of a contact leads to the corresponding MIDI program change message.

The note offset (i.e. the MIDI note number assigned to the first contact) can be set to 0 or 36 with the second jumper. With two more jumpers one can transpose up/down one octave, i.e. +12/-12 semitones.

Instead of these jumpers a 3-position switch (1-0-1) working as an octave switch can be soldered to the corresponding pins of the jumper pin header. In this way the note offsets 0, 12, 24, 36 and 48 are available. If another note offset (e.g. 41) is required the contacts are displaced correspondingly and the unused contact terminals are left free.

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 CTM64 the whole program number range 1...128 is covered.

The 4 potentiometer plugs are used to connect up to 4 potentiometers (e.g. rotary, slider, wheels or others) generating the MIDI messages pitch-bend, modulation (controller #1), volume (controller

#7) and monophonic after touch.

The 1/4“ jack socket can be used to insert a sustain pedal (contact type ”closed at rest” is required) generating the MIDI sustain message (controller #64).

The MIDI channel for all messages transmitted by the CTM64 is set with the last 4 jumpers.

The 64 contacts are connected to four double row pin headers with 16 pins each. 16 pin socketconnectors (female) with flat cable can be connected to these pin headers (not included with the

CTM64). Additionally there is one common pin for all contacts. Pay attention that only free contacts can be used. This means that the contacts are not allowed to be connected with another electronics or connected with a fixed voltage (e.g. GND).

For the potentiometer four male pcb connectors with 3 pins (GND, slider, +5V) are available. Suitable female connectors with assembled cables can be connected to these pin headers (not included with the

CTM64).

CTM64 is equipped with MIDI In and MIDI Out. The incoming MIDI messages are merged to the data generated by the CTM64. In this way several CTM64 can be linked together (e.g. 3 CTM64 required for 2 keyboards with 61 keys and one basepedal with 32 keys, or switch boards with more than 64 switches).

CTM64 is available only as an assembled and tested pc board. The pc board measures are about 90 x 105 mm. Four mounting holes with 3 mm diameter are available for mounting the pc board to a suitable base e.g. with distance sleeves or spacers and screws.

The configuration of CTM64 (i.e. MIDI channel, mode, note offset and so on) is made by the customer with 8 jumpers - as described above.

page 4 CTM64 Version 4 - User's Guide

We do not offer a suitable housing as the CTM64 is normally installed into the housing of the keyboard or switch board. An external power supply (7-12VDC@min. 250mA) is required. It is included with the

CTM64 only within Germany. In other countries the external power supply has to be ordered additionally by the local dealer if necessary.

We offer a suitable connector set for the CTM64 (25.00 Euro in Germany, i.e. about 30.00 US$). This includes four 16 pin flat cables with 16 pin socket connectors (female) pressed to the cables at one end

(length about 50cm) and four 3 pin female connectors with assembled cables for the potentiometers

(length about 30cm, potentiometers are not included). We also offer a suitable power supply (mains input: 90-240VAC with European type connector, output: 9V DC/800mA) with CE and VDE approval

(20.00 Euro in Germany, i.e. about 25.00US$).

Installation of the CTM64 requires some electrical/electronical knowledge by the user. Please leave the installation of CTM64 to an expert if you are not familiar with electronics. We take back only CTM64 modules in the original state, i.e. without solder residues, without scratches and so on.

The counterpart to CTM64 (MTC64) that converts 64 succeeding note messages into 64 0/+5V signals is planned for early in 2001. With suitable drivers relays, lamps or electromagnetic valves can be controlled via MIDI.

Please pay attention to the warranty notes on page 1. Ignoring these notes causes warranty loss and the right to return the goods.

CTM64 Version 4 - User's Guide Page 5