Doepfer MTC64 Midi to Gate Interface (main board) - Manual (Page 7)

MTC64 V2 User’s Guide Page 7
(1) Power Supply (BU3)
The MTC64 does not have a built-in power supply. Instead it uses a plug-in type external
power supply (AC adapter). One reason for this feature is electrical safety. Keeping danger
voltages (main) out of the MTC64 increases the electrical safety. Therefore an external
power supply of high quality and safety should be used. If the keyboard is used in Germany
the external power supply has to be VDE approved. Another reason for the external power
supply is the fact that line voltages and plug types vary considerably from country to country.
Using a plug-in external supply the MTC64 can be used any where with a locally purchased
power supply, thus keeping the retail price down.
The power supply must be able to deliver 7-12 VDC unstabilized voltage, as well as a
minimum current of 100mA. The MTC64 is switched ON by plugging the AC adapter into a
wall outlet and connecting it to the appropriate jack on the CTM64 board. There is no
separate ON/OFF switch. If the polarity of the power supply is incorrect, the CTM64 will not
function. However, there is no danger of damage to the circuitry since it is protected by a
diode. The correct polarity is: outside ring = GND, inside lead = +7...12V. The power supply
is not included with the CTM64 and has to be purchased separately.
The specified power supply current of 100mA is only for the MTC64 electronics and does not
include the current of devices connected to the MTC64 outputs. If e.g. 64 low current LEDs
requiring 2mA each are connected to the MTC64 outputs an additional current of 64 x 2 =
128 mA has to be added to the 100mA of the MTC64. In this example we would recommend
the usage of a power supply with at least 250mA to be on the safe side.
(2) Midi In (BU1)
The Midi In of the MTC64 is connected to MIDI Out of the device that controls the MTC64
(e.g. keyboard, sequencer, CTM64). The incoming MIDI data are used to control the outputs
of the MTC64 provided that the MIDI data correspond to the jumper settings of the MTC64
(channel, mode, offset and so on).
If several MTC64 are controlled from the same device the MTC64 are daisy-chained via
MIDI-Thru Æ MIDI In.
The MIDI input of MTC64 is not suitable for large amounts of MIDI data (e.g. long SysEx
strings or extensive MIDI messages coming from an computer sequencer) as the MIDI in
buffer is only 48 bytes. In case of large amounts of incoming MIDI messages data loss or
delay may occur.
(3) Midi Thru (BU2)
MTC64 transmits the incoming MIDI data unchanged to the MIDI Thru socket (3). Connect
this socket to the MIDI input of another MIDI device that has to be controlled with the same
MIDI data as the MTC64 (e.g. several daisy-chained MTC64). Otherwise this socket
remains unconnected.
(4) Control LED (D4)
The LED is used to display any MIDI In/Thru activity. After power on the LED is permanently
on. As soon as a MIDI out event occurs the LED turns off for a short time thus indicating
MIDI activity. It may be used as a basic control (on after power on) and if MIDI data really
appear.
(10) Voltage Outputs 1... 64 (Pin Headers JP1/JP2/JP3/JP4)
The 64 outputs are available as four double row pin headers (JP1, JP2, JP3, JP4) 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).