Doepfer MCV4 Midi CV/Gate Interface - Manual (Page 4)

MCV4 User's Guide - Page 3
The factory setting for the GATE output is +5V voltage gate. If you want to change the
setting you have to open the MCV4 case. Before opening the case disconnect the MCV4
from the AC adapter and remove all connections. Open the case of the MCV4 by removing
the 4 screws using a suitable tool. Inside you see the pc board with a jumper located near
the Gate jack socket. The jumper can be set in one of 3 different ways:
• +5V Voltage Gate: jumper set away from the pc board edge (factory setting)
• +U Voltage Gate: jumper set to the pc board edge
• S-Trigger: jumper removed (e.g. for most of the Moog synthesizers)
To select S-trigger you have to remove the jumper. +U means that the gate voltage is equal
to the output voltage of the AC adapter used. As the admitted voltage range of the AC
adapter is +7...+12V the gate voltage has the same range when the jumper is set to +U. E.g.
if your synthesizer requires a gate voltage of +10 V or more you should use the +U setting of
the jumper and an AC adapter with about 12V output voltage.
Which type of CV characteristics and Gate is required for your synthesizer you may find in
the manual of your synthesizer.
OPERATION
When using an external power supply the MCV4 is SWITCHED ON
The MCV4 is SWITCHED ON by plugging the AC adapter into a wall outlet and connecting it
to the power supply jack labeled "9V DC" of the MCV4. There is no separate ON/OFF switch.
After power on the LED on the MCV4 will light up for a short time. Otherwise the AC adapter
used is not suitable or does not work.
The external power supply (AC adapter) is NOT included with the MCV4 and must be
purchased locally by the user. We recommend an VDE approved AC adapter but MCV4 will
work with every AC adapter being in accordance with the following specifications. The
adapter must be able to deliver 7-12 V DC unstabilized or stabilized voltage, as well as a
minimum current of 100 mA. The POLARITY of the low voltage plug connected to the MCV4
must be pin = +7...12V and ring = GND (see sketch on the MCV4 housing). If the polarity is
incorrect, MCV4 will not function. However, there is no danger of damage to the circuitry
since it is protected by a diode. If the MCV4 is used in Germany the external power supply
must be VDE approved.
In the normal mode (i.e. not in the learn mode) the LED displays the state of the Gate output.
You may use the LED to control the correct MCV4 function without having a synthesizer
connected to the MCV4.
When turning on the MCV4 the last configuration before the unit was turned off is called up,
i.e. the parameters for MIDI channel, reference note, gate polarity, retrigger and so on.
To adjust the MCV4 parameters (like MIDI channel or gate polarity) you have to enter the
MCV4 learn mode and send the regarding MIDI messages to the MCV4 from your MIDI
controlling while the MCV4 is in learn mode. To enter the learn mode one has to press the
learn button and hold it pressed down for about one second. The one-second-delay was
programmed to prevent the unintentional release of the learn mode. Whenever the LED is
flashing without incoming MIDI messages the learn mode is active. In this mode the MCV4 is
looking forward to an incoming MIDI note on, program change or controller event (see table
Pay attention if you open and close the MCV4 case (e.g. for adjusting the scale or
changing the Gate/Trigger setting). Use only a suitable screw driver and open/close the
case very carefully.. We cannot take back units if the case or LEDs or the switch are
damaged and the warranty will be lost during such manipulations. If you are not sure
whether your are able to do the modification send the unit to your local dealer or to
Doepfer Musikelektronik, Graefelfing (Germany).