Doepfer Wheel Electronic - Manual (Page 7)

User's Guide Wheel Electronic V1.0 Page 7
Midi In Socket (3)
The WE features a Midi input. This input may be connected to another Midi device (e.g. Midi
keyboard). The incoming Midi data are merged to the data generated by WE. The Midi input
may be used as well for daisy-chaining several WE. The Midi input of WE is not suitable for
large amounts of Midi data (e.g. SysEx strings or Midi messages coming from an computer
sequencer) as the WE has only a small Midi buffer. In case of large amounts of incoming Midi
data loss or delay of data may occur.
If the merge feature of the WE is not required the Midi input is left open.
LED Control (4)
After power on the LED is permanently on. If this does not happen probably the power supply is
not suitable (i.e. not the correct voltage range, minimum current or polarity) or defective. As
soon as a Midi out event occurs the LED turns off for a short time thus indicating MIDI activity.
The LED can be used to show the correct function of WE in principle.
Connectors for the four analog controls (5)
Remark: In the following the terms GND (= abbreviation of ground) and 0V (zero volts) are used
synonymous.
The four pin headers ST1…ST4 with three pins each are used to connect the analog controls.
The pins of these connectore have these functions:
Position Function To be connected to ...
left GND
end terminal #1 of the potentiometer
(the terminal that corresponds to Midi data 0)
center
measuring input
(control voltage)
center terminal of the potentiometer
right +5V
end terminal #2 of the potentiometer
(the terminal that corresponds to Midi data 127)
The control voltages are normally generated by rotary or fader potentiometers that are
connected between GND and +5V. In this case the wiper of the potentiometers outputs a
voltage in the range 0...+5V while the potentiometer is operated. Another possibility is the
connection of momentary switches or toggle switches (see below). Special potentiometers (e.g.
modulation wheels, foot controllers, joy sticks) usually do not cover the complete angle of
rotation. If an electronics is used that analyses the full voltage range 0...+5V the higher Midi
data values are missing. For this the WE is equipped with a high-resolution trimming
potentiometer (P1) that generates a second reference voltage for controls that do not cover the
complete voltage range 0…+5V. For each of the analog inputs one can select if the full range
(0…+5V) or the reduced range (0…+V, +V adjusted by P1) is used for generating the Midi data.
Even breath controllers (e.g. Yamaha BC-1/2/3) output only about +3.5V maximal voltage.
For details please refer to jumper area JP1.
We recommed the usage of three-pin cable sets with suitable female connectors to establish
the connections between WE and the analog controls. In this way the controls might be
disconnected from the electronics very easily.