Introduction - What is it?
M2CV is a MIDI to CV converter for use in Concussor, Doepfer and
Integrator style modular systems. It is used to control analogue
modules from a MIDI source.
Specification
Brief Overview:
Pitch CV output: 1 volt per octave (1V/oct). -2v to 6V range
Auxiliary CV output: -2 to 8V range. Variable range
Gate output: 12V
Accent output: 5V
Legato output: 5V
DAC: dual channel, 16 bit
Software controlled fine tune and scale, stored in memory
Transpose: 0 to+15 semitones
Highly stable CV outputs. No drift
1 LED
2 push buttons
MIDI In and Thru
Dimensions: 12HP
Power: +5, +12, -12
Power
M2CV requires +5v, +12v and -12V. The connector used is a 14pin
boxed header and is compatible with Concussor and Doepfer style
power connectors. Ensure the power lead is connected the correct
way round. Pin 1 is -12V (cable stripe).
Note; an adaptor power cable is needed when used in an Integrator
case.
Getting Started
Connect to power cable (see Power above). Connect the MIDI Out
socket from the MIDI controller to the MIDI In socket on the M2CV
Set M2CV to the correct MIDI channel (see later).
Connect the M2CV to your modules (see later).
LED Description
There is 1 LED which will flash only when MIDI messages the M2CV
responds to are received.
If it is permanently on M2CV is in program mode.
Set-Up Editing
MIDI continuous controllers can be used to edit the setttings.
Avoid changing the tune and scale settings. Doing this may cause
your synths to play out of tune.
Controller 0Bh:
Auxiliary CV Range
0-127
This setting alters the auxiliary voltage range. From 0 to 10v,
down to 0-0v (off). A middle setting of aroung 63 will give a
voltage range of approximately 0 to 5v.
Controller 0Ch:
Pitch Fine Tune
0-127
This setting alters the pitch CV output offset (Tune).
Controller 0Dh:
Pitch scaling
0-127
This setting alters the pitch CV output scaling (octave spacing).
Controller 0Eh:
Note Transpose
0 to +15 semitones
This setting allows the received MIDI note to be transposed up in
semitones.
Program Mode
This mode is used to set the MIDI receive channel and CV2 MIDI
source.
To Set MIDI Receive Channel
Press and hold the Program button. Then do either;
Press a MIDI key. This will set and store the receive channel to
the channel received in the note data.
CV2 will set itself to Velocity.
Release the Program button.
Or
Move a Continuous Controller. This will set and store the receive
channel to the channel received in the CC data.
CV2 will set itself to the CC number received.
Release the Program button.
Note; The Program button must be held in whilst pressing a key or
moving a controller.
CC number 7Fh, 0Bh and 0Eh are reserved. Avoid using these
controllers.
How To Adjust Pitch Tune and Scale
Only do this is absolutely neccessary and if you believe you have
the ability. If you mess it up you could completly ruin the
settings. M2CV comes already set-up and is very stable, so it is
unlikely you will need to adjust it.
Connect up a MIDI keyboard with controller knobs to the M2CV.
Connect a voltmeter to the pitch CV output.
Centre MIDI controller 0Ch (tune) to a value of 3Fh.
Set MIDI controller 0Eh (transpose) to 0
Press key C3 (value 38h).
Adust Tune trimmer (with suitable small screwdrive) until the
meter reads 0V. Further adjustments can then be done using MIDI
controller 0Ch (tune).
Press key C5
Adjust MIDI controller 0Dh (scale) until the meter reads 2V. A
value around 0Eh is usually about right.
All done!
Ref: We use a MIDIman Oxygen 8 Controller;
Knob 2 CV2 Scale
Knob 3 Pitch Tune
Knob 4 Pitch Scale
Knob 5 Pitch Bend Range
Knob 6 Transpose
How to Connect up An Analogue Synth/VCO
CV
Connect this to the pitch CV input of the analogue synth. This
input will be labelled something like CV, Key Volt. Keyboard In,
VCO, etc.
M2CV only outputs 1V/oct pitch scale, as used with Roland, Mood,
ARP and most other analogue synth makes. Some, like Korg and
Yamaha use a different system, Hz/V. M2CV can still be used with
these synths, but they will play out of tune.
Gate
Connect this to the Gate input of the analogue synth. This input
will be labelled something like Gate, Trig, V-Trig, etc.
Auxiliary
Connect this to additional control inputs the synth may have,
e.g. Filter Cut-Off control, VCA level, PW, etc. Not all synths
have additional sockets, but we can modify most synths to have
them. Contact us for more details or visit our web site.
Accent
When a MIDI velocity >100 is received this output will go to
5V. When a zero velocity is received it will go to 0V. This can
be used as an additional control source for filters, VCAs or to
clock certain modules.
Legato
When 2 MIDI notes are overlapped this output will go to 5V. When
a note is played that does not overlap the previous, it will go
to 0V. This can be used to control various modules.
Note
If your VCO plays out of tune it may be that your VCO is not
set-up to 1V/Oct. M2CV is set to this at the factory and is very
stable. Adjust your VCO scaling accordingly.
Detail About MIDI Messages
Some information about MIDI messages that may help as a
reference;
(n = 0 to Fh for MIDI channels 1 to 16d) Note Events
8n kk vv Note OFF kk=00-7F key
vv=00-7F release velocity
9n kk 00 Alternative Note OFF
9n kk vv Note ON kk=00-7F key
vv=01-7F attack velocity*
An kk pp Polyphonic Key Pressure kk=00-7F key
pp=00-7F key pressure
Controllers;
Bn 00 xx 0 - Bank Select MSB* (GS) xx=00-7F controller value
Bn 01 xx 1 - Modulation Depth (GM)
Bn 02 xx 2 - Breath Control
Bn 04 xx 4 - Foot Pedal
Bn 05 xx 5 - Portamento Time (GM) Glissando Time
Bn 06 xx 6 - Data Entry MSB (GM)
Bn 07 xx 7 - Volume* (GM)
Bn 08 xx 8 - Balance (GM)
Bn 0A xx 10 - Pan (GM) xx=40 for centre
Bn 0B xx 11 - Expression* (GM)
Bn 10-13 xx 16-19 - GP Control #1 - #4
Bn 20-3F xx 32-63 - Data LSB* for controllers 0-31
Bn 20 xx 32 - Bank Select LSB (GS)
Bn 26 xx 38 - Data Entry LSB (GM)
Bn 40 xx 64 - Hold Pedal #1* (GM)
Bn 41 xx 65 - Portamento (GS)
Bn 42 xx 66 - Sostenuto (GS)
Bn 43 xx 67 - Soft Pedal (GS)
Bn 44 xx 68 - Legato Pedal
Bn 45 xx 69 - Hold Pedal #2
Bn 46 xx 70 - Sound Variation
Bn 47 xx 71 - Sound Timbre
Bn 48 xx 72 - Sound Release Time
Bn 49 xx 73 - Sound Attack Time
Bn 4A xx 74 - Sound Brightness
Bn 4B-4F xx 75-79 - Sound Control #6 - #10
Bn 50-53 xx 80-83 - GP Control #5 - #8
Bn 54 xx 84 - Portamento Control (GS)
Bn 5B xx 91 - Reverb Level (GS)
Bn 5C xx 92 - Tremolo Depth
Bn 5D xx 93 - Chorus Level (GS)
Bn 5E xx 94 - Celeste Depth
Bn 5F xx 95 - Phaser Depth
Bn 60 xx 96 - Data Increment
Bn 61 xx 97 - Data Decrement
Bn 62 xx 98 - Non-RPN* Parameter LSB (GS)
Bn 63 xx 99 - Non-RPN Parameter MSB (GS)
Bn 64 xx 100 - RPN* Parameter LSB (GM)
Bn 65 xx 101 - RPN Parameter MSB (GM)
Bn 78 00 120 - All Sound Off* (GS)
Bn 79 00 121 - Reset All Controllers (GM) Varies between
manufacturers,
but typically Pitch Bend, Polyphonic & Channel Pressure,
Modulation all set to 0,
Expression set to 7F, Hold #1, Portamento, Sostenuto & Soft
all set OFF, RPN/NRPN reset
Bn 7A 00 122 - Local On/Off
Bn 7B 00 123 - All Notes Off* (GM)
Bn 7C 00 124 - Omni Mode Off responds only to specified MIDI
channel
Bn 7D 00 125 - Omni Mode On responds to any MIDI channel
Bn 7E mm 126 - Mono Mode On mm sets the number of individual mono
sounds available, typically 0 to 16, default 1
Bn 7F 00 127 - Poly Mode On
Other Channel Messages;
Cn pp Program Change
Dn vv Channel Pressure
En ll mm Pitch Bend* ll=LSB, mm=MSB, each 00-7F
ll=00, mm=40 for centre
* More on Channel Messages
Note ON attack velocity sets how ‘hard’ a note is
struck (eg how hard a piano key is hit), and should not be
confused with other volume level messages. Depending on how the
patch is programmed, this information is often used to change the
character of the sound as well as the volume. For example, a
piano key that is pressed gently produces a soft, mellow sound,
while the same key pressed hard produced a louder, but also
brighter sound.
Controller 0 - Bank Select MSB is used in conjunction often with
the Bank Select LSB to select the bank for the next program
change message. This means the patch does not change until the
program change is received (bank messages alone are not enough).
The combination of Bank MSB and LSB messages gives a possible
16384 banks, each of 128 different sounds, giving over 2 million
possible sounds! In practice, most manufacturers only use a few
different banks, and you can usually ignore the LSB message.
Controllers 7 & 11 - Volume and Expression are often
confused. Some older sound modules do not support Expression. The
intended use is for controller 7 to preset the channel volume,
and for Expression to vary volume while notes are played (eg a
swell on a brass sound). If you are writing sequences for a wide
range of sound modules, it may be easier to set Expression to 7F
(maximum) and use the volume alone for variations. These volume
level messages should not be confused with Note Velocity messages
and the GM Master Volume system exclusive message.
Controllers 32 to 63 are provided to give extra resolution to the
corresponding control
lers 0 to 31. For example Controller 0 is
Bank MSB (most significant byte) and Controller 32 is the Bank
LSB (least significant byte). The only LSB messages which are
commonly implemented are listed above separately.
Controllers 64 to 69, and any other control which is switched
(meaning that it is either off or on, instead of using a range of
values from 00 to 7F), generally interprets values of 00 to 3F as
OFF, and 40 to 7F as ON. For safety, use 00 for OFF and 7F for
ON.
Controllers 120 (all sound off) & 123 (all notes off) differ.
All Sound Off is not supported by all modules, and cuts sound off
abruptly, while All Notes Off is the same as releasing all notes,
so that any notes programmed to have a gradual decay (fade out)
after being released, will do so.
Pitch Bend is also affected by the Bend Range set with RPN
controllers - see below for more information.
Realtime Parameter Number (RPN) Settings:
These messages specify which parameter is to be set by the
following controller 6 (MSB) and 38 (LSB) data messages. For that
reason, it is important to send a RPN reset message after use, so
that any ‘stray’ data messages later in the song do not
have undesirable effects.
Non RPN (NRPN) messages are used in different ways by different
manufacturers, so you will need to consult the user manuals. For
example, Roland use NRPN message in GS mode to change vibrato,
filter and volume envelope settings, as well as fine tuning
individual percussion sounds.
Here are some common RPN messages, with the MIDI data shown in
bold (and in hex!). Remember, Bn means a channel controller
message on channel n, where n is 0 to F for channels 1 to 16.
Pitch Bend Range:
RPN LSB = 0: Bn 64 00
RPN MSB = 0: Bn 65 00
Data MSB: Bn 06 mm (mm sets bend range in semitones. mm can be
from 00 to 18 for 0 to 24 semitones both up and down)
Data LSB=0 (usually not required): Bn 26 00
Fine Tuning:
RPN LSB = 1: Bn 64 01
RPN MSB = 0: Bn 65 00
Data MSB*: Bn 06 mm
Data LSB*: Bn 26 ll
* mm:ll = 00:00 for -1 semitone, 40:00 for no change, 7F:7F for
+1 semitone.
Coarse Tuning:
RPN LSB = 2: Bn 64 02
RPN MSB = 0: Bn 65 00
Data MSB*: Bn 06 mm
Data LSB = 0: Bn 26 00
* mm = 28 for -24 semitones, 40 for no change, 58 for +24
semitones.
RPN & NRPN Reset:
RPN LSB = 7F: Bn 64 7F
RPN MSB = 7F: Bn 65 7F
Send this alone (no data messages) immediately after all other
RPN and NRPN messages have been sent.
Quick List of Defined MIDI Controllers
High resolution continuous controllers (MSB);
0 Bank Select
1 Modulation Wheel
2 Breath Controller
4 Foot Controller
5 Portamento Time
6 Data Entry
7 Channel Volume
8 Balance
10 Pan
11 Expression Controller
12 Effect Control 1
13 Effect Control 2
16 Gen Purpose Controller 1
17 Gen Purpose Controller 2
18 Gen Purpose Controller 3
19 Gen Purpose Controller 4
High resolution continuous controllers (LSB);
32 Bank Select
33 Modulation Wheel
34 Breath Controller
36 Foot Controller
37 Portamento Time
38 Data Entry
39 Channel Volume
40 Balance
42 Pan
43 Expression Controller
44 Effect Control 1
45 Effect Control 2
48 General Purpose Controller 1
49 General Purpose Controller 2
50 General Purpose Controller 3
51 General Purpose Controller 4
Switches;
64 Sustain On/Off
65 Portamento On/Off
66 Sostenuto On/Off
67 Soft Pedal On/Off
68 Legato On/Off
69 Hold 2 On/Off
Low resolution continuous controllers;
70 Sound Controller 1 (TG: Sound
Variation; FX: Exciter On/Off)
71 Sound Controller 2 (TG: Harmonic Content; FX: Compressor
On/Off)
72 Sound Controller 3 (TG: Release Time; FX: Distortion On/Off)
73 Sound Controller 4 (TG: Attack Time; FX: EQ On/Off)
74 Sound Controller 5 (TG: Brightness; FX: Expander On/Off)
75 Sound Controller 6 (TG: Undefined; FX: Reverb On/Off)
76 Sound Controller 7 (TG: Undefined; FX: Delay On/Off)
77 Sound Controller 8 (TG: Undefined; FX: Pitch Transpose On/Off)
78 Sound Controller 9 (TG: Undefined; FX: Flange/Chorus On/Off)
79 Sound Controller 10 (TG: Undefined; FX: Special Effects
On/Off)
80 General Purpose Controller 5
81 General Purpose Controller 6
82 General Purpose Controller 7
83 General Purpose Controller 8
84 Portamento Control (PTC) (0vvvvvvv is the source Note number)
91 Effects 1 (Ext. Effects Depth)
92 Effects 2 (Tremelo Depth)
93 Effects 3 (Chorus Depth)
94 Effects 4 (Celeste Depth)
95 Effects 5 (Phaser Depth)
96 Data Increment (0vvvvvvv is n/a; use 0)
97 Data Decrement (0vvvvvvv is n/a; use 0)
98 Non Registered Parameter Number (LSB)
99 Non Registered Parameter Number (MSB)
100 Registered Parameter Number (LSB)
101 Registered Parameter Number (MSB)
Channel Mode messages;
120 All Sound Off
121 Reset All Controllers
122 Local Control On/Off
123 All Notes Off
124 Omni Mode Off (also causes ANO)
125 Omni Mode On (also causes ANO)
126 Mono Mode On (Poly Off; also causes ANO)
127 Poly Mode On (Mono Off; also causes ANO)
