ByteNoise

Doepfer MCV-24

Doepfer MCV-24
Doepfer MCV-24

The buttons

Rotate the output knob to toggle which of the 24 outputs is being viewed and altered.

Rotate the menu knob to go through the options at that level. Press the menu knob to toggle between the main outer level and the specific inner level.

Rotate the value knob to tentatively change a value. Press it to set the new value.

If the MCV-24 gets stuck during a warm reboot, press all three buttons together to initiate a cold reboot. You don't have to press them for long, just together. As soon as you let go of one of the buttons, the cold boot will begin.

The menu

The menu only has two levels, an outer level and an inner level specific to the section you're in, but the settings available in the inner level can change based on the values of other settings next to them, which is a bit confusing at first.

Doepfer MCV-24

CV parameters

CV2 slew time only appears as an option if CV1 or CV2 has slew on.

Note event
Controller
Polyphonic aftertouch
Pitch bend
Monophonic aftertouch

LFO and ADSR parameters

Modulation matrix

Controller
Polyphonic aftertouch
Monophonic aftertouch
Pitch bend

System parameters

Global sync parameters

Presets and utilities

Tuning up

The MCV-24's first four CV outputs have a range of -2V to +8V, while the other twenty have a range of 0V to +10V. If you'd like to use it with equipment that's 1V/oct, such as the Doepfer A-100, its output will therefore span a range of eight octaves.

Tuning up the MCV-24 is a little confusing at first, but pretty straightforward once you're used to it. You need to pick any two arbitrary notes, labelled "tune note #1" and "tune note #2", tell it which MIDI note these should both be, and tweak the coarse tuning and fine tuning settings of them until they're both outputting the correct voltages. It will then extrapolate all the other notes, not just in between them but either side of them too.

For example, you can set "tune note #1" to MIDI note 0, play that note in your DAW (for some reason, it seems to be C2 in Reaper, not C-1 as expected; other DAWs may vary), then change CV #1's coarse tuning and fine tuning settings until the appropriate output on the MCV-24 is outputting exactly 0 volts.

You could then pick, for instance, the C five octaves up from that (C7 in Reaper). Play that note in your DAW, tell the MCV-24 which note you've picked by setting "tune note #2" to MIDI note 60, and adjust CV #2's coarse tuning and fine tuning until it's outputting +5V.

By default, the MCV-24's presets have tuning based on MIDI notes 0 and 96. I haven't tried this in any other DAWs, but Reaper doesn't go that high, so you have to adjust tune note #2 to something else. Basically, the lesson I learnt the hard way is: only try tuning the MCV-24 using notes you can actually play.

Syncing

The way the MCV-24 sends its sync outputs is a bit counterintuitive in my opinion. Nina and I hooked it up to an oscilloscope to see exactly what it's doing, and the results were a bit surprising.

The MCV-24 has a DIN sync output on the back, and separate 3.5mm jacks for run/stop and clock pulse outputs on the front. Aside from the physical connection type, these are the exact same outputs.

By default, they both output 24PPQN, the same that a MIDI clock signal will send to the MCV-24, and that other devices will generally like to receive from it. You can change the clock time, which tells it how many clock pulses to pay attention to. The default is 1, which is quite sensible, and pays attention to every clock pulse. Changing it to 2 makes it pay attention to every other pulse, changing it to 3 makes it pay attention to the first of every three pulses, and so on. Surprisingly, this will change the outputs at both the front and back, so would likely confuse anything connected over DIN sync.

The run/stop signal is always +5V when high, and 0V when low, as you would expect. This is regardless of the polarity you select in the menu.

When the polarity in the menu is set to positive, the clock pulse will be +5V when idle and 0V when sending a pulse. When it's set to negative, it will be 0V when idle and +5V when sending a pulse. I can only imagine most equipment you could hook up to DIN sync would expect it to be in its negative polarity. Note that the polarity setting affects both the front and back clock pulse outputs.

Ignore the LED above the clock output at the front. It's much slower than the actual output beneath it.

SysEx dumps

Note that the MCV-24 is always ready to receive a SysEx dump of patches or even an operating system update. You only need to traverse the menu to save a patch by sending it to another device, not to load one from that device.

A SysEx dump of a patch contains not only the patch itself but also its position, whether that's the main editable memory (the "edit buffer") or one of the sixteen patch storage addresses. I took the liberty of gathering the seven preset patches from Doepfer's website, saving each one into a separate patch slot, and then combining them into a single SysEx file of all MCV-24 presets. Whereas loading any single preset from Doepfer's site will overwrite the edit buffer and leave all the patch memories, this single file will leave the edit buffer as it is, and overwrite the first seven patch memories instead, all at once.

Presets

Seven presets are available for the MCV-24, from Doepfer's website.

CTRLTOCV

1 to 24: MIDI CC 0 through to 23

DRUMTOCV

1 to 12: gate
13 to 24: velocity

This preset responds to notes B1 through to F3 (missing a few less used ones) on MIDI channel 10, which correspond to general MIDI percussion instruments "bass drum 2" through to "ride bell":

Note Drum MCV-24 output
B1 Bass drum 2 1
C2 Bass drum 1 2
D2 Snare drum 1 3
E2 Snare drum 2 4
F#2 Closed hi-hat 5
G#2 Pedal hi-hat 6
A2 Mid tom 2 7
A#2 Open hi-hat 8
C#3 Crash cymbal 1 9
D3 High tom 1 10
D#3 Ride cymbal 1 11
F3 Ride bell 12

I made a Doepfer MCV-24 Drum to CV note map for Reaper. Even if you're using a different DAW, this should hopefully give you a head start working out which note corresponds to which pair of outputs.

I also made a handy label you can print out and stick on the MCV-24, available in a TR-808 and TR-909 style. You can download this as a PDF or PNG. I found the PNG printed with a more accurate reproduction of the bold font.

MCV24TST

1 to 24: an LFO

MULTITRK

This listens to MIDI channels 1 through to 12.

1 to 12: pitch
13 24: gate

SIX4ONE

1 to 4: pitch
5 to 8: velocity
9 to 12: aftertouch
13 to 16: gate
17 to 20: pitch bend
21 to 24: mod wheel

Replacing the battery

The MCV-24 has a 3.6V internal battery which should be replaced roughly once every two years. This requires some basic soldering skills. If the MCV-24 gets stuck while booting up, you likely need to change the battery.