Using CellSynth with MIDI

Setting up CellSynth MIDI

Before you can use MIDI with CellSynth, you must have OMS v2.0 or newer installed on your computer

you can download the latest versions of OMS from the Opcode website, which at the time of writing was at http://www.opcode.com.

Setting up OMS

From the Options menu choose Set MIDI channel... in the MIDI submenu.

» CellSynth defaults to using MIDI channel 1. If you want to change this use the above dialog.

From the Options menu choose Choose MIDI InputŠ in the MIDI submenu.

This will display the OMS input selector dialog. Use this to choose your MIDI source as you would in any other OMS application.

Playing Samples and / or Oscillator / Synth Sounds with a MIDI Keyboard

Drag a Sine Cell onto the Matrix. As you may have noticed, most of CellSynth's cells can be controlled via MIDI Controllers. This control is always available (providing MIDI has been setup correctly). Clicking on a Cell's Keyboard button enables MIDI note-on/off control. This can also be done by clicking the Keyboard button on the Cell Edit dialog.

Add an Envelope Cell

A Sine Cell on its own does not give you the control you would expect when playing a sound from a keyboard, as the sound will not stop when you let go of the key. In order that the sound should stop playing when you release the key, you will need to add an Envelope Cell and turn on MIDI note on/off control as described above.

Drag an Envelope Cell onto the Matrix next to the Sine Cell.

Turning on MIDI note on/off control on an Envelope Cell means that the envelope goes into attack mode when a MIDI note-on is received and release mode when a MIDI note-off is received.

You have already enabled MIDI note on/off control on the Sine Cell. This means that the MIDI note from your keyboard (sequencer or whatever) is controlling the frequency of the Sine Cell, adjusting the frequency as you play different notes.

By enabling MIDI Note on / off on the Envelope Cell, it means that the note off information is controlling the Envelope Cell so that the note is released when the key is released. This is, of course, how most MIDI controllable synths operate.

You can adjust the envelope parameters manually using the ADSR edit window: If you leave both Cell's unmuted, you will not hear the effect of the envelope because you will still be hearing the output of the Sine Cell before it has passed through the envelope. If you mute the Sine Cell (press the mute button in the cell edit dialog or command-click cell in Matrix window) you will only hear the output of the Envelope Cell.

» Recap - this is an important point to remember and should be taken into account when designing any sound. If you don¹t want to hear the original sound source but just the treated sound, remember to mute the Cell providing the sound source or it will still be going into the mix and heard at output.

Cells turn grey when muted.

Testing the Sound Using the Keyboard Window

You can easily test your new sound even if you don¹t have a MIDI controller setup. Open the Keyboard Window by selecting "Show Keyboard Window" from the "Options" menu. You can play the keyboard by clicking on the keys with your mouse.

Testing the Sound Using a MIDI Keyboard

To play from a MIDI keyboard (or any MIDI controller) make sure you have chosen your MIDI input in the OMS dialog accessed from the MIDI submenu item "Choose MIDI input" (as described earlier), and that the Controller is set to output on the same MIDI channel.

CellSynth must be active (click the speaker icon on the Matrix window or press spacebar) before it will receive MIDI from an external controller.

Synchronising to MIDI (or Internal) Clock

CellSynth has its own internal Clock which can be used in a number of ways, such as sync¹ing the start point of looped samples, sync'ing looped envelopes to produce a gated effect in time with the music. It is also used to drive the Event Sequencer to produce sequences, arrangements or many other interesting effects.

The tempo of the internal Clock can be set from the "Set Sync Tempo" dialog accessed from the "Options" menu.

CellSynth can, alternatively, be Sync¹ed to MIDI Clock from an external source, such as a Sequencer or any MIDI device that can output MIDI clock. This way CellSynth can be used as part of a larger MIDI setup.

To Sync CellSynth to an external Clock, select "Sync to MIDI Clock" from the "MIDI" submenu on "Options" menu.

CellSynth will immediately become active (you will see the Red LED glow), waiting for the MIDI Clock to start.

As soon as CellSynth receives Song Start or Continue, it will start playing in time with the External Clock.

There are a number of shortcuts to help sync samples, envelopes and delay lengths to tempo (if sync'ed to external clock set the internal clock to the same tempo):
Command-Click in a sample frequency dial to fit to tempo.
Command-Click in a delay dial to fit delay to tempo.
Command-Click in an envelope dial to fit A, D, S or R to tempo. Now use Control-Click to divide by 2 and Option-Click to multiply by 2 to adjust the value to the required multiple if necessary.

Using MIDI Control Messages

MIDI Control Messages can be used to great effect with CellSynth allowing it to be controlled from an external source. Because of the flexibility with which you can design your sounds, all sorts of possibilities are available. Assigning Controllers to parameters is made easy by the ³learn² shortcut.

Two ways of assigning MIDI Controllers

CellSynth actually has two ways of assigning MIDI Controllers. It is important to understand the Pro¹s and Con¹s of each. Each Cell has a main parameter that can be controlled by MIDI Controllers. The controls for setting this up appear in the Cell Edit dialog.

These two parameters are used to assign which Controller will control the Cell and what kind of range it will have. You can Command - Click the Controller LCD to set it to the last Controller received.

You can also assign a value to any Slider. This means that in actual fact, any parameter can be controlled via MIDI. However, this is a low priority function in CellSynth and if your Matrix is hitting your processor hard, you may notice a lag between the adjustment and the response from the Slider.

You can, in fact, assign the same controller in both the Cell Edit dialog and the Slider as we are going to do in this next example, and then you will get a good response and still be able to see the sliders move on-screen.

Setting up a MIDI Mixer

A simple, but very useful, example of using MIDI Control Messages is using an external MIDI device to control the Gain (volume) of Cells, enabling the various sounds to be mixed "live".

First you need a MIDI device with several Sliders or knobs which you can assign Control Numbers to. There are many such devices on the market, and many synths now have a generous number of assignable controls.

Make sure your MIDI device is transmitting on the same channel that CellSynth is set to receive (Options-MIDI-Set MIDI channelŠ) and that the MIDI input the MIDI device will be transmitting to has been selected in the "Choose MIDI input" dialog (Options-MIDI-Choose MIDI input).

A good example of a Matrix that has been setup to use with an external MIDI device is "Sample 5 Loop Mixing and Playing" in the Matrix Files folder (and accessible from the pop-up menu at the top of the Matrix window (under Basic Examples 2). This Matrix has been setup to use MIDI controllers 2 to 6. The Control Numbers are optionally displayed (Options menu: MIDI: Show Controller Names) on each Cell in the Matrix Window. You will also notice that five tear off Sliders have been setup for easy access.

Assigning the MIDI Controller Numbers

Assuming you have set up your MIDI device with appropriate Control Numbers, we can go on to assign the Control Numbers to the correct Parameters.

You can either assign a control value to a parameter in the Cell Edit dialog or, if you plan to use Sliders, it can be done from the Slider itself. See the explanation of the Pro's and Con's earlier in this chapter.

To assign a value in the Cell Edit dialog automatically, move the knob or slider on your MIDI device and then command-click on the Controller Parameter¹s dial or numeric display and the value received will be set. You can also set this by simply typing in the value or turning the dial until the correct value is displayed. Adjust the Control Amount to give a suitable range.

To create a Slider (which can be used independently of the Cell Edit window and also gives a visual reference of the Parameter¹s value) click in the Parameter's LCD display and drag:

In this example the Sliders are controlling the Gain Parameter of the Sample Cells. Because this is the main MIDI controlled parameter on Sample Cells, and we have already assigned a Controller in the Cell Edit dialog, it is not necessary to set one here. However, in order to see the Slider move on-screen, we can still assign a MIDI Controller to the Slider as well.

Simply move the control on your MIDI device that you wish to use and command-click on the Slider. A dialog will appear with the value CellSynth received from your MIDI device as its default. You can also set the control range from this dialog:

Try experimenting with the Sample 5 Matrix example. Assign some controllers to the Sliders from your own MIDI device.

MIDI Controllers in the Event Sequencer

Whilst we¹re on the subject of MIDI Controllers, we could take a quick look at how we might use MIDI controllers in the Event Sequencer.

The Event Sequencer is covered elsewhere in this manual but lets remind ourselves that we can use the Event Sequencer to automate or arrange sequences of events using MIDI controllers. Any Cell can be controlled using MIDI controllers and therefore the possibilities are endless. You could automate filter sweeps, volume changes, delay length, pan and so on.

By assigning Controllers to Sliders, any parameter can be controlled, but it should be remembered that MIDI control over Sliders has a low priority in CellSynth. For smooth response try and use the Cell¹s main parameter assigned in the Cell Edit dialog.

» Here are the Cells¹ Main Controllable Parameters: Sine gain (also known as volume!) Square gain Sawtooth gain Triangle gain Noise gain Samples gain Filters frequency Mixer gain Panner pan amount Black Box gain Delay delay length Envelope gain Reverb gain Sequencer none

Setting MIDI keyspan

When designing a Matrix with the idea of playing the sounds from a MIDI keyboard, it can be useful to assign different sounds to different areas of the keyboard. This is known as the Keyspan.

To set the Keyspan of a Cell, open the Cell Edit window and Option-Click on the MIDI Note on/off button.

This will open the Cell¹s Keyspan window:

To set the Keyspan, either type in the note numbers manually or click on the note at either end of the current keyspan and drag with the mouse.

How you might use Keyspan

Keyspan means that, although CellSynth only receives MIDI on one channel, you can control several sounds by spreading them across the keyboard. One example of this is if you had individual drum sounds. You could assign a keyspan of one note to each sound so that you can play the full kit from the keyboard.

It also means that you could control them from the Event Sequencer, which you could then use to arrange drum parts. Each cell that has MIDI Note on/off activated will receive the output from the Event Sequencer, so this is one Cell that can be placed anywhere on the Matrix and does not need to be connected to the other Cells on the Matrix.