In last month's SOS we looked at how the new Combinator device works and walked through the steps needed to create a new instrument patch. Basic instrument patches in Combinator are typically layered sounds from Reason's other synths and samplers, with dedicated effects, modulation routings and some useful or cunning front-panel control assignments. This month, we'll show that the Combinator can also be used to design your own new effects devices. Let's have a quick recap for those who missed last month: the Combinator is an (initially) empty shell in the rack that can house any number of other Reason devices. The unit has its own audio inputs and outputs that connect its internal workings to the main Reason environment, and it can receive and distribute MIDI data to devices inside. Its front-panel knobs and buttons can be mapped to the controls of the 'combined' devices, so a Combinator can therefore be used to create a complicated multi-device configuration, with its own signal flow and CV patching, and collapse it all into a single 'black box'.
The key feature of the Combinator that allows the creation of new signal processors is the presence of audio inputs. Take a look at the device's back panel (Screen A, left) and you'll see that there's a pair of stereo audio inputs, then just below that another pair of jacks for passing on the incoming signal to a device inside. Let's get stuck into an example to show how this works:
1. Start by creating a new song, then add a Remix mixer, Subtractor synth and Combinator from the Create menu.
2. Click inside the empty box at the bottom of the Combinator and place a DDL1 delay, again by choosing it from the Create menu. Screen B shows the rack you should now have produced.
3. Turn the rack around and you'll see that Reason has automatically cabled the Combi's 'To Devices' and 'From Devices' connections to the delay's audio inputs and outputs. However, it will not have connected anything to the Combinator's inputs and will have patched the outputs to a mixer channel.
4. Re-cable the Combinator's main inputs and outputs as you would when creating send-and-return connections (see 'Connection Conventions' box for more about this) to the mixer, as in Screen C. You can now send the Subtractor signal to the Combinator (and its internal delay) by adjusting the first send control on the mixer channel.
So what has this achieved? Well, apart from demonstrating how you can send a signal through the Combinator and its internal devices, not very much! This Combinator patch does nothing more than the delay unit can already do on its own. However, we can now add further devices to the patch, so that the signal is processed in more complex ways. For example, we could add a reverb, or a flanger. Again, this could be done without putting the effects units into a Combinator (although less tidily), so let's try something a little more adventurous. One thing you might not have noticed is that the DDL1 delay unit is a mono device, despite having left and right audio connections. The left and right signals are summed and panned using the panner on the front of the unit. The Combinator provides an opportunity to parallel two DDL1s, creating a true stereo delay unit.
5. To add a second DDL1, click in the Combinator's device area, just below the other delay. Now hold down Shift and choose the DDL1 from the Create menu. (Holding Shift tells Reason not to create any automatic cable connections. Normally when you create a new effect unit in a Combinator, Reason will assume you want to chain it on to the last device, but in this instance we'll do something different.
6. The plan is to use just one channel from each device (the left one) for each side of the stereo input coming into the Combinator. This will mean that the left and right legs are being processed entirely separately, maintaining the stereo signal, and allowing for stereo effects such as ping-pong echoes or subtle spatial treatments. Check out Screen D to see how the cabling should look.
7. On the front panels of the DDL units, set the pan pots hard left, as we're only using the left outputs. Now try playing the Subtractor with some delay added at the mixer send. You can adjust the left and right delays independently, for some fun results, but even if you don't your delays will follow the panning of the mixer channel, an improvement over the normal DDL1. Also, if you put a stereo signal through your new unit, say from an NNXT sample patch, the delays will now maintain the original sound's stereo width, instead of collapsing into the middle.
Save this patch and you can pull it up any time in the future. Now, though, let's try to create something more interesting. By adding more devices, we'll make a filtered, flanging, ping-pong delay with some distortion that really fattens up analogue synth and guitar patches.
8. Add a CF101 chorus/flanger, again holding down Shift to avoid messing up your cabling. Re-patch the cables so that the outputs from the two delays go into the flanger.
9. Select the flanger and add an ECF1 filter device. The outputs from the flanger will be connected to the filter automatically.
10. Finally, add a Scream distortion device. The Filter will be connected to this so that all the devices are now chained together. Manually connect the Scream's outputs to the Combinator's 'From Devices' jack ports. The final cabling is shown in Screen E.
11. Now we can start playing with the front-panel controls to get the effect we're looking for. Try the settings in Screen F. I've set the first delay to half the step time of the second, creating the ping-pong effect. The feedback amount has to be reduced quite a bit on the second delay, as 'feedback' controls the number of repeats on these devices, so longer delay settings result in longer decay times for the effect. On the chorus device I've set a short delay, high negative feedback, and some modulation to create quite heavy flanging. The filter has a bit of resonance and quite a high cutoff, so it just smooths things out a bit. Finally, the Scream distortion is set to Overdrive, with the Damage Control pulled back, and the Master Output down to avoid a boost in overall level.
At this point you could just save the patch as it is, ready for recall at a later date. This is already a major advantage over building a chain of devices in previous versions of Reason. Before the Combinator, if you'd wanted to re-use a configuration like this you'd have had to open the song it was in, copy all the devices, then paste them into your new song. You'd then have to try to cable it into your new song's rack. By building everything into a Combinator, you can just load it as a patch. However, the Combinator environment has a further advantage, in the shape of the front-panel control system. By mapping key controls from the various devices to Combinator knobs and buttons, you can quickly make variations of your effect, control several devices at once, and limit the parameters to ranges relevant to the type of effect.
12. First, we'll control delay time using the first knob on the Combi panel. Hit the 'Show Programmer' button, and select Delay 1 from the list on the left. Now, in the Modulation Routing section on the right, click on the Target slot next to Rotary 1. Select 'Delay Time (steps)' from the pop-up list. We'll limit the control to a useful range by adjusting the Max field to '4'. See Screen G, above.
13. Select Delay 2 in the device list, and again choose 'Delay Time (steps)' for Rotary 1. What we're doing here is doubling up the mapping for the first knob, so that it controls both delay units at once. Set the Max parameter to '8'. The knob will control the delay time, maintaining the ping-pong nature of the effect by increasing the second unit at a greater rate. Re-name Rotary 1 'Delay Time' by clicking its label on the panel and typing in the new name.
14. Now use the same technique to assign Rotary 2 to control the Feedback controls of both delays. Again, the ranges need to be set differently to maintain the relationship between the units. I've set the Max value for Delay 1 to 103, and Delay 2 to 41. Re-name Rotary 2 'Repeats'.
15. Rotary 3 will be used to control the amount of the flange effect. Select the CF101 in the Programmer page and map its Feedback control to Rotary 3. We want zero feedback when the knob is fully left, then an increasing amount of negative feedback as the knob is turned clockwise. The default range for the chorus device's Feedback control is -64 (maximum negative feedback) to +63 (maximum positive feedback). Set Rotary 3's minimum and maximum to '0' and '-64' respectively, and you'll get the correct behaviour from the knob (see Screen H). Re-name Rotary 3 'Flange Amount'.
16. The final knob will become the filter frequency control. Select the ECF1 and assign Rotary 4 to Frequency. Set the minimum to something above zero — say, 30 — to prevent this control from completely muting the effect when fully left. Re-name Rotary 4 'Filter Frequency'.
We're left with four buttons that I'll let you decide how to assign. I've used one to toggle the filter between Low Pass and Band Pass modes, and another to bypass the distortion. Don't forget to save the patch! You can see the final version on page 246.
Our Ping-Pong Flanger (or whatever it should be called) is only just scratching the surface when it comes to Combinator effects. A Combinator can contain any of the other devices available in Reason, and all CV cables as well as audio connections are saved as part of the patch, so you can be as complicated as you like. A great enhancement to the patch we've created in the example would be to use an LFO to sweep the filter frequency. The filter device has a Filter Frequency CV input, so all you'd need is a device that has an LFO with a dedicated CV output. (The two options are Subtractor and Malström.) The LFO output would be patched into the filter, then the little trim pot next to the CV input would need adjusting to set the modulation depth.
Another area for experimentation is using Matrix step sequencers to create rhythmic effects. This is when you can start trying to emulate some of the cool stuff you might do with Reaktor. An easy-to-follow example of this is the patch 'Simple Pattern Filter', which can be found in the 'Pattern Based' folder of the Combinator Effects Devices collection in the Factory Sound Bank. In this patch there's a filter device, with one Matrix triggering its envelope in a rhythmic pattern, and another setting the filter frequency at each step. A much more complex pattern filter to study, 'Matrix Filter', is in the same folder. This one uses more step sequencers and even a vocoder device.
Thinking up new ways of creating effects, and emulating old favourites is one of the most fun and satisfying parts of Reason 3, mixing head-scratching frustration with moments of inspiration. For example, one of the bright sparks at Propellerheads realised that you could stick the Gain Reduction CV output of the new Masterworks compressor device into a filter to create an envelope-following filter, like you'd find on a Mutator or Moogerfooger hardware processor. In other words, with a bit of imagination you can use Combinators to create signal processes that none of the other devices could achieve on their own.
The example in this article uses the classic 'send-and-return' cabling to allow signals going through the mixer to be blended with varying amounts of an effect. Normally, if you select the mixer and add any of the basic effect devices to the song, Reason automatically sets up this routing for you. With the Combinator you'll need to make these connections yourself, as shown in Screen C, page 247. This is an efficient way of using your new effect unit, as it allows all of the other instruments in the song to share the effect.
There are, of course, many instances (for example, distortion or filter effects) when you'll want to route an instrument straight through the effect (like having a plug-in on an audio track). In this case, just cable the instrument's outputs directly to the Combinator effect's inputs, then connect the Combinator's outputs to a mixer channel. Many effects patches suit one of the two routing options better than the other, so a rough naming convention was adopted when compiling the Reason Factory Soundbank. If you look in the Combinator Effect Devices folder you'll see that some of the patches have '[ins]', or 'ins', or simply 'insert' in their name. These patches only really work well when you feed an instrument into them directly. The rest will probably work best in a send-and-return configuration, but there are no hard and fast rules (and the convention has not been followed strictly anyway).