Reason 3 Jacked Up

This story provides instructions on learning how to use the Propellerhead Reason 3 back panel for patching together new sounds.

Sometimes you just want to get on with making music. You've got a looming deadline or a passionate idea, and the last thing you need to do is get lost in minutiae. Then there are those other times, when inspiration has taken a vacation, and you're searching for something new. Or maybe you want to build a deeper understanding of your gear, so the next time you need to get on with it you'll have a few extra tricks up your sleeve.

Propellerhead Reason 3 is a great resource either way. It's simple to just grab a factory beat or synth patch and lay down a track. But poking around in Reason's back panel, hooking things up without any idea about a specific musical goal sometimes leads to a surprise that can end up being the centerpiece of a whole new piece of music.


Jacked Up Examples.rns
Download this Reason 3 RNS file, which contains Combinator patches for the four example explained in this article. See the top Combinator for the first example and descend from there.

Reason Jacked 1.mp3
Listen to this MP3 demonstrating the "LFO, Meet Your Destination" example, which shows how a single Subtractor LFO can modulate several destinations. A chord progression repeats four times, beginning with a very simple organ sound. On the second repetition, LFO1 is routed to the FM amount from the Subtractor front panel. On the third repetition, LFO1 is also routed to the oscillator pitch from Subtractor's rear-panel jacks. And on the fourth repetition, LFO1 is routed to the FM amount using the Spider CV Splitter.

Reason Jacked 2.mp3
Listen to this MP3 demonstrating the "Follow the Bouncing Envelope" example, which uses a drum beat as a CV source for the BV512 Vocoder. Notice how about halfway through, the beat drops out, and thus the modulation coming from the vocoder also drops out, leaving the raw Malstrom sound.

Reason Jacked 3.mp3
Listen to this MP3 demonstrating the "Enter the Matrix" example, in which a patter in the Matrix sequencer alternates the Subtractor synth's oscillator 1 waveform. The first two bars play the initial setup; afterward, the Combinator's Rotary 1 knob is increased, which changes the Matrix pattern.

In this article we'll tiptoe down that signal path less traveled and take a look at Reason's backside stash, exploring things you may want to do with the CV ins and outs when you have a spare half hour to do a little patching and tweaking. See the “CV Radio” sidebar for the theory behind the machinations.


Get your feet wet by creating a straightforward CV patch. Launch Reason, create a Mixer 14:2 if your default song doesn't include one, and then create a Subtractor synth module. If you look at Subtractor's front panel, you'll see two LFOs, which for many types of sounds will be all you need. But each LFO can have only one destination at a time. What if you want to control the pitch, FM amount and filter-cutoff frequency all with one LFO?

Hit the Tab key to look at the rear panel. Notice the LFO 1 jack in the Modulation Output section? To send LFO 1 to two destinations, simply select a destination on the front panel and then patch LFO 1's rear-panel output to the Modulation Input of your choice. You'll notice a couple of destinations here (Amp Level and Filter Resonance) that aren't on the front panel at all.

Maybe two destinations still aren't enough to suit you. Create a Spider CV Merger & Splitter device. (Hold Shift while doing this so that it won't be patched to anything automatically.) Patch the LFO 1 output to the Spider Split A input, and then patch a couple of the Split A outputs to the destinations of your choice (see Fig. 1). Use the knob beside each input jack to adjust the amount of LFO modulation.

When you come up with a lively LFO patch this way, you may want to save it. If you use the File Save button on the front of the Subtractor, though, your CV connections won't be saved. The solution is to select both the Subtractor and the Spider by Shift + clicking, and then choose Combine from the Edit menu. This will create a new Combinator module and move both of the other modules into it, complete with their CV routings. When you save the Combinator patch, all of its internal patch-cord routings will be included.

Reason owners can download an RNS file containing this patch, and all of the others developed in this article, from


One of my favorite Reason tricks is to load a beat into a Dr.Rex module and then use the beat as a CV source instead of (or in addition to) listening to it. Follow these steps to try it:

1. Create a Dr.Rex device, load a beat into it from the Reason library and click on the To Track button. When you hit Play on the transport, you should hear the beat.

2. Create a Spider Audio Merger & Splitter. Patch the audio outputs of the Dr.Rex into the Spider's splitter inputs (the ones on the right side). Patch the first pair of splitter outputs back to your mixer. You should hear the beat as before.

4. Shift-create a Malström synth and patch its outputs into the mixer manually. Choose a waveform for Osc A. Almost anything will do, but for this example, I chose the PWM wave (clicked on the Up arrow four times).

5. Tab to the rear panel. Connect the vocoder's CV Output 1 (at the left end of the top row) to the Malström's Shift input and the vocoder's Output 12 to the Malström's Pitch input. Depending on the beat, you may need to choose different CV outputs. By watching the vocoder's front panel while the beat plays, you can see which bands have lots of energy. Your patch should look like Fig. 2.

6. Start the transport and play some chords on the Malström. (When the transport isn't running, the patch will do nothing.) Each time the kick plays, the Malström's Shift parameter will move, and each time a snare or a hi-hat plays, the Malström's pitch will go up. Adjust the CV input knobs to taste.

7. For extra rhythmic interest, Shift-create a DDL-1 device. (You can park it next to the Spider.) Patch the DDL-1 between the Spider and the vocoder's modulator input, and turn the DDL-1's feedback down to 0. Now the pulsing changes in the Malström chords will be offset rhythmically from the beat.

The reason this patch works is because a vocoder is built using circuits called envelope followers. An envelope follower tracks the loudness of its input and outputs the result as a control signal. In a vocoder, the incoming signal is split into separate frequency bands before being sent to a bank of envelope followers. The envelope follower outputs from the first 16 bands of the BV512 Vocoder are then made available as CV outputs on the rear panel. Wherever your beat has a kick, the envelope follower for band 1 should peak, and so on.


Although the Subtractor rear panel has eight inputs for CVs, many of the parameters on the front panel have no CV inputs. But if you dig a little deeper, you'll find a way. The key is the Combinator. This patch makes a Subtractor perform a type of wave sequencing — a burbling sound you may remember from such vintage synths as the PPG Wave. For this article, I'll do it by using a CV to change the Subtractor's waveform. This is accomplished by routing the CV through a rear-panel CV input on the Combinator itself.

Start by creating an empty Combinator, and then create a Subtractor inside it. Below the Subtractor, Shift-create a Matrix Pattern Sequencer. The Matrix makes no sound of its own; it's strictly a CV source. Patch its Note CV output to the Combinator's Rotary 1 CV input. Set the Matrix to an 8-step pattern and enter some quasi-random note values.

Next, open the Combinator's programmer by clicking on the Show Programmer button on the front panel. Select the Subtractor in the column on the left side, and in the column on the right side, use the pop-up menu to select Osc1 Wave as the Target for Rotary 1 (see Fig. 3). Now run the Matrix and play a few notes or chords on the Subtractor.

Unless you've slipped up somewhere along the line, you'll hear a pattern of changing waveforms and see the Subtractor's Osc 1 Waveform selector jumping from one number to another. By adjusting Rotary 1 itself and the Rotary 1 rear-panel CV amount knob, you can change the pattern.

With a little experimentation, you can come up with many variations on this patch. (For some extra grit, try using the mod envelope instead of a Matrix to sweep through the waveforms.) Download the RNS file that accompanies this article at, and you'll be able to hear how I've used two Matrix sequencers playing patterns of different length to modulate both the oscillators' waveforms and their phase knobs to produce a rich and haunting electronic tone.


We haven't used a Scream 4 distortion module yet, so create yet another Combinator and Shift-create a Scream 4 inside it. Shift-create a Subtractor in the Combinator and name it Modulator. We're going to use it as a CV source.

Shift-create a Malström in the Combinator and leave its waveform set to Sine. On the rear panel, patch the Malström's audio outs to the Scream 4's audio ins and the Scream 4's audio outs to the Combinator's From Devices jacks. If you play the keyboard at this point, you should hear a distorted Malström.

Now patch the Subtractor Mod Env output to the Scream 4 Damage Control input, the Subtractor Filter Env to the Scream Body Scale and the Subtractor LFO to the Scream 4's P1 input (see Fig. 4).

On the front panel, switch on the Scream 4's Body section and switch the Damage selector to Distortion. Since we're using the Subtractor strictly to generate CV signals, set its Polyphony to 1 and click on the Low BW (bandwidth) button; that will save a few CPU cycles. For this patch, which applies two Subtractor envelopes to Scream parameters, you may want to increase the Subtractor Filter Envelope attack time and the Mod Envelope decay time. And try a synced square wave for the Subtractor LFO.

Experiment with the front-panel settings, especially Damage Control and Body Type. They'll have a big impact on the tone. Play some open fifths on the keyboard; you should hear the sine wave transformed into a pulsing fuzz sweep.

Are you still not satisfied? Here's another idea. Create a second Subtractor in the Combinator, which will also be used as a CV source. Create a Mixer 14:2, route the Scream 4's audio through it and use the Mixer channel's Pan CV In jack to sweep the sound from side to side under LFO control. As you'll discover, the downloadable RNS file adds one or two more wrinkles to this patch for you to explore.


It's been a while since Reason 3 was released. Propellerhead most likely has visionary enhancements up the proverbial sleeve for the next version, but Reason 3 users have no need to moan while they wait. This is a mature product with an amazing set of largely untapped features. Every time I work with it, I learn or try something new. So hit that Tab key and get to patchin'!

Go to for a Reason RNS file with the examples in this article, as well as a couple of audio examples.


CV Radio

In the beginning, there was the analog modular synthesizer. It was the size of a refrigerator, and you designed sounds by plugging patch cords into jacks (hence the word “patch” to describe any synth sound). The synth was built out of separate modules, and one module could control another by sending a control voltage (CV) along the cord.

The electrical details don't matter much anymore, except in the small-but-passionate community of modular hardware synth users. For our purposes, a control voltage is simply an electrical signal that can be used to control some aspect of what a module does. Think of a CV as an extra hand: It can turn the filter cutoff knob for you when your hands are busy elsewhere.

Of course, Reason is an all-digital device and doesn't use real control voltages. But the CV labels on Reason's rear panel indicate that the concept is close to identical. When you patch a CV output from one module to a CV input on another module, the first module will control the sound of the second one in some way.

Some of Reason's CVs are bipolar — that is, they range both above and below zero. The Subtractor LFO output is in this category. Others, such as the Subtractor Mod Env, are unipolar, which means they never dip below zero. (You can use the inverted output on a Spider CV splitter to send them down into the basement, however.) Also, a switch that changes the Curve output from unipolar to bipolar is on the rear panel of the Matrix.