Ratcheting is a Berlin School sequencing technique where an individual note in a sequence has its envelopes retriggered multiple times, usually at a musical subdivision of the sequence’s tempo – such as playing 1/32 notes in the middle of an 1/8 note sequence – to create a roll or what I sometimes (quite improperly) call a trill. Originally attributed to Tangerine Dream (listen to their 1975 track Stratosfear – especially staring at the 3:00 mark – for a percussive example), ratcheting is appearing more often as a feature in sequencers and trigger controllers these days; Doepfer has even released a “ratcheting controller” module.
But not everyone knows how to create a ratcheting patch on their modular. Not surprisingly, there is more than one way to go about it. My favorite “generic” patch combines a sequencer with at least two rows – two voltage control rows, or one voltage control and one trigger row – with a clock multiplier or divider, and optionally a voltage controlled or sequential switch. In the following movies I demonstrate three variations on this basic idea, showing alternatives in case the modules you own might have or lack some features such as voltage control of the clock division/multiplication. I showed ratcheting using pitched notes, but it could also be used for triggering percussion modules.
A Quick Demo
If you’re not familiar with ratcheting, here’s a quick demo along with a brief explanation of the overall patch I’ll be using. (There are far more details about the patch at the bottom of this article). Feel free to skip it if you’re busy and already know what ratcheting is:
Ratcheting Overview + Using a VC Clock Multiplier/Divider
The next movie shows my personal favorite ratcheting patch. I use a sequencer with two voltage rows (a Doepfer A-155 in my case), with one row controlling the pitches and the other setting the timing division on a voltage-controlled clock divider/multiplier (I like to use a 4ms Quad Clock Distributor or QCD for short). In this movie I go over the basic concept of patching ratcheting, and then dive into creating this specific patch:
Using a Voltage Controlled Switch
What if your favorite clock multiplier or divider does not have voltage control over its multiplications or divisions, and instead presents the different timings on different output jacks? In that case, you’ll need to add a switch to the patch. I prefer to use a voltage controlled switch (such as the Ladik S-210), as again I can use the second voltage row on a sequencer to choose between the clock divisions:
By the way, if you happen to have a 4ms QCD plus its Expander, you can set different gate durations for the different clock multiplications. This means you can set a longer gate time the “normal” notes, and shorter gate durations for the faster notes, which helps accentuate them by making them more staccato. The QCD Expander even gives you voltage control over the gate duration. (It also adds an inverting attenuator to the division/multiplication VC input; if you can’t get the above patch to work, make sure this attenuator is not set to 0.)
Clock Dividers versus Multipliers
The previous videos have used a clock multiplier, as I find it easier to wrap my head around “this is my core tempo; the multiplications are the rolls at faster timing divisions.” However, multipliers tend to be more expensive, as they require a Phase Locked Loop (PLL) to synthesize the higher clock rates from the main timing pulse. PLLs also tend to lag behind tempo changes on the incoming clock.
If you have or want to use a clock divider instead, you need a faster main clock – say, 32nd notes (8 PPQN) – and then divide that down to the timings you need. For example, you use the /8 output to get quarter notes, then switch between the /4 and /2 outputs to get 8ths and 16ths. I demonstrate this in the last movie, below.
Using Triggers and a Sequential Switch
What if your sequencer does not have two voltage rows, but does have a trigger output per stage (such as the RYO VC Sequencer with Trig Xpander)? Or if you have a sequential switch, instead of a voltage controlled one? In that case, you will need to use triggers set at specific stages to step between different clock divisions patched into the sequential switch:
If you’ve watched the above movie, you can see why I prefer VC switches over sequential ones: You usually have to program two pulses per ratcheting roll (one to select the faster clock, and one to switch back to the normal clock), and sometimes the switch may miss or double-trigger on an incoming pulse, causing it to get out of sync with the main sequencer. I have found that adding a gate processor or conditioner that outputs a longer gate for a trigger input fixes that last problem; I’ve been using the Gate Delay section of a Roland 572 ; either an EMW Dual Pulse Delay or a Doepfer A-162 – both of which which contain two of these gate processors for well under $100 – are on my wish list.
Of course, there are more ways to create a ratcheting patch. If you have a sequencer that can output a gate for specific steps that lasts the full duration of that step, you can send that through an attenuator to a voltage controlled clock or switch to alternate between two timing divisions. Roger Arrick of Synthesizers.com even uses a pair of VCOs in sync mode to create the different clocks.
The Rest of the Patch
I know some will be curious about the details of the overall patch. Here’s a photo of the entire synth:
I follow my usual color coding scheme where white is 1v/octave for pitch CVs, blue is for other modulation and control voltages, yellow is for audio, red is for gates and triggers, and green is for the master clock. (I’m using Black Market Modular cables and Monomults, as well as the occasional TipTop Stackable cable.)
Pitch CVs come from the Doepfer A-155 sequencer as well as an Expert Sleepers FH-1 USB MIDI converter. They’re combined by an Expert Sleepers Disting in Quantizer mode (2B), which also allows me to transpose the sequences. The Disting goes to a Malekko Performance Buffered Mult, with one output going to a cutoff frequency input on the Rossum Electro-Music Evolution VCF (attenuated to around 50%, so the cutoff partially tracks the notes), and the other output going to an Analogue Systems RS-420 Octave Controller, which resolves differences between the voltage ranges of my VCOs. This in turn goes to an Erica Black Varishape VCO1 (combining a pulse, a subocatve, and an inverted sawtooth at the module) and a Synthesis Technology E350 Morphing Terrarium (set to a throaty digital wave). These are mixed by a SSF Mixmode; I have the Expander for it so I can play with asymmetrical clipping before sending the output on to the filter – the aforementioned Rossum Evolution in this case. A second output from the Mixmode goes to a Mordax DATA so I can double-check the waveform and spectrum if so desired.
The main clock pulse comes from one channel of an Abstract Data ADE-32 Octocontroller set to Pulse output. It is passively split with a Monomult to feed the external clock in on a Doepfer A-154 Sequencer Controller, the 4ms Quad Clock Distributor, and – if I’m not ratcheting – an Intellijel OR logic module. (To ratchet, I insert a clock multiplier in this line between the main pulse out and envelope inputs.) The output of the OR is then split by another Monomult to trigger two channels of an Intellijel Quadra AD AR and a WMD MultiMode Envelope (MME). I used the OR as a buffer as I found sometimes that re-patching the clock signals caused the MME to freeze. I also use the OR to combine trigger outputs from the RYO Trig Xpander, although it is internally buffered and I could just use another Monomult.
The MME is connected to a CV input on the Rossum Evolution LPF. I really liked the ability to shape each stage of the MME – especially the Decay curve – to get the tonal articulation I wanted out of the Evolution. (In an expanded version of this patch, I used tempo-locked LFOs and S/H random outputs from the Octocontroller to also tickle the Resonance, Genus and Species inputs on the Evolution, as well as the Morph X input on the E350.)
An AD channel of the Intellijel Quadra goes through an RYO Airtenuator and to the PWM input on the Erica Varishape; the result is more consistent per note compared to just using the typical LFO (great for sequences). An AR channel of the Quadra opens a WMD Digital VCA, which finally goes to a Pulp Logic Exit Strategy before hitting my mixer.
And that’s the simplified version of the patch! As I hinted above, for my personal version I added a lot more in the way of synchronized modulations, plus also used the faders on my controller keyboard through the FH-1 to add more performance control. But I didn’t want to make this too confusing…