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Something like the varying - multiple hits of the WMD Fracture


is it possible create something like this …



This sounds to me something like a 4MS SCM – a CV-controlled ratcheting/skip effect.

I have done a CV-controllable “ratchet” custom unit, which gets part of the way there. Basically you have a tap tempo unit that generates a multiple of the incoming trigger stream, and then VCA-controlled mixers to select between the “raw” and “tap tempo” trigger streams based on a gate input. Works great. I’m not at home or I would attach it :slight_smile: but it’s just a few units.

To add the pattern/skip effect, you might want to add another Tap Tempo at a different multiplier, then use that (or its inverse) to control a VCA gating the other tap tempo output…



  1. Load up a Sample Player with a variety of percussion hits.
  2. Slice on Onset or Grid, such that you have lots of slices containing perc hits and some empty
  3. In the Sample Player, load a Velvet Noise into Trig
  4. Load another Velvet Noise into Slice.
  5. Adjust the Noises’ rate to get the amount of variance (try using envelopes here too).
  6. Adjust the sample player speed and shift to taste

Now you can use some ADSR envelopes and maybe Freeverb to get very close to Fracture. It really depends on having a good sample of multiple hits and empty space to slice to begin with (which is similar to the way Fracture works).

Hope that gets you started.


Wow rikrak - thanks for the in depth breakdown - I’l give this a go!
and thanks bgribble for the racheting ideas…
I guess the fracture sounds like varying (amount and tuned) flanges … maybe?


I believe they recorded short percussion samples which are grouped into sets and then randomly triggered through a convolution ‘reverb’ (more like a randomised delay).

Imagine a single WAV file which consists of 20 hits of a (real) snare drum, followed by 20 hits of a drumstick on a table, followed by 20 hits of a paper cup being dropped onto a table, followed by 20 hits of a wooden peg being thrown at a wall… and so on… It could consist of 200 individual samples, all stacked together in one long chain (if you have ever used an Octatrack, you may be familiar with the concept of Chains).

In the ER-301, we could chop this into,say, 500 slices - so 200 slices contain a sound and 300 contain silence.

Now we use the Noise unit to trigger the Sample, which happens when the threshold is passed. This results in randomly spaced triggers.

Next, we use a different Noise unit to select the Sample. Given that some of the slices are empty, we will get a random number of hits of percussion, randomly spaced in time.

We can also add an Offset, so that it is possible to choose which set of hits we want. If the Variance of the Slice number (selected by the Noise) is 20 or less, with the Offset at 10, we would get the first group - eg. the Snare drum hits… With the Offset at 170, we might get the Pegs. With the Variance of the Slice number higher than 20, we would get some of the neighbouring types of percussion included every time the Custom Unit was triggered.

Where WMD’s Fracture differs, if I understand it correctly, is that they used an Impulse recording to govern how the multiple hits of percussion are grouped.

This may still be possible but requires more work than using a random (but evenly distributed) Noise unit to fire the Trigger.

I’m just thinking aloud. I’m still getting started with the ER-301, but I did knock up a quick proof-of-concept last night and it sounded close enough for 5 minutes work.

I really should put my money where my mouth is - but real-life keeps getting in the way of Eurorack lately!

EDIT: I really want to do this now. I had been looking at Fracture anyway and had almost convinced myself that I really needed it. But, how can I be sure if I don’t try to get close with the 301? Maybe it will be close enough. I’m doing some experiments now to test my approach more thoroughly. :smile:

EDIT2: I’ve got pretty close now! I just need to make some good sample chains as the source material. I will go in to more detail when I get a chance to type up my notes and upload the Custom Unit - probably tomorrow :wink:


I’ll reupload when I have time to fix all the errors, sorry!


Awesome thread and idea


thanks rikrak - youtube vid sounds great!


Here’s a Custom Unit, “RikFrak” which cheats a little to get to an end result which covers some of the same ground as WMD’s Fracture Module.

The video explains how to set it up and then I play around with the controls a little.

  • load it as a preset of a new custom unit,
  • select the Trig/Gate control and tell it where your gate is coming from
  • select the Micro Grains unit - and load “rikfrak-sample.wav” into it
  • send a Trig in and adjust the Decay parameter OR
  • keep the Decay parameter very short and send in a Gate to dictate the Decay

WMDs Fracture works by having a bunch of samples of percussive hits which are run through a Convolution Reverb to make it sound like they are scattering.

RikFrak works by playing a sample similar to the Impulse Response (which I am speculating) is used by WMD’s Fracture - and then has some randomisation to produce the entire sound.

The output is similar in style but there isn’t the same breadth of control. It is best used for Claps, Sticks and Cymbal washes - which are especially nice and very close to the examples in WMD’s demonstration above.

You could attach controls to the Pitch and Decay parameters to add some variation in real-time.

Please let me know if you have any problems getting it up and running.

rikfrak1.6.zip (542.8 KB)


Brilliant - thanks rikrak!


Wow! Looks great.


When I get some more 301 time, I’ll take a look at the convolution unit as a possible way to get even closer - and add more controls.

I found that attempting a project like this was a great way to discover how much I still have to learn - about the ER-301, but also about modular synthesis in general!


@rikrak I can’t get the file to unzip…


nvm got it thanks~!


@rikrak Thanks a lot man! This looks and sounds great! but I can’t get the Zip file to unzip…


Hey. I actually developed this idea further using the convolution module. It is much more versatile. I’ll find time to upload the new version soon (just in the middle of moving house right now). The existing zip seems to work for me though. I just checked on my (android) phone.


Oh yessss! Can’t wait to try it out, good luck with the moving ! I know it can be a huge hassle ! Thanks again for sharing with us


I made A Fracture style unit on 0.3.x that I forgot about until reading this thread.
Just rebuilt it for 0.4.x


R Size (reverb size)
R Mix (reverb mix)

Create a stereo chain
Load Shatttr into a Custom container
Open the unit
Open the Mixer
Load “Fracture Hit1.wav” (or any wav of your choosing) into the Varispeed Player
Send a trigger to A1

Shatttr.zip (5.8 KB)


Thanks for posting - I look forward to checking it out once I’ve finished unpacking boxes!


Thanks @scttcmpbll really useful for me.