rbss & quantizer issue

Over on the AE Modular Forum (which is a great community resource if you’ve not visited), it has been noted that the rbss does not always play nicely with the Tangible Waves quantizer module — unfortunately, this is ultimately down to a small issue with the output of the rbss (prior to serial number 130). The good news is that this is a relatively simple fix for the earlier revisions of the rbss, requiring just the addition of a single component.

root cause

The problem is due to a high frequency (250kHz) noise on the output of the rbss, which ordinarily does not affect modules connected to the rbss’ output. Unfortunately, since the quantizer module is a digital module which samples the CV input, occasionally it will sample one of these noise peaks and will subsequently flip between adjacent notes.

the fix

The fix for the problem is the addition of a single 10nF capacitor across the output of the rbss. The easiest way is to add the beneath the PCB.

The solution is to connect a 10nF capacitor between the CV Output pins of the output header (counting from the top, that’s pin 4, 5, or 6) and a ground connection (the most accessible will be those on the ‘minimum’ end of the ‘length’ potentiometer.

Step 1:

Here we see a typical 10nF ‘disc ceramic’ capacitor (marked ‘103’) — something like this is ideal since the legs are long enough to stretch between the two solder points.

Step 2:

Form the legs such that they are about 50mm apart; the bends help to locate the capacitor with the solder points

Step 3:

Solder the capacitor from the length pot to the 3rd pin of the output connector. Note that the solder used on wonkystuff modules is lead-free, so leaded solder shouldn’t be used as the joint may be compromised.


So, that’s it – you should now have jitter-free interaction between the rbss and quantizer!

Contact us if you have any further queries and we’ll do our best to answer them…

new design #2

The next module for redesign is the mm33 — the order for the next batch of PCBs has just been sent off…

The redesign of course uses the new font and graphic design previously seen in the qvca, but the mm33 electronics have also been redesigned:

— The module now uses surface mount components, so it’s a little bit neater than the original mm33! We have yet to decide whether to offer a kit for this version, we’ll keep you posted.

— Gain for each channel has been increased to improve the behaviour when using the mm33+ within feedback patches.

— Each output channel now has a switch to select whether the output is targetted for CV or audio (CV signals are relative to 0v, whilst audio signals are centred around 2.5v). It is of course possible to use the audio setting for CVs if that is what you want to do!

The updated module will be available on the webshop just as soon as they arrive!

a new year; a new design

Following the sell-out of the first run of qvca modules, a second batch of PCBs has been ordered, and these will be made available on the webshop just as soon as they are available! Electronically the new run differs only slightly from the first batch, for manufacturing and calibration purposes.

Hopefully it will also be clear that the design has changed somewhat since the first ‘red circles’ version; it is intended that all of our modules from now on will follow the same design patterns. We are sticking with the black PCB panel, with highlights being a combination of silkscreened white and exposed (tinned) copper tracks.

The typeface has changed (using the SB Flip font family from SelfBuild Type Foundry), and the AEModular logo has been replaced (for now at least) so as to indicate that these modules are 3rd-party and not made by Tangible Waves (although we are still of course in close communication with Robert and the TW crew!).

Obviously the panel graphic is a segment of the wonkystuff W logotype!

Anyway, I’m now off to redesign some more panels…


Now that the UK has left the EU, it looks like there will be an impact on selling modules etc. from the website. Information seems very patchy — especially for a new business like us, where we are trying to just keep ahead of the curve!

We have already seen some shipping prices increase, but for the most part these are relatively minor. Since wonkystuff is not VAT registered, we have not been charging VAT (we are legally not allowed!); so unfortunately it looks like customers in the EU will now be charged VAT and import duty by the local customs organisation or postal service. This is subject to any minimum values which may apply in your territory.

This makes me very sad (and worried!), but I hope that some level of ‘normal’ can be reached soon — change is always disruptive, but I am hoping that there will be some certainty in the coming months.

rbss? what?

It seems that we should have supplied some instructions/hints to go with the rbss, so here are some hints and tips!


The best place to read about how the rbss works is by reading Tom Whitwell’s description of the original Turing Machine. The only difference is that the rbss is implemented in software and the 8/16 step switch is replaced by the length control.

Getting Started

To start with, patch clk out to clk in, set the rate control to around the middle position — the LED should now start flashing. Yes? Great!

Now set the length control to its maximum, and the chance control to the middle. Now we’re all set to do something random.

Connect cv out to the cv input of an oscillator and the output of the oscillator to something you can hear. Hopefully at this point you will hear the pitch of the oscillator randomly fluctuating.

Now change the chance control to its minimum position — this will mean that the random sequence stops changing (you might be able to hear the repeating sequence, but it has 16 steps so it’s not always obvious).

Now gradually reduce the length, and you should hear the sequence becoming shorter as it repeats. If you reduce the length to its minimum, the randomness will stop (because the length is now 1, there is no change between consecutive steps), and it is highly likely that if you increase the length again then you won’t get any randomness until you move the chance control away from its minimum position.

If, instead of reducing the chance control to its minimum, you increase it to the maximum, the sequence now repeats after 32 steps (the sequence flips after 16 steps, so descending runs become ascending runs and vice versa). Reducing the length control shortens the sequence as expected, but when length reaches the minimum you will hear the oscillator pitch flipping between two values.

another rbss video

This is something I’ve been playing with for a little while, and the production firmware has now made this more usable — using the rbss as a source for audio. Check the video (and like and subscribe etc. please!)