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.

done

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…