I assembled a Thonk Synth Double Bubble Dual Analog Filter. My Eurorack module collection has always been sparse on filters. Mehr Music Machines Deuxd was a recent addition, and then Double Bubble came out. These two filters have a similar architecture, but with the Double Bubble having more and some different features. Both feature cross-modulation and serial-parallel option, but do it in different ways. This post is about building the Double Bubble.

Assembly

Thonk provides a very complete build guild for the full kit. It’s one of the easy ones that have a fully populated main PCB, stacked with a panel PCB. All the builder has to do is to solder the board connection headers and panel parts. The parts include pots, jacks, buttons and LEDs.

The boards are well laid out, clearly marked, and flow solder very nicely!

Interestingly, though the module is analog, it’s clearly digitally controlled to handle the push buttons. There is nothing in either manual about firmware updating. It came completely programmed and worked perfectly on first power-up.

The only changes I made were to use a shrouded power header, and why not if there is room? And to use Bananuts.

The picture shows Double Bubble, Deuxd, Vult Freak, and Patching Panda Moon Phase. These are all dual/stereo filters. I really need the Bananuts to keep me clued as to where the inputs (Gold), outputs, (Black), and CV inputs (Blue or Green) are located. The silver on one Moon Phase advances the filter types. The Green nuts indicate CV inputs that respond only to a positive voltage, which is something easily forgotten.

Naturally, I’ll be posting sounds and videos with the Double Bubble. In the mean time, watch the DivKid video embedded on the Thonk page linked above.