I’d been eyeing these 4hp single sloths from Nonlinearcircuits for some time, so I sourced two panels and PC boards from Synthcube. The panels are designed by Clarke Robinson. I chose Davies style black knobs, also from Synthcube.

The Sloth Chaos can be built in four different speeds, from fastest to slowest: Lethargy (Regular), Apathy, Torpor (Super), and Inertia (Stasis). I haven’t seen a panel for Apathy, so I just used a Torpor panel. All four variants are built on the same PC board, but with different resistor and capacitor values. Lethargy and Apathy both use the same value of capacitors, with Apathy using larger resistors. At the time of ordering parts, the 10K and 100K Alpha pots needed were out of stock everywhere, so I used a 20K and 250K instead, modifying only one other resistor in Apathy (made R10 820K).

Lethargy cycles every 20 seconds or so; Apathy every minute or so. I noticed that the LED changes color every time the Small output (+/- 3V) crosses zero. It’s red when Small is positive and green when negative. The Large output is not simply a larger voltage range, it moves differently than Small.

The Red/Green LED isn’t specified, so I ordered Kingbright WP7113SRSGW from Mouser.com. I selected 5K6 resistors for RLED to set the brightness.

Construction is fairly simple. Resistors stand on end.

Notice that the jacks are 3.5mm audio jack, kobiconn 16PJ138 (161-3402MHA-E). These are one of the popular Eurorack module jack types, but be sure to order the knobiconn, not any other. And remember to wire the ground jack to the PC board with a piece of wire. A washer is needed under the jack nut, because the hole in the panel is a little too large.