Eurorack Modules
The bug boards, in a rack. Drawn and checked; not one of them built yet.
The stripboard shelf has six boards named after bugs that were always going to end up in one box together. These are the same boards as Eurorack modules: in every one but the mixer, the built board sits inside the layout hole for hole - same strips, same cuts, same parts - and a rack block is bolted onto its right-hand end. The block is the same idea six times over: a 2×5 header for the rack's power cable, a diode on each rail so a backwards cable does nothing, a 78L05 making the chip its 5 V, and a TL072 on the real ±12 V doing the rack-level work - summing, buffering, taking a gate or a clock in through a 100K. The exception is the Dragonfly, which had to become a 1 V/oct oscillator and got a new control path around its old chip.
As on the stripboard shelf, the layout file is the build document: download the
.json, open it in Copper Bottom, and the editor walks
you through the board and checks it. Each guide also carries a 1:1 drill template for a blank
3U panel, drawn for 9 mm pots and Thonkiconn jacks. Every one of these is Unverified
- drawn, checked in the editor, and never soldered - and each page says which of its numbers is
a datasheet's and which is a guess. Build one, and the banner comes off. The size on every card
is strips by holes.
All 6 modules
Hive Rack
The six-voice Hive Drone as a Eurorack module. The built board hole for hole, and beside it a rack block: the 2×5 power header, a diode on each rail, a 78L05 for the chip and a TL072 that sums the six voices onto a virtual ground - which is also the fix for the Hive's old output stage. Six pitch pots and one jack on a 10 HP panel. With the layout file, the netlist and the panel drill template.
Dragonfly Rack
The Dragonfly VCO as a Eurorack oscillator that tracks a keyboard: the 4046 and its timing cap are the built Dragonfly's, and pin 11 now gets its current from a two-transistor exponential converter - a TL072 sums the 1 V/oct jack and the pitch knob through a scale trimmer, a second half serves as the reference - with a second TL072 putting the square out at ±5 V. The drop bend survives as a range switch. Pitch, 1 V/oct, out and drop on a 6 HP panel. The one module on this shelf that is a new circuit around the old chip.
Cicada Rack
The four-voice Cicada NAND as a Eurorack module, with a gate jack for every voice so a clock or an LFO can play the gates the toggles used to. The built board hole for hole, the kill toggles still there, and beside it the rack block: power header, a diode per rail, a 78L05 and a TL072 summing stage. One voice per row on a 12 HP panel. With the layout file, the netlist and the panel drill template.
Grub Rack
The seven-octave Grub Divider as a Eurorack module: patch any square into the clock jack and seven toggles pick which octaves below it come out. The built board hole for hole, the volume pot now a level knob into a TL072, and the rack block beside it: power header, a diode per rail, a 78L05. Seven toggles, one knob, two jacks on a 10 HP panel. With the layout file, the netlist and the panel drill template.
Firefly Rack
The eight-step Firefly Sequencer as a Eurorack module. The built board hole for hole, and at 5 V its steps come out at the 0 to 5 V every rack sequencer speaks; a clock-in jack normalled to its own 555 so a cable takes over the clock, a TL072 buffering the CV out, and the rack block beside it. Nine knobs, eight LEDs and three jacks on an 18 HP panel. With the layout file, the netlist and the panel drill template.
Mixer Rack
A four-channel Eurorack mixer, the Bug Mixer's job done on the real ±12 V: four level pots as dividers into a TL072 unity summer, the other half inverting it back into phase, out through 1K. The one module on this shelf drawn fresh rather than grown from a bug board, because a bipolar supply makes the Bug Mixer's half-rail half of the chip unnecessary. One channel per row on an 8 HP panel. With the layout file, the netlist and the panel drill template.