ERD / Toad  24hp PCB 

  Hermaphroditic analogue computer modul

24HP, 100mA at +12V, 100mA at -12V, 0mA at 5v. Multiple audio/CV inputs and outputs. 

Power is red stripe/-12V towards the bottom of the module.

A rare opportunity to get this limited edition prototype version of this unique eurorack module that is otherwise not available

on the market as diy pcb project only. I have only the items offered here on auction, no back stock.

PCB is an unused B-Stock. That means there is signs of handling, storage and such. Fingerprints included.

Beware these eurorack projects are for advanced builders, most of it SMD / SMT soldering that requires special tool sets, not a beginners project as one needs to check build documentation on the Github of Martin Howses microresearch project. 

This can include the use of electronic design EDA's like KiCAD or such to access the source files for the PCB...

Item Description

ERD/TOAD is an hermaphroditic analogue computer driven by the times of pulses and slopes, designed to model both physical and imaginary processes underlying the vocal emissions of various twinned lunar and solar creatures (such as ravens and toads). Ruddy, bursting and overcharged, running by turns hot and cold, breaking and stretching tracts and redefining pulses and control as the venomous spots on the belly of a bulky blackened TOAD, they bring forth all the rarest colours.

By default TOAD re-implements physicist Gabriel B. Mindlin’s ouroboric differential equation which models the mechanisms of birdsong production, computing oscillations within the bird’s syrinx, or sound producing organ. TOAD’s analogue computing elements are normed to follow this model and generate oscillations; only a clock signal (normed to multipliers and all clocks) needs to be supplied to generate audio. This signal can be any changing signal or pulse (it is converted to a clock internally).

With a few connections, TOAD can also be used to model chaotic equations from J. C Sprott’s “A New Class of Chaotic Circuit,” producing oscillations and filtering incoming signals in the audio domain.

TOAD can compute any number of audible physical and less-than-physical models using three switched capacitance integrators, a square function, three inverters, one signum function and seven multipliers (some of these are embedded within other functions).

TOAD can be used to model one (or more) of the chaotic
equations from J. C Sprott’s “A New Class of Chaotic Circuit,”
producing oscillations and filtering incoming signals in the
audio domain. 
This equation uses our custom SIGNUM function and our three
integrator cells and can be set up quite simply as in
the following diagram with a few patch cables (the SQUARE
function is not used in this case). Note that as the first
integrator cell’s CLK is normed to the second and third,
you do not need to supply three CLKs unless you wish to
experiment in this way.
For the Sprott model, ideally six CVs (some of which could
come from ERD/acquisitio, ERD/VIA or caput draconis) can be
supplied, and one or two pulses (from caput draconis, or
All Colours), changing signals.