Allow me to present Infinity — the electronics inside Thor that handle polysustain (infinite multichannel sustain). Three modules, including power conditioning, signal conditioning, microcontroller, and coil drivers are packed in an area the size of a humbucker pickup. The goal is to make it small enough to make it easy to install in a typical electric guitar without too much modification.
I made it a point to have the microcontroller (MCU) board into a separate module. The global chip shortage hit me hard in the initial stage of production, when the MCU that we use became unavailable with a very long lead time. I was lucky to obtain sufficient quantities, but to be sure, I redesigned the electronics such that the MCU module can be easily replaced, and thus making Infinity future-proof.
Here’s the MCU module:
The MCU module connects to the main board using two 60-pin low-profile mezzanine connectors, one for analog and clean power and one for digital. The noisy digital section is separated from the analog section to keep the latter as clean and noise-free as possible.
Here’s the MCU module underside:
The main board includes power conditioning, signal conditioning, as well as the necessary connectors for the Nu Multi pickup, control potentiometers, multichannel output, coil drivers/actuators, the two 60-pin MCU board mezzanine receptacles, and two I2C (Inter-Integrated Circuit) busses for additional controls (more on that later).
Here’s the main board:
The driver module contains the analog power amplifiers that drive the coil actuators for polysustain. The amplifiers use two power Op-amps, per channel, in a bridged configuration, to provide the required power for infinite multichannel sustain. There are two channels: one for the bass strings and one for the treble strings.
Here’s the driver module:
All three modules are stacked to form one complete Infinity module:
Here’s a short video clip of the entire assembly: