This is a FUN project to implement the pulse audio waveform of the MultiSIgnalGene.
It is another way to do the things than the PulsesDigital project.

It is an electronic version based on 74HC logic circuits and operational amplifiers. The schematic diagrams, the parts list, the tests and a PCB are provided.
There are one PCB per channel, any number of channels can be built.
 
There is an FPGA version of the numerical part as well. It is based on the VHDL export of the numerical schematic (initially intended for testing).


To interface with the software project, it should be set to sine output audio. This project inputs the sine audio.


The project is based on gEda/Lepton-eda and NG-Spice.

The project contains only the sources. To get exports of the schematics, parts lists, synthesis, spice circuits or (later or never) the spice results, check in the artefact

The FPGA does not involve any PCF file as for now, no PCB is planned.

One can re-run everything, especially to include a PCF. The Makefile is provided. Ghdl, Yosys, Icestorm and Nextpnr software should be installed.


The width of the pulses can be adjusted, while keeping the symmetry.

The input is a square or a sine signal, the pulses are generated using the peak (positive or negative) of the input.

It has been only tested at a functional level. Especially, the operational amplifiers model are very basic.

DO NOT reuse the models for another simulation. They have been designed as "simple stupid" in order to speed up spice.


The parts-list points LF355 operational amplifiers, many can be used
The X1 is a preamplifier, according to the input level, its resistors should be adjusted
The counters U13 and U14 does not use the reset (which is done by load 0). Then both 74HC161 and 74HC163 can be used
The counter U14 does not count above 7. Then 74HC160 and 74HC162 can be used as well.