MFOS Envelope Generator


After a lot of test failures after another, I decided to go to Grant’s to see if he could identify what was going wrong with my prototypes, whether it was using the wrong values of parts, the wrong configuration and pathways of components, or something else. We began working on the circuit, and after about an hour I had completed most of the build, but I saw that one of the pins I had to use was already occupied, and after searching, I found out that I had been reading the pinouts wrong; I had been reading the numbers from top-to-bottom-to-top-to-bottom, like a book, and not reading the numbers ascending in a U shape around the ICs. I probably didn’t have this problem in the beginning of the quarter because I had very few tests I was able to complete before I started working on the book work.

After the build, the output was very low, so we prodded along the signal path, and found that one diode was installed backward. After that, we had a working attack-sustain-decay generator. We tested all of its functions on his Serge system, including envelope repeat mode, and both “gated” and “triggered” modes. One thing we noticed was that the output for the self-triggering mode was not as high as the ‘gated’ and ‘triggered’ modes.

One interesting part was using the breadboard to ‘flip switches’ and trigger the envelope instead of connecting hardware switches.

I then took it home and plugged it into the Oscilloscope and the modular and took a few pictures and videos showing the features:

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