MAJOR CORRECTIONS: 1) In the schematic shown at
13:45 and again at
28:37, the inputs of the first OTA need to be switched. The positive input should be grounded and the other connections should be going to the negative input. 2) Around the
12:15 mark, I switch feedback paths so that they're taken from the output of the buffers instead of the input. This only works for the SECOND OTA output, since the current from the OTA is going through Cg. I should have left the FIRST OTA alone, since the current from the OTA needs to go through Cf. The error persists through the
14:35 mark, and appears again at
28:37.
Support this channel via a special purpose donation to the Georgia Tech Foundation (GTF210000920), earmarked for my work:
https://youtu.be/VBu-LST1p9c
I recorded this during the Spring 2021 offering of ECE4450: Analog Circuits for Music Synthesis, but this material will likely be appropriate for future offerings as well.
Be sure to check out Alex Ball's amazing Daft Punk synth tutorial, featuring the Korg MS-20:
https://youtu.be/W1cpim5EAqI