Throughout the reverse engineering process, the LLM and I both were expecting each op-amp stage to use the next ladder value capacitor. We'd talked ourselves into how and why that would make sense.

At the end I was curious enough that I desoldered those five caps and realized that they were all 2.2nF except for the last stage which was 1nF.

I brought that news back to the LLM and we realigned our understanding of how the effect was achieved, ultimately coming to realize that our approach would have created notches at different frequencies instead of just shifting the phase by about 900 degrees.

It was an incredible learning experience. I try hard not to personify LLMs but this really did feel like working side by side with a friend on a problem until it was solved.

IRL, I suspect that most people who would be able to tackle that challenge with me lack both the time and patience to actually do it.

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