OK, here's the third and final video, showing my classy new build, and also showing a neat trick you can do with it to get some pretty fantastic Lissajous figures. Enjoy!
(Incidentally, after spending quite a lot of time troubleshooting, the problem was (drum roll please) another defective 2164 chip (or maybe two). I also found one very tiny solder bridge which was affecting the 1V/Octave input (good thing I decided to tune the VCO, as I wouldn't have caught it otherwise). I don't know if the 2164s came to me defective, or if I fried them somehow while testing the build (probably the latter). In any case, the thing works perfectly now. I spent a lot of quality time hand-selecting caps (for the PDN) and resistors (for the multipliers and amplifiers) and it really shows in this build.
Also, while I was playing with it, I realized that I had forgotten to normal the MIX output jack to the AUX input jack for phasing, so I just plugged the DIFF output into the AUX input, and I took the MIX out to the speakers. Then, when I was playing my guitar through it, I started turning the Output Mix knob to go from SUM to MIX to DIFF outputs, and I was getting some very subtle and different phasing responses. If I had just normalled MIX to AUX, then I would have fed back whatever the mix was from the pot, and it would have sounded the same as the last video. However, by connecting DIFF (or SUM) to AUX and then changing the mix, it is feeding back only DIFF (or SUM) but taking the MIX to the output, and it sounds different. The point is, there is a lot of very nice and subtle variation to be discovered by plugging different outputs into the AUX input when phasing.
And it can be yours for the low, low price of $450 (USD) plus shipping.
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