Waveshaper bug

I finally got around to testing the waveshaper boards last week. Most of it work flawlessly though I get some clicking when doing large frequency jumps for some of the waveforms. Also, saw and sine waves are not as loud as the others at the same amplitude (which is to be expected I guess, I just need to consider if its ok).

For some reason though, two of the TL074 op amps got really hot and the sub oscillator didn't work. After some probing I found that the -2.5v source output 13.5v instead. I had my wife solder a second board but the same happened there.

I couldn't figure out what was going on, but it suddenly dawned on me when I tried to fall asleep yesterday - I have mixed up the op amp inputs when trying to make a voltage buffer :(

The fix is very easy in CAD, but on the boards I have to cut two lines and solder a new wire:

Cutting the input, it goes to the negative terminal of the op amp instead of the positive. I've also scraped away the solder mask to be able to add a new wire to the positive terminal instead. I will see if I can find a wire tiny enough to fit in the via (which is 0.3mm...). I also have to add a solder blob between the negative terminal and the output.

Cutting the feedback loop between the positive terminal and output. It should of course have been between the negative input and the output.

The board is smaller than it appears btw, here is my finger for reference.

UPDATE:
My wife managed to solder this just fine, after that the filter works flawlessly! The tiny diagonal wire is a single copper strand from a networking cable!