Just for the public record:
My Arturia MiniBrute was suffering from non-functioning filters. All filters passed though audio which was barely audible. The exception was the notch filter which acted normally.
I was able to procure a replacement filter switch from Arturia support, and found someone locally with good enough soldering skills to replace it on the PCB.
Now at almost zero-cost I am back in full-functioning condition again! Hooray.
If you are experiencing this issue (I expect others are), there is a relatively easy solution.
Replacement Switch
