Tomasz
I think I see the problem. You are referencing the volume control wire colors for the Amateurradiokits case and Ted is referencing the original uBitx audio connector wire colors. The picture you shows does indeed indicate that for the case wiring the black wire is volume high. However, Philip in post number 67223 pointed out a wiring error in the Amateurradiokits instructions. They reversed the volume high and volume mid in the instructions. The brown wire should be volume high and the black wire should be volume mid.
If you make that correction and connect the R1-R2-C1 junction to the now moved brown wire which is the correct volume high you should see better results. This worked for me.
Lou? W2ROW
