Dang did you read my mind?
Schematic looks good. Regarding the clean blend, I should think you want essentially this:
- Input from the jack goes to IC1B non-inverting input
- Input to the circuit comes at IC1B output
- Tap that line for one side of the blend
- Connect the circuit output to the other side of the blend
- Blend 2 goes to the non-inverting input of IC1A
- Output to the jack comes from IC1A output.
Through all the worry and pain we move on