Searched but no luck. Rob Allen bass with Fishman Natural 1 piezo/preamp. This is the integral sound for this bass. I am adding a single Bartolini pickup and preamp. Can the two preamps be wired to a single output jack or would there be an impedance mismatch ? I know Fishman has a power chip blend pot but I wanted to see if this simpler way would work. I am happy to have two vol controls so do not need a blend pot specifically. Thanks for any advice !