From this test, I believe that the problem is related to impedance. Since the JDI is passive, it is always presenting the 140K Ohm load. With the amp input and mixer input, they may be presenting a low impedance when not powered on, and load down the signal coming from the bass, resulting in the reduced output from the RNDI.I tried running bass->RNDI Thru->JDI->XLR out and that did not affect the RNDI signal to the sound board. It stayed strong the whole time. No difference from when I ran bass->RNDI XLR out-> sound board.