when looking at your BII. with the twisted pears facing upright you will notice the +, and neg. pads at the R17 mark. The R17 is for bypassing the digitizer on the BII., but to disable the power that feeds that component you will remove, if you have installed the middle trident regulator which is the snap in one, the middle one . If you didn't use the trident regulator, disable the resistor on the underside of BII that regulates that middle power supply.
From the WaveI/O master clock signal you will connect the line to the right R17 pad., then the left pad of the R17 is the return signal that goes to the negative of the Master clock., keep both signal at same length as the other signal wires from WaveI/O to BuffaloII . the shorter and of equal length your wires connections from WaveI/O to BII. are the better the signal will respond .
By doing this exercise of using the Wave card and BII it will confirm that your Wave card is faulty, or not .
Oh PS i'm not using the isolating I2S, i rather use the J2 to J5 connections from the Wave card to BuffaloII.