Dear Aart.... you don't have to worry about cable matching for the wordlength. Only for jitter considerations, and in this case, since you are transferring information digitally that has already been converted, jitter is not a problem. If the mismatched impedance works (for a short cable connection), then go ahead and use it. The Hammerfall card accepts 24 bit data in via its SPDIF input. In fact, you must confirm that the Tascam puts out 24 bits. I was told recently (and this may be wrong) that the Tascam only produces 24 bits on its bus outputs, not on the 2 mix. If this is correct, then you can only mix to the bus outputs if you want 24 bits.

Bob