“FREE” Musiland MINI MOD
My Musiland MINI modded for SPDIF output takes the output from the FPGA and sends the signal through a 221 ohm resistor. The input of the comparator has a termination 75 ohm resistor (if you measure the resistance of the Buffalo spdif input to GND, you will find it to be 75 ohm). These two resistors form a voltage divider to lower the levels to consumer-level. More info here.
After looking at the spdif traces (shared by a user over at Head-Fi) of the Musiland 02US (which is based on the same chips as the o1 MINI), I noticed that the level is ~3V.
It dawned on me that I was lowering the level of the SPDIF signal to ~ .75V and then having the Buffalo comparator boosting it back to ~3V. Such as unnecessary step!
SPDIF STRAIGHT INTO SABRE32
The Buffalo II manual (V1.0) clearly states that it can take TTL level SPDIF signals. In order to do this, the spdif switch is in the open position and the SPDIF is connected to D1 and GND. That is what I did. A “free” mod that bypasses the comparator. One less component in the signal path. There is still the 220 ohm resistor in series, but D1 is a high impedance input so the voltage drop through the resistor is minimal, besides it is good for protection.