My thoughts are it would have to degrade the sound of the "pure" SB2 direct to the amps.
When we did our comparison, we were using a modified deHaviland Ultra Verve as a preamp. I can say with certainty that the parts quality was far higher than what would be used in the MF buffer. The quality of sound took an enormous leap when the preamp was removed from the signal path.
The idea is to keep the signal path as short as possible. It might be possibls to use a "Y" to run to your subs. I would suggest you keep the interconnect run as short as possible. With the modded SB2 you have the DAC chip, a very high quality capacitor and the output connector. ANYTHING you put in between that will degrade the signal further.
The SB2 direct to amps is not something everyone can implement. For those that can, they will be rewarded.
