I used a SM on C27...I used a PS series Orange Drop for C30.
Speakers are Scumback H and M75's. Power tubes are Boogie STR440 and 447 6L6/EL34 respectively.
At first I was a little bothered by the aggression...The C30 mod was great, but I'm still missing the "air." The 2k and 6.6k sliders...