The "small transformer" is an inductor, used in power supply filtering. With tube amps, any power rating issues are relative. MC60s are not twice as powerful as 30s. I am not familiar with your speakers, but if they are efficient, an MC 30 would be a good match.
McIntosh MC60 vs MC30
Do they both sound the same.Will the MC30s have enough power to drive my Cremona Auditors? I noticed inside the 60s there is a small transformer but not the 30s.Does anybody know why,Also there seems to be more of the 30s out there to choose from, is there a reason for that? Do the 30s put out as much bass as the 60s?