All tube amps are effected by the loads they drive. So for some speakers the MC30 might be someones delight where others might prefer the little 225. As my Speakers are only 95 db 4 ft 1 watt I would choose the smoother sounding 275 as I did in 1969. The 240s' were a little less firm in the bottom and I thought the 275 was easier to listen to over the 240. I would have preferred the 225, but they just didn't have enough horse Power. Whats my favorite tube amp. MC 3500's. They have 1/3 the distortion of the others more signal to noise and are very easy to listen too, over long periods. They have the delicacy of a 225 and its speed, too. They have lower distortion and more signal to noise than the first generation 2000 series SS amps, too. Thats why they are pushing $15,000 each pre-owned and restored , today. Its a shame only. 193 were built. I wonder what happened to the 5 we sold.
I'd love to have pair to drive my speakers again if I were using passive crossovers again, but I'm not, or to drive a pair of XR290.