klipshorn speakers

Khorns are 104db@1meter sensitivity for 1 watt! They can play really loud with a 2 watt SET amp! How about a Yamamoto 45 SET connected to a First Watt F4, then to the Khorns? This will give 25wpc of pure Class A power - and sound way better than his Mc7300. No need to spend $7.2K! Finesse trumps brawn!

Why would you connect a tube amp to a SS amp? This needs some "splaining"...

I heard a big Mac solid state amp feeding high efficiency speakers and it was a terrible sounding combination.  At any reasonable listening level the sound was lifeless and unengaging.  With high efficiency speakers you don't need much power, you need something that delivers great sound at fractions of a watt output.  Look at low-powered tube amps, most of the best sounding amps I've heard have rated power output under 40 watts.  I don't think the tube Mac amp--275 is the answer either; I heard that in a high efficiency system and it was also pretty bad sounding (also lifeless).

I don't think you need 40 watts, but, the Synthesis A40 is a terrific sounding integrated amplifier (it includes a very good DAC) that would fit the bill.  

my son likes mcintosh! but will the sound be better with a mc602 is what i'm asking! 

No, it will not sound any better. The power advantage is meaningless as the MC7300 will easily drive the Khorns into utter distortion and burst both your son's ear drums. I think a Class A solid state amp would be the way to go. Anything more than 100 watts/ch  is a waste of money.