Krell EVO-1, FPB-750MCX or EVO-900

Short of actually listening, it would help to know how much power you're actually drawing now out of your 750's.

How loud do you listen, how big and sound-absorbent is your room, and how far from the speakers do you sit? The Revels are power-hungry, but 450 conservative watts would probably be more than enough in a lot of situations.

If you don't know what kind of power you need, you can get a Radio Shack sound level meter, and just do the math (or post the readings and someone can tell you what kind of power you're using).

I would add something here too. Remember all this advice is from different sources and set-ups. One, all krell amps sound better at 220 volts, much better that 117! 2nd comparing the KCT and a fresh new EVO 202 are not the same thing, freshin up the caps and replace any aged resisters in the KCT before direct comparison. You will here a difference but not as "DRAMATIC" as everyone describes here. The KCT and FPB "MCX" combo run in cast is pretty damn good with fresh caps and solid power. I have heard many people trash krells and after seeing their setup (poor standard wall wiring) it was easy to see why.

With my brand new house, copper wiring and sockets, the KAV 2250 at least plays on a 15amp circuit and sounds ok, the FPB sounds bad on this and sometimes will not turn on because of low voltage, on a 30amp 220 volt dedicated circuit the FPB750MCX amps sound stunning. Im not saying peoples opinion are not valid but results may vary, I know very few that supply these high end amps with a proper power supply setup, you need more than a power conditioner. Each of my FPB750MCX amps have 6000 watt of transformer in them, running a pair (12,000 W) on a single 15 amp 1800 watt line is not going to result in great sound. I know this makes everything more confusing, but often its not the amps that need to be upgraded, sometimes they just need knew caps and a tune up, the difference on a 15 yo component is dramatic. Krell reccomends replacing the caps and tuning up the amps and preamps every 10 years.

I have the evolution ones with the twos and cypher mcintosh mt10 naim nds and 555 power supply a fbi with two wilson audio thor's hammer subs and westlake audio sm1s and nordost odin thor power unit odin power cords and odin balanced xlrs all krell gear connected over cast..haven't got anything msb?

So, what did you finally decide?

I would stick with your 750 mcx amps for sure!, doing what Rminsf is talking about would be a win, win situation, I know, I did all that he said, except the 220 yet, it's like a whole new amp indeed!, I do not believe their would be a competition if your 750mcx got new caps and a tune up with diodes and transisitors against a msb amp by no means, really, you would not convince me of that!