I'm currently using a pair of krell fpb 350m (mono blocks) to run my B&W 801N. I would like more power for my pair of B&W 801N. And I have located a pair of krell fpb 650m (mono blocks) near by and is available for me to purchase. I would like to know will that be a great upgrade for my pair of B&W 801N. Any advice and opinion will help.



"I would like more power"

I don't think you would gain anything at all, can't believe you don't have enough power already.

What are you trying to get that you can't get with what you've got already, better bass, sweeter mids and highs, change in tonal balance?? list your source and preamp as well.

Cheers George
I have no experience with Krell and cannot comment on your specific question, but when I bought my 801Ns I had an MC7300 that at 300W/channel I thought would be fine. It wasn't. Replacing the MC7300 with a pair of MC1000 monoblocks made a big difference never regretted.


As tested by Stereophile your 350M's can give.

"maximum power delivery of a monstrous 475W into 8 ohms (26.8dBW), way above the specified power. 850W was available into 4 ohms (26.3dBW) and while I measured 1060W into 2 ohms (24.2 dBW)"

I cant see any improvement happening by going to the same topology even more powerfull 650M's driving your 90db speakers, as both amps would drive the 801n speakers on their ear.

This is why I ask what are you trying to get that needs to be different, and what is your source and preamp?

Cheers George
Its moving sideways, and not by much. Look into a pair of McIntosh Mc1200's. That's going to be all you need! Regards,

Matt M
The 650m will have a fuller, heavier bottom end and a little larger soundstage. I would know, I've sold them new. mc and mcx versions are more articulate, clearer sounding. I sold them new when they were current and have sold many over the years.
350m became 350mc then 450mcx
250m became 250mc then 350mcx
650m became 650mc then 750mcx
The transformers and chassis size are all the size within each model upgrade. The mcx version modified a driver board to push another 100 watts out of the amp. It worked. Never confuse a 350mc with a 350mcx the 350mc is a much better (and larger amp)
Hi Highperformancestereodotcom

I am currently using a 200c but not using cast, using XLR.

Are there any improvements to be gained from going to a 300cx?

here is my current sources:
Preamp: Krell evo. 202
CD player: Esoteric sac x-01
Amplifiers: krell fpb 350m
Interconnects: Transparent reference XL (s.s)
Speaker cables: Transparent reference XL (s.s)



Banmac, try this first for no money outlay. This is the way I would use it, and it will be very different.

Leave your preamp out altogether, and go direct, as it looks as though your Esoteric sac x-01 has a volume control built into it looking at a picture of the remote (read your manual).
Try using it (the X-01) direct into the FPB-350 and using the volume control it has, it will still be a perfect match.

As for your 350m amps you have, they would be walking in the park driving those speakers, and quite capable to over drive those speakers you have.
I can only think of one speaker where the 650m would be better and that's with Wilson Alexia's as they are a pig of a load down to .8ohm epdr in the bass, and even then it would maybe just be better.

Cheers George

Am currently using a Krell FPB 200c not running cast but balanced. Would there be any merits in moving to a 300 cx?