Krell FPB 600 or 400cx?


I own Revel Ultima Salon 2s and am looking to upgrade my amp for better performance in the low end. Right now I'm just not getting any real punch or slam in the bass dept, and I know the Salons are capable of much more. I have the opportunity to go with a fpb 600 or the 400cx for around the same price. Any thoughts? Is the extra 200 watts of power on the 600 worth losing any sonic benefits of cx? Or is the cx so superior sonically that there's no comparison?

Thanks.

Josh
punishen1
I lived with the 450 MCX for several years. When I exchnaged it for the Evo 600 (now the Evo 600E) I did not notice a significant difference (I didn;t A-B them at home). Midrange,bass treble all sound great with both amps. Both have excellent 3 dimensional sound stage, instrument seperation (air). My dealer felt the treble was a bit more prestine with the Evo amp, but I am not sure that I agree. The sound is too close to compare without direct A-B. My A-B comparison at the store was a Krell Evo 400 stereo amp A-B'd to a Krell 750MCX stereo amp. The sounded very similar. i guess it is impressive that the smaller evo 400 could match the 750MCX. T really had to strain to detect a difference. I would not trade in the MCX for the evo amps unless you get a great deal. Both are superb. The thing that made a huge difference in audio performance in my hifi was changing my Krell KCT pre-amp and Lexicon MC12B processor for the Krell Evo 707 processor. This made an obvious enormous improvement in all aspects of audio both for music (2 channel stereo using the pre-amp bi-pass in the Evo 707) and for home theater. I noticed it immediately, no AB comparison was necessary. I have been involvrd in this hobby for over 30 years. Upgrading to the Krell Evo 707 is by far the single greatest upgrade I have ever done. The 707 uses a pre-amp section very similar to the preamp used in their top of the line Evolution 2 (retails for $55,000)in all channels. The sound is absolutely stunning. The Evo 707 is amazing, it completely blows away the Krell KCT and the Lexicon MC12B.
Matjet,

Thanks for the great info. I wish Krell would come out with a slightly cheaper version of the 707 with CAST outputs.
If you have a good Krell dealer, between trade-in and discounts, you should be able to buy the 707 for much less than $30,000. $30,000 is a lot of money. On the other hand, compared to the evo 2, which retails for $55,000 for two channels, the 707 could be viewed as a 'bargain' since it has almost the exact same preamp in all channels, along with the processing, EQ, video, etc. The improvement over the KCT (which I used in CAST mode and is a very good pre-amp) is enormous. I was shocked. Better instrument separation (more 'air'), better 3-d sound staging, faster, better dynamics, better transients, much better tighter (more accurate sounding) bass, more detailed but with an analog tube like bloom. The Evo 707 produced a more beautiful, life like sound. This also applies to replacing the Lexicon for HT use (I used the Lexicon for HT, the Krell KCT was used for stereo music).
Krell does have a less expensive pre amp/processor, but I have not heard it. I doubt it sounds as good as the 707.
What are you using for a pre amp/processor?
Matjet,

Thank you for your excellent information. Can you elaborate on CAST technology...(like, what is it!?)...also, on how to mate a preamp/processor with a CAST unit (i.e.: compatibility...what to look for).

I was planning to use my PS Audio Perfect Wave DAC as a preamp. Do you see any issues? Also, did you say that the S-275 as CAST technology?

Thanks again, and happy new year (Happy New Year to All of you sick twisted audiophiles - and I mean that in a very sincere way...tongue firmly planted in cheek!!)

Cheers!

_Ben
Matjet,

I have a Lexicon MC12B and a Pass Lab X-1. I am considering replacing the x-1 very shortly and MC-12B as well.

Most single box ssp don't sound good on 2 channels perhaps, the 707 might be the exception.

I will try to audition the 707 if I can find a local dealer.