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
Rminsf,
Wow!
Cast will cure any interconnect problems/issues resolution and up the quality a notch (sounds like your quality is there -- nothing to snuff about for sure -- better than just about everything out there).
Your statement about the Krells running out of steam "kinda freaks me out" -- I ran a question on this forum about room size and volume not volts-- I sure would like your input on that question.
Kool --
http://www.stereophile.com/content/krell-full-power-balanced-600-power-amplifier-measurements

According to this Stereophile test results, the Krell FPB600 almost doubled in power going from an 8 Ohm to 4 Ohm load, and then again going down to a 2 Ohm load.

There was no indication looking at the test results to support the claim that this was a bridged amplifier. To the contrary, it said that it could drive any load of any impedance.
And the only reason it didn't quite double into 4 Ohms was because the line voltage began to sag.
I completely agree and know of this also, where you are going to see it in the FPB600-700 is driving say Soundlabs or Apogee speakers that are living below 2 ohms most of the time. There is no lack of power with this amp and don't read too much into that difference. It's only in the most extreme loads you would experience anything at all. Mr Dan designed all these amps to be pure voltage source amps, bridged or not, if they are bridged it must be in parallel anyways, I understand it's basically two FPB300's. If they were bridged in series the power would be 1200+ into 8 ohms and that would be restricting the amperage. In order to be a constant voltage source regardless of the load, the current must be unrestricted, this is why the wattage doubles with every halving of load. I'm not trying in anyway to knock any FPB amp, just understand their differences and I do not currently own a FPB600 only the 300 stereo amp and my mono's.

I just ordered a pair of FPB750MCX Mono's should be here in a week or two, can't wait to listen to my first X amps in my own system.

On another note. My son and I were doing the annual cleaning of our equipment and all the connectors. We remove all the panels and clean the inards and boards inside along with all the connectors. So we finished the KRC3 and my bedroom S300i and decided to try something which kind of relates to this thread. We put the S300i in theater bypass mode and ran it directly from the KRC3 with all the silver cabling I normally use. WOW what a difference, I never liked the veiled lethargic sound of the S300i but running in theater mode is a whole different ball game! It must completely bypass the horrible preamp section and route the balanced input directly to the amp? It sounds great not like a BIG FPB's but hey it's a $2500 amp and it sounds tight, SWEET and powerful. Gone is the top-end and mid-range shouting and raspy treble. It sounded much more like the KRC3 itself now, very musical, natural. All of the sudden it has a sound-stage and a good size one at that, depth, it made the 801N's bass sound tight and punchy. It's not the same Majesty and effortlessness you get from the FPB650MC's but hey I could listen and love this all day, and we did.

Looking for a true audiophile bargain, get a good preamp and run the S300i as an amp only, direct in theater mode, you will be glad you did. Granted it too is plugged into a PS Audio P-1200 @117 volts @ 90 hz but damn it really sounds great, it's just the preamp section that sounds so nasty.

Now do I buy a Krell EVO 202 or help my son pay his tickets off?

Rob