Krell FPB-400cx vs. Pass 350.5 for Thiel 3.6

Hey Guys,
I am looking to upgrade my amplifier and have narrowed my choices to these two amplifiers. I want maximum performance and would like to know which amp is going to deliver the goods? :) I have found that the aspects I am looking for are more detail, a wider and deeper soundstage, and images with more substance and shape.

My current setup is as follows,

Thiel 3.6
Classe CP-50
Esoteric X-03
Parasound HCA-3500
Spacedeck/Nottingham Cartridge

You can check it out here,

I would love to hear from some Thiel owners.
Thiel uses Krell i believe to design his speaks, if that means anything
I used Krell amps when I had my CS7.2s for over two years. Before I bought the krells (FPB650M) i auditioned the X600 monoblocks (not for me) and then the 350.5, Better, and I could have been happy with this amp, but I preferred the Krells. Better bass, cleaner midrange, and a little darker on top. these were my reasons for getting the krell. From what I have read, (not heard) the CX series of Krell amps are better than the ones I had. Good Luck.
Mcintosh 501 mono's is what I use - they do a great job controlling the Thiels. Transparent, great bottom end and midrange.

Before that I used Classe CA 200 - Mac's were a big step up.

Can't help you with Pass or Krell, haven't heard them.
Hey guys,
Thanks for the input. Tom, what made you decide to get away from the 7.2's? Pops, I have always loved those big blue VU meters, it's just the 501's are a little out of my price range right now.

Thanks again guys, Keep it coming.
Several reasons. Wanted a smaller, cheaper, more forgiving system. I also wanted to put the difference in price into my vinyl system. but have not been able to do that yet since i lost my job shortly after selling off alot of gear. Really like the harbeths and Manley system.
How would the FPB-400cx compare to the FPB-600?
I also have Thiels CS3.6, I am using Conrad johnson Premier 350. Very happy, very clean and musical! and power is not an issue! I have listened to Pass 350.5 but the cj is far more stable when pushed hard. If Pass 350.5 have enough power than they will not need to produce all the way up to thier 1000 series! cheers.
Luna, I would have imagined just the opposite.
I power my CS6s with the 400cx and feel this is a synergistic match, having tried previously the 300cx (not enough oomph for the 6s, so I immediately upgraded to the 400cx) and Bryston 7BSTs. The Krell had noteceably more dynamic kick than the Bryston and sounded sweeter and more tube like. I know some of you are thinking, "yeah right, Krell and Thiel as tubelike...," but I own tube equipment too and know this from exeprience. Safe to say that in the 6 years I have had the 400cx and the CS6s I have not once felt a desire to change the power amp.

I wish I could comment on the Pass as this is supposed to be a very good amp (Jim Thiel approves of Pass).

The 400cx should provide excellent performance with the 3.6s as their electrical characterstics are close to those of the CS6. Let us know what you decide to do.
I don't think you could go wrong with either one. Those two, in that order, would probably be my top two choices.
I have not heard the Krell myself, so can't comment on that. I had owned the Thiel 3.6 for over 8 years paired with an ML #333. At that time, I had been contemplating about upgrading the speakers. But I was having some problems with the ML#333, so I traded it in for a brand new Pass X350.5. I got to hear the Pass X350.5/Thiel 3.6 combo for a few months (before I sold the Thiel 3.6 and purchased a pair of Verity Parsifal Encores).

I had the Thiels dialed in pretty well from feedbacks I had received from others who are familiar with Thiel 3.6s. Several of my close friends who are familiar with my system were pretty amazed when I first hooked up the Pass. (fresh out of box brand new, not broken in yet) All the improvement you listed above + deeper and tighter bass. It was an eye-opener for me! I was fairly confident that I had driven these Thiels to its "max". And I thought the change of amp would just be more of a lateral move, or the changes would be just minimal.

A friend who has been using the #433 in his system came over to hear the Pass that first week. He went home and put his 433 on Agon, and bought an X350.5 that weeekend.

I had seriously thought about keeping the Thiels for few more years after hearng the combo. But at that time, I really wanted to try different speakers.

On a side note, as much as I liked the Thiel 3.6, I am really glad that I moved over to the Verity Parsifal Encores....