Krell FPB and cast versions

Yikes.You like it bright it bright.Not sure what cable you use but I'd try Cardas (tames mid "nasties").Might make everything tight given your taste.I like three things accurate bass,lush midrange,and bright top end.But Krell and Thiel is for some folks but to much for me.I sold krell through FPB (mainly with a forgiving speaker which did not benefit for tubes being B&W).But So I know amp (great grip on bass,nice highs but for the tube lover in me the mids were a bit metallic and "etched" and Thiel being bright accentuates this).I would go for FPB (same Krell A sound with slight difference).Can't make bogus claim to CAST tech but I sold Krell and do known pricing and hype.I also got a pair of Thiel 7's for a buddy and wish I had gotten 7.2 since outsourcing driver tech was good move on their part.Better speaker.Others will have to chime in on CAST.Then room size and how loud you want it.I have a KSA300S and it is only Krell in their history that went continuous into 1 ohm (for 2,400n wpc).Bigger room and louder music 600 right?All I can say is I installed a CS6 and older Krell with wires which aren't bright (MIT roll off highs and lows) and it still made my ears bleed.I'd go FPB 600 (they can suck it down-dedicated 20 amp lines in houses with no filtering sounded best to me)and cable match carefully.This might not be of much help but sold Krell al the time and know they can be bright.Which is sort of dichotomy since I like lush tube sound on mids but like a bright speaker (so my buddy's tell me.FPB is less $$$ delivers goods and cable match to your taste is my two cents for what it's worth.For hell of it it you might want to head to head Parasound JC1 400 wpc mono's on Thiel's.Not sue if this was waste of time but you did mention not wanting Krell pre so thought I'd throw it out their.
Cheers
Chazz

I had a pair of Thiels CS 2.3s and Krell KAV300i(Some people don't consider this a real Krell).

Chazzbo hit it right on the head, its bright and metallic all the way! I could barely listen to it for more than 30 minutes at a time.

DH,

I have own Krell combos with the Thiels 3.6 and the CS7’s.
The only difference as you have mentioned between the Krell FPB and the Cast are the protocols between the connection. If you don’t have the cast chain then stick with the FPB. The FPB300 will be a nice combo for sure.
I was using a Hovland pre and moved up to a solid state from there with a 600cx now.
You won’t go wrong with the combo. Cables and setups are the major issues with making these things bright and brittle like many say about Krell. My Krell setup now is actually smoother sound that my ARC PRE POWER combo with all the control and resolution I can ask for. Go with some neutral sounding cables and they will work like a charm, Transparent Audio, Clarity Cable and so on…. Avoid the Synergistics Research and others that fall onto the other spectrum of preference.

In your case do try some tube preamps if you are concern by all means making sure their output levels match between one another so that you will acquire sufficient gain for the system.

Krell/Thiel IS NOT BRIGHT!!!

Chazbo what you smokin'? ;-)

Wrong plain wrong.

And 300i powering 2.3s, well duh, of course!

Where the heck does this stuff come from?

Thiels are revealing but the 7 series is not that "bright" Chazzbo. Krell is a great match for them.