Krell FPB 300 vs ML 333 for Thiel CS6

Planning on upgrading from using the front channels on a Proceed AMP 5 (now) to either of the two mentioned in the header. Anyone have any idea of which would be the better choice ? Thanks.
Funny thing is that I have had/have all the amps you have, but slightly different models (ML 331.5, Krell FPB 200, Proceed HPA 3-channel amp). I had Thiel 2.2 speakers. First thing is that typically when I ran the Thiels they were part of a second system that was run directly to the amp by an Audio Aero Capitole CD player. This is a very warm CD player, so this must be taken into consideration.

The ML 331.5 I felt was an excellent match with the Thiel speakers. The bass is not going to be as strong as with the Krell (in my case), but it seems that the ML tamed the potentially forward tweeter of the Thiel a bit more than the Krell did. I almost got the impression that the ML rolled off a bit in the upper frequency range compared to the Krell. This could of course been the interaction with the Capitole. For what its worth, for the most part I kept the ML with the Thiels and the Krell in my other system

When I bought the 331.5, I bought it from a guy who had 7.2 speakers and heard them when I picked up the amp (with the ML amp). That was my first time really listening to Thiel speakers and I was very impressed by the match (even though I think the 331.5 was a bit short in power for the 7.2 speakers).

I have aFPB 300-C coming on Tuesday and I think you would be very good with both/either, certainly better than the Proceed.
I lived with a pair of Thiel 3.6 mated with ML333 for over 8 years. Before that had a pair of 2.2 for another 7 years. I thought the Thiel/ML combo work fairly well until I switched over to the Pass X350.5. Is there any specific reason why you limit your choice to these two amps?

I would strongly recommend not to buy a ML 3xx series amp. They have an issue with caps blowing up. I had mine back in the factory twice. When I spoke to the customer service, I found out the dealer had already sent it back once before. Actually, the amp sounded better when I got it back last time. But I did not want to risk having blown caps again in a few years. The replacement cost me over $1200.

I ended up trading it in for Pass X350.5, which was an eye opener. A much better amp than the ML333 by a big margin. I had been planning on upgrading to Thiel 6, but ended up buying a pair of Verity Parsifal Encore.

With regard to FrankC's comments, I cannot say that I ever had a problem with my 331.5, but am not sure if the .5 upgrades there were done addressed these cap issues, it would not surprise me as I have heard others mention some "minor" reliability issues. My 331.5 performed flawlessly for me. I had a pass 150.5, which was a good amp, but I never played this with the Thiel speakers so I cannot comment on this synergy, but I have heard good things about others running them with Thiels. I ran Totem's and Von Schweikert with the Pass amp. Again, though, I did like the sound of the ML with the Thiel, but would consider Frank's comments. If a ML 23.5 had enough power, that is a very good ML amp, but think it will be under powered for your speakers. I loved the Krells with Wilson speakers, both the Duettes and the W/P which have several common characteristics with the Thiels, FWIW.
A friend of mine has Thiel cs6. He had ML 331 (not enough power, but I liked it), Pass 350 (somehow less dynamic and warmer sound), and finally ended up to have Nuforce 9SE monoblocks plugged into PS audio P300. That is a wonderful combination, smooth, quick, dynamic sound. Also, Nuforce at full swing consume less than ML in sleep mode.
Thiel match well with Odyssey Stratos Extreme,read my
previous thread.I happened to have mine for sale right
now.I dont mean promoting mine, you can read my previous
thread on this combination.I heard the Thiel Pass Lab
x250 also, they sounded good but I prefer the Odyssey
Thiel combination..Thanks
I had a FPB 200 - used with a pair of 2.3s -thought the combo was excellent (acknowledging the very forward Thiel tweeters) - sold a few years back. Just heard MLs and Classe were better with Thiel. Learning about the capacitor issue with the 3s really makes me lean back towards Krell. Also, I have no experience with Pass but have heard a great deal of positive feedback. The X350 sounds great, perhaps a bit hard to find on the used market however. BTW - can anyone tell me how much the .5 upgrade costs for the ML 333 ? Is sending back to Harmon required ?
I cannot tell you the cost of the .5 upgrade on the ML (but would imagine that this would be easily attainable information directly by e-mailing them), but it is my understanding that yes, it does need to go back. Also, with the Pass Labs, the .5 versions are reportedly a fairly noticeable/recognizeable improvement vs. the non .5 versions. But to be honest, I have never compared the two Pass units to confirm this myself. I know the upgrade for the Krell C version to the CX version (for a FPB300-C to go to a 300-CX) is $2,500 including the new center cap faceplate (Krell just sent this to me on Friday). I think with the ML, the cost of the upgrade might be variable depending on whether you update the faceplate as well.
I have not heard the ML amps with the Thiels. I have owned and auditioned several amps(Pass X600, X350.5, Ayre V-1XE, MXR, V-5XE, Mcintosh 1201s, 402, JC-1 monos)with various models of Thiels. And for me, as nice as they have been, none has worked as well as the FPB amps I own now with my Thiels. Good Luck.
I have heard the FPB200, ML 331.5 and 334 on Thiels. All are excellent IMO. Personally I liked the 334 better.

The .5 upgrade if I remember correctly is approx. $2k.
The issue I had mentioned earlier regarding the ML 3xx series has been well documented on the web. Harmon no longer offers the .5 upgrade. I had asked when I sent my amp back for fix 2 years ago.

I think system synergy will play a big part. So you need to think about which preamp you will be using. I am using a GNSC modded ARC LS-25 Mk I.

I had a chance to hear the Pass X350 next to the X350.5 at a friend's house. Huge difference. All present agreed that the non .5 version sounded more like the typical SS amp, cold and sterile. The .5 amp has that midrange warmth that earlier Pass Aleph amps were well known for.

Thanks all for the responses. Does anyone know roughly how much the capacitor repair job costs for the ML 333?
$900 + shipping both ways. So figure about $1200 to $1300. There's another thread talking about this right now.