2-channel + 3-channel amps, versus 5-channel amp


I am considering an amplifier upgrade for my system, which pulls double duty for 2-channel and HT. In truth, I have been listening to more HT (what with kids and all), but most of my critical listening is good old 2-channel. My initial thought would be that a really good two channel amp, and then a separate 3-channel amp for center and surrounds (not worried about 7.1, for now or the foreseeable future) would be the way to go, but I do see a number of really nice 5-channel amps out there (Theta DII is enticing). My concern with 5-channel would be a single power supply trying to handle all 5 channels. But I do see that most of these amps use a very beefy, and significantly upgraded power supply over their 2-3 channel brethren.

And advantage of the 5-channel approach is that all three of my front speakers would receive the same power, which is nice. But then this begs the question of whether or not I would be better served by getting a better/more powerful 3-channel amp, and then a smaller 2-channel amp for surrounds! Talk about choices (then of course, there is the option of 5 mono amps!).

For speakers, I am driving Thiel CS3.6's, which are notoriously hard to drive, and spend a good bit of their time in the 2 ohm region, a Thiel SCS3 for the center (which is loads easier to drive), and currently I have AR TSW-110's for surrounds, though I may replace them with two more SCS3's. My processor is a Rotel RSP-1066. Brands which I have been looking into include McCormack, Krell, Bryston, Theta, and Classe.

Any thoughts, comments, suggestions are appreciated.

Thanks, Tom.
tombowlus
I ended up with two Theta Digital Enterprise monoblocks and a Theta Digital Intrepid, in case anyone gives a hoot. After listening to a number of really great amps, I came away most impressed with Theta, and they really match up well with my Thiels.

Later, Tom.
Here are some possible amp options that I have been considering (listed in no particular order). Any comments or recommendations would be appreciated:

Theta Dreadnaught II (3x225w, 2x100) - single amp solution with 2-channel/surround option.

Theta Enterprise Monoblocks (2), with Theta Dreadnaught II (1x225, 2x100) - higher end Theta route (may have to save up for this option). I may also substitute a 5-channel Theta Intrepid for the Dreadnaught II in this configuration.

Krell FPB300cx (or similar) with Krell KAV-3250 or KAV-250a/3 - I've heard that the FPB amps really match up well with my Thiel CS3.6 (also not a cheap route, though).

Pass X250 or X350 with Pass X3 - for not much more than the Dreadnaught II option, I can get all Pass amps (but no local dealer).

Bryston 14B SST (2x600) with Bryston 6B SST (3x300) - would also consider ST (also no local Bryston dealer).

Bryston 7B SST (2 @ 600w ea.) with Bryston 6B SST - again, may consider ST.

Bryston 7B SST (3 @ 600w ea.) with Bryston 3B SST (2x150) - ditto on the ST.

Classe' CA-201/301/401 (probably 301) with Classe' CAV-75 (set up 3x150) - or some other combination of older Classe' amps.

McCormack DNA-225/500 or upgraded DNA-2 with DNA-HT1/3 - have heard nothing but good things about McCormacks, but wonder about how they will match up with my Thiels.

The rest of my system includes a Rotel RSP-1066, Thiel CS3.6 mains, Thiel SCS3 center, AR TSW-110 surrounds, and no subwoofer for now. For speaker cables, I am using MIT AVt3 (except for surrounds). I am considering adding a sub (perhaps Velodyne DD-12), but I want to hear my 3.6's with a new amp first. The Thiels and whatever amp I pick up are going to be in my system for a good long time. The Rotel, AR's, and all source components are probably all up for grabs at some point in the next couple of years.

Thanks, Tom.
FYI - I do not have a local Pass dealer either. Peter at Pass Labs referred me to Audio Video Logic here on Audiogon. I have an X250 and wouldn't think about letting it go for anything other than another Pass.
IMHO go 5channel only if you believe in 7.1 ...that,s what I did 2years ago ...and i use 5.1 today... how many films do you know at 6.1? yes you can count the crapy ones too..if your setup is good ... room treatments,speaker placement etc.. good sub to pressurize your space you should be in 3d heaven..that's as good as it gets ..now I've
been to demos and movie theaters wwhere there's no 3d surround and it sucks...so i challenge 7.1 8.1 ............
if it isn't seamless who gives a [edited]
Any thoughts on the Theta Dreadnaught II approach of allowing multiple channels (up to 10), but keeping the option of powering just two channels, with all the current going to those two? It seems like an ingenious solution, and quite possibly a great option for me.

Thanks, Tom.
Ideally, you would have identical speakers across the front and identical amps. But IMO, it is going to take a little more power on the 3.6's than the SCS3 to achieve the same levels. You are going to have to calibrate your speaker levels anyway. An X250 driving the 3.6's shouldn't be a lot different than an X3 driving an SCS3, since the SCS3 is going to be more efficient. I considered getting an ATI to use on surrounds, but didn't want to mix brands of amps.
I have, indeed, begun to seriously look into amplifiers from Pass, as many fellow Audiogoners seem to have tried out the brands that I am looking at and settled on Pass. I had briefly looked into ATI, but hadn't thought about mating them with another brand of 2-channel amp. Do you think that by having the same brand, but different model, center channel as my L/R speakers, should I not be concerned about matching the center channel amp as closely as possible to the L/R amps?

Now, I just need to find a local Pass dealer...

Thanks, Tom.
I had a similar setup with B&W's. I used an X250 on the mains and an X3 on the center and surrounds. It worked very well. Currently I'm using an X3 on CS1.6's and an SCS3 and an X5 on PowerPoints and PowerPlanes. This is a great sounding combination. I know I'm wasting a channel, but I wanted to stay all Pass and this was cheaper than going with two X150's.
Vic
Yeah to do HT right, you gotta do a center. If you like no center for your mulit channel music or whatever, or stereo needs, than click off the center! it's that easy. For movies, you simply must do the center thing for off axis listening with multiple seats!...it's just better(I mean the movie mixers/engineers desgigned it that way..duh!)
I am also an avid 2 channel guy(infact my ht has been 2 ch w/sub for years, but then it's just me listening!..no one else. Still, dedicated HT systems for the whole familiy NEED A CENTER CHANNEL!..end of discussion.
To your question, the 2 channel amp(or even mono's) will outperform(all things equal) multi channel amps in the same brand, most every time! YOu might consider 2 channel high end amp like Pass X250 for the 3.6's(which will handle the 3.6 and mate well) and add 3/5 channel amps (like the sonically similar, if less refined ultimately, ATI amps!) for the rest. ATI makes an excellently clear, neutral, musical and extended multi channel, that's very strong, bullet proof, and high end! It's not as good as many high end amp totally, but then you're talking HT. Still, it holds it's own, has the clarity, neutrality of say the Pass, krell, MCCormmack, and similarly balanced sounding/neutral amps, but is strong class B indeed, not A.
Anyway, for the money, this is a no-loose option.
I've sold the Thiels on a retail level, and owned the 1.5's and 2.3's for years. The Pass is world class, and mateches the 3.6's, and the ATI's are a perfect fit for the rest!..without UNECESSARITY breaking the bank.
Hope this helps
Tom- Suggest you try dumping the center channel and go with two good stereo amps. I'm into HT since '97 (purchased laser disk player) and have never found a scenario where the center channel is better than a phantom center image. Sometimes as good, but never better. Just a thought; like the DII though.

Russ