Best affordable amp for Thiel CS3.6

I have a pair of CS3.6's, which I am currently driving with a pair of Adcom GFA-555II's in bridged mono mode. While I am fairly happy with this setup, I realize that the Adcoms may not be in the same league as the Thiels. Any suggestions as to what amps mate well with the CS3.6's? Ideally, I'd love to find an amp (or two, if mono) for under $2,000, but if it's worthwhile, I may go higher. Obviously, if there is a great option out there for less money, I'd be even more interested. Used gear is fine with me, if it is quality gear. I am also considering modding my Adcoms to smooth out the mids/highs and add a little support in the low end.

Another consideration is that I am currently using an Adcom GFA-2535 for my center channel (Thiel SCS3) and surrounds (AR TSW-110), and since it is nice to have matching amps for HT, I'd probably have to add an additional amp or two (eventually).

My sources are currently a Denon DCM-460 and a JVC SA-600, but these are likely to be upgraded in the relatively near future. Both are sending digital outs to my Rotel RSP-1066, which handles the processing.

Thanks for any input/advice.

If you can find a good Threshold Class A amp, such as the SA 1 (monos), SA 2 or SA 3 (only 50 watts, which were enuf for me when I had my Thiels) you'll be pleased. They work exceptionally well with this speaker.
I am driving my 3.6's with a Conrad Johnson MF2500A and am very happy with the results. You can buy one used here on this site or on E-bay for around $1750-$2250.

Thanks, Chuck
Good info, so far. Keep 'em coming!

Thanks, Tom.

If someone has an amp that fits the bill that they are trying to sell, feel free to drop me a line.

I'm driving my CS3.6's with an Aragon 8008BB. I've been very happy with it. You can get one used for around $1200 or so.

Good luck!
How about some Monarchy SE-160s hybrid monoblocks. I've seen these as low as $1800.00 a pair. May add some sweetness to the Thiels.

Good Luck!
I upgraded from a McCormack DNA1 (175 watts) to a pair of Classe CAM200 monoblocks (200 watts). The difference was huge- better bass, better resolution of details in the high end, sweeter. It seems like the ability to 'double down' (400 watts into 4 ohms, etc.) might be the thing to look for- not all amps can do this, and the 3.6's go to 2 ohms at certain frequencies.
GamuT 200W stereo is considered a good match. I listened to that combo driven by a Rowland pre and the result was very musical and nicely detailed. Big room (~35x20).

Good point about doubling down. I know those Thiels present a demanding load, and I want to make sure the amp is up to the challenge. Do you think the benefits from the McCormack to Classe had more to do with increased headroom and the monoblock design, or was it more of a "McCormack versus Classe" kind of thing? I had been considering McCormack as a contender.


I was waiting for someone to suggest Aragorn. It seems to be a logical match. The Bryston and CJ recommendations are also along the lines of what I had expected.

You people have me doing some research! Thanks, Tom.
My local dealer, whom I enjoy working with, sells (among other things) Krell, Theta, and McCormack. I would love to have a Krell FPB300cx, but it looks like I am on more of a McCormack budget, especially if I buy new. Any thoughts on a DNA-225 for the CS3.6's, and a DNA-HT3 for the center and surrounds?

Tom, I wonder how the Theta Dreadnaught would do. It's not too pricey if I remember.
The only disadvantage to Theta, is that from what I recall, their price point is fairly close to Krell, so I'd probably be tempted to go Krell. Still, they definitely seem worth checking out.
I use to drive my Thiels with a Bryston 4B-ST but the Bryston's aren't that good at low impedence loads. I now use the Sim Audio Moon W-5 which has an output of over 700 watts into a 2 ohm load. Lotts of authority in the bass. You should be able to get a used one for $2500 or less.

to answer your question, I have a feeling it is more of a "McCormack vs. Classe" thing, vs. the benefit of a monoblock. I can't remember if the McCormacks of that era were able to double down, and they were at a lower price point than the Classe. On the monoblock topic, I have heard of others having good luck with Thiels and their Classe 300 or 400 series stereo amps. I suspect it is a matter of good compatability between brands.

I have made several other big upgrades to the system (the Thiels have been the only constant over 10 years) and I have always been amazed at how the 3.6's reward you when a higher quality piece of gear is inserted upstream. The Thiels are probably still not my weakest link in the system.

I think you mentioned being a Progressive Audio customer in one of your posts. I know they have their Thiels primarily powered by Spectral gear in their showrooms. I ended up purchasing a Spectral/Thiel system. I have very little experience, so I'm wondering if you (or any one else) have heard this combo and what you think of the compatability. Have you considered Spectral?
Actually, no. I had not considered Spectral, and I had forgotten that Progressive carried them. Which model Thiels do you have? The word that I am receiving is that the CS3.6's are some of the hardest Thiels to drive, and that in fact, they rank up there with some of the hardest speakers to drive. They spend a lot of time down in the 2 Ohm range, and being very flat across such a wide frequency spectrum, they can place a lot of demands upon an amp. Progressive's #1 recommendation for the CS3.6 so far has been Krell. Theta is close, they say, but for slightly more money, a Krell would work better. They do believe that McCormack would be a very large step in the right direction, though, and would bridge the gap cost-wise between Adcom and Krell.

Do you recall the price range of the Spectral gear? I know very little about them. Interestingly, the last time I was down there, I heard Thiel speakers as part of three separate systems. Two of them used Krell gear, and one used Rotel gear. I ended up buying a Rotel RSP-1066 because of how close it came to matching the Krell Showcase. Amp-wise, though, I'd put Rotel fairly close to the same league as Adcom, and since I am looking for an upgrade, here, I hadn't really thought about Rotel. Still, they may be worth listening to again.

Thanks for the feedback. I have been shopping at Progressive since my college days back in the late '80's, and I have come to really trust and rely upon them.

Later, Tom.
Try a PS Audio HCA-2. There is a Positive article on this same speaker/amp match.
Really?! I had thought of the HCA-2, but wouldn't have thought that it would have enough juice for the CS3.6's. I will try to check out that article.

Thanks, Tom.
I'm glad to hear you trust Progressive because I put myself in their hands in large part when I put my system together. I have Thiel 2.4s driven by a Spectral DMA-100S. I got the amp used for just over 2,000 and it drives the speakers well, except for maybe the most extreme volumes. So for the 3.6s, while I'm sure the load would be no problem for any of the Spectral gear, you might want more wattage (mine is 100W into 8 ohms) which would probably push you above your stated budget. This may be why Progressive didn't mention Spectral. The other problem is Spectral demands that their amps be combined with Spectral pres. It wouldn't hurt to ask Progressive for their opinion on how the Spectrals stack up against the other gear if you talk to them again.
I listened to the McCormack DNA-125 and I thought the jump up from the Adcom (don't know what model) to the McCormack was greater, more striking than the jump up from the McCormack to the Spectral. Never auditioned Krell.
Enjoy your shopping.
I used an Aragon 4004 mk2, Levinosn 23.5 and 333 when I had my Thiel 3.6. They are all very good. Levinson 23.5 should almost fit into your budget.
Hi Tombowlus, I have been using a class ca 200 for 3 years - although it's the only amp I've used on my 3.6's I really have no desire to change to another brand - maybe a bigger classe or newer design. This amp drives my thiels with ease in a large room, never reaches strain or congestion and I listen to alot of dynamic music, never runs unusually hot. Top to bottom and thru the midrange I have been very satisfied.
Classe and Levinson have definitely been added to my list. As for Spectral, yes, the folks at Progressive had good things to say about them, but because of having to use Spectral's preamp, and because I also use these speakers/amp(s) for home theatre, they didn't think it was as good of a match. Plus, after looking at photos and discussing my room, they agree with me that I have a "bass-sucking" room, which may require a fairly stout amp.

I am hoping to be able to audition my CS3.6's with amps from Krell, McCormack, and Theta (and my Adcoms, of course) down at Progressive. I'd love to hear Bryston, Classe and Levinson, as well, so I may see if any dealers in my area carry them.

Thanks again for all the feedback, Tom.
Will do. It'll probably be a couple of weeks before I can get back down there, though.
In case anyone has two or more cents that they'd like to toss in, I am presently considering (to some extent, at least) amps from all of the following manufacturers: Krell, McCormack, Theta, Bryston, Classe, and Pass. I might add one or two more to the list, but quite frankly, I will have a hard time auditioning all of these, particularly Pass and Classe, as I don't have any dealers within a reasonable drive. I would very much like to audition an amp before I commit, but I have heard enough good things about Classe and Pass to consider them, so long as I have a return option.

Thanks, Tom.
Tom, it's above your price range ($4700), but I just got a pair of the
new Rowland 201 monoblocks, which I am using with Thiel 2.4's. Very
early impressions are favorable to the point of gaga. Makes my Pass
150 sound broken, which it definitely is not.
OK Tom, bear in mind that a lot of this is subject a lot of personal biases. I love the Krell on Thiels. IMHO they are not nearly as bright and lean as some make them out to be. While the McCormacks have nice tight bass and smooth liquid highs, I think they can be some what forward and shouty, not something that would compliment the Thiels. I haven't heard the Theta's. The Brystons are nice, I particularly like the 3BST. The Brystons are probably some where between what you have now and the better amps on your list. How ever there has been some talk here on Audiogon with regard to their inability to handle low impedance loads. Considering your 3.6's drop to 2.5 Ohms, I'd be more than a little cautious. I find the Classe' a bit soft in the bass and a bit chalky on top. These critisims should not be taken out of context, I really do mean a bit. Rumor has it that the 200 Watt and above models are superior to the lower powered versions. The Classe' is probably between the Bryston and the next level, but I wouldn't argue if others placed them differently. The Classe' is a sound choice for the Thiels. The Pass X series might be the best amps I've ever heard. I love the lack of electronic flavor/haze that dwells in so much solid state gear and they are a lot cleaner and more dynamic than the Aleph predecesors. They should work beautifully with the Thiels. Unfortunatley your budget may prohibit the power levels your accustomed to. From your short list I would consider in order: Pass, Krell and Classe'. If any others come up for consideration I'd be happy to share my arrogant, pompous point of view. While I think that amps may be more important with Thiels than most speakers, try not to forget how the amps will work in the complete system, now and in the future. Good luck
Great response, Unsound! I very much appreciate your insight and assistance. While Pass and the Krell FPB series are both out of my (initial) price range new, I have seen deals on used amps from each that are within my realm of affordability. And ultimately, my goal is to build a system that I can be happy with for some time, so dealing with the Adcoms a little longer, and saving up some more cash, is preferable to playing the multiple upgrade game.

Tom, you are very intuitive. That was exactly my point. Mind you there are some very good deals on the used market. Your current budget may force compromises. For just a little bit more money you can get the level of finess that will be a forward rather than a lateral move and the amount of power needed to really to push the Thiels. The cash outlay isn't really that much more on the used market.
Tom, you are very intuitive. That was exactly my point. Mind you there are some very good deals on the used market. Your current budget may force compromises. For just a little bit more money you can get the level of finess that will be a forward rather than a lateral move and the amount of power needed to really to push the Thiels. The cash outlay isn't really that much more on the used market. There may be some other options as well.
One additional concern that I do have is that these amps will be going into an entertainment center, and even though I have customized it with some fairly nice (and pretty darn quiet) fans from Atlantic (with temperature activated variable speed control), I probably want to avoid the very hottest amps. Any thoughts on which amps run the hottest (or coolest) between Krell, McCormack, Theta, Pass, Classe' or Bryston? Those are probably my front runners.

Thanks again! You folks have been very helpful.

The longer the amps run in class A the more heat it is likely to generate. Mind you many believe that this extended level of class A is exactly what makes them sound better in the first place. Depending on the model, I suspect the Krell and Pass will run the hottest and IMHO will sound the best.
P.S. not all Pass amps are candidates for speakers that drop to 2.5 Ohms. Some of the older 2 stage Alephs don't take kindly to to that kind of load. There are others that just might sing though!
FYI, digital amps are very efficient and generate little or no heat. I'm thinking of the Rowland (no heat sinks even) and probably the Acoustic Arts, Spectron, and Bel Canto amps.
"FYI, digital amps are very efficient and generate little or no heat. I'm thinking of the Rowland (no heat sinks even) and probably the Acoustic Arts, Spectron, and Bel Canto amps."

How will these drive the difficult, low impedance, CS3.6's? I haven't heard much about any of these brands, although I have some experience with digital amps in the live/pro audio field.

forum member (muralman1) is using a digital amp to drive his 1ohm Apogee Scintilla's, he had Pass X600 mono's on them.

I think we have to be cautious about lumping components with similar technologies into overyly broad generalizations. Some typical ss amps do well with lower impedance loads, some rare tube ones can work well too and visa versa. I suspect different digital amps may follow suit. I'm very excited about the potential of these new digital amps, but, have very very little experience with them. I've only heard them at shows. One product in multiple situations which didn't impress me too much and another in one situation that really did impress me.
I have been digging a little deeper into information regarding my current amp candidates, and I discovered that the Theta Dreadnaught II (which can be a 2-10 channel amp) has an option which allows you to place it into 2-channel operation (regardless of how many modules you have) and to send all of its current to just the two channels. This seems like an incredibly smart solution to the whole "2-channel, critical listening" and simultaneous "home theater" system.

Any thoughts on how a Dreadnaught II in two channel mode (that would be 450w at 4 ohm) would drive my CS3.6's? This could be an interesting ticket.

Another attractive option are those Theta Enterprise monoblocks. Hubba hubba! Of course, I would still need a multiple channel Dreadnaught II or Intrepid to keep a consistent HT setup. And that price tag would not be cheap.

Thanks, Tom.
I have listed some of the options that I am considering in my other thread:

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

Any additional feedback from you folks is always appreciated!

Thanks, Tom.
One Call has a close-out on a big ATI 5 channel amp at $1,500. You could use it for all channels or as a bi-amp plus center channel for fronts and add a smaller two channel amp for rears.

Note: Must have 20A circut

I just have to throw in my pitch for the Parasound HCA-3500.

They are real inexpensive and have the guts to drive the CS3.6 and the CS7.

I have used mine with NHT 2.9's and 3.3's and CS3.5's and CS3.6's

I have tried a lot of more expensive units and feel I would have to spend several times the Parasound price for a subtle improvement even.

My friend bought one for his CS7's after trying mine and it does a decent job.
Hard to approach for the price and I saw a new one here today so it should even have a warranty.

My friend ended up with a Levinson ML-3 for his CS7's in the end there is no substitute for High Current Capability. Not as smooth as the Parasound or many higher priced amplifiers but very gutsy for the price.

Good Luck
Thanks for the nod to Parasound. In truth, I had been looking the Halo JC 1 monoblocks, as well. There have been some stunning reviews of these amps, but then again I have heard from several "real world" people that they are not up to the hype. That HCA-3500 certainly looks like it would have the brawn to handle my Thiels. How did the HCA-3500 and the 3.6's pair sonically? What are the sonic characteristics of the HCA-3500?

Thanks, Tom.
I can not speak directly to the new mono-blocks with the Thiels.
I have intalled a couple of them but they were more for show than for go,if you know what I mean.
I feel the other Halo product to be somewhat over hyped and I have not been too impressed with them.
The old standby HCA-2200 was a workhorse and had almost enough guts for the 3.6 but lost some control at high output levels.
The 3500 has been a big surprise to me in that it compares with amplifiers much more expensive without a lot of trade-offs.

The thing I like the most is the overall smoothness and number of things it just gets right. No real glaring defects that I experience and I have listened to it with several pairs of expensive speakers.

I am probably going to end up with something better eventually but have no complaints at all with the 3500 especially considering the price.
Like the Thiels the HCA3500 gives a great bargain for the money.

When my friend got his CS7's we tried both a 2200mkII and the 3500 and it was quite educational as to current demands of a truly difficult speaker to drive. Althought the 2200 never shut down or complained there was just not the sense of ease and breath that more current capability brings.
We listened to several amps,Krell,Levinson,ARC,Plinius,Classe and I remembered the old Levinson ML-3 from systems I had done a long time ago.
The ML-3 was one of the first really high-current designs and could deliver seemingly unlimited power when needed.
Another friend had one and we tried it and finally the cs7 had enough to really handle it.

Although the cs7's are in a large room and the ML-3 is not as refined as some of the other newer amps it handled the big Thiels in a way that could not be matched for the price.

We found another ML3 on Audiogon and that is what he uses still.

The Synergy between ALL of the components is what makes the difference between just good and great sound in my experience and as many have stated already the 3.6 will clearly demonstrate each change for better or worse.

I also have never been as aware of cable differences as with the Thiels and that is fairly hard to exhaustivly compare but worth the effort.

I would listen to as many amps that you can afford but let me know if the 3500 has any real competition at the pricepoint.

I would be surprised.

Good Luck
Thank you for the detailed response, Ed! I do appreciate your feedback. The HCA-3500 does appear to offer a lot for the money. Now, I just need to find one to audition. I have read elsewhere that the JC 1's are based to a certain extent on the HCA-3500 design, but with noticeable improvements. But reviews of the JC 1 are all over the map. Some claim it is the holy grail, and others call it woefully overrated. Again, without auditioning, I will never know for myself. I may have to keep my eyes out for an ML-3, too, from what you say.

I am hoping to audition a couple of amps on Thursday, including Theta Enterpises and McCormack DNA-225. Sure, that's a big price discrepency, but I am hoping to get a feel for the Theta sound and the McCormack sound. I may be able to hear a Classe CA-301, too.

I may be getting out of my "affordable" category, but it looks like I may get a chance to audition some amps from Sim Audio (but not the W-5, it looks like) and perhaps an EDGE NL-10, too. I've heard nothing but good things about EDGE, so I will be looking forward to hearing the NL-10 with my Thiels.

If you decide you can afford the NL-10 (used), then you should try to hear the Rowland 201's with your Thiels. Really.
Unfortunately, the closest Rowland amps that I can find are in Cincinnati. About 3.5-4 hours one way. Still, it might be in the cards. Certainly, I have heard good things about them. The dealer that has the NL-10, though, dropped Rowland in favor of EDGE.

I'll pipe in with some more arrogant, biased opinions. The Rowlands are similar to the Levinson gear. They both have a some what soft laid back presentation. A little too laid back for me with the Thiels. The Thiels while adequate are not the most dynamic speakers, (this may seem contradictory) yet with the wrong gear they can be a bit up front. Where I think the Rowlands surpass the Levinson stuff is in the rich, lush soundstage and harmonics that belies it's solid state technology. Not my personal first choice, but, I can ceratinly imagine it being someone elses. I might pick the Rowlands as my third choice. If you can find one at the right price it could be a worthwhile consideration. I don't think the intergrateds can handle the load, it might be safer to stick with the seperates. BTW, Rowland has great web site, with details about past products readibly avavilable.