Good upgrade amp for my Thiel 3.6s

My apologies if this has been pondered already. I did a quick search of the site for 3.6s and didn't find a similar thread.

I'm looking for opinions on what amp would seriously upgrade my sound from where it is currently. I have a KSA-150 driving the 3.6s.

I've heard people say that 3.6s can sound even better with more power and a dealer recommended 200W/channel as a minimum for them.

He was showing me the Classe Cam350s. Are monoblocks the way to go, or is there a killer stereo amp out there that's not in the price leagues of Boulder?

Obviously, I'm sure there's plenty of great choices, but I'd like to keep costs somewhat reasonable. I know the Classes retail for $7K for the pair. I was hoping to stay at $4K or under, but won't rule out the 350s if they really make a noticeable difference.

I had good success driving my 3.6s with Bryston 7B st monoblocks switched to "high current" mode. These are rated at 500 wpc into 8 ohms and 800 wpc into 4 ohms in normal "series mode," and 500 wpc into 2 ohms in high current "parallel mode." The 3.6s demand this high current capability as their impedance dips below 3 ohms at certain frequencies. The 7B st's have been rated A on Stereophile's recommended list. They're solidly built (20 year warranty) so they're probably pretty decent as a second hand purchase. You can get them below your $4k cap here on Audiogon.
I had always heard that Thiel and Levinson are a match. I had been running a Levinson 27 with my old Thiel CS3's. I recently picked up a pair of 3.6's and, with the 27 (100 watts), there seemed to be something lacking.
I just (literally yesterday) added a Levinson 333 (300 watts) to the 3.6's and it made a HUGE difference. With sensitivity at 83db, they need POWER!
Now, they are remarkably improved -- soundstage, detail, both in the highs and the bass, clarity, etc. If you don't mind buying used, like I did, the 333 is in your price range. You could probably even find one, like mine, still under warranty.
I had been looking for a 332 (200 watts) and had even asked Wes Phillips by e-mail what he thought would be the way to go, including some options for tube monos, like the VTL's. He thought the 332 with the Thiels would be, in his word, "super." I was lucky enough to find a 333 someone was selling, used, for the price of a used 332 and jumped on it. I called Madrigal, first, and they gave me the "in service" date for warranty purposes and checked to see if there was any history on it.
I highly recommend the Levinson, but, whichever way you go, definitely MORE POWER!
I would think that you'd want an amp that was not inherently bright sounding as the Thiel 3.6s can be very revealing. I can highly recommend the McCormack DNA2 or DLX or any of the SMc Revisions. The DNA2 puts out 300/600/1200 wpc into 8,4, and 2 Ohms, and these are probably conservative ratings. The DNA2 amps are "giant killers" well beyond their original $4300-5000. MSRPs. The DNA2s can be found used in the $2400.-$2800. range. I use a DNA2DX Rev. A with Vand. 5 speakers-- the 5s don't need all that power, but your 3.6s could use it.

BTW, McCormack Audio now has the DNA-500 out (that's 500 wpc 8 Ohms), but I've yet to see it advertised used. Peter Moncrief of IAR declared it "the best amplifier on the planet"-- $6700. new I think. Good Luck and Cheers. Craig
I think the perfect thing would be the brand new high power Musical Fidelity amp the 'A300cr' (don't confuse it withthe 'A300' integrated amp). This sells new for around $3400. THe whole A-cr series have been amazing, detailed but not overly bright. This on has all the design features of the NuVista amps, but with solid state noise-floor and convenience. I use the lower power A3cr and would definately switch if $$$ allowed. I believe you can try one at home with a 30-day return from any of the US MF dealers.
I own a pair of 3.6 Thiels. I use a Classe CA-301 to drive them effortlessly. The amp gives me plenty of slam and is very musical. I definitely recommend three hundred watts minimum no matter what you decide. Try NBS or MIT Reference cabling too.
I used to own a Thiel CS3.6 myself being driven by a Krell FPB200, that was a good match with NBS Monitor series cabling. The FPB series Krell amps in my opinion is a good match for the Thiels with the right cabling and room acoustics I have not heard any amp that comes even close.
I would have to give Plinius a vote hear. The SA-100MKIII would be an excellent choice. Pure class A up to 100 watts would make your speakers come alive. They look sweet too! I've used them with a set of 2.3's and it was nothing short of marvelous.
No doubt about it the Plinius SA 250 MkIII will grab ahold of the Thiels and make them perform.
the SA-250MKIII is just a great extension of the sound of the SA-100MKIII. you can't go wrong either way.
I drive my Thiel 3.6's with an Aragon 8008BB, through Analysis Plus Oval 9 cables. This amp has a robust power supply, so that it doubles the current when the load impedance is halved, i.e., 200 watts into 8 ohms, and 400 watts into 4 ohms. It doesn't sound thin or harsh -- I've been pleased with it. You can find it used for $1500 or less, which is a lot less than you'll pay for some of the other units mentioned. You may want to check it out.

Good luck!
Thanks to all the varying responses. I was wondering if anyone out there has a 3.6/Krell KSA-250 matchup. I was thinking that would be a good way to go.

To Jameswei and others:

Isn't 500wpc too much for the 3.6? I thought they were rated for between 100-400 watts. Are you risking damaging the speaker with that kind of power?

Also, I was reading my 3.6 manual this weekend. Sensitivity is rated at 86db in their manuals. Is it actually lower than that?

You're right about risking damage at 500 watts. Damage can occur at lower wattage, too. For example, the tweeter will fry if you put 400 watts into it. Also, if your amp power is relatively low and you turn up the volume until it clips, the clipped signal can damage your speakers fairly easily. I generally regard the manufacturer's upside wattage specification as a guideline not to turn the volume beyond a certain level. The 400 watt specification suggests to me that the speaker is relatively robust and can play fairly loud. I believe the speaker can withstand substantially higher power peaks for very brief periods using musical material.

The low end specification of 100 watts suggests that the speaker is relatively inefficient, which the 86 db sensitivity rating implies also. Of course, you can get decent volume out of the speaker using only a few watts, but you need more to reproduce peaks at realistic concert hall levels. I don't know if the 86 db rating is on target or too high. I would rely on Thiel's honesty in ratings and engineering capability for properly identifying the speaker's sensitivity. Naturally, the loudness we perceive will be dependant on our room acoustics, which could easily cause as much as several db of difference.

I never had any trouble driving my 3.6's with the 7B st's. I never damaged any of my drivers. (I did once overtighten the speaker's cable binding posts, to my huge embarrassment.) However, I rarely turned the volume way up. Mostly, I listened to small acoustic jazz groups at live volume levels. I think the 7B st's are a good match for the 3.6's for their high current and high power capabilities, as well as good sound and reasonable cost.
Justin, what is it about the sound you're getting that you don't like? I can't imagine a KSA-150 not being able to drive the Thiel's adequately, IMO; so I'm not convinced more power is what you need. The particular sound you're getting is another matter. In what areas is the sound lacking? Is it too bright? too sterile? not warm enough? not fast enough? too fast? do you want a bigger soundstage? would you maybe like more dimensionality of images (200+ VTL watts). It's not always clear what "better" is. I look forward to your response.
Frogman makes a good point but in general, a bit more power might give you better defined bass and that over all effortless feeling like the amp isn't constrained at all. This was very noticeable for me when I went from my Classe CA-100 to the CA-200 amp driving the smaller Thiel CS 1.5's. For the Thiel 3.6's I would lean toward an amp that can produce at least 200w/channel but preferably 300w/ch or so into 8-ohms. Used Classe CA-200's can be had for around $1400 and CA-300's for around $2000. I just sold a pristine near-mint condition CA-300 a month ago. Good luck!
My Thiel CS 3.6's have been driven by the KSA-150 which was not bad at all! Then I bought a KSA-250 and it got even better. After talking to the guys at Krell they recommended finding a second KSA-250 and sending them up for conversion to the MDA-500 mono blocks. I'm done! I could not want any better sound from the 3.6's being driven by the MDA-500's. These are incredibly hard to find but you can get the same performance from the MDA-300's for the price you are looking at. The MDA-300's are KSA-150's converted over to Mono Differential Amps. If you already have the 150 then a second 150 would cost you less than 2000.00 *There is also a pair of MDA-300's for sale here from a gentleman in NY which would mean instant gratification without waiting for your amps to come back from Krell. My cables of choice for this system are the MIT balanced inter-connects and MH-750+ series II speaker cables.

The 3.6's can handle large amounts of power and the more clean power you have the less likely you are to damage them. The KSA-250 will sound better than the KSA-150 does. Not by a lot but it does!
Hi Frogman,

I was following some posts that I'd seen here and elsewhere from other 3.6s owners that said that 3.6s like as much power as they can get. The general concensus was that the soundstage opens up more. The imaging improves. The overall sonic capabilities of 3.6s improve with increased power. One poster I recalled saying that "you need at least a 250wpc amp to really make them shine." Though it's not really clear what that means.

I wouldn't say I'm unhappy with the sound of the Krell. I like the soundstage and bass response I get from it. I'd hate to give that up. But I don't have a lot of experience with the sonic characteristics of other amps out there. I'm new to the high-end market, having bought a good system within the last couple of years. Prior to this I was listening to CDs through a Toshiba DVD player into Technics speakers.

Since then, I've upgraded to:

Linn Ikemi CD player
Adcom GFP-750 preamp
Krell KSA-150 amp
Thiel 3.6 speakers

interconnects are another story. Haven't done much with those.

I was just starting to do some research on it. I wanted to get opinions from others who have owned the 3.6s longer and tried them with different amps. I didn't audition that many amps before going with the Krell. I bought it used about 2 years ago. I like its sonic characteristics, it fit my budget, and I went with the dealer's recommendation on it (over new choices like a McIntosh and Bryston 4B). At the time, I listened to a pair of Pass Labs Aleph 100 watt monoblocks, which I liked a lot. I liked the detail they produced but they were more than I could afford.

The Krell literature I have says that the KSA-150s are conservatively rated at 150wpc, and are more likely 250wpc. I listened to a newer Krell series in a store the other night, the KAV2550 I think. I didn't like it. Sounded thin and I thought the presentation was too bright.

I was getting the impression from just a quick look in local shops that to increase performance/power over my amp would be a huge cost. One store tried to "entice" me into buying a Krell FPB300 for $7500!

But maybe there's a used amp out there that might make a difference.
To Bryhifi:

I did look into bridging the KSA-150s to mono and had a chance to pick up a second KSA-150. I thought Krell didn't do it anymore. I spoke with a rep. there and he said they didn't offer that service on older amps like that.

Was I mislead?

I had my amps done just about 2 years ago. As far as being misled, I'm not sure? Like I mentioned mine were done a little while ago (6/00). They may have run out of the parts needed to convert like the new face plates and rear panels. Sorry about that, I didn't know they had stopped. You did see the MDA-300's here for sale by "Fsdizon".

Classe amps seem to be popular with the Thiels but my experience with a CA-200 was not as good as the Krell KSA-150. The CA-200 performed quite well but gave up a little too much resolution around the instruments and also lacked the spatial, pinpointed soundstage that the Krell offered. The Krells seemed to remove the boundries of the walls and opened up several more feet to the outside of the speakers.

If you really like the resolution of the KSA-150 then I'd suggest trying their older mono blocks but make sure you are willing to run dedicated 20 amp service outlets for these amps or they will not rise to their full potential. They are powerful amps but need "homeruns" to the breaker box to supply pure power and not degrade the supply to the front end components. This alone made a huge difference in my KSA-150's performance and would not have even thought about trying the MDA-500's to regular circuit outlets. This would stand true for any mono block setup of real substance!!

Justin, what preamp are you using? If I missed it above, sorry. A really good preamp really shines through the Thiels. I'm driving my 3.6's with classe ca200 and cj premier 14 with Mullard tubes - more than enough power. Great soundstage, awesome midrange,good extension on the bottom, the only thing that might be missing with Classe ca series is ultimate extension and energy on the very top. I think you get that with the cam's and 01 series starting with 301... good luck.
To Pops:

I'm using the Adcom GFP-750 preamp.
Justin, a new thread has been started by David99 that you might find interesting: "NAD takes on the Krell beast.." And thanks for elaborating in response to my question. All the best.
I have the Thiels 3.6 in my system for over 4 years now. Prior to that, I had the 2.2s for 5 years. I've had the Krell KST-100, Pass Aleph Os, and now the Levinson #333 mated with the 3.6s. The Thiels are very revealing speakers. What makes or breaks them is often the components in your system. I had the Krell connected to the 3.6s for a week, and took it aside right away. It sounded cold, bright and a bit harsh in my setup. The Pass was only 60 watts and it can actually drive the 3.6s in low volumes quite well. Of all three amps, this one sounded the sweetest, and musical. (Prior to the arrival of the Levinson, this amp stayed in my reference system for a while. It then got moved to the bedroom) The Levinson sounds very refined, detailed, and excellent soundstage width and depth, good control of bass, and instrument placement. This amp is a bit lay back. So you don't get the music "in your face". So if you like to sit in the first three rows in a concert. This is not the amp. But if you typically sit in the center of a theater, the Levinson would be a good choice. Cable is important. I use MIT balanced interconnects throughout my system, and Transparent Ultra speaker cable. I heard a lot of recommendation on the MITs. I had tried the MH-770s, and the sound is a tad darker than using the Transparent.

I bought mine used and the guy threw in the Sound Anchor stand for the Thiels. I think the Sound Anchors works great at controlling the bass!

Michell Orbe SE + SME V + Benz M2 Turntable
Levinson #37 Transport
Genesis Digital Lens
Sonic Frontier SFD 2 Mk II D/A
ARC PH3 SE phonostage
ARC LS2B Mk II preamp
Levinson #333
Thiel 3.6
PS Audio PS300, Electraglide Referenceglide PCs, Marigo Reference PC.

My room is about 18' x 21'. Good luck!
Anyone have success with Threshold and Thiels? I see one guy on Audiogon is selling a Threshold T-200 that he matched with Thiel 3.5.

To Gundam91, Levinson sounds like a nice choice, but pricey.
I would go with Classe or McIntosh. I have listened to a Classe 400 on CS2.2s extensively and I loved it - very impressive. The owner of the 2.2s now uses a MC352 and I find it is at least as good as the Classe. I had a KSA-150 driving my Paradigm Reference 100s and (happily) got rid of it for a McIntosh too.
this is sort of ancient history, but i believe when thiel was making the 3.5 they voiced it with threshold. i used a threshold sa50 class a amp - it was the only amp i found which could give me a balanced sound. i do not know what amp thiel used to voice the 3.6 but if you could find out that would be a wonderful starting place.
Any opinions on sticking with Class A solid-state circuitry vs. tubes with the 3.6s? There's a dealer near me who's selling a pair of Audio Research M300 monoblocks 300wpc.

I like what I've heard about Threshold. There's a recording engineer I was talking to who has the Threshold S1000 monoblocks in his studio. He loves them. Now if I could only find them somewhere.

Any stores that sell a lot of used gear that anyone can recommend? Preferably not too far from Mass.?
justin, either amp would power your thiels to your hearts content. you will have the classic ss/tubes question to resolve however. you will give up some of the airiness of tubes with the threshold - you will also give up the not inconsiderable expence of maintenance of the m300. if you already have a tube front end i'd go with the m300. if you have solid state i'd stick with the threshold.
Thanks for your advice Newbee. I do have a solid-state preamp. The Adcom GFP-750.

Just had a dealer recommend the Conrad-Johnson MF2500 to me. Actually I was calling him based on an earlier recommendation for the Plinius. He told me was phasing out the Plinius line as they're not selling that well. The CJ sounds like a good deal. $3500 list and I've seen it selling here for around $2K. Doesn't appear to have balanced inputs though. He also recommended the Krell KAV-2250. I heard the Krell before and wasn't impressed. I'd rather keep my KSA-150 than buy the newer one.

Some quick reviews I saw of the 2500 were all favorable, some even saying it beats the Levinson No. 335.
personally, i wouldn't buy any of the solid state amps except the threshold without listening first (because i'm familiar with it), and i would certainly want to hear the plinius - from what i have read and been told your can get a 250IV in your price range used. it clearly has the current and power you want. sonically i suspect it will warm up the tone of your speaker/pre-amp combo somewhat if thats of interest to you
When originally auditioning Thiel 2.3's w/a krell 500 watt integrated- sounded ok. Then I tried Pass Labs x-150 -WOW is all I can say - match made in heaven. I now own Pass Labs x-250 x-1.

Must audition
Best of luck