Tube Amplifier for Thiel

I recently pick up a pair of Thiel CS3.6. As like many reviews online said, they are awesome speakers. I am using Musical Fidelity A5 int amp (200wpc @4 Ohms, 400wpc @8 Ohms) to drive them. I can't say the A5 is not good, but I kind of feel it not quite musical, crispy, fast... These seem to be the strengths I found in most tube amplifiers I have auditioned before. I am thinking of replacing the A5 with a tube int amp; however, I worry that normal tube int amps are not "powerful" enough to drive the big Thiel (I am a bass lover).

I currently have Prima Luna Dialogue 2, Cayin A-100T/A-70T (and probably VTL IT-85) on my list. I would appreciate if some one could comment on these choices. I also welcome any other tube/SS int amp suggestions (even tube pre/SS power amp) in that price range.

Thank you!
I owned those speakers and you need Power to get them to sound their best. I used a conrad johnson premier 350 ss amp and it did a good job. I started out with a conrad johnson 70 wpc tubed premier 11a. And while it did an excellent job with the mid to high frequencies it simply could not drive the woffers and produce any bass. I would look to a Pass x350.5 ss amp as a minimum to drive those speakers. You will never drive those speakers with a 100wpc tubed Integrated and have them sound their best. Those Thiels in general while not necessarily a difficult load they are a demanding load. Good Luck.
I might ad that the problem with these speakers is that you can buy them for the price of a used chevy but you need ferrari electronics to drive them to sound their best.
I agree with Czbbcl.
Biggest, beefiest Audio Research amp you can afford. Rogue would be an alternative and might come in for less.
They do benefit from an amp that can swing the current down toward the 2 Ohm load range without a hiccup. My choice for CS6's, which are similar in load characterstics to the 3.6s, is to go with a stout FPB series Krell amp. Manley Neo 500s would also work if tubes are what you insist on for these.
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To my recollection, the solid state amps that have a reputation for sounding like tubes have been made by Pass and Carver. I'm sure there must be others too.

The Pass Aleph series was distinguished in this regard, although the most powerful one was the Aleph 1.2, which was rated at 200 watts, perhaps not enough for you. You might try out a used one, and it would be approximately the same vintage as the Thiel 3.6.

Carver made higher power solid state amps (like the M1.5t, M500t, etc), many of them deliberately designed to sound like specific tube amps of the time. These used amps are getting long in the tooth, although there are refurbishment/upgrade shops to keep them good. I am currently getting pretty good sound out of a Carver M500t driving Thiel 3.6s.
Thank you all for the advice and comments. I believe I could basically rule out tube integrated amps in the equation for Thiel CS3.6.

Unfortunately, most of the great SS power amp's mentioned here are little too expensive for my pocket. I wonder if any "more affordable" tube or SS monoblocks may drive the big Thiel nicely.
My local Thiel dealer just began carrying the 300W Bob Carver tube power amps and they sound sublime.
I wonder if any "more affordable" tube or SS monoblocks may drive the big Thiel nicely.
Have you considered the Odyssey products? Their monos sounded very nice to me (driving other speakers). Carver mentioned above is another choice. Both are SS, neither is very expensive...
A friend of mine had the 3.6 and we tried a number of amps of all sorts on them (Mark Lev, Krell, you name it). The best sound we got, which was a completely different sound, was with a pair of Symphonic Line shiny mono blocks. It was an unusual sound, very ethereal, lots of high frequency detail and great coherence and, unusually for such a small-medium speaker, very good presentation of a fully blown orchestra. It was surprisingly dynamic as well! Good speaker indeed. (OK, it is actually limited at frequency extremes, but it is not annoying.)
There was a cj MF2500 (250wpc) on this site for sale a week
or so ago for like 1200.00; no affiliation I used one of
these as well to drive the 3.6's and it did a pretty good
job. You could pick up a used cj tubed pre and get some good

What is your budget?
I want to limit my spending on this between $2k to $2.5k.
+2 on CJ 2500. This is a good match for your Thiel 3.6. I used to own this combo. Love them.
Maybe look for some older Classe amps like CA-300/-400?

I had driven mine with a Levinson #333 for a long time, until I blew the caps for the second time. I traded the amp in for a Pass X350.5, and the sound was amazingly good. I was about to change speakers at the time, but it got me to reconsider hard. I eventually sold the speakers because I wanted try something different.

Unjc, how big is your room? Is it lively or more dead? That will say a lot about what you can get away with.
Conrad Johnson is a great match. These speakers need POWER!

Happy Listening!
I had Thiel 3.6 speakers for a number of years and used them mostly with a Classe CA-300. I found the combination generally unsatisfying and kept wanting to try tubes with the Thiels. I managed to audition some custom PP 300B monoblocks that sounded really good. In retrospect, I should have bought them when I had the chance but at the time I focused on how they didn't have quite enough power or bass control. A few years later I bought an old Dyna ST70 on a lark and, lo and behold, I preferred its sound on the Thiels to the Classe. The Dyna was again limited in maximum loudness and bass control, but the sound in all other respects was much more "real." That experience convinced me that tubes were the way to go. I ended up selling the Thiels and getting more tube-friendly speakers. However, for a happy owner of Thiels, I would say this---try a push-pull EL34 amp like a ST70 and see what you think. It will hardly cost you anything and you may just find that it really delivers what you're looking for.
Thanks for the comments. My room is about 12'W x 15'D.

I also enjoy listening to tube sound. Does anyone find using tube pre-amp would help introduce the tube "sweetness" into the system, even through SS power amp?

Salectric, I am curious to know what pre amp you used when you still had Thiel CS3.6.

I read this online "If the amp clip, the AC current become DC current and the voice coil of the speakers burn out super fast with DC". Does it not even worth to try some less-powerful power amplifier (like many tube ones) on Thiel CS3.6? Please advise.
Using a tube preamp with ss power amps does give you some sense of "tube sound" but the amps are even more important in that respect. Most of the time I had the Classe amp, I used an ARC LS-2. Probably not the best match but that's what it was.
That room might be a little tight for the 3.6's. Long wall placement might be worth considering, do use some absorptive treatment behind the listening position if you do.
The bad news is that the 3.6's impedance level is below 3 Ohms most of the time. The good news is that the phase angle isn't too harsh. Still, not a typically a good load for most tube amps, or even many ss amps for that matter. This speaker demands an amp with real grunt, and don't skimp on the power. Such amps exist, even within your budget, but if you intend on using a tube pre, then you have to consider the input impedance and voltage sensitivity for full output of the amp. Many tube pres have a rather high output impedance for the typically low input impedance of most ss amps, and many tube pres have a rather high output voltage for the high sensitivity of many ss amps, rendering the volume control of such a pre with limited range. It can be done, and done well, but one needs to take in all of the above considerations, not to mention how it all actually sounds too boot.
Finding a suitable tube amp for these speakers becomes costly. So costly that one should seriously consider if the money spent would reap better sound with higher level Thiels and ss amps.
Conrad Johnson.
I have used Thiel speakers for many years, in many different systems. They need power, but much more importantly, the need solid state or high powered tube amplifiers that can provide substantial amounts of CURRENT into low impedance loads.
Three good choices that are generally in your budget are the MCCormack DNA amplifiers (like the DNA one), Classe amps from a few years ago, and the previously stated Conrad Johnson solid state amps like the MF 2500.
There are a number of others as well.
I'd use a warm sounding tube preamp that has good impedance match with the amp. Select the Amp first, then the preamp. The Theil 3.6 is capable of beautiful music if fed properly.
Try BEL 1001 monos, in your price range, tubelike w/bass,been have used them to drive Thiels, Apogees, Maggies, and currently Wilsons. Saw a pr. on Canuck Audio.
I owned the 3.6 many years ago. They need "current". I tried Krell KSA 100, Classe CA-150, and VTL 225 monoblocks with the 3.6. They were fine. However VTL 225 could not control the bass as good as the other two SS amps. A good case in point is when I recently auditioned a 180 wpc high quality tube mono amps with the Revel Salon 2, the bass was not there. It is the current that counts.

When I got the Brown Electronic Lab (BEL) MKIII monoblocks, the sound of the 3.6 became spectacular. I used tube pre to introduce some tube characters into the sound though. I was using CAT SL-1 Signature. Unfortunately, BEL is not around anymore. You can only buy used and they are very rare.

I recommend good SS amps (at least 100wpc but 200wpc or more is better) that can dive deep to 2 ohm with the 3.6 and also a good tube preamp. If you really want to use tube amp, I suggest you try it home to make sure it can work with the Thiel. For SS amp, I think the Parasound JC-1 monos could be a good candidate.
Buy the first pair of used Bob Carver VTA180s you see. Retail prices vary.

They run cool, hand made point to point in the U.S. have a 2 ohm tap and a seven year transferable warrantee.

They drive my Avalon Eidolons effortlessly.
Ahhh. Played my 3.6s at volume today.

Clean, loud, lithe, liquid, beautiful music. (Like a beautiful gymnast.) And lush, too.

Gobs of power from my Carver. Made me feel refreshed from listening, but also just knowing that there's acres of headroom was boffo all by itself.

No strain whatsoever.

The M500t is rated at 370w/ch and 470w/ch dynamic for 8 ohms and 4 ohms respectively. (If you choose to have Rich Pecoro do his Mark 2 upgrade, these numbers become 520 and 920, with 1214 at 2 ohms, where the 3.6s live. --Not affil., just sayin'.)

The M500t was voiced to sound tube-like and has been described as the most musical of Carver's M amps and one of Bob's favorites.
Tube pre-amp + SS amp is the combo I decide to go after. For power amp, I hope to find a Krell or Bryston monos or CJ within my budget.

Good Decision IMO as those speakers love power and can sound very good when feed properly. Good Luck and keep us informed with what you end up with ..

SS amp is best way for Thiel I believe. Tube pre-amp should have good musical synergy. Lots of good choices there. ARC is one of the safest and best for a newbie. That's the way I went a few years back and have not regretted. Just be aware that tubes require periodic maintenance, though for a tube pre-amp, nothing more than periodic tube replacement when a tube goes or becomes too noisy should be needed. That has been my experience with ARC sp-16 now for the last 3-4 years.
I've owned various Thiel speakers for over 20 years. Currently I'm driving my 3.6s with a Naim 300 amp and this, along with a Naim preamp, really drives these speakers properly, with loads of control, dynamics and proper timing. But no -- they're not tubes -- and upper-level Naim gear is expensive.

Previously I drove the 3.6s with Bryston 7B STs; the Bryston amps drove the Thiels well, but the Naim really brought a new level of timing, detail and control. However, Naim electronics don't have the depth of some other stuff, so if you value depth over timing and pace, then Naim may not be the way to go for you.

Good luck.
Last night, I come across this article written by Marc Mickelson from SoundStage.

"I've used my Thiels with a variety of tube amps, including a conrad-johnson Premier 11A (70 watts, ultra fidele), a pair of Lumley monoblocks (ssssmoooth) and a Mesa Baron..."

I just wonder if anyone have tried any of the tube amps Marc mentioned. It seems that tube amps with >70W output could possibly drive CS3.6 pretty well.

I also read some forums saying that class A amp with large damping factor would probably do the work too. Could someone please explain the theory behind this? Greatly appreciate it.
You'll get sounds out of them, but not the full potential. Spend your money wisely, and get the appropriate amplification for the speakers.
I had those speakers too and loved them. Audio Research Classic 120 was good, Vt100iii no good! Vt200+ may be good! Under power tube amps will made poor bass. CJ Premier 350 very good and musical for SS.
I think audiovalve challanger 180 monoblocks would do a fine job with the thiel's;180 watts class A using KT-88's.
I run these on my soundlab m2's and they perform as well as my roland model 6 monoblocks.German made very high quality,great looks and perform extremely well;if you can find a pair they are worth considering.
What do you think of BAT VK-500? It sounds like a power horse with lots of power. What do you think a good matching tube pre-amp for it? The problem is that my CDP doesn't have balanced output; so I need to find a pre-amp, best under $1500, that has both XLR and RCA. Any recommendation? Thanks!!
As others have noted, you need current with the Thiels. Medium sized SS or tube amps are not going to cut it.

There are 3 options;

1. buy the big CJ or VTL tube amps, but that will run you some coin.
2. buy a big SS amp, not as good as the tubes, but wont cost as much.
3. Buy a small tube amp you like that has the sonic characteristics, and feed its output into a pair of the Musical Fidelity Super Charger amps.
CJ PV-12 + CJ EV2000 + CS3.6

I would offer 1600 on that CJ Evolution 2000 listing which expires April 13th.

I 2nd Jafant's recommendation for CJ.

I 2nd Usound's suggestion of using the long wall and the importance placed on a low impedance capable amp.

I 2nd Jdolgin's recommendation for pairing the 3.6s with a warm sounding preamp. 3.6s are bright and the PV-12 mitigates that. And use RCA Cleartops.

I 2nd Salectric statement about tubes having a bigger effect in the amp section than the preamp section. Unfortunately such an amp is prohibitively expensive for speakers as hungry as yours.

You are on the right track with tube-pre and ss-amp. The EV2000 is really a SS beast with some tube accoutrements. It's rated at 200wpc and idles at 210w (measured with a kilowatt). If you are drawing 300w at the wall than you are already above most people's comfort zone. If the music has heavy bass, the same volume will draw between 400w and 450w. The most I've pulled from the EV2000 was between 600w and 700w. You will have tinnitus before this amps fails.

I think you (like I) place high value on bass energy so the tube integrated amp is not really a candidate. For fun I tried my friend's 60wpc LA Audio amp and it bested my EV2000 in many ways, though it did not deliver the high energy nor the depth I get from the EV2000. When pushed the LA Audio's bass rolled off gracefully and it's treble clipped ungracefully. I would bet for many audiophiles the 60wpc tube amp would remain a fine match for the CS3.6s, so long as they stick to their vocals, classical, and jazz. Those listeners would actually be fine with expensive bookshelf speakers like Harbeth or B&W.
I run a Manley Steelhead ( with Skipjack for multiple line level inputs) into NEO 250s for my CS6s and they are as dynamic and extended as when I powered them with a Krell KCT pre and a 400cx amp. The imaging is far better though with the tubes.

Thanks! for reviving this thread- stevecham

it would be interesting to learn if the members above are still listening to

Thiel speakers. Happy Listening!

I have Thiel CS6's.  I don't use them often, preferring B&W 801S3 but when the 6's are used they are with VTL 450 MKII amps.  Like Stevecham I was using Krell then switched to tubes.  Big changes, the bass became less pronounced, still very good just not that Krell Slam and the mid and high frequencies warmed up nicely.
Those VTL amps look very sweet- vegasears
Are you still using an Esoteric DV-50 spinner?
Happy Listening!
Yes from time to time I'll play SACD or DVD-A disc.  Since adding a video monitor to my system I've been using it for DVD Concerts and loving it.  
Nice! vegasears
Happy Listening!
I have had multiple pairs of Thiels including 2 pairs of CS5i's.
I have had a wealth of experience modding the Thiel and have found that the issue / reason that everyone wants a tube amp is the hardness that they exhibit.  Knowing that the drivers in these are used by many other manufacturers without the hardness I decided to figure it out when I got my second set of CS5i's. Well it is NOT the drivers!
It is the styrene caps that they used everywhere. Styrene has good dielectric properties however they can sound hard and close to half of the 84 of the 1uf styrene's caps in the 5i's were loosely wound and spongy soft.  Replacing then with the right flavor modern caps will transform ANY Thiel that is using the 1uf styrene caps that they used everywhere. I have my secret formula that several people are now using with raving results. I wound up buying hundreds of these so I could affordably recap all 4 of my 5i's and have a lot left.

PM me and i will give you a set and you can keep your SS amps. You can have your cake and eat it too. 

On the thread subject there are only a few tube amps that will make the Thiels sing. I have a rare pair of MB Tube amps with 1 ohm taps that are incredible. I also have had the CAT JL2  monster and that does it as well.

I owned Thiel 3.6 and the more power (current) the better they sounded because they are mostly 2ohms for most of the audio band and only 85db efficient . Look for a quality solid state amp as Thiel states of 100-500w and I would also look for quality amps that use bi-polar output devices, as these deliver current better than Mosfets can.

From Stereophile bench measurments:
" The low impedance value explains the CS3.6's need for the iron-fisted Mark Levinson No.23.5 to provide control in the bass; the CS3.6 would appear to be current-hungry."

Cheers George 

Thanks! for sharing- George
compared to the 3.6, the newer models benefit from high current power amps as well.
Happy Listening!
PM sent.
Even if Thiel 3.6 not at all designed for tubes tubes are still desirable toys ant they?! 
Hey now…that's a 4 year thread jump! Is that even legal?