Intregrated Amp for Thiel 2.4 s

I am getting a pair of Thiel 2.4s in a 15ft x 20 ft room. Any recommendations from owners? Thiel are rated 4 Ohms (minimim 3 ohms). Budget is flexible $1500-$4500. I like to spend less. I have a Rogue 90 amp, is it enough for CS2.4?

Krell 400xi (a little concern with JA's test in stereophile)

Bat 300xse
Musical fidelity A5, trivista or KW500
Unico SE (140W)
Pathos logos

I don't like ML 383 and Rowland concerto.

Classical, Chamber, Jazz, no rock.

Any input is appreciated. Thanks.
First suggestion is don't do it... Too many people have tried to power thiels with an economy mix of electronics and regretted it. Pick up a very good used power amp for at least $2-3k used. I personally prefer the Sim Audio Moon W5 for this. If you are able, run the source direct into the power amp initially. Add a tube linestage down the road.

The 3 essential criteria for any amp powering thiels are power, current, damping factor. You want about 200 wpc into 8 ohms. Something that doubles the power as the resistance halves. Very high damping factor, don't go less than 400. Damping factor advertised by the manufacturer is computed with 8 ohm load. The W5 damping factor is 800 but my thiels drop to 2 ohms so at that point the damping factor is only 200.
I just auditioned the Thiel 2.4's with the Musical Fidelity KW500 yesterday in Illinios. I actually went to audition the conrad-johnson Premier 17LS2. I spent four hours listening to the c-j with Vienna Acoustics speakers. Then the Musical Fidelity KW500 (I have MF equipment myself) with the Vienna Acoustics speakers.

The salesman then brought in the Thiel 2.4's and set them up with the KW500. It was unbelievable! He told me that my MF A308cr Power Amp at 250 wpc in 8 ohms/450 wpc into 4 ohms would work fine too. I'm looking into selling my B&W Silver Signature's and getting the 2.4's too now.

You can check my system out here, and also see that I used to own the Krell KRC-3 and KSA-50S combo and replaced it with the Musical Fidelity A308cr pre-amp and amp combo.

Jazzdude is correct. I tried a VK-300x on my 2.4's and it just didn't work for me. They need some power. I'm using a GamuT D200 and the sound is significantly better with more authority. I'd say the W-5 would be a good choice also.
Thank you for your advices, guys. Jassdude, would you please explain more on damping factor and interaction with speakers. I have taken some EE in college but I love to learn more. Vgrubb, sorry for late feedback. Krellman, how do the 308 separates compare to trivista and kw500.?
I thought damping factor is increased by having negative feedback, which is view by some to have bad sonic implications. Increased damping factor means the fluctuation in speaker impedance would introduce less variation in the amp's performance. Therefore, sonic gain in lowfeedback amp needs to be weighted against the stability of output into varying impedance.

Please correct me if i am wrong. I cannot be offended.

I don't know how the A308cr pre-amp and amp compare to the Tri-Vista or KW500 integrated's.

I'm sure a MF dealer or the US distributer, Signal Path, '', could give you an honest evaluation. They've always emailed me right back on any questions I've had.

Before they were discontinued (just recently) their price was $2800.00 for the pre-amp and $4000.00 for the amp. They were made in England and have the Choke-Regulated power supplies. From what I understand, they are heads and tails above the A3.2 cr pre-amp and amp.

To give you an idea of how good the amp is supposed to be, I called Sound By Singer to see about trading in the amp for a conrad-johnson Premier 350, $8,000.00, and the salesman told me to keep the amp, that I didn't know how good it was. If the salesman gave up the commission on an $8000.00 purchase in telling me that, what do you think?

There are reviews on the internet that rave about it. It's supposed to one of the most neutral amps on the market. Like I said, after hearing them while waiting for my Tri-Vista 21 DAC to arrive, I traded my Krell pre-amp and amp in the next week on them.

Check out the new Blue Circle integrated. 110wpc solid state, very tube-like in sound. Would be a great match with Thiels. Heard it at HE2005 and thought it was one of the best sounds in show (paired with Focus Audio FS78 speakers)
Glai - damping factor is determined by dividing the load resistance by the output resistance of the amp. The W5's output resistance is 0.01 ohms at the low end but increases slightly in the upper frequencies. The W5 has zero global negative feedback. The tonal balance is neutral. The control is visceral but it also has a touch of sweetness which allows it to convey delicate passages with the proper neuance. The gain is 33db which means it can be used without a preamp providing you have some means of volume control in the source. But IMO it sounds its best with a tube linestage.

There is no perfect or best amp. Power amps should always be considered based upon the speaker they will be driving. For speakers like thiels the w5 deserves very serious consideration.

There is another audiogon member, bunkeromantik who has thiel cs2.3 and purchased the w5 based partly on my recommendation. You might contact him or maybe he'll see this thread and chime in.
Hi Jazzdude. Sure I see this thread. And I bought W5 thanks to you. It is a one heck of an amplifier. Tells my Thiels what to do in a way no other amp I tried did.

I wouldn't recomend any integrated to drive Thiels. I tried this with MAc 6900 and was totally unimpressed. I also had MF A308 integrated and that was even worse.

Seems like you can't avoid muscle poweramp to have your Thiels sound right.
I decided I had to have the Thiels 2.4 after I heard them on the MF KW500. I don't have enought experience to tell you what is better that what other than to say I gained new respect for the 2.4 when I heard them thru that amp. The B&W equipment in the room at 2x the price was still not matching the 2.4 which will be bested by the new 3.6 replacement design early '06.

The KW500 simply has the fine details in the uppers and resonances and balance the Thiels will give you for the music you've listed above. My custom amp has the power to run the 2.4s all day, but not the details. It's better than the intergrated Mackies they had... KW500 all the way IMHO.

Give us an update as I see it's been a while since this thread was started.

I've been accused of coming into the store just to hear my music on that amp as I'm scrounging the money for the kW500 in such a way the wife won't complain. The accusations are correct and the thiels are still waiting for there master (amp) at home.
Have sinced owned many amps on Thiels 2.4 at home. Pass x250.5, Classe 2200, Rogue 90, Belcanto evo4, KW500. They all have plus & minuses. best synergy probably x250.5 but not an integrated. KW 500 is very satifying too. Strongest bass. Rogue 90 is a good amp & does an okay job.
Thanks Glai.
2.3 Owner here.KST 100wpc Krell working really well with melos tube pre.
Listen to a Blue Circle NSCS.
I have also found the GamuT D200 Mk III to be a great amp. As a 20-year tube system person, the Gamut D200 is the only SS amp I have tried over the years that maintains a similar sense of harmonic completeness with no typical SS down sides. (Tried BAT VK-500, Plinius SA102, Goldmund M28, 47 Labs Gaincard-S, Sunfire stereo amp.)

Tonal balance is neutral with no glare, no listener fatigue, good dynamics, good bass extension and punch, etc. (Speaker = Coincident Super Eclipse III.) I would not be surprized if the D200 mated well with the Thiel 2.4, but give it a try first, of course.
I use a Gamut D200 Mk2, and it drove my Thiel 2.3'svery nicely before I got my current speakers, the Vr4jr's.
Iagree with Kalan, a very smooth amp with low fatigue factor. Seem to be available used a fair bit, too....on Agon
I once hear a pair of Thiel 2.4 driven by Audio Research tube preamp, Audio research SS amp using Acoustic Zen cables and the whole combo sounded fantastic. Probably one of the best soundstage I've ever heard. Can't recall the model's name though.
Try the McIntosh MA6900. I think the list price is now near $5,000, but there are usually a couple of used ones available on Audiogon. McIntosh amplifiers lean toward a warm full sound, which to my ears works very well with Thiel speakers.
I agree the MA6900 would be an excellent match for your speakers. The A5 would be good too IMO.
Well after the fact...

Hooked up my Musical Fidelity A5 integrated to my Thiel CS6s for fun and was impressed at how well they drove these speakers. Not quite as full and dynamic as my Krell 400cx but at reasonable levels, nearly as so. And the MF retained low level detail retrieval and was nicely extended into the bass. Again at around 80 dB levels from a nominal 12 ft listening position. Not too shabby and these can be purchased for around $1600 on the used market. I imagine this amp would work at least as well with the 2.4s (I'm looking for a pair hint hint!).
Anyone using an integrated amp on their Thiel speakers now?