Help choosing an amp for Thiel 2.7s


I just upgraded from Thiel 2.2s to Thiel 2.7s and my source is both vinyl (VPI Scout) and digital (PeachTree Idac) through a Classe Model 6 Preamp and B&K EX 442 AMP – both recently recapped. I am looking to replace either the amp or both amp and pre-amp. My first trial was with a pair of Bel Canto REF500M. In many ways they sound amazing – tighter bass, more extended highs, much blacker background. My only hang-up is that they seem to lack some of the body (midrange presence) of the B&K. As an example when playing Stevie Ray Vaughn my daughter asked why the guitar had moved so far to the background. Is there any way to have my cake and eat it too – or are these necessary trade-offs at my budget -- $5000 for the amp?

Any advice would be very appreciated
kadlec
If you aren't dead set against tubes, a tube power amp can mate well with Thiels. Midrange presence with a slightly forward sound is fairly common in tube amps. The trick will be finding one that doesn't mind the load impedance of the Thiels---tubes prefer higher impedances.

The 2.7's have a nasty (2.4ohm at 160Hz)load, this together with whatever negative phase angle, could go even lower.
This is probably why the Bel Canto's Class D's lost out in the lower mids, as below 4ohms Class D's usually cannot double.

If you want the very best out of them I would look at solid state amps that can come close to doubling wattage for each halving of impedance, which means they can deliver good current.
IE:
8ohms 100watts
4ohms 200watts
2ohms 400watts
These would be solid state amps with BJT ( bi-polar not Mosfet) output stages, with nice hefty power supplies, in other words big heavy BJT amps.

Cheers George
I would suggest a used PASS x250.5 at your budget.

Chuck
If you get the chance, audition any amp from Symphonic-Line. Combines the best attributes of tubes and SS. The finesse and liquidity of tubes plus the slam and power of SS. I once had a RG1 MK2 paired with Thiel l1.5s. Never heard the Thiels sounded better. Good luck on your search.
I just checked my Music Reference RM-200 amp, and it has 8ohm, 4ohm, 2ohm, and 1ohm taps! It's a very stable circuit, and a good sounding amp. And the only tube amp I can think of that would work with the load of the Thiels. Give Roger a call and see what he thinks. He's an expert with difficult speakers, having designed the electronics for the Beveridge Electrostatics, and having a current direct-drive ESL/tube amp product.

06-19-15: Bdp24
I just checked my Music Reference RM-200 amp, and it has 8ohm, 4ohm, 2ohm, and 1ohm taps! It's a very stable circuit, and a good sounding amp. And the only tube amp I can think of that would work with the load of the Thiels. Give Roger a call and see what he thinks. He's an expert with difficult speakers, having designed the electronics for the Beveridge Electrostatics, and having a current direct-drive ESL/tube amp product.

These would be nice as a tube alternative but you would have to use the 2ohm if not the 1ohm tap. But you'll only get around 20watts per channel off these taps, then only problem is at 87db the Thiel's won't go too loud before the RM200 clips. Ok if you don't listen too loud.

Cheers George
Kadlec-

you have some excellent options;
Conrad Johnson
Audio Research
Aesthetix
Pass Labs

all of these will really make those 2.7 speakers sing!
Get out there and audition this gear, so you may make an informed decision, and buy used/demo.

Most importantly, which brand(s) of cabling do you plan to use? Keep me posted & Happy Listening!
Maybe one of the Anti-Cable impedance transformers to get the Thiels impedance high enough?
My guess is that the impedance dip is in fact the culprit and must be addressed in spades. I appreciate all of your input – several good suggestions to pursue.
For many years, Audio Research tube pre, Classe amplification and MIT cabling is what was highly recommended with Thiels. I used a Ref 1, CA400, MIT Ref350 interconnects and 850ref speaker cables with Thiels CS5i's.
I know someone who swears by his 2.4 driven by McIntosh MC275 driven as monoblocks. I have a 275 driving B&W 804S which most drive with SS, but when I auditioned the 804S with the 275 vs McIntosh MC252 (250 W per channel, SS), I preferred the tubes. If you can, listen to tubes with your speakers.

Having said that, Thiels are generally suggested with powerful SS. You have good recommendations above. I would add Rowland to the list. Oh, and once I also heard the 2.4 driven by Ayre and it was great too, but that was a short audition.

Congrats on your new speakers!
I'm using Thiel 2.4 SE (great speakers BTW) with a BAT VK300-Se integrated (300 watts @ 4 ohms).
Don't be afraid to turn up the volume on your Thiel's.
This may solve your problem.
I've heard the Thiels with a Plinius amp (SA-100 I think) that sounded fantastic, so I can confirm that Plinius mates well with the Thiels. It was one of the more three-dimensional and lifelike presentations I've heard over the years.

Michael
I am driving a pair of Thiel 2.4 with a VAC tube amp - 100 watts per channel with excellent results.
All excellent suggestions- guys! It is interesting to read that both Mac & Plinius are sonic matches for Thiel.

Also, and more importantly, it is good to read that MIT cabling does well w/ Thiel. Kadlec, has many, many choices now. Keep me posted & Happy Listening!
Used Pass 250.5 jump on one now.
For what it is worth I am running a pair of Thiel 3.6s with a W4S ST1000, 1100 watts into 4 ohms. No problem.
I had 2.4s and compared the McIntosh MC402, Pass X250.5, and XA-30.5. The 30.5 was the best option, natural tone, great textures, and beautiful soundstaging/imaging. The 250.5 had a bit of midrange harshness that didn't sound right. I was warned of that by Kent at Pass Labs (he suggested the 350.5) and tried it anyway, ended up selling the X250.5 and keeping the XA30.5.

I heard that VAC used to be voiced with Thiels. If I was going the tube route, I'd try either VAC or AR. If I was going SS, I'd stick with Pass.
I went through a few amps with my 2.4's until I added a Krell FPB 300. Wonderful match with the Thiels. Totally controls the speaker, doubles down to 600 watts and then again to 1200 watts. I use Sanders interconnects and speaker cables, with a Krell Evolution 222 preamp. I was a happy camper at last. Until I twisted off and got a pair of CS 5's, which are a really tough load. I have concluded that I need to go up to an FPB 600, which by the way was what was used on the CS5i's at the Lexington plant of the original (not the new thiel) Thiels. I also learned the hard way that there are no shortcuts with these great speakers; stick with the big boys: Krell, Classe, Pass, Bryston, Ayre: any amp that doubles down should be considered.
Looking for Thiel 2.7's. Have a question about your suggestion on bipolar. Like Threshold T-50/T100?

Still enjoying your Thiels?

Regards,

Jim

Hello Jim,

the Threshold should be a fine match. Seek out a T-200 or T-400 for good measure. You may want to have it serviced and replace critical capacitors throughout. Same thing for an older Krell power amp.

There is a wealth of info over on my thread- Thiel Owners.
Keep me posted and Happy Listening!

JA FANT