Amp upgrade from Bryston 4B

I currently have Thiel 3.6s main speakers driven by an older Bryston 4B amp that has been a good match. I have been considering upgrading the Bryston 4B amp to used Bryston 7B mono blocks(?) However, the Bryston 7B amps have had mixed on-line reviews. Any other recommended amp upgrade recommendations in the $5K used range that would be a good match for the current Thiel 3.6 speakers and potential future Thiel 3.7 speaker upgrades?

OTHER EQUIPMENT: I am setting up a 5.1 surround system with an existing Rotel 985 5 ch amp to drive Thiel SCS4 center and Higherplane 1.2 rear surround speakers. I am currently using an Outlaw Audio 995 processor in bypass mode for 2.1 stereo listening.
I upgraded to a Classe ct 2300, 300 into 8 / 600 into 4, and was surprised how much of an improvement it was over my previous amp, classe ca2200 not subtle. I too plan on upgrading from my current 3.6 to 3.7s. Main improvement in the upper mid and highs less etched more smooth no compression. I also noticed a little more bottom end punch. The amp does not run out of juice and for me makes the 3.6s better or allows them to be better. I think the moral of the story is that Thiels love power. I have seen them used for about 5k
I used an old 4B in my system for several years and was very happy. I then began to upgrade the components around the amp in a leisurely and admittedly unorganized manner. Went from a Rotel processor to a Krell HTS 7.1(Excellent 2 channel bypass). Upgraded my speakers from Klipsch RF7 towers and Klipsch CC amd surrounds, to Hales Transendence 8's and Hales CC and surrounds. Upgraded IC's along the way. Finally needed to upgrade the amp. Researched for a few months. It's hard to demo equipment, so I finally decided on a Spectron Musician, just from reviews and reading the forums. Found one here on Agon used(a Musician ll Hybrid Plus with Bybee upgrade), and could not be happier. The seller through in the Remote Sense cables after the sale(Amazing! Cables and Seller!) The Spectron is light years ahead of the 4B in every way. And the new Mus. lll Mk2 with Bybee upgrade is in your price range. I think they also have a satisfaction type return policy. I use a Parasound 1206 for CC and surrounds. Haven't felt the need to further upgrade yet, but never say never!
If you like the sonic characteristics of the 4B, the 14B SST Squared is magical in its combination of power and staging, detail and depth. I have heard them both sound quite excellent with THIEL.
I would upgrade to Class A solid state. Pass Labs, Accuphase, etc. The difference is not subtle.

I'm going to move out of 4B-land (I have the SST model)and into a Class A amp myself. The Bryston is good but not spectacular.
The Spectron is a great amp, good recommendation!

Spectron...looks interesting. But, it can't be better than a Class A amp, true?
"I would upgrade to Class A solid state. Pass Labs, Accuphase, etc. The difference is not subtle."

Dave, have you heard both Bryston and Pass XA? I would be very curious to hear how they compare.
I'm kinda thinking upgrading your amp and using it with your Outlaw prepro is a bit of a mismatch. If 2-channel is important to you I'd consider getting a better stereo preamp and use that to drive the Bryston (or whatever else) and let the Outlaw do the rest. You may find the improvement of a better preamp might make living with your 4B fine for a while, and then you'll be in a better position to upgrade your amp later. In my experience preamps can frequently have a bigger impact on overall performance than amps. Not that your Outlaw is bad, but it's not a Pass Labs, etc. Or maybe a better prepro if you don't want a stereo pre -- maybe something like an Anthem. Point is, the preamp is important and you might consider addressing that before spending $$$ on another amp. Best of luck.
I would tend to agree with Soix that a pre amp processor might be a better place to look for upgrading. However, if you are still on the hunt for a better amp. Have a look at this Llano A-200 that's on Audiogon.

Hi Hasse,

As a matter of fact I have, not side by side though.

Anyway, the Pass Labs Class A amps are arguably better built, are more musical, and are more dynamic. I believe they can drive lower impedances better too.

If you have a Pass Labs dealer in your area, have a listen and see.

Thanks Dave
"If you have a Pass Labs dealer in your area, have a listen and see."
Unfortunately I do not have a dealer locally for auditioning. I am interested in either the 7/14B SST2 or the XA100.5 for my Magnepan 3.7´s.
Can you get to one out of your area? Pass Labs is a nice friendly company that'll steer you in the right direction if need be.

Imo, the XA100.5 will blow away the 7/14B SST2.
Thanks for the responses. The pre amp is currently a weak point in the system. After spending the wk end using the Outlaw Audio processor in bypass mode for 2.1 listening I switched back to my passive preamp which is a big improvement in clarity and much more pleasing sound. I will eventually replace the Outlaw Audio processor, but 5.1 surround listening is not a priority. Therefore, I am concentrating on upgrading the stereo components first.

My current Bryston 4B amp with the passive pre amp has been a good match for the Thiel 3.6 speakers, but would like to upgrade. A bryston pre amp with a bryston amp has had good synergy reviews. The bryston pre amps have a stereo selection that is not a true bypass for fully using a surround sound processor.

Some of the fd back on this thread has indicated that a bryston 14b amp would be a good match with the Thiels. My understanding is the 14b amp is essentially two 7bs combined in the 2 ch amp. Any reason not to lean towards the 7b mono amps vs the 14b? Some of the other recommended amps with are also worth considering with a pre amp upgrade.
step up to the 4B SST.
I believe some say the 14B sounds better. Don't hold me to that, however. According to Bryston, the 7B has more capacitance than the 14B, plus you can run shorter speaker cable, always a plus in my book.
Or SST2, that's not a bad, and cheaper, idea as well. But stuff like Pass Labs is in another league.