Bridging Bryston 3B-STs a few questions

Usually when bridging amps you want to keep the speaker impedance no less than 8 Ohms, because the current is already doubled in bridged configuration. If I remember right, Thiel 3.6's are more like a 4 Ohm load, which is going to get the amps awfully hot. Since they're Brystons, they'll most likely take it, but a better (and cheaper) solution would be to sell the 3BST and buy a 4BST instead.

I do not have first hand knowledge in this, but I agree with Karls. I once emailed Bryston and asked about bridging two 4Bst amps. They said bridging is not a problem. However, running a higher powered stereo bryston amp (the 14Bst)or two 7Bst's would result in better imaging and soundstage. Based on this advice from the manufacturer, one 4Bst would sound better than two bridged 3Bst's.

I used two 3B's once (can't recall if they were the ST's though) and had great results with my 804's. Now using a 4B-ST and feel that there is a difference. Unfortunately sold the 3B's to buy the 4B's, so there was no way to A-B the two; and also changed rooms which probably could have been the difference also. Have talked with the guys at Bryston before and they also told me the same as Bwyoung above. Best, Charlie

I would check the bridged power rating for the 3b-st on Bryston's website. I think you will see that it has a 8 ohm rating when bridge but no 4 ohm rating. There is a reason for it, email Bryston's technical support for the full spill. Your Thiels are rated at 4 ohms nominally and I think they dip below 3 ohms in places. You'd be better off biamping with the Byrston's but I think the Thiels only have one set of binding posts.

Thanks for the insights folks. I had not considered some of these points. This forum is truly a blessing to the hobby! The Thiels can not be biamped unfortunately. I suppose Jim Thiel has his reasons. There is no advice in the Bryston owner's manual regarding bridging, but as was pointed out, there is no mention of using the amps with a 4 ohm nominal rating. I will e-mail tech support shortly and if their response is worth a read I will post it here asap. I do not think the Thiel CS 3.6 impedance is a very reactive one, but it is a low impedance regardless. Interestingly I almost purchased a 4B-ST initially, instead of the 3B-St in 1997, but it was clearly sonic overkill for my Thiel CS 2s (now 4 sale) and my listening habits/room size. Perhaps there is a moral in this for those of us that tend to upgrade even periodically. I knew I wanted 3.6s in 1997, but I did not know WHEN I would get them if ever. I did not know we would move and my listening room would double in volume either. In the future I will buy as much amp as I can! I'm in the process of also trying to sell the 3B-ST and find a used 4B-ST or SST. Surprisingly lots of dealers are still selling NEW 4B-STs. I suppose it is not possibe to upgrade to a 4B-SST easily. The 7B-ST monos are out of my budget (happy wife = limits on equipment budget....lol). I had a Krell 250a in house briefly X-mas day. The extra power was noticed, hence the 4B-St will be a welcome addition, but I really didn't warm to the Krell. My c-j tube amp will back from the shop soon....wonder how that will do?

I have Thiel CS2.3 speakers. I used to drive them with Bryston 4B-ST (still have it) but I just got a Sim Audio Moon W-5. The dynamics are stunning but it has a certain airy/delicate touch through the upper-midrange and treble. I think the midrange would be well suited to your Thiels. I've seen these amps sell used on audiogon for about $2500.

I'm open to all suggestions on amps and preamps for the Thiels. I've heard them with Krell, BAT, Gryphon, c-j, Bryston, B&K, Levinson, Hafler and Audio Research. Many of these amps have not been heard in their latest incarnations however. I was happiest way back when with c-j, but I can't afford the big mono tube amps. My MV-75a1 is quite dated and broken too. Levinson was my fav ss sound. Bryston was the best combination of availability, performance and price. I'd have to find a Sim Moon dealer. I do not think we have a rep locally. Tell me a little more about the amp.