Bryston: THX for 2 ch - a good thing or not?


Several Bryston amps are available with THX certification and badging at extra cost. Is this a good thing for 2 ch setups?
I recently had an email exchange with an Audiogon seller of a Bryston 8B ST amp. I told him I was also looking at two Bryston 8B ST THXs on eBay. He related to me an opinion he had heard that the ST THX versions were somehow inferior to the ST versions. Was he just hyping his amp or is there something to this allegation?
I googled this issue every which way without much satisfaction. One source mentioned that the THX stardard required expanded dynamic headroom, which sounds like a good thing, but doesn't the ST version also meet this requirement?
I spoke to a Bryston designer at the factory in Peterborough some months ago, before the current question became an issue for me. I got the impression from him that the THX versions were just the ST/SST versions with THX certification and badging, for which Bryston had to pay Lucas for the priviledge. Therefore, amps were certificed as THX compliant more for marketing reasons than due to any design modifications, except perhaps for some features (like a different input gain for the THXs).
Bottom line, is there any reason I should avoid THX versions for 2 ch listening? Are they better, worse, or just about the same?
russelllondon
I'd be anxious to see if this is even worth worrying about. Buying used, shouldn't age, condition, model, proximity of seller etc. be much more important then if it has a THX logo on it? I see Monster selling really cheap cables badged THX and believe they're junk. But sure enough, the big box retailer's salesperson is quick to point that THX certification a reason for spending a little more on them.

Hope you don't miss a perfect Bryston amp for you worrying about this.
They are the same amps. Whether THX or not, a 3B ST is a 3B ST from all I have known. They meet the standard easily in stock form. Try the Bryston owners circle at Audiocircles.com for more clarity. In fact James Tanner (VP at Bryston)may have already answered this question.
THX is simply a licensing certification that an amp meets certain operating conditions, and has nothing to do with the design of the amp. As the previous two posts indicate, the "ST" and "SST" amps comply with the THX certification requirements, and Bryston had to pay for right to use the logo. I own a Bryston pre-pro and two of their amps, and find them excellent for both music and home theater. Don't worry about the THX version -- the "regular" Bryston amps work just fine.
I agree with Sailfishben, Mcfavre4 & Sdcampbell. Whether THX or not, it's not worth worrying about if ST/SST versions are in fact exactly the same as the THXs.
However, have a look at the following from an Audiogo.com item currently for sale as "Bryston 4BST - Thx
RE: THX certification taken from Bryston website....

New Standards of Accuracy:The Bryston THX amplifiers incorporate the use of an innovative gain stage topology, which yields the quietest possible noise floor through the use of low-impedance pathways within the amplifier. This approach also has strong advantages in improving overall distortion performance. Bryston's computer-controlled distortion analyzers confirm intermodulation distortion levels less than 10 parts per million (below 0.0009%) are typical for this new circuitry."
Doesn't that imply that this THX amp is superior to a 4BST without THX? It's totally misleading if everything claimed for the THX also applies to the 4BST. So why would, or should, anyone pay a premium price to get the THX badge on their amp? I agree that they shouldn't, but I still have an open mind on the topic if anyone out there has evidence to the contrary.
BTW Mcfavre4 I tried Audiocirles.com but it doesn't seem to be an active site.
Mcfavre4: I found the site at audiocircle.com (w/o the plural "s" and certainly not my mispelled "audiocirles"), but haven't found Tanner's comments on THX. Thanks for the suggestion. I am very impressed that Bryston and Tanner are so supportive of the Bryston owners' community.