[electrafixion]

I recently upgraded my speakers from Thiel CS1.5's to CS2.3's and I've found my existing power amp simply isn't up for the task of powering these beauties.

I can spend up to $1500 for a replacement amp, so my first inclination was to look for a a used 4B-ST, however I've started to wonder if a used 3B-SST might also be a suitable choice.  Would the sonic merrits of the SST series trump the additional power offer by a 4B-ST?  My listening room isn't enourmous, but from time to time I do like to listen at very high levels.

I've tried a few amps with these speakers so far, and they really responded well to an old Bryston 1980 built 4B Pro, but of course it really can't offer the resolution and finese of Bryton's newer designs.  My preamp is a Sonic Frontiers SFL-2, and sources include both high-end digital and analog setups.

Any insights would be appreciated.

[Phil A]

I recently upgraded my speakers from Thiel CS1.5's to CS2.3's and I've found my existing power amp simply isn't up for the task of powering these beauties.

I can spend up to $1500 for a replacement amp, so my first inclination was to look for a a used 4B-ST, however I've started to wonder if a used 3B-SST might also be a suitable choice.  Would the sonic merrits of the SST series trump the additional power offer by a 4B-ST?  My listening room isn't enourmous, but from time to time I do like to listen at very high levels.

I've tried a few amps with these speakers so far, and they really responded well to an old Bryston 1980 built 4B Pro, but of course it really can't offer the resolution and finese of Bryton's newer designs.  My preamp is a Sonic Frontiers SFL-2, and sources include both high-end digital and analog setups.

Any insights would be appreciated.

I owned 2.3s many moons ago and used a 4BST and then got 7.2s and now have 3.7s.  I have a very large (you can see it in one of the pictures in my gallery) 2 story room that is about 16x20 with 19 ft. ceilings and opens into other spaces.  Much depends of course on what type of music/movies you play, the size and treatment of your room and how loud you like it.  If you have a very large room and play things very loudly you might need more power than a 3BSST.  When a 2.3 is driven very hard you will hear distortion from the midrange/tweeter unit and the SST series will be a bit smoother.  Do you have the original tweeters for the 2.3s or the newer vented ones?  You might want to call Thiel with the serial nos. or look at them.  Sometimes they've sent new drivers for free.

[electrafixion]

Thanks for the reply.  I listen to a wide range of stuff, but mostly like to crank it up when I'm playing classic or hard rock.  For movies I have a dedicated HT system.  I ran a 3bSt around 10 years ago with a big pair of Mirage speakers and found it fit the bill fine, but those were much more efficient speakers than the Thiels.  I originally thought the 4bST would be nessisary, but I see that the SST series are slightly more powerful than the ST series, so that's why I got wondering.

I've been in touch with Thiel and these units have the original tweeter / mid units.  Do you think the $300 cost is worth it for the upgrades? 

[Phil A]

Thanks for the reply.  I listen to a wide range of stuff, but mostly like to crank it up when I'm playing classic or hard rock.  For movies I have a dedicated HT system.  I ran a 3bSt around 10 years ago with a big pair of Mirage speakers and found it fit the bill fine, but those were much more efficient speakers than the Thiels.  I originally thought the 4bST would be nessisary, but I see that the SST series are slightly more powerful than the ST series, so that's why I got wondering.

I've been in touch with Thiel and these units have the original tweeter / mid units.  Do you think the $300 cost is worth it for the upgrades?

Whether it is worth it or not is subjective.  My friend used to work at the high end shop (up until about 5 years ago) and for a 5+ yr. periods before that I did virtually every set-up/install with him (he is more of a salesperson) and set-up many pairs of 2.3s.  I haven't heard the 2.3s in probably over 6 yrs?  I changed a pair of tweeters for my friends old neighbor about that far back but he bought used 2.3s for the rears as he was running 2.4s up front.  An older customer of he store had died (he was 91 and still an audiophile) and my friend's neighbor bought the MCS1 and the 2.3s.  I'd say do a google search and find people who have lived with both.  I got rid of my 2.3s before the upgrade was available (I would have done it but that's just me) and I changed a few pairs of tweeters over the years but really wasn't there long enough before nor came back after.  I've also owned Mirage many moons before the Thiels (SM-3s I think - it's probably been over 20 yrs. - since I was three of course ).  I'd guess the harshness when the midrange/tweeter is driven hard will be a bit less with the new tweeters.  There is a similar issue with the 2.4s but to a little lesser degree.  My friend has those with a 9BSST (essentially a 5 channel version of the 3BSST) and his room is about average and when driven hard I can hear the distortion (as can he).  Based on what you've told me I'd try to wait for a 4BSST.  You can always buy something like a used Adcom 555 (the orig. made by Rotel not the two series) in the meantime and won't lose much when you sell it.  It is 325W into 4 ohms and can be had for $300-350 while you save.  I actually have a used pair of Thiel SCS2s (picture in the gallery too) in the bedroom system and since I didn't want to tax the receiver too much (have an SCS2 center too) I made some cables for someone and took an Adcom 555 in trade.  I watch for local used 3BSTs or 2 or 3BSSTs every now and then (I don't use the bedroom system tons) and someday I might be a 3BST (which will fit a drop easier than a bigger amp behind the TV.

[95Dyna]

Hi Electrafixion,

I have a pair of Adcom GFA-555's I just decommissioned when I installed a new pair of 7B SST2's if you're interested in Phil's recommendation.  They are not the MKII's but I'm not sure about Rotel being the manufacturer

Bill

[Scottdazzle]

The 555's may have had some parts in common with some Rotels, but they were a Nelson Pass design made with imported parts and assembled in New Jersey. 

[95Dyna]

Thanks Scotthobby,

That's my understanding as well.  All my docs and the plate on the back of the amps identify N.J. as the location of Adcom's facilities.  I wasn't aware of the Rotel connection or the Nelson Pass design.  No wonder they were such good amps and are still humming after 19 years. 

Bill

[electrafixion]

Thanks all but I'm ok for amplification for now...I have a Sunfire 300, a Bryston D4B pro (original), and a PS Audio HCA-2 on hand, all of which I'll flog once I settle on a permanent replacement.  The PS Audio shuts down when I play the Thiel's at extended levels, and it sounds quite shrill with them, despite is fine performance with other speakers.  I thought the Sunfire was quite capable, but I found the 30 year old Bryston actually brings out some qualities that I'm not hearing with the Sunfire...the sound seems more effortless, and bass is more defined, and better dynamics.  I concluded that a new 4bST would fit my budget, and probably sound better everything I have on hand now, but then I got reading about how much better the SST series was supposed to be, and wondered if a 3bSST would be a viable choice (since they're close in price to a used 4bST).

Incidentally...my first 'real' power amp many years ago was an Adcom 555mkII...also Mr. Pass' handiwork I believe.  I'm not sure how the mkII compares to the original.

[drphoto]

People really pay $300 for used GFA-555s? Damn, I just sold my pair for $50/ea! What a dummy.

[electrafixion]

People really pay $300 for used GFA-555s? Damn, I just sold my pair for $50/ea! What a dummy.

$50 each? Do you have any other gear for sale?