218W into 2 ohms is more than 100 amps going to the speakers, easily enough to start a fire. I have a 1996 4B, amongst others, and the combination works well. But the newer 4B3 sounds better in every way because everything is different - circuit, components, boards etc. 4B3 also has a slightly warmer sound than previous 4Bs and can be useful if you want the Bryston detail with a less uncompromising presentation.
33 responses Add your response
The Bryston 4B is not rated into 2 Ohms. The earlier version's measurements show that rather than increasing it's power output into 2 Ohms it loses power output. Bryston 4B power amplifier Measurements | Stereophile.com |
@nmmmusicman, The Vandersteen Quatro's are a very different speaker load than the Thiel CS 2.3'.: Vandersteen Audio Quatro loudspeaker Measurements | Stereophile.com Unlike the Vandy Quatro's the CS 2.3's don't come with a built in 250 Watt amp to take care of the heavy lifting. The CS 2.3's are recommended to be used with a minimum of 100 Watts per channel of amplification. The CS 2.3's impedance dips to 2 ohms, stays below 4 Ohms for most of the time, and has a high capacitive phase angle. The Vandersteen Quatro's briefly dip to 7.6 Ohms, stays above 8 Ohms the complete rest of the time, and has a low electrical phase angle. The Aleph 3 can't double down it's 30 Watts per channel into 8 Ohms down into the 120 Watts into 2 Ohms asked of it with the corresponding reduction in sensitivity into the 2 Ohm load of the Thiel CS.2.3's. Stereophile (probably as an act of mercy) only tested the Aleph 3 into a 2 Ohm load into 1 channel where it barely increased it's 30 Watt 8 Ohm rating to 39.1 Watts. Keep in mind that the minimum power recommendation for the CS 2.3's would have been the equivalent of 400 Watts into 2 Ohms. These speakers present very different loads to an amplifier. I'm not sure where your quote comes from, but when one describes an amplifier as being stable into a given load; all they are saying is that the amplifier won't go into oscillations at that load, not how much power it produces, how it sounds doings so, or what levels of distortion it resorts to in order to comply with that criterion. Yes, "Not everything can be derived from measurements....", but some measurements can reliably provide, consistently predictive results. |
unsound I didnt think the Aleph 3 would be a good match with my Vandersteen Quatros but it drives them with no problem and sounds heavenly. There is also this since you're drawing from reviews.. "Speaking of speakers, this baby appears to be stable into any load, all the way down to a dead short across the speaker terminals!" Not everything can be derived from measurements... |
The Pass Labs Aleph 3 is not an ideal candidate for amplifying the Thiel Cs 2.3's.: Thiel CS2.3 Loudspeaker Specifications | Stereophile.com Thiel CS2.3 Loudspeaker Measurements | Stereophile.com Pass Labs Aleph 3 power amplifier Measurements | Stereophile.com |
OP I have been driving my CS 2.3 using: Pass XP-22 > Pass X-250.8 with absolutely wonderful results. I upgraded my electronics last year and these Thiels have never sounded so good in the 20 yrs I have owned them. Phenomenal bass control with great imaging and soundstage. Not bright at all with the Pass electronics. They are good speakers if you have an amp capable of driving them with authority. The Pass X-350.8 would also be a great match. |
Here you go: https://www.youtube.com/watch?v=PEcFkSQMc8g I'm not sure why he thinks it's a rant, or how starting his speaker company is going to change things. His points are right on target. And he gives a fair appraisal of the virtues of some of the renowned speakers that fall into the category of low impedance loads. He's correct that the standard spec has changed, and that it is now more complicated for the consumer. On the other hand the current spec is more accurate as speakers have typically never had a static impedance, and it really isn't too difficult for the consumer to calculate what amplification is appropriate so long as they know the minimum impedance. And while it's true that amplifiers tend to distort less into higher impedances, it's also true that amps and speakers prefer to work with more linear impedances, and that can be done by lowering the impedance but not by raising it. Furthermore, amplifiers that double down, or halve up with impedance do so with concurrent sensitivity changes, and therefore are better at maintaining frequency linearity. Also lower impedances are more immune to noise infiltration. Originally replacing larger speakers with smaller ones and replacing less powerful amps with more powerful amps allowed for more domestic acceptance of hifi. Now with home theatre and surround sound it's even appreciated more. |
When a manufacturer claims that their amp is “stable” into a given impedance; all they are saying is that the amp won’t go into oscillation into that impedance, it doesn’t suggest how much power, distortion, or quality will be delivered into that impedance. Don’t assume the amp is truly capable of performing appropriately into a given impedance, unless they spec it as such. If the amp can deliver the goods; the manufacturer will brag about it. |
If your looking for a great amp for the Thiel CS2.3's check out a McIntosh amp like the MC352 or MC452, these amps are stable down to 2ohms and don't run HOT, like some pure class A designs. Either of these two amps are of super high quality and are built like battleships and sound even better, probably the last amp you'll ever want or need. Matt M |
Had CS 3.6 for many years and of all the amps used the best match that I came up with were the Krell KSA and MDA series amps, A Krell KSA-250 was a staple for quite a long time with the Thiel CS 3.6 Detail and absolute control of the 3.6 was high on the list and the KSA-250 did not disappoint. They dipped down into the 2 ohm range but that never phased the older Krells. Even a KSA-150 works well if your room is not too large or you don't push to a ridiculous dB level. My old room was rather large so the KSA-250 and MDA-300's had more reserves for large dynamic swings. Power output from the 150 and 250 was - 150 w > 8 ohm 300 w > 4 ohm 600 w > 2 ohm 250 w > 8 ohm 500 w > 4 ohm 1000 w > 2 ohm |
Hello cortw1965! I have the Thiel CS 2.4 and have been very happy driving them with a Bryston 3BST which is now 20 years old and still going strong. Bryston amps are generally a good match for Thiels. Most important thing is to keep in mind that speakers like the CS 2.3 require a quality high current amp that can handle the fact that Thiel speakers impedance will often drop considerably below their nominal 4 ohm rating. As per Stereophile the CS 2.3 drops down to 2 ohms at 450Hz ... so need to make sure the amp is stable down to 2 ohms. Suggest you check out the Thiel Owners thread here on Audiogon for more ideas. |
