Hi Unsound,
It would seem(once again) that actual performance and listening in one`s system is far more meaningful than speculation based on measurements. Steve has actually compared the CJ amp to'3' more powerful SS amplifiers and the CJ sounds better(is`nt that the point of audio gear). Regardless of what'should' be the result based on amp power and supposed speaker requirements. What is there to debate or question other than your own personal belief that the 50 watt tube CJ should`nt outperform the bigger SS amplifiers. Should steve disregard what he`s heard in his own system? Why question his real life results? |
Here is Stereophile's measurements of the the Thiel CS 2.4s:
http://www.stereophile.com/content/thiel-cs24-loudspeaker-measurements
I think it fair to say, that it doesn't appear to be that easy a load for a typical low powered tube amp. |
With all due repect, and despite the included commentary in those test results, those measurements aren't exactly impressive; clipped at 36W (15.6dBW) ("isn't bad", really ?), and well below Thiels recommendation. If anything, perhaps it's the power supply and output trannies that make this amp perform so poorly on the bench? |
Apologies; it was Martin Colloms, not John Atkinson who made those measurements.
Bottom line is that more power does not necessarily translate into improved sound with the 2.4s. I failed to mention earlier that I have also owned Musical Fidelity's 250 wpc, Krell's 150 wpc and CJ CA200 185 wpc integrated amps with these same speakers and, by far, and to my ears, the CAV50 outperforms the other sonically with these same speakers. It simply provides that "ahhhh" factor much better than any of the others; I know I was hoping that either the CJ CA200 or the Krell integrated would be preffered, but such is not the case. What I also know is that the 2.4s are nowhere as diffcult to drive as Thiel's older models, such as my 6s, which I power with a Krell 400cx. The 2.4s are highly, and I emphasize, highly, revealing of the quality of the power feeding them. |
As Atkinson noted in his technical review of the CAV50, "On the test bench, the Conrad-Johnson CAV50 delivered a just-to-spec 53Wpc into 8 ohms (17.2dBW) for 1% distortion, midband. Loaded down to 4 ohms, it measured 78Wpc (15.9dBW) single-channel, showing a respectable load tolerance for a tube amplifier. The output rating fell 1dB with both channels driven (eg, to 16dBW, 40Wpc, at 1kHz). At low frequencies (20Hz) the amplifier clipped at 36W (15.6dBW) (which isn't bad), and raised 65W at this frequency into 4 ohms (15.1dBW). At the other end of the audio band, the amp delivered a true 56Wpc at 20kHz into 4 ohms at 1% THD, with 45W available into 8 ohms (16.5dBW). This is a good result, confirming low shunt losses in the output transformer." I have had audiophile friends both of the tube and solid state culture, listen to this system and they all are impressed by the results. I get decent bass response, not up the level of my Krell/Thiel CS6 system, but convincing enough, and the notes are felt as well as heard. Incredible midrange and high end. I think it's the power supply and the output trannies that make this amp a gem. |
Stevecham,
I find you experience interesting with the CJ amplifier.How good is the quality and control of the bass driving the Thiel woofer? what type of music? Is it possible The CJ handles the thiel better than a SS Pass amplifier? Strange things can happen within audio systems sometimes. Could the CJ actually have a better power supply and/or transformers? |
Ayre makes very fine gear....to get the most from it you should run it balanced |
The Pass INT-30A certainly makes absolutely stunning music on the Thiels... but only with certain types of content. |
Stevecahm, I've heard an older similarly powered cj tube amp running older 2 series Thiels that were a much, much easier load, and while it could make sounds, those Thiels never could produce all they were capable of with that amplification. |
Guys, next time you plan to be in Eugene, OR, please let me know so that you can stop by to hear my system. That's the only way I can convince you that I have plenty of power with the CJ into the 2.4s. And my room is not small; it has a high ceiling. |
Based upon some comments posted here on Audiogon, the cost of refurbishing Krells can be quite expensive, with that it mind, it might be best not to purchase anything too old, unless it has documented proof of already being appropriately refurbished. |
Nope, haven't started to look through the options to learn their lineup yet... but I'll take a look. Any particular models you're a fan of? At one point I was considering Mark Levinson, but the reliability complaints and all the posts about getting the caps replaced turned me off. |
Have you considered Krells? |
Stevecham, as Unsound pointed out I do find it surprising that you're getting enough out of the CJ. I'm certainly not in a big room (or a small one for that matter), but my current Pass (the INT-30A... which gives 60 W of class A power into 4 ohms, and probably tops out around 200 wpc) just doesn't control the lower end of the 2.4s. Bass is just all over the place, sometimes it shakes the windows, other times there's just nothing there even when it clearly should be. With the same amp, my Thiel 1.6s actually produced more bass on a couple tracks that I sampled. |
I'm willing to spend up to $4000 (on agon)... just trying to explore the options and figure out which of those might be worth "auditioning" (i.e., purchasing used and reselling if they don't compare favorably to my current XA-30.5/INT-30A). I'm going to keep it and use its preamp so I can get a good A/B comparison. Getting a cheaper option is simply attractive because it opens up the cash for some other audio purchases... hence the flirtation with the Aleph 2s and the Ayre V-5xe. I'm in Boulder, I wish Ayre would just let me borrow one for audition (I checked and they won't... despite not having any CO dealers). |
Stevecham, with all due respect, he's already unsatisfied with much more power than your currently running with Thiel 2.4's. IMO, it might be enough, then again it might not. Depends the room, and the expectations.
Cal3713, may we ask how much do you comfortably want to spend on amplification? |
At 150 wpc into 8 Ohms and 300 wpc into 4 Ohms the V5ke is going to power the 2.4s just fine. I use a 45 wpc CJ CAV50 with the 2.4s and have plenty of power. |
Sorry V-5xe... stupid typos. |
