Steve, Unfortunately I can't seem to veryfy it but, I believe the unique TacT class D (perhaps the only true class D) amps (on the other hand perhaps they're not amps at all?) can pass a square wave.
Class D amp driving Thiel
I was honing in on a 2 channel system and had seriously narrowed down the contenders until last Saturday. After not being impressed with a pair of B&W CM7's I was encouraged to listen to a set of Thiel 1.6.
It was amazing. Driven by a Bryston amplifier they had detail and precision with beautiful tonality. Yes, they did lack bass under 50 hz. But completely different and world's better than the Thiel's I owned and powered with tubes years ago. So now I have to rethink things. I have only a small shelf for the SB3 and amplifier and can't fit (or afford) anything above 30 lbs or 5 inches tall.
Maybe a second hand Krell 400xi would work but Krell's rap is that they can be bright and fatiguing. And I can't do anything bigger or costlier. While the Naim forum has good reports of Thiel's being driven by even a Nait 5i I am a little cautious based on my previous experience. As I learned the hard way you have to muscle up on Thiel's or they sound bright and nasty.
So, the thought of a class D amp came to mind. Small, light, and powerful. Though I haven't even heard one before (hard to find them in Chicago, believe it or not) my interest is piqued. But would it be up to driving the load I am contemplating without getting bright or harsh? Any thoughts but more importantly experiences are appreciated.
It was amazing. Driven by a Bryston amplifier they had detail and precision with beautiful tonality. Yes, they did lack bass under 50 hz. But completely different and world's better than the Thiel's I owned and powered with tubes years ago. So now I have to rethink things. I have only a small shelf for the SB3 and amplifier and can't fit (or afford) anything above 30 lbs or 5 inches tall.
Maybe a second hand Krell 400xi would work but Krell's rap is that they can be bright and fatiguing. And I can't do anything bigger or costlier. While the Naim forum has good reports of Thiel's being driven by even a Nait 5i I am a little cautious based on my previous experience. As I learned the hard way you have to muscle up on Thiel's or they sound bright and nasty.
So, the thought of a class D amp came to mind. Small, light, and powerful. Though I haven't even heard one before (hard to find them in Chicago, believe it or not) my interest is piqued. But would it be up to driving the load I am contemplating without getting bright or harsh? Any thoughts but more importantly experiences are appreciated.
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Auh, I just got a new QSC PowerLight 380 for my Electric Bass rig and while it's not exactly intended for High Fidelity it definitely puts a grip on things. This is my third QSC and it never fails, people can be very hard on my gear with loading and unloading but I've never had a failure in the fifteen years I've been using their gear. Another established and reputable amplifier manufacture who has embraced class D. Below is a description from their website Products / Amplifiers PowerLight 3 Series Professional Power Amplifiers The PowerLight® 3 Series is designed for the most demanding live audio users, whether in touring rigs or fixed installations. The most requested features of the PowerLight 2 series have been upgraded to deliver "the ultimate analog amplifier", while the QSC Dataport ensures full compatibility with advanced digital processing and QSControl. Three models range in power from 1250 watts to 4000 watts per channel at two ohms, all in two-rack space chassis that are only 15.6" (40 cm) deep and 22 lbs (10 kg). In addition to higher power, the PowerLight 3 Series offers higher input voltage, selectable sensitivity, and easily adjusted rear panel switches with color coded LED indicators. For those users who simply want a high performance amplifier to go with their existing processor or console, the PowerLight 3 Series is an ideal choice, offering high power, excellent value, and zero signal latency. When complete integration of amplifier control, monitoring and DSP is desired, the PowerLight 3 Series is fully compatible with the QSControl BASIS networked audio platform, with its comprehensive drag and drop DSP functionality. Simpler DSP requirements can be met with the DSP-4 processing module. PowerLight 3 Power Amplifiers Watts at Clipping Watts per channel Model 8 ohms 4 ohms 2 ohms PL325 500 850 1250 PL340 800 1250 2000 PL380 1500 2500 4000* EIA 1 kHz 1% THD * Burst mode testing required due to AC service current limitations The flagship of the PowerLight 3 Series is the new 8000 watt PL380. This highly refined, all-switchmode amplifier incorporates nearly 40 years of QSC engineering experience, resetting expectations for Class D audio quality. The PL380 combines a pair of 4000 watt Class D amplifier channels with the well proven PowerLight supply, to deliver more than twice as much audio power as previous 2 rack unit PowerLight amplifiers. Reactive "back EMF" from the speaker is recycled to the power supply, and unmatched "plug-to-plug" efficiency of 85% keeps AC power needs to a minimum, while delivering more energy to the speaker. Years of patient development have resulted in outstanding 20 - 20 kHz audio performance, plus complete protection from normal hazards of the trade. Even simple features such as dependably silent, surge-free on/off switching indicate the special care taken to keep things safely under control. The most pronounced "sonic signature" of the PL380 is one of immense headroom, sailing through even the most difficult loads with no signs of stress or change of tonality. In keeping with normal QSC design standards, back-to-front airflow provides up to twice as much long-term average power as most competitors, without dumping hot air into the rack. All PowerLight 3 models are built in the same chassis size, with common back panel layouts to facilitate easy racking and hookup. |
So.. I'm guessing you don't 'care a damn' how it sounds but only how it measures? Must be easy to make buying decisions for you then. Just check measurements and your done, end of story? Generalized pronouncements make me wonder if there's something else going on to make you so adamant. Does all your equipment and cabling display a perfectly square wave? And in the end, How satisfied are you with your decisions based on a square wave? How many preamps and amps have you owned? Don't get me wrong. I'm not being sarcastic. I'm just curious how this hobby and love of music we share works for you because your perspective is unusual if I'm interpreting it correctly. Oh.. almost forgot. I've recorded and produced records as well for Polygram. |
And he said it but didn't show it. This is my opinion: Class D amplifiers are not ready for prime time yet, except for a narrow frequency range as required by a subwoofer. And car stereo with all the attendant road noise. Those who will embrace Class D at this time will do so by looking the other way when it comes to measurement because they don't care a damn about measurement but only how it sounds. And that's fine by me. |
Stevecham: I'm must be missing something as a result of this form of communication and I'll apologize in advance if I missunderstand your original statment but it seemed you were putting down all class D amps because of the apearance of one test signal. I doubt I would have responded had you singled out a particular class D amplifier and after seeing the test signal it somehow confirmed your listening experience. I take exception when I think I hear or read negitave generalities and I guess that's how your remark struk me. I have four amplifiers for stereo, two of which are class D. I'm extremly happy with their preformance but unlike the tube and the linear solid state amplifiers a great deal of care was taken with regards to VAC quality and cable selection before they came into their own. |
Vic, but that tube amp's squarewave sure does look much better than that D amp. I am totally cognizant of what happens as soon as acoustic sounds is trasduced to an electronic signal, the phase shifting, the compression...we have to accept that as part of the recording chain. I too am a musician and a recording engineer. But I want my playback system to reflect what was recorded, for better or worse, as accurately as possible. In other words I want the quality of the performance and the production to define the musicality, and, as little as possible, the playback system. |
Stevecham: Speaking as a musician I have yet to hear ANY form of reinforcement, back line, or playback, reproduce the timbre and or harmonic content of acoustic instruments correctly. Most home systems that are assembled to produce "warm" or "musical" aesthetic are the worst at providing accurate playback. If you ever have the opportunity to visit a quality pre or post production facility you will be struck by the analytical nature of the playback system. Even more stunning is the degradation between the original track recording, the post production, and the media/final product your listening to at home. Some engineers I've worked with work towards bettering speed and the dynamic feel (LP like) of their work so naturally their playback systems need to reflect this input. I'm seeing more and more class D amplifiers powering these systems. Even though some of these systems are by far the most accurate systems I've ever heard it doesn't necessarily make them "right" for everybody's choice in a home system. Class D amplification is simply another developing tool in the audio world. All amplifiers have shortcomings and class D is no different. I'm not sure what you mean by "tizz" but class D does "boom" real good. I've got a tube amplifier that doesn't produce an impressive square wave either but it sounds sweet to me. Cheers Vic |
As long as Class D amps cannot make an accurate looking 10 kHz squarewave, one will not find a place in my listening environment. There are some things that an amp has to be able to do on a test bench accurately or it will never get timbre and harmonic content right, no matter how much tizz and boom it creates for its size and weight. |
My Thiel 1.6's arrive Friday and one of the two amps I'll be experimenting with over the weekend is NuForce IA7-E (the 100 watt version). I am very optimistic as the latest version of this imtegrated is extremely clean and clear sounding, with some of the nicest and least harsh treble extension I've ever heard out of any amp, tube or solid state. I use a REL Strata III for the foundatation. Art |
Vicdamone, the Thiel reps said it in just such a context, as a gross generalization, that should be taken in that context, with the obvious exceptions that may or may not exist, in other words, so far as they have heard. Mind you I'm very optomistic about this technology. I suspect great things on the horizon, if it hasn't already happend. IMHO, the TacT approach appears to the most promising. I agree with Denjo's suggestion, try it for yourself. |
Unsound In regards to the Reps at Thiel. I find it questionable at best, of anybody who would make such a gross generalization. I seriously doubt that anybody has had the opportunity to seriously setup and audition ALL the class D amplifiers on the market today to make such a comment. Unfortunately there are a few manufactures of class D amplifiers that have discovered the economy and availability of off the shelf components which has allowed them to produce products with less than desirable sonics and large profit margins. On the other hand there are class D amplifiers that are so uniquely designed that their abilities have been very well received. Whether these amplifiers have a desirable synergy with any or all of Thiel products is another issue. Regardless of the Reps obvious shortcomings I still find Thiel and the importance they place on time and phase puts them in very select company in the dynamic loudspeaker industry. |
From what I know from listening about the Thiels is that after long listening sessions they can become tiring. Don't get me wrong, they make great speakers in many regards. My experience was that I loved them in the morning and afternoon, but after a long day and a full head, the detailed sound became hard for me to listen to for extended periods. I have Totem speakers and these are known to be a bit bright on top, but have a very nice mid. I bought the Channel Islands (used) and have found them to perform very well with my speakers. They cut some of the brightness on the top but still have a very nice top end - much less fatiguing, even at night. The mids have been great and the bass is still tight, strong and I have plenty of reserve power for my needs. As a reference, I have also been running the same Totem speakers (Arro and Hawk) with my B&K 507 S 2 AVR Receiver at about 150 WPC and a Golden Tube Audio SE 40. I do not feel that I have given up any of the emotion versus the Golden Tubes and feel that the detail delivered with the 507 has improved (better imaging/sound stage, improved rythm, etc. (PRAT). I really have enjoyed them and if you can buy them on a 30-day trial or used (which means you could re-sell them easily), I think they are worth a consideration. If you lived in Southwest Michigan I would loan you mine to try. BOL |
Matching the amplifier to the speaker is what I am trying to do. It's not about this sounds good with that, or something else doesn't. There are real requirements that these speakers make on an amplifier - nominal 4 ohm impedance, reaching 3 or so at various points. Many amplifiers will not respond kindly to this type of load. |
Wdrazek, Just my opinion, but the whole idea of an amp sounding good with this or that speaker is one of many audiophile misconceptions. A great amp is a great amp, period. And great sounding speakers are great sounding speakers, period. It is far wiser to get the best amp you can, regardless of the speakers you're using. That said, you do want to make sure that whatever amp you choose, has enough power to drive your particular speakers. |
Thanks very much for all of the replies. It looks like the Bel Canto and Rowland are tested and confirmed matches and that CIA is well regarded although nobody responding has direct experience with them and Thiel's. Nobody that's heard class D and Thiel has given a bad report on the combo. Given that I want to minimize boxes and not drop over $2k or so on the amp/pre the next step is exploring the Bel Canto and PS Audio integrateds. Too bad Rowland and CIA doesn't make any integrated class D amps. |
My 1.6s sound great driven by a Classe CAP-151 integrated which is 150 wpc. You want a high current amp and something that leans toward the "warm end" to compliment the detail in your Thiels. The real solution for the bottom end, however, was to add a Rel Britannia 3 sub, which made them glorious: full bass and much improved percussion and soundstage. Choice of CDP will also bring out the best in these speakers. I went with a Cary 308T with Mullard tubes, which has taken the last bit of harshness out of the chain. Best of luck, JR |
John Potis over at Six Moons just reviewed the Bel Canto e.One REF1000 digital amps driving his Thiel 2.4's and really liked the pairing. The Bel Cantos may be over budget new but there is a used pair up for sale. http://www.6moons.com/audioreviews/eone2/1000.html |
Get a set of Channel Islands D200s. Buy them from Musicdirect and you'll get a 30 money back gaurantee. That's how I bought mine. Needless to say, once I heard them they weren't getting them back. I've had them for about two years now, and find I have never even considered attempting to find something better. For me that's saying alot... |
Drubin: Thanks for sharing your experience. The 102 looks interesting. Did you use that or the 201 (or some other model)? I'll need to listen again to the 1.6 to see how I feel about its bass performance. Not that I'm a bass freak but it's always been my feeling that 42 hz (the bottom note of a bass guitar) is the least extension I would be comfortable with. Narrod: I humbly disagree with you on Thiel. My earlier experience was negative but properly driven I found a lot to like. To each his own. Jaybo: I liked the Bryston a lot. Unfortunately, it's $3k second hand. I'm not ready to go there. The B60 might work but it's only 60 per side. |