Thiel Owners
I want update my journey with the Thiel CS3.7 now that some changes were made. 1) A speaker repair tech came to my house today and re-soldered the crossover wires to the tweeter and midrange of my right speaker. They were wired out-of-phase during a prior DIY OEM COAX replacement. The speaker seller has volunteered to pay for todays repair. 2) I discovered a damaged screw thread on the left speaker frame. Rob Gillum pointed me to a toolkit to repair that. It is being shipped to me now ($44). The original speaker dealer seems to have gone torque crazy with the driver screws. 3) I will sandpaper and lacquer the speaker because this speaker is never leaving. Rob Gillum gave me instructions on best approaches for that. 4) I ordered the outriggers from Rob G. for the day that my 4 year old son decides to climb the speaker. After #1 was done today the speaker sound just opened up. The harshness is gone and the soundstage is huge the imaging is better. Just like I remembered 12 years ago at the store demo. I think it actually sounds better today on my all Benchmark stack than the all Classe gear of the demo. Getting to that Benchmark stack. I have been disparaging the AHB2 Stereo amp with the CS3.7. Saying it sounds lean and not dynamic. I was thinking in my small room 194 watts at 4 Ohms should have worked. The amp also goes down to 2 Ohms but I do not remember the numbers for that. However, the sound was not that good wherever I positioned the speakers. I think I said on a scale of 100 it felt like a 75, even less on dynamic music. Today, after the out-of-phase fix the sound is powerful, dynamic and glorious. I would say a 95 out of 100 now. The room is still there so not a 100. I am kind of curious still about the CODA #8 amp with the CS3.7 but I do know that the AHB2 will never leave this system. I caught a lucky break by not selling it a few days ago to fund the purchase of the #8. So in a small room, see my Virtual Systems, the Thiel CS3.7 + an all Benchmark stack (with a single AHB stereo amp) sounds amazing. I will explore the DRC implementation tomorrow now that the drivers are working right. BTW - I was just thinking that reason that the it was easy for me to hear the out-of-phase problem was because of the revealing nature of the Benchmark gear. I also now feel that for my room the Luxman m900u and the CODA #16 would also be viable alternative amps. I do not need the massive amounts of power at 2 Ohms for this room. |
@tomthiel, Yes, you would think with quality that originally went into them, that some of the amplifiers on the used market would be especially appreciated at their now discounted prices. Too many are caught up in marketing of the “latest and greatest” gear getting all the most recent attention. While there has been some improvement in some specific parts, these parts are not necessarily exponentially better, and many can be retrofitted to older gear. Some of the newer amps don’t actually perform as well as the older stuff with the speakers at hand. Interestingly, some of the more recent amps are actually based on even older circuit designs. Which in itself might or might not be a good thing. The perception of the suitability is sometimes different than the reality. The physics hasn’t changed. Not being mindful of the criterion used to make the lists, or how the maker of the lists keeps a revenue stream going; it’s as though if it’s not currently on a Class A rating list it can’t be any good. I hope all your super good work(!) comes to fruition for us Thiel lovers soon! |
Unsound - As you say, sufficient power is an absolute requirement. I may be naive, but I'm thinking that with good used equipment available at bargain prices, education would be fruitful because many folks could actually afford good to great solutions. In addition to EMI and RFI from the interactions between the crossovers and the drivers, there is the proximity to metal driver frames and pressure fluxuations. A big deal is that cabinet vibrations necessitate every component being glued down to avoid microphonic and fatigue vibration. Plus the cabinet is a closed cavity, so heat generated by the crossover losses as well as the driver motors, wh heats up everything, changing the component values and circuit functions. It's not subtle. By outboarding I can dump crossover heat at the crossover and driver heat via heat sinks and thermal malpractice and compression are greatly reduced. each component can be mounted for maximum cooling. The baffle stuff is quite intriguing - newly developed plate resonators to quiet and organize the launch waves. Coupling of driver motion to proper air waves is less than trivial as well is the chaos of early diffraction. Thiel paid lots of attention to that, but more attention is fruitful. Here's an aside. I can play a woofer in a cabinet adjacent to its mate with the mid-tweeter. Same feed signal. Taking the woofer-induced vibrations out of the (upper) cabinet cleans up the high end considerably. Imagine that. I thought the CS2.2 cabinet was quite quiet, and it is by comparative standards. But better is better. I can remove the cabinet top and bottom to doctor the cabinet walls, newly accessible from taking the crossover outboard. Two versions under development. Underslung Crossover places the 3D network in a vibration-insulated and ventilated chamber under the cabinet while the Outboard Crossover version puts it in a free-standing enclosure about 3' behind and connected by an umbilical to the drivers. To your point about the flat coaxes. Jim wanted coaxes from the very beginning for their solutions to placement and lobing problems. It took till the SCS in the late 80s to execute the coax and gradually get the outer cone more and more shallow to minimize the squak-effect. The flat-wave solves so many issues. |
@tomthiel, I wish I could share your faith in Thiel users getting amplification right. It seems that many seem to choose to ignore the basics. It’s not entirely their fault. I’ve seen different dealers offering what to me where incredulous demonstrations. Such as powering CS 3.6’s with 20 Watt intergrateds or CS 5’s with 50 Watt amps all the while resorting to their cheezy salesmanship gimmicks of grinning with crossed arms, nodding their heads up and down, tapping their foot,...all at barely audible listening levels. They were none too happy when I increased the volume to much, much less than typical listening levels. They would then lower the volume some and say that at these volumes the amps were sufficient, all the while the sound was of crunching distortion. Your points about radiation patterns and room placement were spot on. And let me clarify that even with DSP it would be preferable to work with a speaker that already was designed for a specific predictable placement rather than against it. Even if we’re not quite there yet, I firmly believe that DSP is the future. Though we may have to abandon previous notions to embrace the advantages of a new paradigm. The shared insights as to why the Thiel’s tend have low impedances was most interesting. In that there are still a few amplifiers to choose from that are up to the task justifies the gains in cohesion, ease of placement, and especially reducing lobbing effects. I am continually impressed by the latest flat co-axils. Your comments about free standing cross-overs was most interesting. I seem to recall reading an article where Richard Vandersteen had the same “AhHa” moment with similar circumstances of free standing first order cross-overs. I never gave it much thought before. Perhaps vibrations, EMI, RFI, all, some combination, or none of the above? I’d be most interested in following your research on the matter. I’m still curious about your research on baffle reflections as well. Thanks so much for maintaining the research progress of our favored Thiel’s. |
JA - what a trip indeed. Circumstances have prevented progress in ways that many here assumed or wished for. I’m not yet discouraged; and I’m stirring the pot every day. My personal interest drives me to decipher some of the mysteries of Thiel and the idiosyncracies of its product performance. As you know, I have speculated that phase coherence allows the audio-brain to scrutinize sound differently than non phase coherent sound - as I formerly have written here. I beleve that, but many elements don’t neatly fit into that narrative, including the opinions of knowledgeable practitioners to the contrary. My search and questoning have taken unexpected turns. An early assumption of low-hanging fruit was crossover component upgrade. Indeed good results were gotten there; similarly hookup wire and softening the wave launch surfaces on the baffle. But a derail occurred serendipitiously on a flight of fancy when I fantasized with an audio friend about some aha moments during early product development experiences in the 1970s. We identified the let-down when the ’hanging sculpture’ of the free-air crossover-in-development was nailed down and put in the cabinet. Magic went missing. Long story shortened, we re-created a bird’s nest crossover hanging in space. And, guess what - magic. I have developed and tested some hypotheses and solutions and identified some obscure aspects of performance that migrate the musical experience from somewhat canned to substantially transparent. A relevant result is how ancillary equipment interacts with my speakers under test. Thiel fans have spent enormous time, effort and funds finding source equipment that works. And when it works, it works well. Shortened story: the outboard crossover has opened doors not only to better music, but to finding solutions to some pretty subtle problems, including broadening the range of acceptable drive components while increasing the level of detail, transparency and 'rightness'. Anyhow, in moments of nostalgia for a company history that never was, I wonder about what we might have built if we had asked these questions and found these solutions in parallel with Jim’s relentless progress in the areas of his interest and expertise - where his innate comprehension of physics met his unique engineering ability to convert his best ideas into uniquely satisfying products. But, there is always more potential, isn’t there. What a trip finding some buried gems hiding in plain view within the platform he created. |
Thielrules - it all depends. A very big deal is running out of power. The Adcom and Benchmark have overload LEDs. Listening at 95dB peaks at listening position, the Benchmark overloads consistently in stereo with one amp channel driving the woofer and the other the mid-tweeter. The bass amp can be bridged and its input sensitivity reduced to match the stereo upper amp. The upper stereo amp then becomes the overload limit, so it also must be used in bridged mono. Clipping is unacceptable. The Adcom at twice the power is better, but marginal on the mid-tweeter. It has no input sensitivity selector and therefore in stereo it cannot be easily gain-matched to the bridged woofer. So no go for tri-amping. Classe DR9 has similar power to AHB, so I assume it clips even though it doesn’t give LED proof. If you had 4 amps and could dedicate one to each woofer and one each to the two mid-tweeters, that is theoretically better than a single bridged amp to all three drivers, at twice the amp/cable expense. I am personally at peace with a Bridged Benchmark driving each channel with 3 separate cable runs or two runs: one to the woofer and another to the mid-tweeter. To your question of best configuration - Because low impedance loads cause higher distortion in normal (non AHB) class A/B amps, I would prefer a stereo amp with one channel for the woofer and the other for the mid-tweeter. Those amps would need to be a few hundred watts minimum per channel into 4 ohms in order to stay clean. My amps in my space don’t deliver the goods satisfactorily in stereo mode. Let’s do some history. As you know, the CS3 was set-up for bi-amping / bi-wiring. It separated the tweeter from the rest of the signal because the equalizer boosted the bass which included contribution from both the midrange and woofer, so they couldn’t be segregated to different amps. Audible improvement was gained by separating the tweeter. But the preponderance of users chose small SET or tube amps for the tweeter with no consistent way to gain-match the low frequency amp. Solving those variables would have required a different kind of dealer. Jim assessed that we didn’t have that expertise in the field to his satisfaction and removed the bi-amp /bi-wire option. The scene is different today in that remaining Thiel users are likely to commit to getting it right or staying on the sidelines. It is tricky business, especially in the absence of clipping lights and with uncompressed and/or otherwise very dynamic music. Underpowering makes distortion and distortion fries drivers. Be careful. |
Unsound and Tom. As you know the 3.5 individual drivers are all above the 5 ohm across the whole range and combined stay above 4 ohms. Makes it very suitable for tri amping or bi amping. I would guess that bi amping the bass and mid-tweeter with one amp would be better then using the amp in serial configuration for all drivers. Is that consistent with your experience? |
From a placement standpoint the coax is magic.I agree. I have had a few speakers with the tweeter and mid on the same driver unit and it has always made placement much easier. I am slightly off center in my seating. With my KEF LS50's (also a similar type of driver) I had to make an adjustment on my preamp's balance to give the far speaker a bit more juice. With the CS3.7 I set the balance to 0 and it sounds great. The sweet spot is bigger than most speakers. The KEF Blade is also like that with a big sweet spot. Sounds like you are a music fan. When my kid was under 2 years my office/audio room was in a laundry room. I would work and listen while a washer and or dryer was going full blast next to me usually washing kids stuff. Still enjoyed music. |
@yyzsantabarbara1 I bought 3.7s in 2012 and had kids in 2013 and 2014. Audio dropped way down on my priority list and I had them in several far from ideal spots. I had them right next to each other for a while and they sounded great. You don't get much in the way of imaging but otherwise great. I had them nearfield for a while on each side of my desk with my head a couple of feet in front of them but way off axis. Still great. I worked from home for a few years and I was always amazed at how good they sounded in this far from ideal situation. I couldn't believe how well the image held together. From a placement standpoint the coax is magic. |
Unsound - I agree to wanting 4 ohms minimum which would roughly double the impedance of many Thiel models, making them far easier loads to drive with lower amplifier distortion and fewer cable interactions. Jim committed to underhung voicecoils as a way to reduce motor distortion by an order of magnitude. Walter Kling developed the methods and machines to make those drivers. He shared that industry driver manufacturers considered them nearly impossible to make and therefore expensive and ill-advised. Jim and Walter took that as a challenge and took it on and never looked back. One of the downsides includes the coils being only a few winds long (short?) x 4 layers thick, which is precarious geometry indeed. More turns would raise impedance, but also add mass and mechanical reactance in a system short on gap flux due to the thick coil. The feasible balance point seems to have been where he landed. He wasn't really out to make our lives difficult driving them, it just worked out that way. |
I have no doubt that identical individual amps for each driver would be ideal, especially when one considers the potential of DSP when so configured. I would have preferred 4 Ohm minimum loads. The difference is not as insignificant as might first appear, particularly for those that might prefer tube amplification (which doesn’t include myself). That would also allow consumers to use standard ratings and measurements without prevailing doubts. |
unsound & thielrules - about individual amps. I’ve been comparing configurations these past few days and conclude that it’s very murky water. I have matched pairs of Adcom GFA-555 mkII, Classe DR9 and Benchmark AFB-2s. The power is similar, but the clipping characteristics are different. Even with using same source, preamp, cables and speakers, the amps’ characters change when stereo or bridged and how hard they are pushed. All things considered, it would be hard to make any ’best recommendation’. I agree with unsound’s thought about ’same amp’ for bass and treble. Gain matching is very important as well as overload characteristics. At this point what I can say for sure is that among my amp stable, the AHB-2 is the cleanest, clearest, most harmonically convincing. To my previous comment about its possible bass ’deficiency’: I suspect it is outputting most accurately, even though other amps might be more appealing. After speaking with John Siau of Benchmark and poring over test results of all the amps, I’m convinced that the AHB-2 stays extremely clean (until it clips), whereas other amps delay bass frequencies which is experienced as hanging longer in time, and produce harmonic (distortion) addenda which is experienced as more amplitude. Combining time delay and more harmonics produce bigger bass. But, the AHB-2 bass is so clean and articulate with considerably more inner harmonic detail. The problem still remains that it admittedly produces "less" apparent bass than other amps, so the producers’ intent may have more bass than the listeners’ experience with the AHB-2. My preferred setup is running a pair of AHB-2s in bridged mono, each driving a full-range speaker with 3 separate, identical cable runs (or two runs that combine midrange and tweeter feeds. I rigged some 6’ and 12’ runs and cutting the runs to half length increases damping factor by 2 and tightens up the bass that was loosened by bridging. If I could afford to splurge, I would use 4 AHB-2s, all bridged. One for each channel’s woofer and the other for the mid-tweeter. But, I don’t feel the need, a bridged pair doesn’t clip in my situation, and unlike normal amps, the AHB-2 distortion stays near zero into any drivable impedance until it clips. JS says that impedance limit is around 2 ohms, so some Thiel models are in jeopardy. But I haven’t experienced it with my 2.2 and 3.5 testing. I wish Jim had kept his loads above 4 ohms nominal, 3 ohms minimum to stay out of trouble. |
I cannot play with the placement other than these minor movements. I bought the CS3.7 on the assumption that if it did not work in the office. I could eventually move them downstairs to the much larger living room. The living room is my sons play room at the moment. However, the placement that I just did is great. Given the circumstances of this room I am extremely happy about the sound, except for that harshness. which will be resolved on Tuesday. I will say to prospective CS3.7 buyers that the speaker will play in a acoustically treated room small room, see my Virtual System on A'gon. I understand that I am not getting the very best sound out of the CS3.7 but, what I am getting is very good. Reading everything on the web on this room size issue made me think it would not work. I am shocked actually that this is working so well and I am not getting overwhelmed with bass. I still have the DRC implementation that I can bring to the table to potentially make things even better. |
Thanks everyone for the great info provided here. It has made this problem pretty easy and fast to resolve. I have a speaker repair tech from the local high end audio store coming to my home next Tuesday. The cost is not much for 1 hour work and the speaker seller has volunteered to cover the expense. The estimated cost is pretty low (so far) so not concerned. I will have everything ready to just unsolder and re-solder. The speaker tech is aware of the battery test though the sound engineer in Canada told me to send him another set of measurements and he will tell me if it is setup correctly. I will see how experienced the repair guy is before I figure out which way to test it. I received the following feedback from Rob Gillium today about the wiring. The CS3.7 is a three way speaker, with a Passive Radiator. Each crossover section has a pair of output wires. There are three pairs. One pair to the woofer, one pair to the midrange (coax), and one pair to the tweeter (coax). The coaxial driver is a two driver combination, (midrange and tweeter). Each driver has a pair of wires. The white output wire is positive and should be connected to the red terminal of each driver. The black wire is connected to each unmarked. terminal of the drivers. These wires must be connected in this fashion, to be in phase with each other. If one of the drivers are connected out of phase (reverse polarity), then it will cancel the output from the other driver, thus rendering poor sonic quality. It is very important to connect the midrange pair to the midrange, and the tweeter pair to the tweeter. If these are connected wrong, then the tweeter will see the mid frequencies, and be destroyed in most cases. I was also speaking with a CS3.7 owner in Brazil who is active on the ASR forum and he thought the Coda #8 V1 would be what he would select from the #8 options. However, he did mention that Purifi is going to come out with a new module that will have similar specs as the NC1200. He is waiting on that before any new amp purchase. He suggested I do the same. I have a feeling the current Purifi module sounds very similar o the AHB2. A future module with the the same sound but NC1200 power specs would be great for the CS3.7. I should say again how happy I am that I payed attention to TomThiel’s post about positioning. I was initially trying to get max space between the speakers with low side and later low front wall spacing. Now with the speakers around 2 feet from the front wall, 2 feet from the side, and only 6 feet in-between, the sound is really good, the best so far. |
Yyz - the definitive test is to make a momentary connection from a 6 volt lantern battery (or other 6 volt DC source) to the XO inputs. All drivers should move forward. You can readily see the woofer and midrange move, but may have to feel the tweeter. And Thiel uses silver solder which has a higher melt temp than utility solder. A 140 watt gun is just right. |
yysantabarbara Nice catch or should I say good ears , but strange because the coax speakers polarity are clearly marked with the red and black wires going from the solder pad to the speaker , and if the crossover is like the 2.7 the negative / black wires from the tweeter and midrange are soldered together . I hope that wrong wiring is your problem . Good luck and hope it's not to big of a repair bill . |
I called Rob Gillum about the COAX installation know what needs to be done to resolve the out-of-phase issue. I have decided to use the services of a local audio store in Santa Barbara. They will send a repair tech to my home next Tuesday to do the soldering. Learning a lot of technical stuff with this hiccup. I decided to move the Thiel CS3.7 to a new position. I now have them 2 feet from the front wall and about 2 feet from the side wall. The speakers are now closer together about 6 feet apart. The sound now is better than any other prior placement. Even with DRC I will keep this positioning, mainly because I have 3 out of 4 sources that will not use DRC. Only my digital streaming via ROON will use DRC (if I like it). So next week is when the interesting stuff happens. Enjoying the out-of-phase tunes until then. I also bought an CS3.7 Outrigger for the speaker feet. My 4 year old first words when he saw the CS3.7 in my office was "I want to climb it". |
Some important news was found out from my DRC measurement steps (first step actually). I want to clarify a point about the slight harshness I was hearing on the CS3.7 top end. I was saying it was not as smooth as the KEF LS50. The measurements showed that right speakers Coax driver is out of phase with the left speaker Coax (maybe one can say the opposite). There is some harshness on the frequency response due to this miss-wiring. I guess my hearing is good. Prior to the sale I knew that the previous owner got a new Coax driver from Rob G and soldered the Coax wiring himself. He was a little worried about the wiring since there was a 2 week delay with shipping the driver to Rob and getting the new one. Anyways, the previous owner and I are working to get this fixed, should be an easy job. I will give Rob a call tomorrow to find out the specifics of the job. So the DRC work is halted until this out of phase issue is resolved. I am going to find some electronics guy/gal to do the solder, since I am a newbie on that and I want it perfect. BTW - the engineer up in Canada, Mitch Barnett, used to owned Thiel CS3.7 and he loved them. @jafant My pressing of the SACD is from SME records. I now have my SACD player less than a foot from my seating position. Makes things easy. Getting real lazy with age. |
^I agree, when there is no DSP. But, that’s the beauty of DSP, it has the potential to remove those “assumptions” and replace them with real time and space measurements. Problems arise when the those measurements correct the relatively small in volume (not sound pressure) though more important primary direct sound as though they were the larger in volume (again not sound pressure) though less important reflected and distorted room sound, creating a weird primary direct sound. By placing the initial primary source of the sound close to the room boundaries they are more similar and there is less difference between the two. Flush mounting would be ideal. Due to the inherent bass reinforcement, it can also relieve the amplification of some burden, that might or might not be exacerbated by the DSP processing. |
Keep the time domain in mind, especially for phase coherent speakers. On and off axis radiation patterns are different as the frequency rises. The speaker is balanced into an "average" environment with assumptions made as to where the front and side walls "might likely" be. Those assumptions never include placement near a wall. Perhaps you can unscramble the changes with DSP, but the differences with placement will be significant. |
@vair68robert Thanks for your input. I am going to stick with the GIK panels for now because I am low on funds and also these panels made my room sound great with the KEF LS50s. Prior to the panels the sound was awful. I understand the CS3.7 is a different beast but I am getting close to the sound I want. I am taking the the suggestion of unsound and moved my speaker back 1 foot from the back wall. This is the closet I have had any speaker in this room. Still trying to figure out if I like that positioning. Though with DRC it will not matter. I am playing Santana's Caranvanserai SACD and it sounds pretty good. Thought last night when I played it on my headphones I was wowed and thought I need to hear this again on the CS3.7 in the morning. It is not as great on the speakers and I think it is not the room this time, Ii is the amp. This is an album where some power is required out of the amp. There is a lot of percussion on this album. I got feedback from the DRC engineer this morning after I sent him my 2 preliminary measurement files. He plotted the measurement on a graph and the lines were very close from the 2 different days. The measurement with the desk in the room actually had a little better base. Though I liked the sound without the desk. I will be sending more measurements today to get him going on the Convolution file generation for my room. |
yyzantabarbara I'd like to throw my 2 cents in , not about amps because of the cost but about room acoustics . For a very reasonable price you could try replacing the 4 inch thick panels you are using for the side reflection with 1 or 2 inch thick ones , on the acoustimac site the give the graphs for each of thier thicknesses . You can see how you can absorb higher frequency reflections while allowing the lower ones thru , this might help with your lack of bass . Just a thought Rob |
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thoft62 posts10-27-2020 12:12amSo uh there’s a set of 3.6 for sale next state over. They’re asking 1500. It’s itchy.." I've owned my 3.6's since shortly after they were released in late 1993. I still find their sound very very satisfying. I sure would recommend them to anyone. I did have issues with the tweeter and a midrange driver on one of the speakers...about 6 years apart. I spoke with Rob on those issues when he was still at the original Thiel, and had the drivers rebuilt and returned. They have worked just fine ever since. I've tried lots of power amps with them over the years and found that I've been most happy using a Threshold SA/4e pure class A, Nelson Pass designed amp. That combination just works really nicely. I've tried others, including an Adcom Gfa 555 Mk II, plus a pair of Emotiva XPA 1 moniblocks. They all sound good through the Thiels, but I keep coming back to the Threshold. |
I’m not trying to discourage you from using DSP, just what might be involved. I think having the speakers right up against the wall behind the speakers could reduce demands on the amp, and perhaps more importantly not over correct the direct primary sound from the corrected reflected room sound, as the two sounds will be so similar. |
That’s OK, I paid good money for the amp, need to put the amp to work. When I first got the Thiel CS3.7 into my room I said the sound was like a 70/100. I got improvements with various steps. This room changes today take me to about 90/100. I am very interested to see what the DRC Convolution files do to the sound. I emailed the file to the engineer to do his magic. Good thing is that it is a matter of flipping a switch to either use the DRC or not use it. |
My last comment on the AHB2 so I do not drone on and annoy people. I am doing acoustic measurements with REW software and Minidsp microphone. I am doing these measurements to have Accurate Sound of Canada’s Mitch Barnett analyze my room measurements and make me some Convolution files to run on my ROON server. My first set of measurements came out with some graphs that seemed to me that the sound was bad. I though that cannot be good and decided to do some surgery to my room. Mind you I have no idea what the graphs mean. There was a lot of red colored measurements which could not be good. I removed a side desk and some plants and moved my system even further away from the speakers. (the last 2 photos are the result of the surgery) https://systems.audiogon.com/systems/7605 I ran the measurements again and this time hardly any red in the graphs. Maybe good news maybe bad news, no clue. What I do know is that the sound is much improved. The room sounds bigger and the amp sounds better. I could actually live with this sound. Though I still will get that Coda #8 amp given how much money I have already saved with this system. |
As a point of Thiel history, Jim used very good amps to design the speakers. His attitude was that making a good amp was the ampmakers’ business, and making a good speaker was his business. We generally had on hand the best from Levinson, Krell, Audio Research and others for comparison. His workhorse for the 3.7 development was the Krell FPB-600. But at shows, Thiel usually exhibited with amps priced commensurate with its products. No $30K amp for a $10K speaker. Bryston was often used. I found the Bryston amps rather coarse compared to the better stuff at the factory. Many reports said that all changed with Bryston’s ’cubed’ series - which are more refined. Thiel used the a cubed series amp (perhaps 4B3?) to introduce and show the 3.7. That was the combination that George Cardas dubbed the best sound he had ever heard at a show. Bryston offers trade in and upgrade packages. I suggest that the ’cubed’ Brystons come very close to supporting Jim’s design intent for the 3.7, even though it doesn't meet the double-down standards for full current delivery into low impedance loads. |
One of my CJ amps had to go in to the shop momentarily and an audio-pal lent me his Bryston 4B3: https://www.soundstagehifi.com/index.php/equipment-reviews/1073-bryston-4b3-stereo-mono-amplifier I tested it on my Spendor S3/5s and then my Joseph Audio Perspective speakers. I had the usual reaction when I use solid state: wow, neato grip and power, density, transient edge vividness etc. Really fun. But once I got my CJ amp back and compared...I was definitely still in the "tube" camp. They sounded about as powerful, but richer, fuller, more organic and beautiful. Next up I'll be trying the Bryston with my Thiel 2.7s. I've never heard the 2.7s with solid state so this should be interesting. |
@xyzsantabarbara, As I understand it; yes. I believe many of the Krell’s do, that the Mark Levinson ML 2’s did, some of the Pass Labs might (limited to 4 Ohms maybe?)? I wouldn’t swear on it though. I’ll hazard a guess that the Class A output is halved as the output doubles as impedance is halved. Though most times one cruises along at low power output, that output increases rather dramatically exponentially. You’ll have to decide how relevant the Class A output in your circumstances. Keep in mind that available higher total output can potentially protect drivers from under powered clipping damage, and the ear tends to be less sensitive to the cross-over distortions of Class AB at higher volume levels. These are the areas that separates typically have advantages over their integrated brethren; the ability to double down and and the ability to stay in Class A output longer when doing so. |
@jafant You might be interested to read the new AX-5 Twenty review in Hifi News https://www.hifinews.com/content/ayre-ax-5-twenty-integrated-amplifier On the bench, it produced 650 W into a 1 load under “dynamic conditions” (I think this similar to the tonebursts that Stereophile did for an interval, more music like than steady state test signals; not specified whether that was for one or two channels driven). Eye-popping how much more powerful the Twenty is compared to the original even though Ayre did not change the spec. Pretty well confirms what my ears hear paired with the CS2.4. |
I have just received an 11 foot pair of Van Den Hul D-352 Speaker Cables they are without termination. I would like to connect my CS-5 speakers to my Conrad Johnson Premier 350sa power amplifier. Both are factory unmodified 5 way binding posts. I am asking this group for recommendations based on sound quality from experience. Thank You All in Advance! |
