I just scored a sweet pair of CS 2.4SE loudspeakers. Anyone else currently or previously owned this model? Owners of the CS 2.4 or CS 2.7 are free to chime in as well. Thiel are excellent w/ both tubed or solid-state gear!
@sdl4, I’m not completely sure of the following, but I seem to recall reading a discussion where Bruno Putzeys said something to the effect that GaNFETS were indeed superior devices but a their current costs one could just as easily build Class A amps and that would defeat one of the main reasons of going with Class D in the first place; efficiency/cost. If I recall a correctly he was waiting for the price of the devices to come down. On the other hand, he’s also indicated that he's become a bit bored with amp design and would like to give more of his attention to speaker design. Honestly, I would take everything I just posted with a grain of salt, my recollections could be failing me.
I will say that the specs I previously posted on the link for the upcoming new amps look way better than anything I’ve seen for any(!) GaNFET amps I’ve seen so far, especially with regard to those specs that would be of particular interest to many Thiel users. And at more affordable prices too!
@tomthielI am leaning more towards replacing the tonearm cable and / or experimenting with damping fluid since for the most part the speakers only sound bright when I play vinyl. It's a jelco 750d with a jelco cable.
@improvedsoundWow, that outboard cabinet is really impressive! The attention to detail off the charts.
I see you put aluminum cooling fins on the bigger resistors. Tom had me try a similar cooling mechanism in my build. But it seemed to produce an echoey anomaly. Subtle on many tracks but I heard the best sound without the aluminum heat sinks. One of the advantages of an outboard XO is you can just vent the cabinet, no need for heat sinks. Simply add holes to the bottom and, maybe, top of the rear panel. When I was considering outboard, I imagined the top of the cabinet would just be stainless steel mesh.
I see coils on left side of coax and woofer have the same orientation, almost stacked. I suspect those are close enough to cause interference. Here are a couple of resources for your consideration: http://www.troelsgravesen.dk/coils.htm
Finally, the binding posts look like Thiel gold over brass (or equivalent). There are better choices out there, and it appears you have the budget. I used Cardas rhodium over silver.
Please hear those as friendly suggestions, not criticisms. You have done a lot of hard work!
roxy - I actually don’t know the name. It was his prototype he brought to CES, possibly around 1980. We used it in our show system and took some flack because the cable cost more than our speakers and power amp combined. Seems like it was a woven mesh, perhaps 3/4"- 1" wide x very thin. I remember Ray saying the insulation (perhaps Silicone) was applied with a mouse during layup. It may not have yet been finalized or had a name. Whatever it was, his cable lifted the veils, tightened the image and the bass and pulled out the stops in a jaw-dropping way. There were industry folks in the room (this was Thursday, setup day, Chicago, June) who were all impressed. Remember this is when ’the industry’ had not yet admitted that wire could matter, therefore it was snake oil. I do remember that Ray wanted us to use his wire for internal hookup wire, which seemed to cost more than the drivers. Out of the picture for us. Sorry I don’t remember or ever knew any more about a model or name.
Oh yes, I told Ray about Guarana, the Amazonian stimulant, and he eventually imported it and made a product called ’buzz gum’. Guarana is a left-handed caffein-like molecule that makes work in the Brazilian jungle possible (and pleasant.) To this day I keep some buzz-gum as a conversation piece to spread around our woods’ work crew when I was producing tonewood. . . . But still no cable name.
I have some samples of Iconoclast to get into my works. They use similar principles to those Kimber from the 80s (don't remember the name) that were woven, flat, and cost $1K/pair-foot. They were mind blowing. I'm looking forward to the Iconoclast because of their particular pedigree and geometry. They may serve as a reference of reference-level internal hookup wire. But . . .
@tomthiel I agree! I don't understand enough about how cables interact with speakers and specific electronics to be able to predict which ones will sound best in my system. To find cables that work well and don't have crazy-high prices requires a lot of patience and extensive trials to compare cables. As far as I know, @jafant is still on his extended cable quest, and I can't promise that I won't keep listening to new cables myself.
Cables are indeed fascinating, and their interactions with sources and load are beyond my understanding. And a lot of them don't work well with Thiel speakers. For the record - much of my approach to this playback thing holds cost and cost effectiveness as central values. I have auditioned some wonderful-sounding cables (including Cardas) that could simply not stay on my radar for reasons of cost alone. Independent of my own constraints, I live in the world of Thiel's classic orientation: creating musical tools and solutions that give access to sophisticated, satisfying musical playback experiences within the budgets of ordinary people.
@unsound Thanks for helping me understand some of the intricacies of the CS3.5 EQ and providing some clues toward what's happening in the evolving world of Class D amplification. I agree that Bruno Putzeys has been the brain behind many of the most important advances in modern Class D electronics, so it's interesting that he hasn't yet jumped on the GaNFET bandwagon. From what I've read, it appears that most of Bruno's work continues to use MOSFETs instead of GaNFETs. We'll see if that changes in the future.
For the present, I'm generally happy with the Class D PSA M700 monoblocks powering my Thiels, but I think it's likely that newer Class D offerings will sound even better and cope with low impedance loads more effectively - even in speakers that present a less benign impedance profile than do my CS2.2s.
@tomthiel Thanks for keeping us updated on your recent changes in cables and electronics as you look to optimize the functioning of the CS3.5 EQ. I agree with your suggestion to @Big_Greg to try the Benchmark cables to see if they reduce his concerns about brightness with his Thiel speakers - at least when reproducing music from vinyl - but I would also suggest that he try several other different interconnects and speaker cables as well. My experience has been that Thiel speakers (even my CS2.2s) can be pretty revealing of differences between cables and electronic gear. That's a good thing if you find a good cable match, but a problem if you don't.
For my own listening, I'm trying to find the best balance between high frequency air and detail, midrange fullness and realism, and low end impact without boominess. I'm also trying to achieve excellent imaging while minimizing listening fatigue. I've been generally happy with Cardas cables (like Clear Reflection) that blend the classic Cardas midrange liquidity with the high-end detail of the newer cables in the Cardas line. I don't get concerned when I read about listeners who are looking for uber detail and think that Clear Reflection softens detail too much. Not every listener has the same gear or the same preferences.
I've tried several interconnects (including Vovox Sonorus and Zavfino Fusion) that provide nice high frequency detail and natural tone, as well as seemingly adequate low-end heft, but I've found that over time they just sounded a little too thin and lacking in the richness, fullness, and coherence of the Clear Reflections. I'm not suggesting that everyone should use the cables I use, but I am suggesting that everyone should at least demo a range of cables to see what sounds best with their gear and their preferences. Thiel speakers are revealing enough to show off cable differences, so Thiel owners already have that going for them.
Yes, your experience with the Benchmark cables mirrors mine. I have Aurender N10 > DAC3B > LA4 > AHB2 x2 > 3.7. I've posted several times here about how glorious this sounds. I tried some upper-end Morrow speaker cables a while back. Frankly, and not to detract from Morrow's fine work, they didn't add much to the perceived sound quality when using all stock Benchmark wire.
Outstanding! Beautiful work. You are in good company here as there are several DIY members on the Panel. Keep me posted as you massage this loudspeaker back into your room/system.
As we can see, I left the original internal wiring, but lined it with some cotton. The four binding posts are made of copper. I replaced the plastic plates with aluminum plates and fixed them with neoprene gaskets. I respected and kept the graphics
big_greg - I’d like to address your brightness problem. It is odd that the Thiels alone are bright among good company. It seems reasonable to assume a speaker problem. I don’t know the 2.3s, but hear that the original tweeter could be heard as ’strident’ and the vented replacement 'fixes' it. I do know 3.6s and the only brightness, stridency, etc. I have found is from a baffle surface propagation phenomenon which is greatly reduced with grilles in place, and is being addressed in my present work.
There is the possibility that something has gone wrong in the XO which is disabling a shaping network in a tweeter or midrange. A physical XO inspection might be in order. But such an instance would be rare, and becomes statistically next to impossible in more than one speaker.
So here's another thought. I’ve had an interesting (disorienting) experience since getting my Benchmark front end yesterday. First of all: it seems phenomenally good compared with the PS Audio Stellar gain cell / DAC and S300 amp. BM is better in every way. The ’interesting’ part is how much more obvious are the cabling differences. I have some Straightwire, Audioquest, Morrow, Mogami, and the standard Benchmark / Canare that came with the stack. Hard for me to believe that the ’normal’ $35 BM interconnects seemed so much more ’right’. Same goes for the speaker cable (with not as much comparison.) I’m in cognitive dissonance since I’ve been doing wire for nearly a half century. I am presently evaluating execution levels in the 3.5 equalizer within two driving systems. The big tip-off was the Bass & Mandolin cuts. I have played the mandolin and was involved in the development of the Collings line. The nuances of chop and gulp, box and ring are in my ear and under my skin. I stopped blaming the equalizer when I added ’straight wire’ to my protocol. When I got to the all-BM / Canare cables things settled into that remembered musical reality. It sounds right and good and I’m not missing those audiophile traits that might be artifacts.
My point is that before you give up on the Thiels, you might make some comparisons with BM cables. The phase / time coherence of all Thiels puts the ear-brain in a different hearing space than do non-coherent speakers. I’ve addressed this idea before, and I admit it can sound hoaky, but my consistent experience over these many decades is that when the system gets right, the speakers disappear. Something smells wrong about your Thiel brightness problem. I hope you can fix it.
bobscliff check out speakerworks they have a good video on repairing speakers .
big_greg. I have a Merrill Heirloom TT with an outer clamping ring and I think it makes a big difference , I am surprised that there aren't more TTs with either an outer ring or vacuum hold down .
As for your 3.6s. have you thought of rebuilding/upgrading your crossovers ?
@vair68robertMy Sota doesn't have the vacuum hold down. Maybe someday. I use Sota's reflex clamp, which is good, but not as good as holding down the edges of the record. Prior to the Sota I had a VPI Classic 2 and their periphery ring. I initially had a hard time paying what I did for a big metal ring, but it was very effective and worth every penny.
unsound - that self-surround does break down over time. At the time we were trying to minimize the standing wave reflections and non-linearities between the cone and surround as well as ultraviolet deterioration of soft plastics. It worked well when new, and held up pretty well. Natural rubber turned out better.
Thanks to those who posted the earlier advice on the amp. I took a chance on the used Nova 300 and hopefully it’ll work out well.
I had another question if anyone has any experience with basic speaker repairs. The surround on the midrange driver on my 2.4 appears to be coming loose from the cone, and causes an awful rattling sound at certain frequencies, esp acoustic songs.
I was hoping to glue it back on with some sort of rubber cement or flexible adhesive like E6000. Any advice on what to use and how? Image of driver:
Yes, of course. That circuitry is already extant in the eq. There is only 6dB of boost at 40Hz vs 12dB @ 20Hz. Tomorrow I'll run today's trials at 40Hz vs straight wire.
It's not that Jim didn't know about CDs dynamic peaks, it's more like he was trying to cope to keep the equalized bass viable. That woofer was the first driver with his magnetic shorting rings for a more stable magnetic field and it had a huge overhung coil to handle the required excursion. The overhung motor requirement was the largest cause of the end of eq. He figured out the drastic distortion of reduction of underhung motors and powering long gaps was virtually impossible because rare-earth magnets weren't yet in the mix. Long excursions and underhung motors contradict each other.
Phase angle was not a thing in reviews at that time. In fact Jim goaded JA / Stereophile into measuring phase at all. JA and Larry A came to our factory in 1988 to spend a day in Jim's lab learning why he thought it mattered, how he measured it and so forth - and they gradually entered the arena of phase and time.
A promising solution to the dynamic limit would be to match a powered subwoofer with probably a second order crossover at 80Hz to limit the woofer excursion while getting true integrated bass to 20Hz.
@tomthiel, thank you. I’ve always wondered about the phase angle, measurements for which weren’t published back when these were released. I’m in complete agreement, I’ve always thought the area of dynamic range / ultimate loudness was where the 3.5’s could use the most improvement. Fortunately for me, it’s one of my lowest priorities. Still, it would be nice to be more completely relaxed when knowing volume peaks are pending. I am a bit surprised that Jim wasn’t prepared for the dynamic range of CD’s, they had been out for about a 1/2 dozen years by the time the 3.5’s were released.
sdl4 - unsound has a good handle on the factors. But there are even more complexities. Jim did a lot of work on that balancing act including the unusually low reactance of his early bass tunings. The phase angles are quite low and at higher impedance where the amp can handle it better. But to your question: not quite even in today's world.
This afternoon I drove the system up to flickering clipping lights on the stereo AHB with Chris Thile - Edgar Meyers 'Bass & Mandolin' album. The calibrated Benchmark preamp clipped the AHB @ 2dB lower with the 20Hz equalized signal compared with straight-wire / no equalizer. I got similar results with Patty Larkin 'Strangers' World' cuts which are mixed for 'impressive' bass impact.
Jim's intent was to get that extreme and excellent bass extension without significant penalty. And it worked in the 1980s. Remember that vinyl was still the standard which is bass limited by cartridge tracking ability. But the landscape changed not only with digital, but with showcase albums from David Wilson and others which were engineered for 'unbelievable' bass. The Watt/Puppy could handle the real cannons in his recording of the 1812 Overture, but Thiel's model 3 would bottom out because they actually reproduced those deep frequencies. Similarly digital bass could go deeper with more power, and was therefore no longer predictable. So, even though Jim took great care, and his parameters balanced out to require little to no more power in the bass than that required by midrange transients, when the signal landscape changed, the elegance of his solution became practically less safe.
You have a lot more experience with equipment than I will ever have , but your thoughts about the phono stage is something I can totally agree with . Does your Sota have the vacuum hold down ?
My experience is with MM cartridges only using a phono stage that is 100% tube for MM's is that a world of difference can be had with changing just one tube or with matching the one 12au7 with different sets of 3 x 5751's .
Also the setting up of a cartridge an art in itself ! Something that I am continually learning to improve my skill at .
I should be receiving my ESRE capacitors soon and will be upgrading the coaxial boards resistors and capacitors next week , except the 1uf bypass caps that will have to wait until the Clarity PUR's are available . I hope the mids and highs sound as good as the lows have sounded since upgrading the woofer boards .
@vair68robertA lot of vinyl sounds really good with the Thiels, and I do listen to mostly "classic rock". I have two turntables in my main system, a Sota Sapphire and a Technics SL 1200 MK2. The same record that sounds bright on the Sapphire will sound "good" (not bright) on the SL 1200, but loses a lot of detail, imaging, etc.
I'm using the same phono stage for both, but have a MM cart on the SL 1200 MK2.
It's quite possible it's not the speakers, it could be the cartridge, that the cartridge isn't set up right, the tonearm or cable, or how my phono stage handles MC vs MM cartridges.
The thing is, I have a number of other speakers that sound great in that system with the same electronics, so it feels like I'm trying to fit a square peg in a round hole.
@sdl4, Yes , the amp power output would drop with the impedance rise. But that’s because with that impedance rise, the sensitivity of the speaker will rise. As the eq is demanding more power, the speaker is a actually demanding less work from the amplifier to produce the same volume output, and with less distortion too.
I feel a little guilty even mentioning the "new" generation of amp modules. It’s really premature to do so. There are companies just now taking built to order amps. So far they seem to be foreign companies, so problems might have shipping and time issues. They are smaller and lighter than typical amps though. Some but not all companies making similar products have been taken to task for shoddy workmanship. Some of these companies haven’t been around that long. The sturdiness of their business legs might still be in question. It’s still yet to be seen if durability, parts, and service can be relied upon. Or what the potential resale value can be expected to be. Some of these types of companies seem to treat early adopters as beta testers. There could be growing pains before a product is truly consumer ready.
There has been a review of a prototype using power supplies that are incapable of extracting the full potential of these new modules. FWIW, the anecdotal review was very favorable in comparison to the current SINAD class leading Benchmark.
Since you asked::
Purifi1ET7040SA
From the pen of Bruno Putzeys, perhaps the foremost Class D designer in the world.
Rumor has it that Purifi is currently working on a power supply to fully extract all the potential from this module.
I'll partially agree with you on the highs using vinyl but I don't fault the speakers ,
there are some " rock " albums from the mid/late -sixties that can sound awful .
I have not noticed " brightness " in Classical or Jazz or Folk music but there are a few " rock " and "soul" albums that I have a hard time listening to ,
my opinion is that the mixing for AM radio was the culprit .
@unsound, I forgot to ask you about the new generation of Class D amps you're waiting for. Are there any specific amps or modules that might be especially promising?
@tomthiel, thanks for the additional info! I hope you enjoy your new Benchmark gear. I'll look forward to your more detailed comments on the extra load of the EQ for the CS3.5, especially with respect to what @unsound mentioned about dealing with the impedance "bump" in the low bass.
@unsound, thanks for the discussion of the comparison between Figure 1 and Figure 3 in the Stereophile article on the CS3.5. Does the impedance rise vs. the EQ boost in the low bass fully offset the extra demands for more power when the EQ is used? If an amp puts out only 100 w/channel into 8 ohms, wouldn't available power drop even lower when the impedance goes above 8 ohms?
On the 3.6s I’ve replaced the mids with rebuilts by Rob at CSS and also changed out the ferrofluid on the tweeters. The updates resulted in a very extremely small softening on the highs, but only perceptible and barely so on a few tunes. This was all done prior to auditioning the previously mentioned DACs.
@sdl4, If I may, yes, bridged stereo amps typically don't handle lower impedances well. They are better suited for insensitive, high impedance speakers, where the extra power can be better appreciated, with the added benefit of better stereo separation, though typically with higher distortion levels.
Yes, the CS 3.5's eq makes greater demands on the amp. But.... this is mitigated by cleverly using the impedance peak that typically naturally occurs due to box resonance.
Compare fig. 1 with fig 3. (you can ignore fig. 2 as those measurements would be specific to the testers individual room). Jim Thiel with his uncanny cleverness has the eq nearly identically overlap the impedance hump with the eq boost. This not only relieves the amp of power draw, but it also mitigates the draw from sucking power from the closely overlapping 1st order midrange. Converting a deviance from linearity into an advantage. All towards full range extended bass from a relatively small footprint, with superior time and phase coherence. Brilliant!
Full range Class D has not traditionally worked best with low impedance loads, Specialized Class D subwoofer amps are different. Though these Class D sub amps are reputed to be the most failure prone components in the field. Parts and repairs are not especially likely to be counted upon either. On the other hand there is a new generation of Class D amp modules just coming to market that hold special promise. I'm eagerly waiting for consumer reports on these new amplifiers.
sdl4 - you are correct about bridged amps 'seeing' half the load impedance of a stereo amp. That said, the 2.2 is a fairly benign load, especially as Thiels go.
I recommend you compare your PS to the AHB if you can. I was gobsmacked by the difference between my S300 and the AHB. I'll soon have more to report, I'm expecting delivery today of a BM DAC3B and HPA4 front end. Better than Christmas.
I also have some thoughts about the 'extra' load imposed by the EQ - more on that later.
@duegi I have used an Aqua La Voce DAC in my system with the 3.6s and it sounded great. They are too bright with my vinyl setup. I haven't used my TEAC NT-505 with the 3.6s, but it is also very warm. It uses the AK4497 DAC chips. It's been discontinued and the new model uses a D/S chip, due to the fire at the AKM factory and probably sounds different. If you can find a used one, it's very nice. It's also a streamer, so you could ditch the Bluesound. I would look at R2R DACs like MHDT Labs and others before Schiit. I had a Bifrost in a second system and it was very good for the money, but did have some glare. Things sounded much better and warmer after I moved the NT-505 into that system.
@cascadesphilI have the first version of the tweeters in the 2.3s. My room has wood paneling, so not the greatest listening area, but I have numerous sound treatment panels in the room, and a thick rug in front of the system. I moved my Klipsch Quartets into my main system a few days ago just for fun and they are easier to listen to (less bright) than either my 2.3s or the 3.6s.
I hear (or read) repeatedly that Thiels are very revealing of the source and I have to agree. With my Aqua La Voce DAC, there's very little of that hard edge, only on a few recordings, while with my vinyl setup things sound too bright with close to half the records I play. Vinyl sounds great with my Quartets, my Harbeths, KEF Ref 1, and Stirlings. I think both speakers are great, they just don't seem to be a good match with my room and system.
Trials and tribulation about DACs in my system and searching for input from you all. To date I’ve tried DacMagic 200m, Ayer Codex, Benchmark DAC3-B, Chord Hugo TT2, and a Bryston BDA-2. All being fed by a Bluesound Node gen 3 or Rasberry Pi via Cardas Clear (USB & Coax). Comparing to vinyl, all the DACs come across as very bright on the highs for my listening tastes.
So far the best sounding DAC has been feeding through the unit built into the Yamaha CD-S2100 utilizing USB or coax. It doesn’t over drive the bass or create piercing highs like all the previously mentioned DACs.
I’m starting to look in the multibit or R2Rs from here out I think perhaps giving Schiit or Denafrips a try. Maybe even searching for an older ML No36 or the like. I do realizing clocking/jitter can be an issue with earlier DACs. I’m getting the idea that the Sigma/Delta dac isn’t the way to go with my set up.
Oh sorry, using Mc C22 tube pre and MC462 amp feeding into the 3.6s, as a repeat the set up sounds excellent with vinyl and regular CDs (Yamaha). And as a side note I'm keeping the Bryston for the upstairs system as it does work well with the Anthem pre, amp, and Polk LSiM 705s.
Thanks so much for the additional info about the Benchmark amp in your system and room. I think my room is a little smaller than yours, which could affect the amp-speaker match a bit. My current amps are the PSA M700 monoblocks, which have plenty of power and sound really good, too. Your S300 is a lower powered stereo sibling of the M700, and I wondered how the CS3.5 works with the S300 compared to the Benchmark amp.
I may not be remembering this correctly and it may not apply to the Benchmark amp anyway, but I thought that most stereo amps in bridge mode didn't handle lower impedance loads as well as the stereo version did (which could make it a less good match with the CS2.2). It also seems like the use of EQ down to 20 Hz with the CS3.5 could require quite a bit of juice from an amp, and the non-EQ'd CS2.2 wouldn't require as much power from any amp.
It would be fun to compare my M700s to the AHB-2 directly, but I remain more fascinated with how the new Atma-Sphere Class D amp might sound with my CS2.2s. The A-S amp uses GaN-FETs and is rated at 200 w/channel at 4 ohms. I won't be attending AXPONA next week, but I'll be looking for comments on the sound of the A-S amp at the show before I decide whether to try to demo any of these options.
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