@thoft, the DR version is the predecessor to the slightly different, more recent "regular" non-DR designated follow up.
Showing 50 responses by unsound
I might have gotten distracted at some points during video. Does he address foils or ribbons? It would seem that such a shape would address many of the concerns mentioned. Is Belsen capable of such a shape on an economical level? Was such a shape disqualified for reasons other than absolute performance? Towards the end, he was quite candid about how the pricing was determined by competition for space and time with other unrelated products. Would a leaner more focused company be able to offer better value? @tomthiel I think Wireworld’s (w/ former Straightwire designer) more recent products might qualify as braided flat wire designs? Would such a design introduce inconsistent contact and strand jumping? Alpha-Core’s twisted more solid core “purled” approach without the staggered, overlapping of braiding would seem to offer much of the advantages with less of the disadvantages? |
@tomthiel Alpha-Core on some of their products lays down ribbons of copper and/or silver flat, then puts flat thin ribbons of polyester terephthalate between other flat layers ribbons of copper and/or silver on top of those layers, then twists the assembly and then encases the twisted assembly in a thick wrapping of polyester terephthalate. This keeps one side of the ribbons in constant contact rather than rotated intermittent contact as happens in braiding. Though this purled (twisted) process should have some advantages, many believe that the non-twisted completely flat versions sound better. It has been suggested that this might be due to the thinner outer casing of the flat series. The twisted "purled" versions are said to be much more durable though. I believe Thiel Audio used the "purled" versions for the added durability. The beefier flat MI 2 & 3 and AG 2 & 3 speaker cable versions are separated by Teflon rather than polyester terephthalate. (There is a glitch on this website, please click on "specifications" on the interconnects page to see specs of the purled speaker cables here): High Performance Interconnects by Bridgeport Magnetics Group goertz alpha-core purled - Bing images The flat untwisted versions: MI/AG Speaker Cables by Bridgeport Magnetics Group Straightwire has been using CCT (Compressed Conductor Technology) since 2001 and multi-tubular cores since 2006 and combinations therein since 2011 STRAIGHT WIRE - HISTORY & FIRSTS: Audio cables, video cables, connectors, HDMI, Home theater cable Wireworld claims their ribbons lay flat but the images suggests this might only be partly the case. wireworld - Bing images ...And foamed teflon had been introduced sometime ago. |
@thoft, O.K., an older DR 25 with an updated newer faceplate. I thought you bought 2 and were running them as monos. With the 3.6’s 2.3 Ohm minimum impedance you’re better off with one stereo amp that is not bridged. You should have plenty of available power with one stereo unit, especially in a smaller room. Classe’ is a nice match for Thiel’s. Congratulations, enjoy. |
@woodysticks Ideally; 100 to 500 Watts into 4 Ohms depending on desired volume levels and room. 8 to 10 feet apart from tweeters. 3 feet or preferably more from wall behind speaker backs.* 3 feet or preferably more from side walls. Ideally 10 feet (+/- 2’) from tweeters to listeners.* Jim Thiel originally used Straightwire and later Goertz Alpha-Core cables. *important |
@thoft’s suggestion has merit. At low volume levels in a small room one can get away with 100 Watts @ 4 Ohms, but one should keep in mind that even with an accommodating impedance rise in the range at which the equalizer does it’s thing, the eq still adds extra demands on the amplification. Personally. I would at least double that previously suggested 100 Watt @ 4 Ohms minimum for my own use. |
If I might add to @tomthiels ‘ comments; though both the 3.5’s and 2 2’s had power amp recommendations of between 50 and 250 Watts ( using standard 8 Ohm power ratings, rather than actual specific load recommendations ), as well as the lower lower crossover point of the 3.5’s, the 3.5’s eq was boosting the bass response by up to 12 dB. Though the boost was targeted for the woofers, as Tom points out the shallow 6 dB 1st order crossover would extend the boost beyond the targeted woofers. |
@tomthiel, re: your earlier post re: bi- or tri- amping the CS 5's; this would require modifications, 2 to 3 more outlets, 2 to 3 more shelves, 2 to 3 more power cords, 2 to 3 more pairs of interconnects, 2 to 3 more pairs of speaker cables. The extra Benchmark's would still be limited to the Thiel minimum recommended 100 Watts per section. With all due respect, I really don't put much stock on what a manufacturer claims off the record; let them put the specs in writing or provide third party measurements (interesting that Stereophile excused the Benchmark from full 2 Ohm testing, either in stereo mode single channel, simultaneous dual channel stereo mode, or mono configuration measurements). While I do respect the Benchmark's low distortion specs, and especially the adjustable gain options, their amps don't read as suitable candidates for sub 3 Ohm loads, and are not exactly power houses above 3 Ohms. In that the Thiel's shallow 1st order cross-overs have so much more overlap than other networks, using identical amps for multi-amp use is of even greater importance. One used Krell FPB 600 costs about the same (actually a bit less) as two used Benchmarks and can provide substantially more power to each and every driver, without compromising frequency linearity into a speaker thirsting for power, and do so maintaining Class A operation the whole while. One Krell seems like a much better match for the CS 5's. While with appropriate amplification ( the Krell KMA 400's are the best I've heard them with) I think the CS 5i's are on absolute terms the best sounding Thiel's ever made, and amongst the best speakers I've ever heard, including much more expensive alternatives. Without appropriate amplification they can be disappointing. I found your earlier posts suggesting reshaping the CS 5's baffles in order to simplify the cross-over as a more interesting/promising proposal. P.S. I started this post some time ago. I've been a bit busy, but I hope to respond to your other inquires in the near future. |
@Jafant, am confident that I am not alone in thinking that there are instances where the CS 2.7 and/or the CS 3.7 would require subwoofers. Utilizing a proper power amp will not unto itself act as an equalizer to yield aural results across the frequency spectrum beyond the scope of a loudspeakers limitations. There was a reason that Jim Thiel made other models besides the 2 and later 3 series that had a broader aural frequency spectrum range, as well as a range of subwoofers to facilitate a broader aural frequency range. |
While there are arguments to be made for either separate transports and DAC’s, or all in one players, but ultimately I think that all in one players with input capabilities tend to be the value leaders. Digital products tend to hold their value much less than other audio gear, and IME are the products that need replacement the most often, Let the buyer beware. As has already been noted few separate DAC’s are capable of SACD playback. As for the Benchmark DACs; while I realize that a DAC is more than the sum of it’s parts, I find it irksome that Benchmark chooses to cheap out and use the lesser Sabre chips when much less expensive DACs use the the top of the line Sabre chips. |
@ctsooner , I couldn’t agree more, but it’s curious how many that don’t appreciate the time coherence assume that there wouldn’t be cross appreciation of the brands by the owners of each. I regularly read of people that have or do own both. FWIW, I think the Dunlavy’s are in the mix, and perhaps even more so for Thiel owners. |
@tomthiel, I’m glad your trip was fruitful. Hopefully we’ve found a resource to help further the Thiel legacy. I’m truly excited by the eq projects. The more I think about your earlier posts about making the Thiel’s cross-overs external; the more I think this the preferred way of doing things. Perhaps there could be some overlap with such external cross-overs and the eq projects? With more multi-bit DACs (32 etc.) the more direct drive of amplifiers by such DACS become more viable without risk of bit stripping . Thus making active linestages superfluous in many systems. One concern is that the otherwise preferred balanced outputs with their higher output voltages might still need too much attenuation to avoid the aforementioned bit stripping. Of course, amps such as the Benchmark with adjustable input solve this issue, but this very useful feature is unfortunately not all that common. Perhaps some sort of attenuation option on the proposed eq’s could facilitate such a system arrangement? |
@decathlon1991, Which models? |
@thosb,: Thiel CS2.3 Loudspeaker Specifications | Stereophile.com Thiel CS2.3 Loudspeaker Measurements | Stereophile.com Thiel's recommended power for the CS 2.3's was between 100 and 400 Watts per channel for an amplifiers standard 8 Ohm rated output. Thiel also suggested a minimum of a 3 Ohm load, how ever as indicated in the 2nd link independent testing demonstrated a 2 Ohm minimum load and with a high capacitive phase angle to boot. This all suggests that ideally one would have amplification capable of delivering between 400 and 1600 Watts per channel into 2 Ohms, depending of course on one's room and desired volume levels. Be wary of amplifier manufacturers claims of "being stable into 2 Ohms". That only suggests that the amp won't go into oscillation when presented with a 2 Ohm load, not how much power it will actually provide, or how much distortion will occur at 2 Ohms, or how it good or bad it will actually sound into 2 Ohm loads. I think you'll find that theses requirements will make your short list that much shorter.
|
^The Benchmark amps are at the very top when it comes to a lack of distortion within their load tolerance. They are also somewhat special in that their input allows for a variability that is somewhat uniquely accommodating for system matching. Regrettably, many Thiels have impedance loads that is outside the window of ideal operation for them. The Benchmarks are not designed to work optimally with many Thiels. While I'm hardly the one to make such a supposition, I don't believe that Jim Thiel would have traded his Krell for the current (or lack thereof) Benchmarks. They could very well be the very best amps for different speakers. |
@tomthiel, the impedance limits of an amp depends on the speakers attached to it. Most later floor mounted Thiels from the 1.7's / 2.3's / 3.6's / 5's / 6's / 7's have a minimum power recommendation of 100 Watts per channel into 8 Ohms. The nominal impedance of all these speakers is at least 4 Ohms. We all know the actual minimum impedance can be less than that, and quite often for more than just a slight dip. Models | The Coherent Source (wordpress.com) The Benchmark amp in stereo mode is spec'd at 100 Watts per channel into 8 Ohms and is not able to keep up with doubling down even into 4 Ohms, just missing the minimum recommended 200 Watts into the nominal impedance. Things get a bit worse as we work down into actual minimum impedances, as rather than reaching the recommended 300 Watts into 3 Ohms the Benchmark comes up short at 240 Watts per channel. In Bridged mono mode the Benchmark isn't even spec'd below 6 Ohms. Benchmark AHB2 Power Amplifier - Benchmark Media Systems With the right speakers the Benchmark might well nigh be the most perfect amps available. They might work beautifully with some older legacy Thiels, or with the Thiels that are not floor standers, but I think there are more suitable options for the more recent Thiel floor standers. |
@tomthiel, While Benchmark’s class leading distortion specs are truly impressive, their use of non-standard standards is curious. One has wonder if the difference between the vanishing low distortion measurement standards of the Benchmark compared to the 1% standard measurements is more academic than of practical use to the consumer. I’d be more impressed if Benchmark would spec in writing their power delivery into load with a reduced distortion criterion, than to avoid addressing whether it can deliver the goods for my application. While I don’t doubt your reporting what you’ve been told, the cynic in me doesn’t buy what they aren’t willing to put in writing. It has bee quite obvious that Stereophile doesn’t measure amps into 2 Ohms unless the manufacturer specs their amps into 2 Ohms. And even then they often only do the 2 Ohm measurements from one channel, even when a stereo amp shares power supplies between the 2 channels. One might question whether or not Stereophile is more concerned with avoiding embarrassment to potential advertisers than providing useful guidance to its subscribers? And if manufactures spec their gear in such a way as to avoid the exposure? That the Benchmark uses what appears to be a rugged protection circuitry is nice in that it prevents an over stretched Benchmark from causing further damage down the line. Some manufacturers go out of their way by over building their gear to eschew protection circuitry because they believe the use of which has negative sonic characteristics. To be fair the Benchmark’s exemplary noise and distortion measurements might put that argument to rest. Still, I wouldn’t want my automobile or even my washing machine to shut down because it was overstressed, and given the choice after sitting down for a nice recreational listening session, I’d prefer to be able to avoid protection saving shutting down altogether if possible. The Benchmark comes in at the minimum suggested 100 Watts per channel power rating at 8 Ohms for many Thiels, and struggles to keep up below that 8 Ohm rating, there is no extra power to start with to offer some wiggle room below. A Benchmark could be generously compared to an 80 Watt per channel amplifier that could truly double down. And as we know how the sensitivity decreases with impedance, I don’t think that’s an unfair comparison. The above is regard to it’s stereo performance. In bridged mono mode the Benchmark might be excellent for insensitive speakers with a high impedance load, but as spec’d doesn’t appear at all appropriate for low impedance speakers. The price for the Benchmark for it’s performance within it’s limitations is favorable, but for the similar money there are other options that might be better suited for some Thiels. t |
@tomthiel, I was suggesting that if the Benchmark’s are capable of delivering power into lower impedances that they rate their amplifiers into such impedances with what ever distortion level they choose so long as it doesn’t exceed 1%.. If the distortions levels are lower; kudos. While flickering is better than shutting down, such flickering suggesting pending overload doesn’t exactly lend itself to a relaxed listening session. In the mean time, for those that are enjoying their Benchmark’s on their Thiels, carry on, enjoy! For those on the fence about such a pairing, please consider the limitations and options. |
@bobscliff, the CS 2.4's impedance drops to below 3 Ohms. You're not likely to find many amps spec'd to the 2.4's specific minimum impedance. One might find some amps spec'd to 2 Ohms. If you want to get what that the 2.4's are capable of you'll want an amp spec'd to a minimum of 400 Watts into 2 Ohms. If the amp is not specifically spec'd into 2 Ohms, it 's not very likely that it's capable at that load. Being "stable" into a load only means that the amp won't go into oscillation into that load. It is not a guarantee of performance. |
@cascadesphil, but how much power are these amps delivering into 2 Ohms and at what levels of distortion? |
@casecadesphil, As you may well know as a loudspeakers impedance drops so respectively does it's sensitivity. The 400 Watts into 2 Ohms previously suggested is similar to 100 Watts into 8 Ohms. 100 Watts is the minimum Thiel recommended for the CS 2.4's. But that's at an amps standard 8 Ohm rating with the assumption that the amp is of such quality that it can double down with impedance to compensate for the actual impedance load. Amps are typically rated from 8 Ohms/ 4 Ohms / 2 Ohms and in some cases 16 Ohms, so that's what we have to work with. So with that in mind the as used minimum recommendation would be 400 Watts into 2 Ohms. If an amp can't double down from the minimum 100 Watts into 8 Ohms recommendation then the speaker is losing potential useable power. Many amps can not keep up with the power to sensitivity ratio -3dB for each halving of impedance. In which case one would need to start with more power. In the case of these Thiels at least the impedance is fairly consistent, so the loss of frequency linearity doesn't suffer that much. Being "stable" into a given load only means that the amp won't go into oscillation when presented with such a load. It is not a measure or power delivery, distortion or the quality of sound when presented with such a load. |
@beetlemania , The "random peaks" I was referring to was in regard to your comment regarding my listening levels. I don’t listen at sustained loud listening levels. Almost never at levels that would occur during live concerts. I scale down to room size. I do have a fairly generous sized room, and power accordingly. I drive Thiel CS 3.5’s which don’t drop below 4 Ohms. The suggested minimum power levels I previously posted are not something I made up. Those are the minimum power levels Jim Thiel would recommend. For my CS 3.5’s the minimum would be, depending on vintage, between 80 and 100 Watts per channel into 4 Ohms. The high Wattage numbers posted are a consequence of impedance. I don't think many would think that the comparable minimum 100 Watts per channel into 8 an Ohm load would be excessive. And, often times it's not so much the power output but the low impedance that many amps find difficult. |
^As is often the case, unless a manufacturer offers a 2 Ohm spec Stereophile doesn't do a complete test at that load. Even then they will often just test one channel of a stereo amp, even knowing that the amp shares its power supply between both channels. The skeptic might presume that Stereophile is more concerned with avoiding embarrassment to a potential advertiser than offering useful information to its subscribers. Furthermore, there seems to be a pattern from manufacturers specs sheets that suggests that manufactures have figured out how to avoid Stereophile's 2 Ohm testing. That this manufacturer suggests suitability of the unit under test for 2 Ohm applications, Stereophile offers incomplete testing into 2 Ohms for distortion. While the results of the 2 Ohm distortion testing suggest significantly higher distortion into 2 Ohms than is the case into 4 or 8 Ohms it is still within reason for the end user. Importantly there is no measure of power output into 2 Ohms. |
@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. Thiel CS3.5 loudspeaker Measurements | Stereophile.com 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, 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. Here is a particularly promising offering: P501 Mono-Block Power Amplifier - March Audio Please note that asking price is in Australian $, the currency exchange is favorable to US $. Be sure to click on "SPECIFICATIONS".
|
@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. |
@fsgattuso, While I typically suggest going low at the cross-over point to subwoofers; with the CS 1.5’s I think you’ll need to go higher to reduce strain on the woofers. Perhaps to 65-70 Hz. BTW, I strongly suggest going with at least 2 subs rather than just 1, even if the two are both smaller than the one.… …Or, just sell the 1.5’s and move on to bigger Thiels. |
@stanleym9999, IME good cables can be can be had for much less money. The savings might be put to better use elsewhere. May I offer for consideration : Alpha-Core Goertz MI series. Alpha-Core used Thiel as a reference. Jim Thiel reccommended the Alpha-Core’s, and the Alpha-Core’s are known to be a good match with Threshold. I strongly urge you to use Alpha-Core’s "L-C networks" (AKA: zobels), especially with wide bandwidth amps such as the Thresholds (at least the earlier models were, not so sure about the post Nelson Pass models). Another good match, previsoulsy used by Jim Thiel are the Straightwire Maestro’s. Also, your Thiel’s are internally wired with Straightwire
|
@stanleym9999, I’d be curious to know the output impedance of your SET preamp? |
@stanleym9999 , The T200 was designed by Michael Bladelius, and used IGBT devices which Nelson Pass was not a fan of.
|
@stanleym9999, Thanks. I might have mistakenly called Alpha-Core’s zobles "L-C networks", I think they call them R-C networks(?). |
@tomthiel, There aren’t many transports that will output native SACD, etc., and those that do are usually more expensive. The closest machine than comes to mind for those prerequisties is the Oppo 105. The Oppo 105 can output SACD but might require a bit of technical gymnastics to do so. The Oppo 105 also does analog output, as well as high quality video and HDCD too. Oppo is out of the a/v business, but it is still offering quality customer support. Cambridge offered some transports, but some of those were just stripped down Oppos. Though I have no hands on experience with some of the new transports available, multiple reports of quality control issues with some, some use unappealing to me feeder loading, most just don’t appear to be very good values to me. |
CS 2.4's : ..."Easy to drive as well". ? Thiel CS2.4 loudspeaker Measurements | Stereophile.com I have to disagree with JA; better to go with an amp that is spec'd to deliver appropriate power into 2 Ohms not 4 Ohms. |
@oblgny , While the Thiel's and the Magnaplanars have an uncanny resemblance when it comes to transient response (though the Maggies are planars they are still techically dynamic speakers), and the Maggies though more coherent than most, are not quite as coherent as the Thiels, but the dispersion characteristics are very different (point source vs. dipole).. Both would make my short list. You might want consider Magnaplanar's new subwoofer with dispersion characteristics that are meant to compliment the Maggies.
|