tomthiel
Thank You for the follow up. I hope that you are well and ready for Summer.
Happy Listening!
Kimber discontinued the Black Pearl due to time consumption and production requirements that couldn't be sustained at any asking price. Ray had gifted a first-run pair to us around 1980 and later traded them for a last-run finalized version. He, of course, used our speakers in his development work. I was honored and pleased to evaluate the finalized CS2.7 even though I was not involved in its development. I saw the careful and sustained work of Team Thiel to bring that product to market in Jim's honor. |
Your description of the Maestro sounds very sophisticated. I don't see it in their present offerings. Steve has told me that they no longer use individually coated wires due to centering difficulty, expense, etc. Their present core technology is to compress the bare copper wires to maximize and unify contact, then insulating those groupings and applying their various cable geometries. My StraightWire is way down the line at Octave which utilizes their core compression technology, their insulation mix, geometry, etc. He characterized the Octave II (now III) as most of their available performance before climbing the cost ladder of 'designer sound'. I don't remember which SW cable we had at Thiel when I left. I do know that the music room was outfitted with the Kimber Black Pearl when I auditioned the 3.7 vs nearly finalized 2.7 in 2012. Those cables are astounding - at $5 figures.
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@tomthiel, I would characterize “their very obvious differences” as how they appear visually. :-) I believe the Straightwire Maestro’s use individually coated strands layered in side by side groupings that are then woven in an interleaved fashion ultimately resulting in a co-axial configuration. Only the 2 & 3 series of Goertz speaker cables separate the positive and negative with Teflon.
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unsound - no doubt you're right. Jim gravitated to the Geortz from StraightWire. I think it was Tony Cordesman or John Atkinson who borrowed those Goertz for their reviews and considered them an improvement. I haven't gone there myself because I prefer to stay in the middle lane with ancillary products that are likely to be in widespread use among Thiel owners and fans. However, I would love to audition some flat-ribbon cables for comparison. My recent wire excursions have me cross-checking driving speakers with and without crossover networks. The SCS4 is quite well behaved with no XO at all. And, guess what, cables interact differently with bare drivers vs networks. How would you characterize 'their very obvious differences'?
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I believe Jim Thiel was using Straightwire Maestro’s before moving on to the Goertz speaker cables. Both can be found for relatively inexpensive prices on the used market. The Goertz cables models/gauges choices will depend upon the power output of your amplification. As @tomthiel previously touched upon the Goertz cables can put some amplifiers into self frying oscillation. This can be avoided by using Goertz own small, fairly inexpensive “RC networks” (zobles) at the speaker binding posts. Should you go with the Goertz, I strongly (!) recommend you use their RC networks. There is no sound reason not to. As different as these designs appear, they share some characteristics. Both keep the positive and negative poles in constant close proximity with Teflon barriers. Both have somewhat similar technical properties of low inductance / high capacitance. FWIW, to my ears, despite their very obvious differences, they sound more alike than different. |
@tomthiel thank you for the in-depth analysis of cable options for the 3.7. Morrow sounds interesting but it looks like they are hard to get here in Europe. I think I stick with the idea to look after some Straight Wires. If I buy used ones even the top-tier Straight Wire Crescendo or Serenade are in reach. |
Hello Anthony, Glad to know we are both still around. The points I supplied you were most likely Audiopoints a product line that I have long supported and do till this day. If the points are attached to a metal platform you have a Sistrum platform now called Rythm platform. Both have brass points with a select geometry facing up and down attached thru the channels of the platform The company name is now Live-Vibe Audio. Let's keep in touch. TomD |
@theaudiotweak, It was you, I checked my old receipts, don’t ask me why I still have receipts from the early 90s. I appreciated your assistance. You also were able to provide me with brass point stands for my Thiels, you knew someone that made them. Thanks. Anthony |
We first discovered eddy currents in the steel baskets of the O series. When we auditioned the phase coherent version we heard weirdness, but the phase-correct / time incorrect third order slopes 'erased' the weirdness. We thought it was mechanical / vibrational, but all the epoxy we could pile on the basket didn't help. It turned out to be magneto electrical eddie. Aluminum baskets cured it. Later we tried aluminum voice coil bobbins for their thermal conduction. Eddies were purely electrical, but problematic nonetheless. This wavelaunch stuff I've been working with lately is a manifestation of the same effects in the realm of surface propagation and boundary layer turbulence. And, of course, the binding posts. Jeff Roland first brought that problem to my attention. They had put huge output posts on their amps seeking better performance and a marketing ploy. They failed sonically. Yep, same file cabinet. |
When you say 'nude termination' I take it to mean the cable is self-terminated with no additional hardware. Good move. But now to the speaker input terminals. Whenever there is a cross-sectional excess of conductor in the signal path, eddy currents are induced along with other forms of non-linear flow. Those induced reactive fields present erratic impedance to the input signal. I suggest you put some straight or 45° banana plugs on the ends of your SP7s and fit them to the terminal center holes. Set the nut aside. (The actual post is OK.) Compare. Report. |
A cable note worth mentioning (again?) regards binding posts. Going back to the 2002 CS1.6, Thiel used gold plated brass binding posts with a big knurled knob. I could speculate about how that came to be, but I won't. I will say you can achieve considerable sonic improvement by removing the knob and using banana plugs. The slightly opaque, clacky quality, especially noticeable on the high end will vanish. Easy, inexpensive, worthwhile. A complication is the center hole being slightly undersized so all males plugs do not fit. I re-bore with a 4mm / 5/32" drill. I use the WBT-style angled, stackable, expanding male ends, and make contact in DeOxIT contact grease. Much is often made of the large surface, high pressure connection of spades. My exploration led to examining field propagation along the wire run and its scrambling at a bulky binding post. A low bulk, straight connection does everything right, and an expanding plug makes good contact. Try it. |
2nd Note; Kimber does offer Entry-level, Mid-Level and Top Tier cabling options. I have always wanted to audition this brand. A strong dealer/retailer is Goldprint Audio in NC. Taylor represented Thiel Audio and was quite fond of the CS 2.4 , CS 2.7 loudspeakers. In 2023, he still represents Kimber Kable.
Happy Listening! |
lloyd - I'll chime in. I don't know the HMS cables. I do know the StraightWire Octave II (now III) which I can recommend. I can speak generally to the subject, having taken a very deep dive over the past couple of years. I suggest avoiding any cable with out-of-the-ordinary technologies, unless proven to work both with your amp and speakers. I would put Goertz Alpha in that camp. As ribbon conductors they may react erratically with some amps. But Jim used them including for the 3.7 development and he also used Bryston over the long haul - so they are a good bet. My personal experience is to recommend avoiding any cable using non-insulated stranded construction. Every example of this common technique imparts a wooly haze to the sound. On the flip side, any configuration with coated strands has a high likelihood of goodness. Such cables tend toward expensive. I love Morrow which uses individually insulated conductors, cotton dielectrics, and bonded twisted pairs - all technologies the float to the top of my list. Now, some exceptions. StraightWire does not individually insulate, rather, they compress the conductor bundle bringing the multiple conductors into close contact along their whole length. Kimber has a multi-gauge conductor strategy which does not individually insulate, but packs them tightly and technically which seems to remove that stranded wire wooly haze. And then there's braid as in Kimber's Black Pearl and Iconoclast's speaker cable (generation 2 is better). The braids use bonded pairs and 'good sounding' insulation materials. Wire is reactive and variable based on materials and geometry. I suggest paying less attention to the purity of the metal and more to the insulator / dielectric. I like organics best - cotton, jute, etc. Hydrocarbons are suspect to me, even as shrink tubing or exterior jacketing. Teflon (and its family) are clean and clear, especially when un-pigmented. But they're quite expensive. Only one form of polyethylene seems OK to me: XLPE. Most moderately priced wire uses 'bad sounding' hydrocarbon insulators, in my opinion. Now a story. In this exhaustive cable journey I faced a 'crisis of reference' - too many variables with too many unknowns and interactions - functionally non-analyzable. I contacted Ray Kimber for a chat, citing specifically that magic Black Pearl wire that had been part of Thiel Audio since the early 1980s (with upgrades along the way.) Ray suggested that an impeccable reference would help and I agreed. My working sample is 5' (2' tweeter and 3' woofer) in the SCS4. So he sent me a couple of samples including his Silver Stealth Magneto, and Copper Gyro-Quadratic series, both in virgin clear teflon. They use open braid geometry with the central air core as the optimum dielectric. Magic. I can't afford it for my present Thiel Renaissance vision, but it did its job of establishing a neutral, detailed, problem-free reference. I suggest Kimber to be on your look list. I'm glad to compare notes behind the curtain. Cable is a wild ride. If anyone tries to make the case that it doesn't matter, ask them to listen. Not only do these differences show up in measurements, they fit with what the physicists know. It's computational feasibility that requires combining causes to reduce effects into a LRC formula that can be easily interpreted. But we hear the issue of the complex causes, not the simplified summaries. Enjoy the ride. |
Hi all, |
Thank You jafant It's been a long journey with trails and errors of trying to use different damping materials , wiring gauge size and configuration and scariest of all stripping the threaded inserts out of the MDF ( don't use a drill ) . But upgrading the components on the XO boards has been a great success . While I am waiting for Clarity to release their 630v Purity caps to finish the upgrades I have started to think about moving the boards out of the cabinet . |
Thanks Tom Yes they were , I replaced the woofer and radiator with brass and the coaxial with reinforced nylon , as well as the crossover boards with brass because they too were magnetic . Only the screws holding the speaker terminals were non-magnetic. I didn't think about it until unsound wrote about it . |
Tom "It seems that later (after TT) products migrated to a very thin foam interface that essentially collapses under mechanical load while forming an air seal." I did not notice any kind of seal when removing the speakers from the cabinet , (maybe because New Thiel had removed them first ?) although they did tend to stick a little the first time I removed them , I thought that they were sticking to the paint . Should I be contacting Rob about the availability of these foam seals for the 2.7 speakers ? Thanks Rob
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anzen - lots of interacting variables and solution visions. Among those is de-coupling which Thiel rejected. Thiel’s vision landed on maximizing the connection between the driver and cabinet to reduce recoil, increase effective mass and stiffness to tighten the onset transient wave-form. Early-on we used a thin gasket-paper interface. As we developed precision CNC machining we eliminated that gasket by using an O-ring at the ID of the mounting rabbet as an air seal. The mechanical joint was driver to baffle with no interface. It seems that later (after TT) products migrated to a very thin foam interface that essentially collapses under mechanical load while forming an air seal. In all cases Thiel attempted to unify the driver with the baffle for maximum rigidity. The opposite approach of ’floating’ the driver with its claims of resonance isolation may have merit, but I never found it in total system analysis. The decoupled driver vibrates more and longer than the coupled one and its recoil is far greater - producing transient slur. I should note that such slur is without much consequence when a speaker’s onset transient is already compromised via non-coherence. But a coherent waveform begs the brain to figure out what’s wrong with the slurred leading edge, and that 'work' decreases musical intimacy. Another problem with de-coupled drivers is keeping them tight. A vibration-absorbing gasket permits relative motion between the basket and baffle. That motion induces loosening of the fasteners - a very bad deal. So, Thiel unitized (as much as we could) the vibro-mechanical system of drivers and cabinet. The cabinet-floor interface is another very complex equation to solve. Stand by for future reports on that front. |
I have been using brass fasteners for many years. Here is a useful video as to the how and why. I know he moved back to Canada. TomD. https://youtu.be/piWxZK_9hyQ |
What about modifications to the driver mounting? Guessing there is a better term, but a gasket for vibration absorption? Thinner for higher frequency drivers and thicker for lower frequency drivers. Air tight. Installation might be tricky (over torqued if an elastic material used) and the design potentially complex. Might provide some decoupling of the driver. |
My external crossovers have 1 single input pair from the amp and 2 output pairs from the board to the 2pr of terminals mounted to the back of the speaker cabinet. The leads from amp to crossover are 6 ft. The leads from the crossover to the speaker cabinet are 30in. The speakers rest on Sistrum stands the crossovers on Sistrum platforms all direct coupled to the floor for maximum resonance grounding. TomD |
unsound - thanks for the input. What may not be self-evident is that changes such as these wire lengths require system tweaking. I had presumed that the system would be optimized around some fairly short umbilical length, but am open to reconsidering: perhaps a short and long version such as 1/2 and 1-1/2 meters. Of general interest may be how Thiel approached this tweaking problem. We assumed user preference for amps and cables. Voicing and final adjustments consumed months of iterative listening tests. The (sometimes maddeningly) long delays between projected new product introductions and actual roll-out included this micro-voicing to levels considerably beyond measurement. Add to that the unannounced XO revisions during a product's life for further refinements. These micro-voicings take internal wire lengths into consideration along with the myriad other variables and interactions.Outboard XOs extend the complex cable contributions from a few feet to many feet. An additional system variable. I'm glad you brought up this issue - I'll add it to the list of considerations. |
Unsound - that's a complication I hadn't anticipated. Wire is highly reactive and susceptible to noise from multiple causes. Having long runs between the XO and speaker would require specific engineering to maintain target performance. I've become a big fan of shortest practical speaker cable runs via a pair of amps part-way between the centered source rack and speakers, with XOs part-way again. I've been presuming 1/2 meter umbilicals. Could be a meter. |
There is a method of material coupling where the collection of resonant energy is transferred to a large disc of the same material effectively increasing the surface area many times. And if you have 3 or 4 these devices then you effectively have the same shelf or floor surface under each and every component set up this way including the speakers. It works. TomD |