Thiel Owners

Pretty sure you can get outriggers from Coherent Source Service. At the least, they are part of the kit to upgrade 2.4 to 2.4SE (which also includes the Clarity SA caps for the coax feed).

@holco Regarding coils, as Tom noted, you need to verify whether your boards are point-to-point on masonite (made in Lexington) or PCB (made in China by FST). The coils values are slightly different for the latter to account for subtle changes in that environment. The layout you have is for the PTP and the PCB values are somewhat different.

I recommend upgrading all resistors to Mills MRA including that 16 ohm. Not sure why you have the one in parallel. Is it becuase you can’t find the correct value? Sonic Craft has all the correct 2.4 values. But note that the “Mills” are older and “Vishay Mills” are newer after Vishay bought out Mills. You’ll have to mix and match the old and new but that is of no issue. 

That 43 uF cap is a subfeed and deserves attention. That is a tough value to get in a quality cap. You can get that value in ERSE Pulse (Tom had this option on his short list), or run a parallel (eg 10 + 33) higher quality. Tom has a custom Clarity CSA for that cap, not sure whether/when that might become availability. Note that you can go with a lower voltage for that one as it is downstream of that 16 ohm resistor.

You might also replace those big 100 uF electrolytics with ERSE Pulse. Tom is getting a custom low voltage Clarity to replace those but, again, unsure of its availability. ERSE could also be a decent option for the woofer caps (33 and 56 uF).

@holco Your PCBs look a bit different than mine in that you have different brand caps. Mine are CYCs other than the Clarity SAs in the coax feed; yours might be Solen? Regardless, your cap quality looks superior to mine other than those Claritys. My CYCs are MKTs whereas your caps are labelled as MPTs. Also, the coils appear to be higher quality in that they are more tightly wound. Finally, the board itself doesn’t appear to have any labels.
Here is the backstory on the coils. When I upgraded my resistors, I noticed the PCB had the parts’ values printed on the boards. I wrote to Tom Thiel:

I forgot to mention an interesting artifact I noticed when I replaced the resistors yesterday. The PCBs have all values labeled. On the woofer board, instead of inductor values 0.72, 0.3 and 0.06 mH per schematic and layout, it has 0.65, 0.22, and 0.06. On the coax board, instead of 6 and 0.15, it has 5.78 and 0.13

Tom investigated this and discovered the PCBs were sourced from FST whereas Thiel traditionally made everything in house using point-to-point. Apparently, the modified values are to compensate for the PCB environment. But maybe it’s even more complicated given that you have a different generation PCB than me? My SEs are among the last built. The seller claimed they were built in 2012. I’m guessing your 2.4s are older. Perhaps Tom can add his thoughts about your coil values.
My rebuild will be point-to-point on Masonite and I’m going to use the coil values as indicated on the layout and schematic (I plan to build completely new boards other than I will reuse the MRA-12s). If you are keeping your PCB, you might need to use the modified coil values if upgrading.

Brand new 3.7s? Wow, nice!

CS3.7 coax with the CS5 sealed bass for me ;^)
Incorporate Tom Thiel’s ideas for crossover components.
Tom Thiel would make the diaphragms of carbon.
Anyone have $5M for a company start up?

@tomthiel Interesting that there are 3 iterations of the CS2.4 XO. It appears that, other than the Clarity SAs on the coax feeds, my SE version has the lowest parts quality of the 3! I suppose the sandcast resistors are equivalent for each iteration.

 

@holco, unless you opt for a full Tom Thiel-style XO rebuild, which is my plan, I wouldn’t change much else on your boards other than the resistors. Your woofer board has better caps and coils than my FST-sourced boards. I would replace the resistors with Mills MRA and call it a day.

 

On the coax board, I would replace those resistors as well, maybe try to figure out a way for them to breathe for better cooling under those big Jantzen caps (perhaps a thin aluminum bar underneath them to draw heat to the sides?). It is highly desirable to replace those 100 uF electrolytics with MPT-type (Erse PulseX is a good option that won’t break the bank) but it will be really tough to fit those on your PCB. I suppose you could just replace those with fresh electrolytics of similar size. The only other thing I might consider is adding a high quality bypass to the 43 uF subfeed. The cap itself is labelled as MPT type (might be a Solen?), so already good quality. But you might try a ~1% bypass. I am going to use a 0.33 uF REL Multicap bypass with that cap (planned as a Clarity CSA 250 V). Cornell-Dubilier 0.1 uF is also worth considering for a bypass. You might even experiment with 1% bypasses on your Jantzens if you’re really adventuresome.  

@stspur 
The “S” are probably Solens. Those were probably pretty good for their time but the Claritys should be notably better.  Pretty cool to see “Thiel” on those resistors just like Tom wrote. Still, I would upgrade those to MRAs, especially if direct feed to the driver. Also, those coils look high quality, again “Acousta-coil” like Tom has written. I would leave those although tempting to try a foil inductor if on direct feed path to midrange or tweeter. As long as you’re in there you should replace all the electrolytics. Ideally switch these to film caps but if space and budget don’t allow at least put in fresh ELs.

$0.02

Sonic Craft has all the values for CS2.4, either Mills or Vishay-Mills. I imagine they can ship to Europe 

@mr_bill All time best Thiels are 7.2, 3.7, and, maybe 5. What is your budget? Keep in mind that Tom Thiel is planning upgrades for crossovers of many models, including 2.4 and 3.6. Could get a superb, updated Thiel at a great price (ie, used speaker plus upgrade kit, tbd). 

I am gathering the parts to start the 2.4 upgrade in earnest, including most caps, coils, and board from Tom Thiel. I plan to post a journal of the process, including pics. I don’t see a way to include pics on Audiogon, though. I might use audioasylum to host those, if not the whole thing. Anyone here have a better idea of how to keep it on a’gon but include pics?

@holco after you factor in extra shipping and VAT, maybe it wouldn’t be too much more to stretch for locally-sourced Path Audio resistors! They are said to be the very best available.

I have come to agree that quality can easily trump quantity. In my 2 channel set up, I drive KEF Reference 3's with a Pass Labs INT-60 which is "only" 60W into 8-ohms, the first 30 of which are Class A. Lemme tell you, the sound is extraordinary, and capable of volume far beyond levels I enjoy listening!

Absolutely! I don't think you can well predict the sonics of an amp/speaker without listening to it, although many Thiel models should probably be mated with 4 ohm rated amps (or lower for something like the CS5). And personal preferences as simple as desired SPLs are not accounted for when amps are dismissed out of hand for being "too low powered".

From the CS2.4 owner's manual:

It is important to have enough power to play at the level you desire without distortion. If high sound levels are desired, the CS2.4’s are designed to be used with amplifiers rated up to 400 watts per channel (into 4 ohms). If you play the speakers more loudly than the volume the amplifier can cleanly produce, the amplifier will produce overload (clipping) distortion.
. . .

Keep in mind that sound quality is usually much more important than sound quantity. There can be large differences in the sonic performance of two amplifiers of equal power, and this is more important than large differences in power. Most everyone will be happier with a 100 watt amplifier of high sonic quality than a 200 watt amplifier of mediocre sonic quality. For this reason, we feel there is no substitute for listening in making your amplifier decision.

Charles Hansen (RIP; Ayre):

At some point, you just have to let go of the specs and trust your ears. It's the only way to get something that sounds good.

link to full post

2.7 as it was the last speaker Mr. Thiel designed and built.

Yesterday I posted false information about who completed the CS2.7, which was finalized and released after Jim Thiel passed. I have since deleted that post. From Tom Thiel’s PM to me:

The project was engineered by Warkwyn / Canada - Tim Gladwin leadengineer. . . . The development job was actually directed by the Thiel Team and every engineering step was approved and/or re-directed by Thiel. The job would have been a minor one in Thiel-land because the actual-same coax was used and FST-China developed the 8" woofer as a near clone of the 10" 3.7 woofer. Virtual piece of cake transplant job.

Tom included some information regarding how Jim Thiel would have created a passive coax for the 2.7 had he survived to do so (the 2.7 shares the 3.7’s double-motor coax).

On this site many believe the 2.4 is the best sounding

I don’t recall reading those opinions here but I see that Tom Thiel considers the 2 to be Thiel’s sweet spot. That said, the "hot-rodded" 2.4 should push performance to the next SQ tier. In the context of Stereophile's rating scheme, the upgrade might be considered as "Class A - restricted" (ie, limited low frequency extension). Stay tuned . . .

Seems like an amp list might be heavily biased to simple measurements, and it’s tough to meaningfully measure either speaker or amp, never mind their interaction. Most Thiel models drop below 3 ohms over part of the audioband but what can you say about how phase angle confounds that? Might be even worse with amp measurements. And to predict the interaction from measurements? Good luck!

I drove my CS1.6s with an Ayre AX-7e, 60 W into 8 ohms, doubling into 4. The 1.6 impedance drops to about 3 ohms over part of the audio band. AX-7 has 66 1 dB steps on the volume control. I usually listened at about 30, maybe low 40s if I had the house to myself and wanted to rock out (my room is 18 x 19 with a vaulted ceiling and two large openings on the rear wall). Much louder than that and it became painfully loud. I found out later, when I switched to the low efficiency Vandy 2, that my combo of amp and source would result in clipping starting at about 45 on the volume control. That little amp had plenty of balls to drive the “low” impedance Thiels.

Yes, some Thiels are tough loads. The CS5 comes to mind, dropping to about 2 ohms in the low bass and even lower where musical content peters out. So, extra care is probably a good idea for some models. But most any amp that is comfortable at 4 ohms can probably adequately drive most Thiels. 

The extra headroom from more power is certainly audible and desirable but less so, IMO, than the SQ from a superb amp regardless of its measurements. As it says it Thiel’s manuals, most users will be happier with a great 100 W amp than a mediocre 200 W amp. If a list must be done, I suggest maybe categories of amps: clearly underpowered, probably adequate depending on user/room, and fully adequate. I would not dismiss out-of-hand a “mere” 100 W amp. Just look at the many reports of good results with tubes!

@tomthiel Happy Birthday! All the best to you - have fun! Thanks for sharing Thiel history here and encouraging our XO mods.

I investigated the Vivid speakers. They are seriously competent. But I can't find anything about their filter alignments; I strongly suspect they are higher order, whereby they can more easily solve all the other design aspects and produce convincing music.

If I had deep pockets, Vivids would surely be on my audition short list. But until then, I'm plenty happy with my 2.4s and anticipate being even happier soon!

My short list of best-ever speakers includes those with and without first-order filters, so uncertain how important that feature is to my ears. But I notice that since I moved up from mid-fi to hi-fi that I've only owned either Thiel or Vandersteen. Hmmm.

To be fair, domestic production and affordability were also factors in my decisions but I did prefer the sonics of the CS1.6 to the widely acclaimed Revel M20s, among other contenders. FWIW

Thielrules is the owner of that last pair of 3.7s.

Thank You for the continued research and development on Caps, Drivers and XO upgrades.

Just received caps, coils, pre-drilled boards, and other parts from Tom Thiel. Something of a pre-cursor for what the kits might look like. I am impressed by the quality of parts and the attention detail Tom lavished on the boards/layout. Probably some bumps in the road await but this is a good starting place.

Last few parts from other suppliers are on the way but I am going to start assembling the new boards this week. If all goes well, one channel will be live next weekend. I plan to share a journal of my process. I wish this forum had a way to include pics. Anyone know if audiogon’s TOS prohibit cross-posting? I might double-post over at audioasylum which allows image uploads.

We chose the Chiquitano because of their protected generational custody of their land, factually safe from the intrusion of MacDonalds slash and burn farming. Poverty with Gringo beef practices is the root cause of tropical deforestation. When you buy Thiel Morado or Amberwood, you are buying a significant and unusual piece of integrated ethical policy.

That is fantastic! Yet another reason to own Thiel speakers!

Pick a dozen brands / products at $20K and compare your new 3.6s toe to toe. I bet you'll be thrilled.

Yes! There are 2, maybe 3, speakers south of $20K that I would *consider* trading my CS2.4SEs for. And that's before I finish my XO upgrade . . .

the relationship between price and performance is extremely weak

Indeed, I can think think of a few models as high as $40K that I would not trade my 2.4s for. But I can also think of a handful north of $40K that I would pick over any Thiel (maybe I would change my mind after a Tom Thiel XO upgrade?). But they damn well should sound better given the chasm in pricing. The bottom line is an audiophile can be *really* happy with a pair of used Thiels and not have to worry about how to get some incremental SQ improvement . . . until after winning the lottery.
:)

Craigslist is also a place to find strong, young movers!

If they need help, Rob will help you. If you want to take them to the next performance level, we'll have an upgrade path for you.

 

IMNSHO, buying a nice pair of used Thiels might become the most-cost-effective way to get near SOTA sound. For starters, the stock versions are already excellent (as Tom noted), sonically competing with new models many times their price. Buying a used Thiel is not worrisome given the available service and parts from Coherent Source Service.

Tom Theil’s crossover upgrades should push sonic performance to the next tier. We’ll soon know. If that’s true, you can buy a nice used pair and upgrade the passive parts to get something that approaches SOTA sound. As a bonus, you have speakers that look really good in your listening room.  

@andy2 The CS2.4 goes down to about 30 cycles in my room and I have them well away from walls. That’s enough to reproduce all but the left most one or two keys on a piano. Not much music down there. My previous speaker was Vandy 2CE Sig II, useful output into the mid 20s. My collection includes a single song wherein I noticed the deficit via the 2.4s. If you can afford Vandersteen 7s, go for it. They are fanatstic *and* have full output down to about 20 cycles. Or, if you really want those last couple of notes, you can add a subwoofer or pair to the 2.4s. I seriously considered subwoofers when I had the CS1.6 but that model quits at about 50 cycles. I have zero desire to add subwoofers to my 2.4s.

Too bad they don't measure at distances that allow for proper driver integration, time accuracy or actual listening positions.

Most Thiels measured by Stereophile (at 50") show a suck out at the mid-tweeter XO point. Sometimes the text would explain that this was likely a problem of distance and sometimes not (but kudos to them for even trying!).
Soundstage measures at 2 m, about 79". If the CS2.4 was disadvantaged in their test you can't tell by the "listening window" graph. +/- 2 dB from about 33-20K! I've only noticed one other speaker in their database that can match that! (A $$$$ Magico - no thanks)

• Bad (compromised) information is in some ways more harmful than no information. Real anechoic chamber or outdoor measurements are expensive and Stereophile et al choose to side-step that expense without, in my opinion, proper contextualization / education for their readers.

I agree that JA often fails to include a few simple statements that can help the reader interpret the graphs, including how the measurements might be misleading of actual performance. IMO, the quality of that publication has slipped over the years.

It is impolite for manufacturers to raise such issues in print, thereby becoming complicit in the misleading measurements.

I recall at least two examples where Stereophile printed measurements provided by the manufacturer (Vandersteen and Avalon) but, yeah, risky for manufacturers to push back.

Jim does not add the customary underdamped bass hump, so Thiel bass is honest.

Teeheehee. I think I know which brand you're referring to ;^)
Soundstage's loudspeaker measurements are done in a true anechoic chamber and, therefore, do not suffer the compromises of quasi-anechoic measurements done by Stereophile. Anyhow, if you look at their measurement library, the CS2.4 is down 6dB, relative the level at 1K, at ~31 cycles. This compares very favorably to other much more costly designs such as the Wilson W/P 8 (~38) and KEF Blade2 (~31). Nevertheless, some of the other designs with slower roll off can benefit from boundary reinforcement to increase low bass in an actual room.

When I got the CS2.4s, the first thing I noticed was improved bass definition relative to the otherwise well-accomplished Vandersteen 2Ce. I listened to many tracks before noticing the 2.4s don't go quite as low (specifically, a Tracy Chapman song with organ tones).

@prof 
Tom Thiel described Thiel Audio’s measurements earlier in this thread, maybe February-May?

@stspur 
I don’t think you’re going to find a 630V EL. If you’re swapping for fresh ELs just match the voltage rating. The high voltage *film* caps are for critical feed path placement in which higher voltage = thicker film = better sound. 
Now, if your 3.6 is like @vair68robert CS2.7 and you have ELs in the feed path and you want to upgrade to film caps then you might need to go to an outboard solution. And be prepared to $pend.

Do you really want to hear the crap from these dealers?

I wonder how much of this is a genuine expression versus sales pitch designed to sow seeds of audiophile doubt in hopes of getting you to buy new speakers. High-end audio is hurting. These brick and mortar stores are disappearing; manufacturers are struggling, too (compare numbers of ads in Stereophile now versus 15 years ago). The middle class is crushed, reducing the pool of potential buyers.

What do your ears tell you about your 3.6s?

I have no interest in active speakers. I’m confident my amp is far more capable than that in any active speaker. There have been *some* improvements in speakers over the past 10-20 years, namely carbon and beryllium diaphragms. But Thiel drivers are excellent even now, all the more so considering the price of speakers with exotic diaphragm material. My CS2.4s are probably my last speaker, almost certainly if my XO rebuild is successful.

KEF is highly regarded and Andrew Jones is a hall of fame level designer but I would stay with the Thiel. You *know* it’s beyond mid-level good, matches your stuff, and is made in US.

Jim to take the bass as deep as possible in each model - because subs are inherently difficult.

The CS2.4 has useful output down to ~30 Hz. The 3-series down to upper 20s. The CS7.2 down to the mid 20s. Compare those to the lowest fundamentals of all but an organ:http://acousticslab.org/psychoacoustics/PMFiles/Module05.htm
Until I win the lottery, I'm going to put my money where >99% of the musical content is.

I once heard the Wilson W/P 7. On a live recording, it produced an eery facsimile of the hall. I've never heard anything quite like it and I initially ascribed it to the Wilson's low bass. But, while that model does have some useful sub 30 energy, turns out I was hearing the Wilson mid-bass hump; a pleasing *coloration*!

@prof
Yes, that’s fair. Richard Hardesty outlined those benefits in his review of the Vandersteen 2WQ and I considered him a highly credible reviewer. Still, at my budget I want want something that crushes it from the mid bass up. Getting quality subs like SS1s or the Vandies pretty much doubles my investment. I’m putting my money into this XO project and am happy with the 2.4 low bass even if it’s not the final word in extension or definition. 

Edit: lol, Tom Thiel replied while I was typing all this

@samzx12 Tom Thiel is hoping to eventually address the 2.7 but it is the very newest design and he has it as lower priority after older models such as 2.4 and 3.6.

If you read thru this thread you can see his intentions. The sandcast wirewound resistors are replaced with Mills MRA-12. I did this in May, a very worthwhile and cost effective upgrade. Most importantly, it mitigated a glassy quality in the midrange and with added ease of presentation. But I also heard some improvements in microdynamics, “fullness” of sound, soundstaging, and, maybe, a bit more bass impact. I highly recommend this to all Thiel owners.

Tom has decided on Clarity CSAs for most caps. Clarity CMR might be a possibility for cost-no-object CS7.2 and 3.7 when/if he addresses them. @holco used Janzen to good result in his 2.4s (check his comments in this thread or the one regarding CS2.4 upgrades). I currently have CSA in one channel, bypassed with 1% Multicap RTX. I also replaced all of my coils which were OEM from FST-China. These were poorly wound. New coils are ERSE or Janzen, including a couple of foil types, and are clearly of higher quality construction.

I haven’t done any serious comparisons yet as things are still burning in (just did this Sunday). That said, my initial impression is improved resolution and microdynamics. For example, I’ve been startled a couple of times at the clarity and focus of vocal inflections from background singers. My goal was to have a near-SOTA speaker from the midbass up, for a fraction the cost of new. I think I have a good chance of getting that.

@holco PM sent

@andy2 
Understand I am building completely new boards. When I finish, *everything* will be new from the terminal posts to the output wire to the drivers. Only the drivers and cabinet will be OEM.

That said, when I upgraded the resistors last May I took the boards out of the cabinet. I found that easier but another 2.4 owner replaced the coax caps with the boards in place. The PCBs are soldered from the bottom, so you at least need to unscrew the board from the cabinet even if you leave the input/output wires attached. 

Smoking good deal on those 2.4s. I’d almost buy ‘em just for the spare drivers. 10-12 hour drive for me during winter, no thanks.

Cool history regarding Dave Gordon! I’m an A-hole: my favorite electronics are Ayre, Aesthetix, and ARC.

From memory, the 1.6 front facing port is about 1.5” wide and maybe a foot tall. Probably about 2” thick and I’m going to guess the inside edge is square. Doesn’t seem like many 1.6 owners post here.

@jafant not a garage like Tom’s who has 2.2, PP, 3.6 with 1.6 on the way. I only have my SEs, which are no longer SEs. I am giving Tom subjective impressions of a couple of caps and bypasses among other XO possibilities. Already did the Mills resistor subjective comparison. I’ll just say that the improvement put a smile on my face. 

I don't have any information on the cables used, something tells me the CS2.4 could use some improvement on the cables used in the xover wiring.

Rob Gillum informed me that my 2012 built SEs have wire sourced from FST. Supposedly it’s equivalent to what was on Lexington sourced boards but, judging from the caps and coils, I’m doubtful. Tom Thiel supplied me with, I think, Straightwire for the onboard jumpers. I plan to replace the input and output wire with Cardas. The coax out looks to be challenging, however, as the wire is in a tube so that the coax chamber is isolated from woofer movement.

Regardless, this will be the last thing I change. I’ve been making some of the changes one channel at a time so that I can control the variables in subjective mono listening tests. I hope to know sometime next month whether replacing that wire makes an audible improvement. But my test may not have inference for non-FST 2.4s?

My Cardas wire is, maybe, 5% of my total costs. For me, that’s not a dealbreaker when I’m trying to maximize SQ (short of $$$ Dueland caps and Path resistors). Now, the Cardas binding posts are more expensive and I’ll compare those in conjunction with the wire. If/when Tom brings kits to market he’ll have to decide on what to include.

With the 2.4 there are at least 3 iterations of XOs. IMO, the FST boards have no parts worth salvaging (the Clarity SA caps are good but are now surpassed by two generations of Clarity caps and the resistors, coils and other caps are plainly subpar) but Lexington boards have good coils that can be reused, probably a cap or three as well. I imagine Tom will need to accommodate these differences, perhaps also accounting for each owners preferences (which might include budget?). My beta-boards will probably be the only ones with this combo of parts, still under test.

That said, note Tom’s caution that additional delays are probable, even beyond the ongoing testing.

@sgmlaw 
I was disappointed to learn that my late SEs had Chinese-sourced crossovers and probably would not have bought them had I known this. Nevertheless, the drivers are superb and the cabinets are good . . . and now Tom Thiel is working on an upgrade that will handily surpass any OEM Thiel XO regardless of its source. My new boards have Clarity Caps (UK), Erse coils (USA, Rob Gillum told me some coils were sourced from Jantzen), Mills resistors (USA and Mexico), and Cardas or Straightwire (USA).

@jafant
Yes, I have 163/164. What a memory!

Given that the SE was released before Jim T passed in 2009 and my pair was built in 2012 (as reported by the seller and confirmed per label on a woofer), I suspect SEs were built as orders trickled in. But it’s hard to imagine that your even newer pair does not also have FST sourced boards. Obviously, you are plenty happy with your sound, so all is good.

In my case, I was very happy with the OEM boards but heard a slight “glassy” quality in the midrange. Encouraged by Tom Thiel’s participation here, I upgraded the resistors which cleared that issue and provided other sonic benefits. And now I have made global changes and am discovering what the Thiel CS2.4s are capable of. Literally put a smile on my face.

Regarding the FST coils, I sent pics to Tom Thiel and he noted the apparent loose winding. When my new ERSE and Jantzen coils arrived, I was stunned at the difference in tightness of the windings. Given my global changes, I cannot say to what degree replacing the coils has improved SQ.

I was surprised at the CYC caps on my OEM boards and an Internet search revealed little about their quality or construction. But I was especially disappointed to discover that they are MKT (polyester) instead of MKP (polypropylene). As I suggested in my previous post, there is nothing “wrong” with their sound, but other caps have better SQ. Earlier 2.4s apparently have MKP caps.

I was unable to determine the manufacturer for the resistors but they superficially resemble those on Lexington boards I’ve seen on the ‘net. Nevertheless, replacing those with Mills MRA-12s was money well spent. 

@cascadesphil 
I cannot imagine modifying the filters for the CS3.7 (really, any speaker but especially first order designs) based on John Atkinson’s quasi-anechoic measurements! That’s whack.

 I actually exchanged messages with that ebayer (his ebay history is spotless!) as I was buying my 2.4SEs. He had an ad for tweaking the 2.3 and 2.4 XO. I was flirting with the upgrade idea even before exchanging ideas with Tom Thiel. I am super glad I worked with Tom instead! 

@andy2
Keep in mind that my SEs had FST boards. Compared to (most?) standard 2.4s, these have better coax feed caps but potentially worse caps and coils elsewhere.

Here is what I wrote regarding the Mills resistors
https://forum.audiogon.com/discussions/thiel-owners-2/post?highlight=Mills&postid=1555245#155524...

Also
https://forum.audiogon.com/discussions/thiel-owners-2/post?highlight=Mills&postid=1562426#156242...

In hindsight, I would add that the Mills completely removed the “glassy” quality I was hearing and also made extended listening more relaxing. My more recent work has replaced the boards entirely, with the Mills kept. I’m not yet at a final configuration, auditioning another cap combo and still plan to replace input/output wiring plus terminal posts.

That said, direct comparisons in mono revealed the new boards to have notably more resolution and transparency. The FST (with Mills resistors) was relatively veiled (yeah, I know) and muddied. The new boards have textures and microdynamics previously unnoticed. I hear an ease of presentation and more presence/immediacy. These improvements sound evident for all instruments and voices. Bypass caps make a more subtle improvement. Just a scotch more resolution with improved transients, “jump factor”. Listening in stereo with the new parts in both channels is when I smiled. For the last many months I’ve been hyping an opinion of what might be possible with better passive parts. I, um, wasn’t wrong . . .

@sgmlaw
I agree there is a good amount of art to voicing a XO. But know that Tom T has put in a mountain of homework, drawing on his own experience and that of several industry professionals with decades of knowledge/experience. The idea for these kits was introduced about one year ago and here we are still in beta version for the first model tackled. Tom has been quite deliberate and considered in his approach and has been willing to change his plan as new information is encountered. 

But even a full-time designer cannot listen to all the possible combinations. Let me just say that I lack sophisticated measuring tools but what I do have confirmed that the overall balance was not upset. And, to my ears, the end result is spectacular.

@jafant
I have never noticed any stress from my Ayre AX-5 at any SPL in my 18x19 room (vaulted ceiling with large openings on rear wall). With my combo of amp and DAC, clipping sets in at an indicated “40” on the volume with a typical CD. Even for something like Zeppelin or The Who, “32” is plenty loud for me. I have plenty of headroom.

@tomthiel This thread
https://forum.audiogon.com/discussions/thiel-cs2-4-upgrade-to-cs-2-4-se

Desmond put CSA 250V on the coax feeds (had to parallel 10+3.9 and 18+10 uF). He reported his perception of a change in balance and suboptimal neutrality and “clean”. Quite a different experience than what I’m hearing albeit his starting and ending points are very different. I wonder if his expereince is at least partly a function of burn in. Would be interesting to read an update.