Thiel Owners

@sdecker - wow also. I didn't know about the wayback machine!

pieper1973 Nice work. Your CS2.4 serial numbers @253-4 are right near the transition from Lexington-made original boards with American / European parts, point to point on masonite boards - to FST-supplied clones. If your boards are printed circuits, they're from Asia, but your parts may be original, which I consider higher quality. What I know from Rob is that somewhere around 220-230, production went to Asia, and parts sourcing gradually migrated toward Asian parts.

Regarding your cap question. I've corroborated Jim's migration to single caps rather than the 1uF bypass. A single value is superior when the cap is of very high quality, which you are proposing. FYI: Jim tested all the high end caps and chose ClarityCap. I did also, landing on the ClarityCap CSA, which is considerably superior to the original SA. CSA has (or will soon have) an improved version called Purity or Purity+ with thicker copper end caps and even better performance than CSA, at lower prices than your targets. You might put them on your radar. Keep us posted.

To tomthiel and pieper1973.  We had discussed this some time ago, but a reminder that my CS2.4, bought from the original owner after one year, are SN 611 & 612, and have the entire Lexington masonite XOs and best parts of the era.  Seems unlikely they'd use Asian XOs at 250 and switch back to Lexington XOs at 600.  My 2.4s were nearly brand-new and certainly unmodded when I bought them.

Speaking of modded, I revisited what I had done around 2010.  I used 250V Clarity Cap ESAs, a 27uF, and a 10uF || 3uF.  For the 1uF bypasses I kept the existing Thiel bright yellow Elpacs in place.  And added the then-recommended Vishay MKP-1837 10nF bypass across both cap combos, improving the ESA sonics that smidge more.  The CSA versions were not yet available at that time AFAIK.

I'm not losing sleep over not using 630V, subbing in CSAs, or keeping the Elpacs instead of using a much-better 1uF bypass, but by now others have done more and may suggest improvements.  My guess is finally getting to Mills resistors would be a better use of my time.

ESA Sound: Similar in overall character to the Clarity Cap SA [used in the 2.4SE] but with more clarity and therefore a fraction more spatial. Like the SA they could still do with a bit more transparency but with a small capacitor placed parallel to the ESA this can be improved. The ESA also has a slightly warmish presentation and also benefits from making a total value using about 90% Clarity Cap ESA and about 10% Mundorf Supreme. This opens up the top end just nicely without altering anything else. Good overall qualities and an upgrade from the standard Clarity Cap SA.

CSA Sound: The tonal character of the Clarity Cap CSA has in common with all Clarity Cap capacitors that is well balanced and never fatiguing. The CSA shows a pleasent intimacy combining the clarity (pun intended) of the ESA with the smoothness of the larger MR. Relatively speaking, I actually found the step up in sound quality from the ESA to the CSA to be greater than from an MR to a CMR. Both the CSA and CMR use Clarity Cap's Copper Connect Technology but it seems to have a greater effect on the SA range than of the MR range. Maybe it's easier to improve lower down the scale than further up it, I don't know, but that is how it cames across to me. Anyway, in direct comparison to the CSA the ESA sounds a little rougher, the CSA seems to produce a more civilized image that is at the same time more neutral. "S" and "T" sounds that were first maybe a little bit rough around the edges with the ESA (I am being very nit-picky here) become free from grain with the CSA. I also found the CSA to mix extremely well with the Jantzen Audio Alumen Z-Cap. A mix of a minimum of 20% Alumen Z-Cap with the rest Clarity Cap CSA enhanced realism of space and lushness of tone. They blend together seamlessly. All in all the Clarity Cap CSA is a well balanced, neutral capacitor that is a welcome addition to capacitors in the lower price range.

@pieper1973

The thought of putting Dueland caps into CS2.4 is wild to me. Even if Dueland makes the proper capacitance values (I don’t see anything close at Parts Connexion), the price would staggering. Multiples of the original price of the full speaker. But I would love to hear the outcome!

I suggest taking Tom Thiel’s advice, go with Clarity Cap CSA. Ideally, get full capacitance in single caps. 14 and 28 uF are tough to find but I would avoid going with 13+1 and 27+1 as in the original CS2.4. Running caps in parallel, I would go with something like 10+3.9+0.1 and 18+10. Try to get a more even balance among the two bigger paralleled caps. The 0.1 uF bypass is where you might go crazy and install a super-ultra bypass like a Dueland or Jupiter (even those are expensive!). You could add a 0.1 bypass to the 28 uF position as well.

Tom pointed out that the higher voltage models (eg, 630 V) have thicker film which is desirable, especially in the coax feeds. But I heard a difference even in the woofer shunts with 250 V version sounding more impactful than 100 V version of an otherwise identical cap. If your budget extends to Dueland$, definitely you can afford to replace the electrolytics in the coax shunts to film caps. Clarity Cap is a great choice for these, although be warned that their size is far greater than the electrolytics. That is, you might be challenge to fit everything within the passive radiator chamber.

Definitely upgrade the sandcast resistors to Mills MRAs or, if your pockets are Dueland-deep, maybe try Path or Dueland graphite resistors. Again, those ultra re$i$tors are hard to find in the proper values for the CS2.4.

About the CS2.4 serial numbers . . . I’ve been piecing together the history puzzle. What seems clear is that the transition to Asian inputs such as CS2.4 crossover manufacture was far from smooth or steady. Even though Rob says Lex 2.4 XO manufacture ceased around #220-230, that’s only part of the story. We have evidence from participants on this forum that later XOs were Lexington-built and that some later Asian XOs were decidedly inferior to some earlier ones. One key is that FST, the "best" supplier wasn’t the first supplier and that the road was pretty rocky to arriving at well-made units with top grade parts.

The Lexington XO department was not disabled until New Thiel moved to Nashville. While it was operational, runs of "old Thiel" crossovers could be and were made in Lexington with classic Thiel parts to fill in until acceptable units arrived from Asia.

With the records gone it seems the most reliable test is whether a board is built on masonite or not. If yes, then it is from Lexington with classic Thiel parts and QC - which means very tight performance assurance. If fiberglas, then more is unknown. Some Asian boards that I’ve seen are quite poor and some quite good.

Another potentially confusing element is the SE designation. The Signature Edition had a special cabinet with red Birdseye Maple veneer, SS bolts and outriggers, and larger, signed back plate. The only electronic upgrade was the ClarityCap SAs in the coax feed replacing the standard Solen caps. I think that run had its own serial numbers (1-300?) However many regular 2.4s have had the SE cap upgrade or better and some designated (red BE, etc.) SEs use Asian boards with SA caps. So, there are more variants of the 2.4 than might be assumed. I now have a pair on loan from a collaborator (#3729-30), in mature-Asian form with clean coils, polyester (MPT) caps and PP 1uF bypass caps, rather than classic polypropylene caps and tin-styrene bypasses. This is a de-spec iteration which I predict would sound inferior to a classic Thiel build. But it does sound delightful. Despite its somewhat shady history, what a wonderful product!

My CS2.4 serial number 384X, the last digit faded out unreadable, this is xover photo taken 5 years ago before modding.