Thiel Owners

My hope is to supply subtle information that may not be obvious to all. Crossover networks can be very easily scrambled via changes with unintended consequences.

I suspect I speak on behalf of this community in saying how grateful we are to have you here! I am very much interested in tweaking the last drop of performance out of my CS2.4s. But I have not the expertise, time, or money to try a multitude of mods. Your advice (and, hopefully, that of Rob Gillum) is *greatly* appreciated! I'm hoping you might write more about:

If I were hotrodding an upper end Thiel, I would consider a Teflon bypass in the tweeter feed.

^Agreed!

Beetle, I am glad to be here. My hi-fi life has been fairly well buried until recently. Nice to find you guys.

Regarding capacitor bypasses, we discovered in the 1970s what has now become fairly commonplace knowledge, that small value high-grade capacitor(s) in parallel with the workhorse will keep the upper frequency leading-edge waveforms, etc. intact at a higher performance level per cost than a single type cap. My brand knowledge is a couple decades old and lots of progress has been made, so I will be finding my solutions just like you guys. We don't have Jim's lab and expertise. Nonetheless, Thiel's development MO was to experiment with cap configurations via blind listening to rank sound quality among the combinations. Then the highest performance / cost solution was identified and subjected to rigorous analysis regarding waveform integrity, ringing and so forth. The winner was always a bypass pair or triplet. The rank of (affordable) cap types (at that time) from best downward was: Teflon, Styrene, Propylene (foil or metalized depending on current requirements), Polyester (Mylar) and electrolytic, with some variants such as Tantalum, oiled, etc. Mylar was a bargain because propylene was very expensive due to production losses, which is now cured. Notice that older Thiels contained multiples-in-series propylenes or mylars to make the value in order to reduce costs. (Eventually a wound film cap will fail in testing due to a thin spot in the film carrier, so cost rises geometrically with cap value.) Another thing that has changed is that Styrene caps (our favorite bypass) has been obsoleted in the marketplace. Teflon over propylene and/ or electrolytic has a high likelihood of success on those large value caps. Rule of thumb is to bypass at 1% to 10% total requirement, more or less. More for high current requirement. Example: 100uF EE + 10uF PP + 1uF Tef > 111uF value at much lower cost than eliminating EE. 

This whole upgrade enterprise runs contrary to the rigor we applied at Thiel Audio. But I am fairly comfortable flying blind since I do not have access or time to test with instruments. I am also fairly confident of my approach due to serious personal experience. I also will employ a few twenty-somethings including two young women with extraordinary hearing to supply observations beyond my present hearing acuity (I am 69 and ears suffer with age.)

That's all for now. I'm expecting 4 XO kits for my PPs this week from Rob. I'll open my cap investigation and layout next week. 

This is easily one of the best,  most informative and civil forums I've had the pleasure to come across on this site since joining,  oh,  about five years ago.  There had been a rather lengthy stray from the "hi-fi" scene in my life,  perhaps a 25 year long span,  during which I listened - and rarely - through a series of vintage receivers from the 1970's; those Pioneer,  Sansui,  Marantz receivers still have a hold on me to this day.

I believe I stumbled upon this site whilst actually looking for yet another relic from my mis-spent youth,  in the process becoming beguiled by a tube amplifier someone had put up for sale.  It's been all downhill since...

In a good way,  if that's possible.

As I've said before,  I don't know a mosfet from a  misfit,  but I know what I like.  I may not be able to contribute anything substantive to the current and quite technological discussion currently being followed,  but I read,  as I have read in the past,  with a keen interest in learning what it is about Thiel that captured me in the first place.

A few years back with my first pair of Thiel 3.5's I opted,  as a result of  one of the midranges going in and out,  to remove it to see what was causing it.  In the process I slipped with the screwdriver and poked a small,  but worrisome hole in the midrange's surround - not the driver itself.  It was through this forum that I discovered Rob Gullom was still repairing drivers for the model,  and so sent the pair off for repair.  I gifted that pair to my nephew.

So much of our possessions are disposable.  So much of what we purchase IS disposable,  designed for the short term with nary a forethought as to how much we consume and ultimately discard.  The purchase of Thiel legacy models is an investment,  not merely a purchase in and of itself.  Fixing/repairing any model is indeed an investment,  not a patch.

There have been too many times here,  in too short a span of time,  that I've said "I'm done" upon finding a great system recently.  (As if it's possible to reach that point.)  I ain't done,  and I never will be.  Forums like this,  with contributors who don't get snarky or preachy,  are the reason why I keep reading,  keep trading,  keep interested.  Thiel is special stuff,  and the community of fellow fans continues to be a learning experience for me.

The only reason I'd be interested in replacing caps in my 3.5's is due to the age of them. While they seem to be fine, I suppose it's just a matter of time.