Thiel Owners

And … are they Picofarad or Nanofarad? 

Does anyone know the capacitance  of the 6 small polystyrene caps in  3.5’s crossovers?  

In the crossover schematic in my possession the capacitance of these units is not indicated, they are instead identified only with the letter "S" (which perhaps stands for styrene). 

The actual units installed in my speakers have the writing "ASC 12000H" (they should therefore be 12000 Picofarad capacitors, built by ASC Capacitor), but according to what can be found on line these caps should be 15000pf.

Therefore I’d like to ascertain the exact capacitance and brand of the stock units installed by Thiel (in order to ascertain if my capacitors are original or have been replaced at a later time). 

Thank you all 

DIY is different than manufacturing. From 1983 / CS3 onward, all our film caps were custom with a target and a tolerance window, not necessarily symmetrical. Our commitment quantities were in the range of 10,000 pieces spread over the product life. Today we’re doing the best we can. The reason I first steered magnet7 toward 8 is that the original cap was a 7, so I would prefer a 7.8 over an 8.2. But as we say, we play our best with the hand we’re dealt. And the sound will be glorious compared to stock.

@tomthiel 2.5% over target may be so, but I recently sent back five(!) pieces of 6.8 uF caps (CC) because all of them were 7.0 uF.. I would not have minded this very much, were it not that they sell 7.0 uF caps as well.. that for me was reason to send them all back.. and now I'm waiting for Rob to send me five be says he has (and which he says sound excellent..).. 

magnet7 - He is correct, that's 2.5% over target, which is OK.

@tomthiel - Yes, I know that according to the scheme it should be an 8uf.  I ordered the 8.2uf because the Clarity CSA does not exist in 8uf, only in 8.2uf.
The technician who is helping me with this upgrade project says that a difference of 0.2uf is not relevant.  What's your point of view?

jafant - the pleasure is mine. Good work here, guy.

magnet7 - my latest schematic (22dec'87) shows an 8uF (not 8.2) which had replaced the original 7uF spec.

magnet7 - yes, that 8uF tweeter blocking cap is the best bang for the buck. Psychoacoustically, its function range in the midrange and treble is where our hearing is most sensitive. 

@tomthiel 

Tom, can you confirm that in your view the most effective (both, sonically and economically) upgrade for 3.5s is the 8.2uf cap replacement in the tweeter feed?

tomthiel

I hope that you are well and ready to kick off Spring starting this Sunday.

Thank You for being a strong supporter in this thread and the advancement of our beloved Thiel Audio loudspeakers.

Happy Listening!

magnet7

Good to see here again. Thank You for the 3.5 upgrade, update.

I know that Tom is working very hard to deliver a viable upgrade path 3.5 loudspeaker. Stay tuned.

Happy Listening!

jeff_pvd

Thank You for the follow up and citing Serial Numbers (S/N) on your speakers.

Those are nice, low, numbers. Good to read that a Rotel receiver can drive the 03.

Happy Listening!

For those interested, the original 03 EQ was similar to the 01 as a fixed point boost at 30Hz, enabling the speaker's -3dB point at around 27Hz while maintaining 90dB sensitivity at 8 ohms (6 ohms minimum). Those early EQs had less sophisticated circuitry and implementation, with electrolytic caps in the signal path and so forth - creating a transistory veil on the music. Each generation got better with the CS3.5 becoming direct-coupled.

Jeff - you're not alone in preferring the direct path and sacrificing the deep bass for more transparency. You might consider the CS3.5 in your replacement search. The EQ is getting upgraded well above stock and the speaker is in line for significant driver and crossover upgrades.

tomthiel wrote:

"Jeff - my memory was unclear about the ported 03. Please confirm NO equalizer."

My ported 03s came with the Thiel equalizer. Early on I made the determination that I liked the sound/setup better without the equalizer in the pipeline. I no longer have the EQ box, I should have hung on to it. 

Jeff - my memory was unclear about the ported 03. Please confirm NO equalizer.

BTW, it's great to know these speakers have given you joy for so long. They were made in our first garage shop on the little farm outside Lexington, about the time we were building the new 16' x 28' addition onto the original dirt-floor 15' x 22' garage. Memory Lane Lives. 

Good weekend too you all.. 

Tom gave me some tips on cables for my speakers and I must say that they are both more open ( the one on the right was a bit cramped/ held back and on the first listen benefits more than the left , but both are more present with my self made new cables. )

I've got the electronics for my surround speakers nearly finished and ask in their own little boxes (filled with holes for venting). Just need one or two resistors and caps and Rob to finish my coax...

****** Weekly reminder ******

Just to remind those willing to upgrade their 2.4

Clarity Caps PUR 14 uF@630 VDC for €165,00 / piece

Clarity Caps PUR 28 uF@259 VDC for €142,50/ piece

This would total in USD something around 670 for the set

******** PM me if interested ********

Cheers

Pieter

@tomthiel - Thank you so much!!  

I'm aware of the non-essential importance of shunt electrolytics in the woofer cell. Precisely for this reason I have already ordered two 8.2uf ClarityCap CSA polypropylene capacitors to replace the 8uf Solen caps in the tweeter path. From what I understood these units are the ones on which to invest the most in terms of cost /sonic results.

As for the other electrolytics:

- the two 100uf caps in in the midrange cell (one in series and the other in parallel shunt), essentially for budget reasons, I thought  to replace them with new 100uf Mundorf electrolytics (RAW series - ECAP 100), and to replace the 1uf Solen with one 1uf “Audyncap Q4” (polypropylene). The small 12,000pf bypass polystyrene capacitor would remain in place;

- I would follow the same path for the 100uf electrolytic in the tweeter cell: replacement with a new Mundorf electrolytic of same capacity and replacement of the 1uf Solen with a new 1uf Audyncap Q4, keeping the small 12000pf polystyrene cap.

This is why in my previous post I asked for advice only on how (and with which units) to replace the woofer capacitors. However, if collective knowledge / experience of this Group believes that I’m taking the wrong path as regards the intervention on the crossover, I still have time because I have not yet sent the order for the new capacitors.

Thanks

    
tomthiel - Thanks for the history, makes good sense! 

BTW, the 03s I have (SN 0287, 0288) have a round 2.5" port below the woofer on the left side. 

Jeff - here's a lesson from Thiel history. All our products shared the same goals of flat frequency, phase, time, and dynamic response. The family signature is quite similar between models. Also, along the time-line, new technologies were invented and incorporated, so a newer product will always be more sophisticated than prior ones. Higher model numbers get you more bass. In your particular case, you will sacrifice bass extension and power going from your equalized, sealed 10" woofer to the 2.4's reflex 8" woofer. (Unless you weren't equalizing your 03.) The 2.4 is a highly mature product, whereas the 03 is the first generation of its format. Huge difference in subtlety and sophistication, but very similar family resemblance.

Notes about your 03. Only 500 pair were made before the upgraded 03a (2500 pair.) Your 03 is the base on which Thiel succeeded. Its phase/time coherence was unique and the equalized bass was unusual and powerful. They earned immediate distribution and reviews in Europe which seeded interest from east coast US dealers - and the rest followed. The 03 is quite rudimentary compared with later models, but in 1978 it shone quite brightly.

jafant  - Thanks for your response!

After looking at all the Thiel models on https://coherentsource.wordpress.com I can see why the CS 2.4 would be considered the sweet spot, the most modern model before the price starts doubling. 

I know this is a hard / subjective question to answer, but I'll ask anyway :) If I go from my 03s to something like the CS 2.4s, what can I expect? Will it sound like a completely different speaker/a huge jump in performance or just a nice refinement of what I already have?

As for my system: I'm guessing it's rather basic or maybe even "crude" to what others have on here, but I have a good ear and find it highly enjoyable to listen to. 

I  play mostly high quality recordings / files from a MacBook Pro feeding a Schiit Modi Uber DAC then to a Rotel 1052 receiver (100 wpc) out to the 03s.

magnet7 - Others here might help you find your best brand fit. Here’s my broad input. Those woofer electrolytics are in shunt (shaping) resonance circuits which are the least sonically important. The Solen 1uF bypasses are very good. The styrene ultra-bypasses are extravagantly good. Those woofer shunt circuits are least worthy of expensive audiophile electrolytics.

On the other hand, the caps in the midrange circuit are of greater sonic importance. The 100uF electrolytic mid feed cap is worthy of the best cap you can afford, perhaps a ClarityCap 250 volt (or $higher) CSA with a very good 1uF bypass and then decide by ear to keep or toss the styrene bypass. Similarly the 100uF mid shunt.

The tweeter also has a 100uF electrolytic feed, which is at least as important as the midrange.

Short story, concentrate your budget on the upper drivers. I suggest looking at Nichicon for those woofer shunts. (high quality pro-level audio cap.)

Hello everybody.

I would like to ask your opinion on the crossover update of my CS3.5.

I have already ordered (and am awaiting delivery) two 8.2uf ClarityCap CSAs, which will replace the two equal capacity Solen polypropylene caps installed in the tweeter’s cell (these are the two units to which - following the precious advice of Tom Thiel - I want to allocate the largest budget).

The doubt concerns instead the replacement of the two electrolytics in the woofer cell. As you may know, in the latter there is a 66uf electrolytic cap (branded "Versa-Tronic") and another 24uf electrolytic cap (also branded Versa-Tronic). These two capacitors are bypassed by a 1uf polypropylene (Solen) and a small 12pf polystyrene.

Now, as the two electrolytics mentioned above have come to the end of their service period I would like to replace them.

With which units do you recommend replacing them, having to replicate the overall capacity of the two groups of capacitors (that is 25.012uf (24uf + 1uf-12pf) and 67.012uf (66uf + 1uf ​​+ 12pf))?

Thanks to everyone who will want to advise me!

Happy Friday! All

jeff_pvd

Welcome! Good to see yo here today. Thank You for sharing your Thiel 03s experience.  After 34 years, you are certainly due for an upgrade. IMO, the sweet spot is a pair of CS 2.4 loudspeakers. These are easily found all over the internet.

Model CS 2.4 can be placed 8-10 feet apart. Then, 2-3 feet away from back walls/side walls. This particular speaker sounds great with as little as 75 watts up to 200 watts per channel (wpc). Again, easy to drive and easy to place without too much fuss. Most sellers are honest about the condition of a demo/used pair of Thiel Audio loudspeakers.

What other gear is in your system? I look forward in reading more about your Musical taste.

Happy Listening!

Looking to upgrade my Thiel speakers - What should I get / look for?

Back in 1988 (when I was 23) I was looking to upgrade my Polk Audio floor standers, the Polks had plenty of bass and treble but lacked detail. I made my way over to a small audio store in Cambridge, MA  (Q Audio - still in business after all these years) and saw a pair of used Thiel 03s. I listened to the Thiel’s briefly, was impressed but the setup in the store was less than ideal to make any sort of sound judgement. The salesperson very kindly told me “take them home and try them out for a few weeks, if you don’t like them, bring them back and i’ll happily give you your money back no problem!” I took them home and have now been delighted by them for 34 years! What I noticed right away was their uncanny ability to reproduce the human voice so naturally. The Thiels are not just “speakers” but really fine instruments that come alive with the right recordings. After many years of use I had the foam around the woofers expertly replaced. A few years ago I also added a subwoofer to the 03s, extending the bass but more impressively adding more 3-dimensionality to the sound stage. 

After 34 years, I’m feeling the itch to upgrade:) I need some help. I want to buy a more modern/advanced pair of Thiels (used of course) in the $2K range. I have a few questions If anyone has some input:

1) When evaluating a used pair, what should I look for a far as defects, things that might to be fixed? Ideally I don’t want to fix/restore too much.

2) My current listening room is narrower than ideal but my 03s work just fine in the space. Do all the models require the same space or are some better suited to narrower L to R walls? I can sit as far back/away as needed. 

3) Is there a particular model in my price range that stands out?

My idea is to look at any that come up for sale within 100 miles away to check them out in person. It may take a while for the right ones to appear.  

Any thoughts are much appreciated, I found this wonderful forum a few days ago!

~ Jeff
 

@vair68robert thank you very, very much👍🏼🍻

pieper

partsconnexion says that the resistors are a few weeks out if you can wait ,

I had to contact about purchasing 8 Mundorf electrolytic capacitors , so I asked they about your resistors .

Excellent discussion Guys , on the CS 2.4 / CS 2.4SE loudspeaker.

Happy Listening!

I see MRA-12 12 Ohm on Sonic Craft and Parts Connexion websites

???

If *I* was going to spend $25 per resistor, I would get Path and put them only on the coax feeds. I recall looking into this and some of the values are not available in single resistors. And it gets super complicated, with the available Path values,  trying to get the proper values by combining resistors.

It looks like it's not super hard to make your own graphite resistors but it probably takes *many* attempts to get the correct value, especially as a matched pair!

@vair68robert ... I already checked there it seems. They don't have the 12 Ohm 12 Watt resistors, unfortunately..🤷🏻‍♂️

@vair68robert thank you. I'll look.

@beetlemania I'll keep that in mind when I get around to the 2.4's. I had my eyes on some hand made resistors from Poland.. think they would come down to 20-25 dollars a piece... 

pieper

have you tried Partsconnexion ? 

they list that they are in stock .

Some of the power resistors can benefit from 25 watt versions, thus 2x12watt. This resistor thing was a short suit for Jim (in my opinion), since the compact layouts can only afford so much real estate. Modeling software can ID those candidates; so can pink noise and a thermometer (or fingers.)

Beetle - I do remember the aluminum cooling bar mis-step. Moving air and greater distance work better.

@tomthiel thanks for the information. Heat management was definitely on your radar when I did my build. You’ll recall an early solution that we abandoned. But it sounds like you continued to work things out. I hope you can share this with the world sooner than later (products or “how to” manuals).
 

@pieper1973 when I upgraded the sandcasts on my OEM boards (sourced from FST), I bought all Mills in identical values. But when I did the full rebuild, Tom had me parallel 60.4 ohm Mills for the 30 ohm position - more surface area for cooling that big resistor. The downside is it costs twice as much. But there is a sonic benefit to running in parallel, at least for bigger resistors. 

@beetlemania 

Among others I have the 2.4 ..

The 12 Ohm is needed for my one point monitor with the SCS3-N Thiel coaxes.

Audi, I don't want to combine resistors to get to 12 Ohm. I'm just looking for a good substitute for the Mills, if anybody knows of one.. 

Beetle - I looked extensively at thermal dynamics as a source of 'aural congestion', drifting crosspoints, etc. That's where the new layouts came from, which have all the resistors separated from caps as well as positioned over ventilation holes in the board for natural convection, and moved either to the exterior of the cabinet or to separate XO enclosures. The hookup wire(s) also mount to pin-type heat exchangers close to each driver to drain voicecoil heat directly through the lead wires. Taken together the thermal management significantly improves dynamic range and 'sonic orderliness' during high-power use. The small-signal Thiel reputation got bigger.

My investigation began by remembering 'warranty claims' for melted caps and charred XO boards in the old days. In my power tests, some resistors got too hot to touch. Series coils also get hot - I put them on 3 rubber feet for all-round radiating and convection. My tool of choice is a non-contact infra-red thermometer to identify small scale/ local differentials. That led to some heat-sinks being added in-line on the XO board for dissipation before entering caps. I don't remember at what stage all that investigation stood when we hot-rodded your 2.4s. There's always more. 

Nice tweak, @tomthiel Curious to hear the back story on how you discovered that.

@pieper1973 you have CS2.4, right? Why do you want 12 ohms?

Also, I forgot to mention one of the Mundorf lines is comparable to Mills . . . It’s a re-badged Ohmite.

pieper

try using parallel resistors 

http://www.sengpielaudio.com/calculator-parallel.htm

a 20 and a 30 = 12

Adding to Beetle’s excellent summary, here’s a cheapskate trick for the Thiel resistors that you might keep.

Turns out, a big part of those resistors’ ’sonic problem’ is the thermodynamics due to their mounting. They are non-inductive wire-wound with current flowing around their coil circumference, dissipating into the ceramic body. The bottom of that body is glued to the panel, creating a large differential in wire heat distribution. Solution is to mount that same resistor on an edge rather than a flat. Put the edge on Mortite / BluTac pads for even better results. Cheap fix, much of the improvement of Mills, suitable for woofer and midrange. Spend your savings on a Path, etc. for the 12Z tweeter feed.

@pieper1973

Are you in the US? Sonic Craft is your friend. They stock MRA-12s in all the values used in the CS2.4 although you do have to mix and match the old Mills (brown body) with the newer Vishay-Mills (black body). Fast shipping, fair pricing, and excellent service. IIRC, I paid for the mid-grade level matching and they gave me the full set measured at better than the top-grade level matching.

If you are really stuck, the only thing comparable, from my extensive research, is the Ohmite. Wilson uses Caddock but I could never figure out anything that would be suitable in the CS2.4. If you have really deep pockets, you might try Path or Dueland graphite resistors. People say they are the best. They better be at those prices - 5-8 times the Mills! At that’s if you can get the correct resistance in a single resistor. You have to get really creative running in series/parallel to get the proper values. Other than Mills, those are your choices. Otherwise, just keep the OEM resistors.

Good day to you all..

I'm having a problem getting my hands on Mills resistors 12 Ohm @12W.

The sender has given me a very long list of other brands..

Anybody here recommend a substitute for the mills at same price range and sonic performance?

Thank you

 Pieter

@tomthiel 

Thank you for the detailed answer. Interesting observation re: Thiel v Vandersteen house sound.

Those 7 uF PURs are the first I’ve seen in that capacitance value. Will be interesting to see if the North American retailers stock those. In the meantime it looks like @pieper1973 has a lead on getting the 14 and 28 in single caps.

If I ever make any further mods it will probably be to try an ultra bypass (eg, Jupiter copper foil), Path graphite resistors in the coax feed path (really tough to get the correct values at all positions), or, if your reports are over the moon, PUR in the coax feeds. Regardless, I’m sitting on some tricked-out, sweet-sounding CS2.4s.

vair68robert,

Please let us know what the results turn out to be. 

Tom T. & Duramax747

You got me rethinking the shunt circuit on the 2.7 , so I'm sticking with 

the 220uf  6% ERSE and the 330uf 10% changing it from a Topmay ? %

to an ERSE , I was thinking 2 x 220uf 6% and 110uf 6% .

But I will be changing the 400uf ? % Topmay to 2 x 200uf 6% ERSEs .

I also ordered new 6 x 15uf 400V PulseX caps up from 250V .

Thanks again for all your insight .

Rob

In most all applications I never liked the addition of bypass caps especially those on speakers. At one Thiel dealer in 80s we did a comparison of bypass caps on and off the result was they were left off.  For what its worth 3 of the 4 listeners on that day.continued on in the business at least one to this day and still dug in. Tom D

@beetlemania

re: " Curious if you have an opinion or knowledge about how to pair "main caps" if the full capacitance is not available in a single cap. Is it best to optimize balance between caps (eg, 7+7=14) or is there some degree of leeway (eg, 10+3.9+0.1)?"

My opinion is based on Thiel experience and related observations - both approaches are valid, but will produce slightly different sonic signatures. I believe the cascading bypass format compensates for deficiencies in the large cap which produces dielectric cycle anomalies (charge lag, erratic discharge, Effective Series Resistance irregularities relative to power levels, etc.), along with possible smoothing of the signal in general.  A small cap is inherently less reactive, plus a higher quality small cap is more affordable considering budget constraints. As you have previously mentioned, Thiel’s 1uF bypass cap might sometimes introduce less-than-best characteristic balance when bypassing at greater than 10% of the base cap value. We arrived at our format because we developed that great 1uF tin foil / styrene film cap for the CS5, bought 6-figures of them, and put them to work wherever they made an improvement (that we could afford.) Our main (base) cap was a single cap unless its value exceeded 100uF, where the deleterious secondary effects broke through. In those cases, we used single value multiples. You’ll see ganged 100uF caps (often electrolytic) bypassed by a good polypropylene, bypassed by the great (yellow) 1uF tin/styrene. 100uF was the maximum cap value we identified from listening, and same-value was identified as more correct than cascaded values.

Note this scheme runs contrary to common practice. Note the CS2.7 (outsource engineered after Jim’s death) uses a 400uF lytic in the midrange feed (400E/15PP/1S) and other large, cascaded lytics in that shunt circuit (330E/220E/15PP.) That scheme differs from Jim’s. Note that people who prefer the 2.7 sometimes note they like the "smoothness" or "refinement" of that model which may be attributable to this cascaded approach. Note also, that Vandersteen employs such a cascaded-value, multi type approach to cap bundles. I have wondered if that difference might be a significant contributor to the obvious character difference between Thiel and VdS. The two brands share very similar philosophies and solutions down to wire configuration, but exhibit very different personalities. Jim’s engineering approach was always to identify the solution that addressed the hard-core principles most directly, optimize the particulars and confirm by ear that the most accurate solution had been found. Little to no slack was cut to make harsh recordings sound smoother or mitigate other signal chain problems.

In summary, I would choose the 7+7 option as truer to Jim’s approach. There is, of course, leeway and your other string presents the option of using a CMR (PUR+) as the 0.1uF value without breaking the bank.

If you climb back into your 2.4s and try these options, let us know what you learn. No end to the fun.

prof

out of curiosity what 5751 tube are you using ?

I've had an interesting time tube rolling with my Conrad Johnson Premier 12 tube monoblocks.

Same ones I drove the Thiel 3.7 and now my 2.7s.

When I had both the 3.7 and 2.7 in the house I was trying to decide which one to keep.  One of the distinguishing factors is the 3.7s sounded like they were: a bigger speaker.  Even though by specs only slightly extended further than the 2.7, there was a sense with the 3.7s of the proportion of the sound being a big different.  Bass went a bit deeper, the scale was a bit larger on everything.  The 2.7s seemed like putting a bit of a girdle on - like the bass frequencies were lifted slightly upwards, putting more emphasis on the punchiness of the mid-bass.

I finally tried replacing the 6550 power tube on my amps with the larger more powerful KT120 tubes.  What a difference!   Bass feels deeper, the scale of everything - soundstage, image sizes - expanded.  Now the 2.7s truly remind me of the 3.7s in that sense.   Pretty amazing.

Rob - I can recommend the SonicCap from Sonic Craft that still has the old aspect ratio. Anything Sonic Craft carries has been carefully considered and chosen.