Thiel Owners

Todd, I run the CA-301.  Running unbridged, it is plenty enough for a 3 Series as long as you don’t try to fill a stadium with it.  Mine only have to fill a 600 sq ft listening room, and they can go as loud as I can tolerate.  And then some more.

Thiels are more about quality than quantity anyway.  If I wanted my neighbors a quarter mile away to hear Sinatra, I’d be running horns.

I’m winding down at this point, so this will probably be my last high quality system heading into retirement.

Got your pm.  Recapping won’t add watts, per se.  But it will stiffen up the power supply rails back to specifications so that they won’t sag as much under a heavy or sustained load.  Capacitance on the filters can start to fade a little after a couple decades.  Most of the time, with most speaker pairings, it won’t be noticed, because these instruments were so overdesigned to begin with.

But with a heavy sustained load, the quality of an older supply output can start to falter at the margins.  And as we all know, Thiels are all about plenty of sustained, very high quality current.  Not watts.  Current.  I’ve known this since the first day I owned a pair of these.  Your DR8 running bridged has more than enough high quality current reserve to drive a 3 Series Thiel.  But your Thiels will tell you without fail, every time, when its amp is starting to miss a beat here and there.  They are that relentlessly revealing of anything substandard, IMO.

Since they have emerged from their own recent reorganization, I found the people at Classe to be more than helpful with us old owners.

They would have no problems supplying a replacement jack set or screw, I’m sure.  And if not, an RCA jack on these is a generic part.   The originals are nothing fancy.  A basic Vampire or similar grade is probably an upgrade on it.

The current design team was fairly busy with some new product work, and they were not able to get back to me with some rather esoteric capacitor performance and specification questions.  But the tech and CS people were more than helpful and gave me detailed bench data to do the job I wanted.  I stayed as close to the original Nichicon parts selections of the original designers as they would have done.  No mods, no hot rodding.  All at original values.  A classic recap job.  Just a little better due to improvements with the latest electrolytic technology.  And they were rather impressed with the results, too!

The other thing you can do to keep your Classe (or any higher power amp) from straining, and your Thiels sounding their best, is a dedicated circuit and a high current power cord.  I run my Classe straight into a hospital grade dedicated outlet (20 amps via 10/2 Romex straight to the service panel) with an ancient Tice Infinite Speed cable that only provides some transient protection.  No other power conditioning.  The only ‘conditioning’ is a $99 iFi AC Purifier in the same duplex outlet, which does not impede raw AC delivery in the least.  And it sounds terrific, better than ever after two decades.

Keep that Classe, kdross.  I've run a Thiel/Classe pairing for over two decades now.  And you cannot better it.  Believe me, I've tried.  The electrical and timbral match is perfect.   The closest on tone was a big Threshold, but it lacked the dynamic headroom and full resolution of the Classe that these Thiels often demand.  The Krells are a little too iron-fisted with Thiels, which thrive on the finer tonal nuances of any good amp.  The legacy Classe amps present a slightly finer tonal palette on a Thiel than the Krells as you climb the octaves.  

One tip on the older legacy Classe amps:  Once you get about 20-25 years out, they really do benefit from a full recap.  After extended conversations with their service techs and customer service department, and upon their recommendation, I recently recapped my old CA series.  

Classe designers used exclusively Nichicons during that era, and all the capacitor families they specified in the early models have since been superseded by Nichicon with improved audio-grade versions.

It was about a 75 capacitor job.  I do my own work, so the total cost was only about $250 for the parts.  But once given about 100 hours to settle in, the older Classe is even better than new.  Everything improves up a notch, and absolutely nothing is lost.  It revived into a real sonic tiger, and a perfect pairing with the Thiels.  Jaw-dropping, actually.  Dynamics through the roof with spectacular tonal nuance.  Now it's good for another two decades . . . and I probably won't care by then.  Highly recommended.

I just wanted to circle back and add this, as I noticed a few folks are connecting their Classe amps to switched power conditioners, either for convenience, or because it may sound better to do so.

In my opinion (so keep it in context), putting any legacy Classe, or any high current SS amp for that matter, through a conditioner, power regenerator, or isolation transformer almost always shaves a little off the dynamics.  IMO, it is a huge mistake to do so.  And it is also possibly accelerating the demise of some filtering elements.

When the transformer primary demands more current in these, they want it right NOW.  Otherwise, you are counting more and more on the filter banks to carry the draw until the tranny can catch up.  And you are only working those filters harder.  And now they are already over 20 years old in some cases.   

Many power conditioners incorporate devices in series, and the current has to fight its way through those elements before reaching your amp.  What you gain in perceived quiet (and most passive conditioner schemes do not filter much below 10 mhz anyway), you give up in reduced dynamics.  While they may work to isolate digital and switching supply noise from surrounding components, they are ultimately no friend to higher current amplifiers.

Unless you are prepared to spend enormous sums on full wave regeneration, and put up with the resulting conversion heat loads, no conditioner can provide current as quickly -- or in the quantity -- that a direct-to-mains connection can. 

But these instruments do need some transient protection, for reasons I will point out.  So you have to balance those two considerations: mains current delivery and protection.

When I set up mine, I made it a point to go straight to the mains, with only some local transient protection (I also have cascading protection through to the meter, all of it in parallel).  The biggest reason these should have at least some local protection is . . . surprise, surprise . . . that all the CA series use op amps in their front ends.  In the case of the x01 Series, the BB OPA2134.  It is a very nice, warm sounding op amp, with its own separate, independent, supply.  I can't speak to the original CA series or earilier DR series, as I have yet to break one down.  But I am told that the original and x01 CAs share nearly identical topology.   And there are numerous other IC chips across the lower control board on these for circuit monitoring, fault protection and power up sequencing.  While the big Motorola outputs are pretty hardy, none of these IC components should be forced to suffer heavy, or too many, transients. 

Way back when, when I was first setting this one up, there was one high current cord option that satisfied both concerns, and that was the Tice Infinite Speed.  I opted for the Tice cord because at that time, it was the only cord rated for up to 20 amps continuous delivery (not including the connectors which are UL-limited) including protection, and because George Tice was including parallel transient protection in the cord, so it was still a straight wire direct-to-mains implementation.  And parallel protection is the key here.  And it was after the clock debacle, so I was able to grab one for peanuts.

I'm not a disciple of exotic power cord geometry, other than that it needs to provide a high maximum sustained current.  If you feel differently, no problem.  But every Classe legacy amp advertised at 100 watts nominal or greater should have at least a 12 awg power cord connection direct-to-mains, with nothing imposed in series.  Whether that is a $20 home brew romex cord, or a $5,000 high end exoticord, is up to you.

But besides that direct to mains power connection, paralleled transient protection and noise conditioning is all you need.  Because there were no other serious parallel conditioning products available when the CA series was around, I ran with just the Tice cord.  And it sounded great, with unrestrained dynamics.  That was a long time ago, so the entire issue of general mains noise existed, but was much less profound than it is today.  

Fast forward to today, and there is far more noise and interference on the mains.  High amplitude wideband noise from a sea of digital devices and supplies everywhere that never existed in the 1980s or 90s.  And general mains quality outside at the grid has declined as well.  But now there are new products that we only dreamed about that can deal with it.

Using today's line conditioning technology, I recently added the iFi AC Purifier.  It delivered an instant and shockingly good sound improvement that everyone noticed, and added some additional transient protection, all parallel to the Classe mains supply.  There are higher grade competitors, but the iFi product uses proven wideband out-of-phase active noise reduction (like noise cancelling headphones for your mains), for only $99.  I have found this little plastic can to be better than any passive conditioner box I've used in a very long time (some of which cost four figures).  And most importantly, all of its activity takes place IN PARALLEL, which does not restrict mains current delivery by one electron.  I cannot recommend this new product technology, and its competitors, enough.  Again, the key with any of them is IN PARALLEL.  With one, there is no need for any further conditioning of the amp's mains supply.  

As I mentioned above, I use a dedicated circuit 20A hospital duplex outlet for my legacy Classe.  The AC purifier sits in the top outlet, the Tice cord in the bottom one.  And that is all you really need to get the very best out of a legacy Classe amp.  Full dynamics, ample protection, and very quiet.  No conditioners in series around here, ever.

 

This is outstanding information, Tom.  Many thanks.

I was aware of the Solens that the crossovers were often fitted with.  Can you add anything as to the electrolytics Thiel has used over the years? 

I say this because typically electrolytics do have a serviceable time window before capacitance starts to shift, and techs tend to focus on them when addressing older instruments.

Tom, I noticed in one of your recent posts concerning internal wiring that Jim settled on 18 awg solid core.

I find the decision for 18 gauge very interesting.  Bell Labs and NBS research culminating in the early 1930s determined 18 gauge the optimum conductor cross section depth for the transmission of audible audio frequencies.  This early research comtemplated both skin effect behaviour at higher frequencies and core transmission behavior at lower frequencies.  

Matthew Bond confirmed the same conclusion in the early 1980s.  However, it appears that Jim’s decision for 18 gauge even predated Mr. Bond’s work.

This indeed underscores your point that meaningful and established physics and engineering research was the primary guide for Thiel Audio’s materials selection.

While a heavier gauge in a single conductor may allow a higher ampacity, I am curious how signal response across the contemplated frequency range through such increased conductor cross section would be impacted.  Perhaps a multiple optimum conductor scheme would be a more desirable arrangement under such circumstances, or over longer distances where such frequency distortions are compounded.

All of this seems to reinforce a common EE maxim that even a straight wire distorts an audio signal to a degree.

I understood you, Tom.

I am somewhat flabbergasted that any Chinese elements were ever used in a Thiel Audio product.  You certainly have your work cut out for you.  I wish you and Rob every success.

Mr. Beetle - I have routinely used Mills wirewounds in my own crossover rebuilds and upgrades over the years. And they have routinely been an improvement in nearly every instance. I am glad that your experience has confirmed my own. They are quite good.

But I will add this. I have learned that materials and parts selection, and their implementation, is as much of as an art as a science. That process of ’voicing’ more approximates a very complex cooking recipe, where some ingredients balance and offset against others, and must be combined in a careful blend.

While normally the superior materials and parts prevail, some of the critical listening outcomes can be quite surprising, indeed.

As an example, I am always reminded of one of my favorite stories involving David Hafler, who many years ago was voicing one of his amplifier designs, and was working out the selection of one particular coupling capacitor. While the design team had access to every conceivable exotic capacitor design, including those with copper and silver leads, a very simple, very humble, and very inexpensive steel-leaded model always prevailed in every single listening test. The amp went to production with that inexpensive steel-leaded capacitor.

Prof, welcome to the final destination on the ride.

Been there, done that.  Could have bought cars over what was spent.  Now my system is a lot like yours, beautiful, ever-present and faithful Thiels, fed by a big warm Classe, with a 58 year old tubed preamp full of ancient bottles conducting the arrangements.

Is it full of distortion and is ruefully unfaithful to the waveforms?  You betcha.  But when Nancy Wilson steps up and starts singing, she is RIGHT THERE.  Goosebumps always, media permitting.

And isn’t that why we go to all this trouble, to come home, pour a nice drink, and luxuriate in our musical retreat?

IMO, when you are left always listening to the equipment itself, and never the artistry of the music, you have forgotten the destination.  Others I’m sure will feel differently.