Thiel Owners

@sdl4, Yes , the amp power output would drop with the impedance rise. But that’s because with that impedance rise, the sensitivity of the speaker will rise. As the eq is demanding more power, the speaker is a actually demanding less work from the amplifier to produce the same volume output, and with less distortion too.

I feel a little guilty even mentioning the "new" generation of amp modules. It’s really premature to do so. There are companies just now taking built to order amps. So far they seem to be foreign companies, so problems might have shipping and time issues. They are smaller and lighter than typical amps though. Some but not all companies making similar products have been taken to task for shoddy workmanship. Some of these companies haven’t been around that long. The sturdiness of their business legs might still be in question. It’s still yet to be seen if durability, parts, and service can be relied upon. Or what the potential resale value can be expected to be. Some of these types of companies seem to treat early adopters as beta testers. There could be growing pains before a product is truly consumer ready.

There has been a review of a prototype using power supplies that are incapable of extracting the full potential of these new modules. FWIW, the anecdotal review was very favorable in comparison to the current SINAD class leading Benchmark.

Since you asked::

Purifi1ET7040SA

From the pen of Bruno Putzeys, perhaps the foremost Class D designer in the world.

Rumor has it that Purifi is currently working on a power supply to fully extract all the potential from this module.

Here is a particularly promising offering:

P501 Mono-Block Power Amplifier - March Audio

Please note that asking price is in Australian $, the currency exchange is favorable to US $. Be sure to click on "SPECIFICATIONS".

@vair68robert A lot of vinyl sounds really good with the Thiels, and I do listen to mostly "classic rock".  I have two turntables in my main system, a Sota Sapphire and a Technics SL 1200 MK2.  The same record that sounds bright on the Sapphire will sound "good" (not bright) on the SL 1200, but loses a lot of detail, imaging, etc. 

I'm using the same phono stage for both, but have a MM cart on the SL 1200 MK2.  

It's quite possible it's not the speakers, it could be the cartridge, that the cartridge isn't set up right, the tonearm or cable, or how my phono stage handles MC vs MM cartridges.  

The thing is, I have a number of other speakers that sound great in that system with the same electronics, so it feels like I'm trying to fit a square peg in a round hole.

@big_greg 

You have a lot more experience with equipment than I will ever have , but your thoughts about the phono stage is something I can totally agree with . Does your Sota have the vacuum hold down ?

My experience is with MM cartridges only using a phono stage that is 100% tube  for MM's is that a world of difference can be had with changing just one tube or with matching the one 12au7 with different sets of 3 x 5751's .

Also the setting up of a cartridge an art in itself !  Something that I am continually learning to improve my skill at .

I should be receiving my ESRE capacitors soon and will be upgrading the coaxial boards resistors and capacitors next week , except the 1uf bypass caps that will have to wait until the Clarity PUR's are available .  I hope the mids and highs sound as good as the lows have sounded since upgrading the woofer boards . 

duegi

Good to read about your positive experience with Rob at CSS.

Happy Listening!

sdl4 - unsound has a good handle on the factors. But there are even more complexities. Jim did a lot of work on that balancing act including the unusually low reactance of his early bass tunings. The phase angles are quite low and at higher impedance where the amp can handle it better. But to your question: not quite even in today's world.

This afternoon I drove the system up to flickering clipping lights on the stereo AHB with Chris Thile - Edgar Meyers 'Bass & Mandolin' album. The calibrated Benchmark preamp clipped the AHB @ 2dB lower with the 20Hz equalized signal compared with straight-wire / no equalizer. I got similar results with Patty Larkin 'Strangers' World' cuts which are mixed for 'impressive' bass impact.

Jim's intent was to get that extreme and excellent bass extension without significant penalty. And it worked in the 1980s. Remember that vinyl was still the standard which is bass limited by cartridge tracking ability. But the landscape changed not only with digital, but with showcase albums from David Wilson and others which were engineered for 'unbelievable' bass. The Watt/Puppy could handle the real cannons in his recording of the 1812 Overture, but Thiel's model 3 would bottom out because they actually reproduced those deep frequencies. Similarly digital bass could go deeper with more power, and was therefore no longer predictable. So, even though Jim took great care, and his parameters balanced out to require little to no more power in the bass than that required by midrange transients, when the signal landscape changed, the elegance of his solution became practically less safe.