Thiel Owners

sgmlaw - your Hafler story represents the approach of a wide range of designers, and practically the entire DIY community. I will offer a different perspective which included Nelson Pass, John Dunlavy, Benchmark's John Siau and Jim Thiel to name a few.

That Thiel approach says that in a situation where an inferior part creates a better sounding outcome - that is evidence of another problem. Something else is going on which has not yet been identified.

Your Hafler experience happened routinely in Thiel product development. As a matter of process, we took that outccome back to the lab to figure out what was happening. Usually that "fix" was masking something much like dither noise masks or randomizes artifacts of digitization. Our MO was that a solution had to both sound better and measure better or our work wasn't finished.

I recognize that I am speaking anathema to many or even most of you. But I offer it as a signpost along the Thiel road.

beetlemaniaThank You for reporting on your Ayre AX-5. I poised the query to address integrated amps, as well as, separates. The notion was in the back of my mind last week during my time spent with the Pass Labs (very robust for a 150w into 8 Ohms) power amp. We all know that some manufacturers do not list 2 Ohm specs. Surely,  those great designers behind Audio Research, Ayre, Conrad Johnson, Parasound and Pass Labs,  test those loads on the bench.

Happy Listening!

@sgmlaw
I agree there is a good amount of art to voicing a XO. But know that Tom T has put in a mountain of homework, drawing on his own experience and that of several industry professionals with decades of knowledge/experience. The idea for these kits was introduced about one year ago and here we are still in beta version for the first model tackled. Tom has been quite deliberate and considered in his approach and has been willing to change his plan as new information is encountered. 

But even a full-time designer cannot listen to all the possible combinations. Let me just say that I lack sophisticated measuring tools but what I do have confirmed that the overall balance was not upset. And, to my ears, the end result is spectacular.

profThank You for the PM.  I enjoyed reading your speaker shoot-out from last year. You auditioned quite a number of different loudspeaker brands. Very informative, insightful.  Happy Listening!

JA - I suspect you haven't gotten satisfaction re your impedance / phase query. Technical study and understanding underlies amp loads. Here's a superficial sketch: Impedance (AC resistance) can be mechanical, electrical, inertial, etc. Voltage is the driving force. Current flows during motion / work. Phase shift occurs when current (work) lags or leads voltage (motive force). That situation exacerbates amplifier difficulties. Changing impedance and phase angles cause amp distress which is especially troublesome when reaching for max current delivery ie low impedance load.

You are correct that those top-tier, and probably all, designers know how their amp responds to 2 or 1 ohm loads under various phase angles. If that performance is exceptional or even good, they publish it. If not, they suggest its un-importance by their neglect.

Test specs can be misleading on many fronts. User success with a design proves its worth.