Has anyone heard the new North American products preamp and amp?

Someone who is a member here and now, stepped away from his use of an active servo isolation platform made in Europe and costing many thousands of $..this was many years ago. I wonder why.

To Roger,

Many years ago Polk Audio used laser interferometry [probably from Johns Hopkins] to measure the cabinet motion of a new time aligned speaker. They found a speaker that sits directly on a hard surface or a carpet over foam floor and played at a reasonable volume level causes the cabinet to travel further than the excursion of the tweeter. This cabinet activity greatly reduces the advantages of time alignment. Would this severe cabinet motion with drivers enclosed or attached also create unwanted and audible Doppler distortion? Tom

theaudiotweak
1,337 posts
02-28-2016 9:24pm
"Someone who is a member here and now, stepped away from his use of an active servo isolation platform made in Europe and costing many thousands of $..this was many years ago. I wonder why."

I'll go out on a limb here: operator error. Am I close?

theaudiotweak,

Many years ago Polk Audio used laser interferometry [probably from Johns Hopkins] to measure the cabinet motion of a new time aligned speaker. They found a speaker that sits directly on a hard surface or a carpet over foam floor and played at a reasonable volume level causes the cabinet to travel further than the excursion of the tweeter. This cabinet activity greatly reduces the advantages of time alignment. Would this severe cabinet motion with drivers enclosed or attached also create unwanted and audible Doppler distortion? Tom

Yes I would say it has to have an impact although the underlying time alignment is still valid and the additional vibrations (caused by the cabinet) will add blur to an "aligned" image. IOW objects would have an average (out of focus) location contaminated at least in part by the motion of the cabinet.

Roger

I previously wrote,

"theaudiotweak
1,337 posts
02-28-2016 9:24pm
"Someone who is a member here and now, stepped away from his use of an active servo isolation platform made in Europe and costing many thousands of $..this was many years ago. I wonder why."

I’ll go out on a limb here: operator error. Am I close?"

Addendum: unfortunately we had to listen to the person you’re referring to rant and rave about the European active servo isolation platform in question for years before he suddenly had a (weird) change of heart. Now, there are many reasons why someone might have a sudden change of heart, after ranting and raving for many years, not the least of which is some problem or another creeped into his system and he blamed it on the iso platform. Who knows? Something doesn’t add up. The person in question had this whole backstory that the Halcyonics platform had no resonant frequency. Pu-leeze!! If that were actually true I’m pretty sure the LIGO project would have looked them up a long time ago since the LIGO isolation team is the best in the world. As I have commented repeatedly the effectiveness of an isolation device is a function of many factors involved with set up, E.g., how the component is interfaced to the top plate, how the platform is mounted, whether a rack is used to mount the device, how much damping is applied to the top plate, things of that nature. Isolation is a black art and not for the squeamish or all thumbs types. lol

geoff kait
machina dramatica

Roger wrote,

geoffkait, I will be the first to admit you guys have a better grip on the physical vibration issues. I'm still learning. But I do have a grip on electronic signals and how they behave in amplifier circuits. That has been my life's work. My obsession with accuracy has taken me down to the "tiny" world of analog errors. I wanted to see the first [velocity error] happen before it manifests itself as full blown distortion. That's the place to clobber it before it gets out of hand. I can force the phase of fundamental to stay within fractions of a degree of dead true.

The equivalent physical vibration would be extremely high to cause the fundamental to move a full octave or more away from true producing harmonic distortion. That is a serious shift in velocity."

Unfortunately it's all part of the same thing.  It is probably wishful thinking to sweep structureborne vibration, acoustic vibration and vibration induced by motors and transformers under the table.  I don't care how obsessed or how long anyone has toiled in some subject or another. If hard work was all that mattered we'd all be rich.