Pass labs irony

[Box860]

I'm not being disingenuous. In the passage I cite, Nelson Pass enumerates four cases in which negative feedback is used: 1) to stabilize the gain, 2) to increase the bandwidth, 3) to lower the the output impedance, 4) to lower the non-linear distortion.

I think it a fair reading that by use of the pronoun "we" he refers to his company among those who use feedback for such purposes.

He devotes the remainder of his paper to discussing the 4th use case. It is only here--the use of negative feedback to lower non-linear distortion--where he argues that minimal feedback is best. But he does not argue that no feedback should ever be used. He sums up his general thoughts on the use of feedback thus:

I think it's a bit more like a credit card – convenient if used wisely, but carrying interest payments and penalties when it's not.

Compare this to Charles Hanson's take. He makes it clear that he believes that no amount of negative feedback should ever be used. Ayre advertises the complete of absence of negative feedback in the description of every amplifier on its web site, including the P-5xe. He goes frequently goes on about it in interviews as well.

To borrow Mr. Pass's metaphor, if Mr. Pass believes credit cards should be used sparingly, Mr. Hanson believes everything should be paid in full with cash.

Am I splitting hairs between Mssrs. Pass and Hanson? I don't think so first, given that Mr. Pass limited his discussion of his preference for minimal feedback to only one of four use cases, and second, given Mr. Hanson's strident view on the matter, which he (or Ayre's PR department) has made a hallmark of Ayre design.

But I fear we're getting far afield of my original point, which was to rebut any insinuation that Pass aped Ayre's design. Given Nelson Pass's reputation, I'm willing to venture most people would agree that he brings plenty to the table on his own. And despite his and Mr. Hanson's philosophical differences (nuanced, in this particular manner as it may be), both have designed some very fine sounding gear.

[skyblue]

Having different philosophies are fine. Let them duke it out and let the best design win

[PlanarSpeakerFan]

Many different ways to skin a cat. Both achieve outstanding results with their respective approaches to amplifier design.

Ken