American Hi-Fi: Inferior?

[christopher3393]

On 8/17/2018 at 6:19 PM, GUTB said:

Why can’t America raise another Nelson Pass? 

 

 

JD: I don’t want to open a whole can of worms, but you seem not to be overly concerned about getting very low distortion. For your First Watt amps you have made the point that at the low levels where most listening takes place, the distortion is very low. Yet, at high level peaks (especially with low- to medium-output power amps), distortion does rise considerably. But people like your amps. Does it have to do with the way the distortion rises, or with the spectral make-up of the distortion?

 

NP: The characteristic I get is the result of simple FET circuits running in Class A. This means minimal or no feedback, low-order harmonic characteristic, and monotonic but pedestrian distortion numbers.That approach usually (not always) delivers the sound that I like, and apparently my taste matches up with a portion of the buying public. The only magic involved takes place in the neural networks between our ears. What happens there is still poorly understood and varies between individuals. Whatever the deal is, ultra low distortion doesn’t seem to have much to do with it.

[christopher3393]

A relevant passage from another Nelson Pass interview:

 

JS:I’ve noticed more solid-state amp designers seem to be trying very hard to take distortion to the vanishing point. Some of these products can sound a bit sterile, however. Can you explain your philosophy about measurements, and discuss the role played by low-order harmonics in the Point 8 Series?

 

 NP: I like measurements, and I use them all the time, but they don’t get the last word.  Generally, there isn’t much conflict between what we measure and what we like to hear. I’ve spent decades working to correlate good sound with measurements, and we have a reasonable picture of what works, and you see that in our products. These represent our own listening tastes, and appeal to a large enough portion of customers to keep us in business.

 

With low-order harmonics, there is agreement that low-order distortion is much less offensive than high-order harmonics and IM (Inter modulated) sidebands, and this drove the development of the Threshold 800A back in 1975, where the nature of the distortion was considered as important as the size of the “single number.”

 

By 1991 when I started Pass Labs, I began to focus more on the specific character of second and third harmonics, and slowly settled into a character where negative-phase second harmonic dominates at low levels, segueing into symmetric third harmonic at higher power. The second fosters an illusion of expanded space and localization, and the third seems to improve dynamics. The distortion of these amplifiers is still quite low, but they are not sterile.

 

 JS: You’ve been creating amps for decades. What have you come to believe are the most critical factors in getting great sound out of a product?

 

NP: It helps a lot if you understand the problems and solutions technically, but in the end it comes down to a lot of work, in which critical listening plays an important part. I have lots of prototypes that measure well and whose ingenuity is a source of some pride but which don’t sound special. And then there is the occasional piece which has conventionally abysmal measurements, but which many people really like – single-ended tubes and Static Induction Transistors (SIT) amplifiers being good examples.

 

I always keep in mind that we are in the entertainment business.

 

For the whole interview: https://parttimeaudiophile.com/2018/02/21/an-interview-with-hifi-legend-nelson-pass/

[christopher3393]

AR: In 2011, have we reached a point where amplifiers won't be getting much better or does amplifier design have a long way to go towards perfection?

 

NP: There is progress to be made, and the necessary tools are already on the table.  From a strictly objective standpoint we are largely finished - adding more zeros to the usual distortion numbers isn't going to improve the sound very much.

 

What remains is the need for clearer insight into subjective effects.  Our brains are very much different from test equipment and are easily fooled by some phenomena and very sharp at discriminating others.  Reading the literature in cognitive psychology, it's clear that we don't know very much about musical perception.

 

As a practical result we have to emphasize critical listening with potential designs.  The necessary tools for this are experienced ears and perseverance.

 

https://audiophilereview.com/amps/nelson-pass-interview.html