Dynamic Wow and Flutter

[haraldo]

So are you saying that only amplifiers that employ zero feedback designs are optimal designs?

I don't know, and it's not what this thread is about
But it's a claim here that any kind of negative feedback is harmless, at least it's what I read from previous posts....

 

[jinjuku]

Hi, as there are so many AES members here, I would be curious if someone would have any useful input....

As far as I understand this AES paper goes into detail about FM distortion artifacts that's been more or less known to be an issue for a long time, but never been addressed or never been measurable, but still audible to the human ear, this kind of distortion will be neglectable by those who only rely on the measuring equipment and say that the measurements present the only and whole truth.

I believe there's much more to amplifier technology and what makes a difference, than what's known so far.... If we close our eyes and say that we know everything we need to know audio technology will not get further but come to a standstill...

Much of the measurements that we have today was developed as a result of audible distortion properties that we were unable to explain and as such not measure, so new theories were developed and new measurement techniques and standards were developed. I'm no expert on this but it's what I read from a some respected amplifier designers, although.... I don't think this fact can be challenged.....

I think there's much more to amplifier technology and audibility of different distortion mechanisms than what we know today, but I can't prove anything.... but if we close our eyes we will not advance....

Now it's time for you guys to roll the sabers....

Still not sure what you are getting at.

Is there two amps that you have SBT A/B'd that you can reliably tell a difference between?

 

[haraldo]

Still not sure what you are getting at.

Is there two amps that you have SBT A/B'd that you can reliably tell a difference between?

You are going off topic my friend, this is not what the thread is about
Please discuss what this thead is about

it's about the AES paper referred to above !

btw, the answer is yes.....

 

[jinjuku]

Which AES paper? Can you provide a link to the one you are speaking to?

I'm with you on the able to tell a difference. I could 10 out of 10 tell if my Crown XLS 402D or Parasound HCA1000's were connected. Hands down.

 

[haraldo]

Which AES paper? Can you provide a link to the one you are speaking to?

I'm with you on the able to tell a difference. I could 10 out of 10 tell if my Crown XLS 402D or Parasound HCA1000's were connected. Hands down.

AES San Francisco 2012 » Poster Session P7: Amplifiers, Transducers, and Equipment

P7-3 Further Testing and Newer Methods in Evaluating Amplifiers for Induced Phase and Frequency Modulation via Tones, Amplitude Modulated Signals, and Pulsed Waveforms—Ronald Quan, Ron Quan Designs - Cupertino, CA, USA

This paper will present further investigations from AES Convention Paper 8194 that studied induced FM distortions in audio amplifiers. Amplitude modulated (AM) signals are used for investigating frequency shifts of the AM carrier signal with different modulation frequencies. A square-wave and sine-wave TIM test signal is used to evaluate FM distortions at the fundamental frequency and harmonics of the square-wave. Newer amplifiers are tested for FM distortion with a large level low frequency signal inducing FM distortion on a small level high frequency signal. In particular, amplifiers with low and higher open loop bandwidths are tested for differential phase and FM distortion as the frequency of the large level signal is increased from 1 KHz to 2 KHz.
Convention Paper 8722

Can't find a link to purchase paper.....

If anyone can find a way to get hold of the paper, plz tell....

 

[jinjuku]

So we are talking about an amps susceptibility to interference? Just want to make sure I am reading the abstract correctly.

I wonder if an email to Ron Quan Designs will net a copy?

I have to be honest and ask the question of what color paint you think will be on the brush with this? It's also digging into a prior work of AES Convention Paper 8194.

 

[haraldo]

So we are talking about an amps susceptibility to interference? Just want to make sure I am reading the abstract correctly.

I wonder if an email to Ron Quan Designs will net a copy?

This is extremely difficult to grasp.....
From what I heard Ron Quan spent considerable time with personal consultation... trying to explain this to world leading amp designers, and they're still having a hard time understanding what the heck this is.... so even for us to understand this, would be a long call.....

First step to get hold of the papers....

 

[jinjuku]

To further expand this:

What happens if there is negligible FM/AM in the environment to begin with? If a tree falls and no one is around to hear it...

 

[jinjuku]

This is extremely difficult to grasp.....
From what I heard Ron Quan spent considerable time with personal consultation... trying to explain this to world leading amp designers, and they're still having a hard time understanding what the heck this is.... so even for us to understand this, would be a long call.....

First step to get hold of the papers....

induced FM distortions in audio amplifiers

 

[haraldo]

To further expand this:

What happens if there is negligible FM/AM in the environment to begin with? If a tree falls and no one is around to hear it...

I'm novice on this so I can't say anything with credibility on this, but.....
it's claimed that there's no research that shows anywhere... what is audible and not audible, when it comes to FM induced distortion....

But it's there, in all Transistors, IC's opamps, you name it.....

Perhaps it explains some of the reason why you never hear the full scale of a symphonic orchestra at home, with your own equipment....
There's always a blurring and never full scale dynamics as in a concert hall

 

[jinjuku]

I'm novice on this so I can't say anything with credibility on this, but.....
written in another site: there's no research that shows anywhere... what is audible and not audible, when it comes to FM induced distortion....

But it's there, in all Transistors, IC's opamps, you name it.....

And sunlight is filtered by the earths atmosphere...

What other site?

 

[haraldo]

And sunlight is filtered by the earths atmosphere...

There's a new invention to cater for this, if filtering is not good enough.... sunglasses

 

[Irvrobinson]

Perhaps it explains some of the reason why you never hear the full scale of a symphonic orchestra at home, with your own equipment....
There's always a blurring and never full scale dynamics as in a concert hall

Oh come now, not only isn't any "blurring" audible, but microphones are far from perfect, most speakers aren't capable of concert hall dynamics for a symphony orchestra, not to mention that most rooms (like 99.999%, probably) won't support the sound levels necessary to make an orchestra sound live, but an amp will make the difference?

I'm convinced by experimentation we can already make anything that fits in a given listening room sound very nearly live, so the notion that removing some extraordinarily difficult to detect distortion is going to make a significant difference in orchestral reproduction stretches credibility.

 

[jinjuku]

Gentlemen, sorry to say but you're completely off topic

Dynamic wow and flutter exists in all amplification components and as I understand the leading designers of amplifiers are trying to understand what this is, nothing to do with "wow and flutter"

Ignoring something and saying it doesn't exist because you don't know about it is not the way to go, I think.....

High tide raises all boats....

 

[haraldo]

Oh come now, not only isn't any "blurring" audible, but microphones are far from perfect, most speakers aren't capable of concert hall dynamics for a symphony orchestra, not to mention that most rooms (like 99.999%, probably) won't support the sound levels necessary to make an orchestra sound live, but an amp will make the difference?

I'm convinced by experimentation we can already make anything that fits in a given listening room sound very nearly live, so the notion that removing some extraordinarily difficult to detect distortion is going to make a significant difference in orchestral reproduction stretches credibility.

With this attitude I doubt there would ever be any progress in the field of Audio

 

[jinjuku]

The other possibility:

Intentionally create an amplifier that has a 'sound' and then market that difference.

Nothing stopping an engineer from doing that and I'm certain some have. While I haven't heard every amp under the sun I am willing to make a few observations:

1. Not all amps are going to sound the same
2. There are some really whacky amp designs out there
3. Not all engineers are mentally rooted here on earth

 

[JerryLove]

Am I missing something?

Measuring FM modulation should be easy on an osciliscope or looking at a waveform (well, letting a computer look at one) for any given tone.

Indeed: we've been measuring wow and flutter caused by tapes and records for decades.

 

[Irvrobinson]

With this attitude I doubt there would ever be any progress in the field of Audio

No, with my attitude I'm just less likely to be taken-in by silly claims that can't be explained by physics or engineering.

 

[Irvrobinson]

Am I missing something?

Measuring FM modulation should be easy on an osciliscope or looking at a waveform (well, letting a computer look at one) for any given tone.

No, IMO you're not missing something.

 

[mtrycrafts]

This is something John Curl posted in another location, ..... LOL

Oh, please!!! He was a good amp designer, a long time ago. Now, he has fallen for the dark side of the force.