Slew, Tone and Bullard Laws of Harmonics - is there a link?

I want to try out the following sequence of arguments on readers to see if it makes sense and has legs.

1. Low slew rate CD player op amps have a wider output to input time delays compared to high slew op amp/players.

2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.

3. these time-related added odd-harmonic error differences result "partly" in the differences in what is heard between op amps with different slew values.

4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD replay or call it less tone-full. High slew op amps will have less odd harmonics and sound less edgy and less clean and will be perceived as having more tone.

I suppose i wanted to find a reason why high slew op amps are associated with more tone. And from my reading of Bullard Laws of Harminics, this seems to unlock some of this question. Op amp tone is clearly a function of a number of things. Lower op amp noise will increase tone but others might say that colouration distortion can add to tone. Tone is a pretty nebulous concept anyway but it is an audio attribute we strive for. Bullard Laws link odd harmonics to slew value. What we are hearing is different amounts of odd harmonics and this is interpreted as tone.

do the sequence of arguments work? or am i barking up the wrong tree.

You are a true knight in search of a windmill. I suggest you stop 'reading' and start listening. When you find a complete system that appeals to your ears irrespective of what it might include, go with that for a while - several weeks at least. If and when it continues to appeal to your ears *STOP THERE" and make it your baseline. Give it a few months.

And:

THEN: start experimenting with that system, element by element as your curiosity and wallet permit. That which does nothing - let it be. That which improves its appeal (after that minimum of a few weeks) keep. That which causes a negative reaction - much more likely to be immediate than not - delete.

CD players - every one of them from that $19 Chinese knock-off to the outrageously costly Moon pull from the same universe of chipsets. Where they differ would be in in the transport, and in the analog output chain. And, as with any other mechanical or analog device, there is but so much that can be done to solve an entirely basic audio requirement. After which smoke, mirrors and yiches are the drivers. Once upon a time, a part-time used car salesperson (and a very successful one) let me in on his secret: One is not selling a vehicle. One is selling s "STORY". The story is how the customer got a great deal by being very clever and very persistent, even perspicacious. This, the customer can take with him/her and resell as-needed. He spent years at the same dealer, and most of his customers were repeats and direct referrals. Your ears are your 'story' - let them be the clever ones and draw you away from 'received wisdom' bottled as magic.

Peter Wieck
Melrose Park, PA

On Monday, October 17, 2022 at 12:34:08 PM UTC-4, oben...@gmail.com wrote:
On 10/17/2022 5:30 AM, oben...@gmail.com wrote:
>
> Slew, Tone and Bullard Laws of Harmonics - is there a link?
>
> I want to try out the following sequence of arguments on readers
> to see if it makes sense and has legs.
>
> 1. Low slew rate CD player op amps have a wider output to input
> time delays compared to high slew op amp/players.

Who cares about the delay? Why is this important?

> 2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.
>
> 3. these time-related added odd-harmonic error differences result "partly" in the differences in what is heard between op amps with different slew values.
>
> 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD replay or call it less tone-full. High slew op amps will have less odd harmonics and sound less edgy and less clean and will be perceived as having more tone.
>
> I suppose i wanted to find a reason why high slew op amps are
> associated with more tone.
WRONG question: the right one is "is there a relation between "high slew rate"
opamps and "more tone"?

And even THAT question is flawed because you've presented NO agreed upon
definition of "more tone" or even that such a definition exists.

Nor have you presented any relevant definition of "high slew rate" that's
relevant in this context.

Let's, indeed, look at what IS relevant. Assume the bandwidth of the CD
player is 22 kHz. And let's further assume that the maximum output voltage
is 2V RMS or 2.8V Peak.

As

SR = 2 pi f Apk

where SR is slew rate in v/s, f is frequency and Apk is the peak amplitude,
from the above assumptions, the slew rate is:

SR = 2 pi 22000 Hz 2.8 V

SR ~= 387000 V/s

or, in more common notation, .387 uV/s

Now, I ask you to make one more assumption: let's assume we're simply talking about
a signal from ANY source, not a CD player, but ANY source, like a precision laboratory
pulse generate on which you can arbitrarily set amplitude and slew rate. HP made a
bunch of them.

Now, with this last assumption in mind, it makes NO difference whether we're talking
about the output from a pulse generator or a lightning bolt hitting your cable
or your CD player or your phone preamp: a signal bandwidth of 22kHz swinging 2.8 volts
peak will have a slew rate of .387 uV/s.

Now, what might be an example of a "slow" slew rate amplifier in this context?

Well, let's go back a few years, perhaps, like 54 years at the introduction of the 741
opamp by Fairchild. It had a slewrate spec of 0.5 V/us. That's 30% faster than is required.
But let's call that one "marginal".

How about a TL081? For that, we only have to go back 45 years for that one. And it has
a slew rate of 13 V/us.

So far, we're still at least 7 years befoe the commercial intruduction of CD
players.

In 1982 (40 years ago), Harris introduced the HP-2539 with a slew rate of 600
V/us.

Okay, enough of the history lecture, let's ask a question more relevant to the
topic at hand:

Are there ANY CD players on the market within the last, oh 35 years that
have opamps in the audio signal path with slew rate under 0.5 V/uS? How
about less than 13 V/us.

If the answer is NONE, than I believe your entire thesis was born devoid of legs.
> do the sequence of arguments work? or am i barking up the wrong tree.

Assuming you were dragged to the tree (y'know, that leg part alluded
to above), most assuredly, you are.

--
Dick Pierce
Diverse Pursuits
Technical Engineering/Development
cartchunk.org
Boston - Spruce Head

On Monday, October 17, 2022 at 8:06:23 PM UTC+1, Dick Pierce wrote:
> On Monday, October 17, 2022 at 12:34:08 PM UTC-4, oben...@gmail.com wrote:
> On 10/17/2022 5:30 AM, oben...@gmail.com wrote:
> >
> > Slew, Tone and Bullard Laws of Harmonics - is there a link?
> >
> > I want to try out the following sequence of arguments on readers
> > to see if it makes sense and has legs.
> >
> > 1. Low slew rate CD player op amps have a wider output to input
> > time delays compared to high slew op amp/players.
> Who cares about the delay? Why is this important?
> > 2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.
> >
> > 3. these time-related added odd-harmonic error differences result "partly" in the differences in what is heard between op amps with different slew values.
> >
> > 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD replay or call it less tone-full. High slew op amps will have less odd harmonics and sound less edgy and less clean and will be perceived as having more tone.
> >
> > I suppose i wanted to find a reason why high slew op amps are
> > associated with more tone.
> WRONG question: the right one is "is there a relation between "high slew rate"
> opamps and "more tone"?
>
> And even THAT question is flawed because you've presented NO agreed upon
> definition of "more tone" or even that such a definition exists.
>
> Nor have you presented any relevant definition of "high slew rate" that's
> relevant in this context.
>
> Let's, indeed, look at what IS relevant. Assume the bandwidth of the CD
> player is 22 kHz. And let's further assume that the maximum output voltage
> is 2V RMS or 2.8V Peak.
>
> As
>
> SR = 2 pi f Apk
>
> where SR is slew rate in v/s, f is frequency and Apk is the peak amplitude,
> from the above assumptions, the slew rate is:
>
> SR = 2 pi 22000 Hz 2.8 V
>
> SR ~= 387000 V/s
>
> or, in more common notation, .387 uV/s
>
> Now, I ask you to make one more assumption: let's assume we're simply talking about
> a signal from ANY source, not a CD player, but ANY source, like a precision laboratory
> pulse generate on which you can arbitrarily set amplitude and slew rate. HP made a
> bunch of them.
>
> Now, with this last assumption in mind, it makes NO difference whether we're talking
> about the output from a pulse generator or a lightning bolt hitting your cable
> or your CD player or your phone preamp: a signal bandwidth of 22kHz swinging 2.8 volts
> peak will have a slew rate of .387 uV/s.
>
> Now, what might be an example of a "slow" slew rate amplifier in this context?
>
> Well, let's go back a few years, perhaps, like 54 years at the introduction of the 741
> opamp by Fairchild. It had a slewrate spec of 0.5 V/us. That's 30% faster than is required.
> But let's call that one "marginal".
>
> How about a TL081? For that, we only have to go back 45 years for that one. And it has
> a slew rate of 13 V/us.
>
> So far, we're still at least 7 years befoe the commercial intruduction of CD
> players.
>
> In 1982 (40 years ago), Harris introduced the HP-2539 with a slew rate of 600
> V/us.
>
> Okay, enough of the history lecture, let's ask a question more relevant to the
> topic at hand:
>
> Are there ANY CD players on the market within the last, oh 35 years that
> have opamps in the audio signal path with slew rate under 0.5 V/uS? How
> about less than 13 V/us.
>
> If the answer is NONE, than I believe your entire thesis was born devoid of legs.
> > do the sequence of arguments work? or am i barking up the wrong tree.
> Assuming you were dragged to the tree (y'know, that leg part alluded
> to above), most assuredly, you are.
>
> --
> Dick Pierce
> Diverse Pursuits
> Technical Engineering/Development
> cartchunk.org
> Boston - Spruce Head

Thanks for this. i see what you mean about "more tone" question and stating the slew value. Re time delays: These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.

> Thanks for this. i see what you mean about "more tone" question and stating the slew value. Re time delays: These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.

What Dick gave the science for, and what I am suggesting:

Can *you* hear it?
Does it affect *your* enjoyment of what you hear?

That windmill is calling!

Peter Wieck
Melrose Park, PA

On Monday, October 17, 2022 at 8:04:10 PM UTC+1, Peter Wieck wrote:
> You are a true knight in search of a windmill. I suggest you stop 'reading' and start listening. When you find a complete system that appeals to your ears irrespective of what it might include, go with that for a while - several weeks at least. If and when it continues to appeal to your ears *STOP THERE" and make it your baseline. Give it a few months.
>
>
> And:
>
>
> THEN: start experimenting with that system, element by element as your curiosity and wallet permit. That which does nothing - let it be. That which improves its appeal (after that minimum of a few weeks) keep. That which causes a negative reaction - much more likely to be immediate than not - delete.
>
> CD players - every one of them from that $19 Chinese knock-off to the outrageously costly Moon pull from the same universe of chipsets. Where they differ would be in in the transport, and in the analog output chain. And, as with any other mechanical or analog device, there is but so much that can be done to solve an entirely basic audio requirement. After which smoke, mirrors and yiches are the drivers. Once upon a time, a part-time used car salesperson (and a very successful one) let me in on his secret: One is not selling a vehicle. One is selling s "STORY". The story is how the customer got a great deal by being very clever and very persistent, even perspicacious. This, the customer can take with him/her and resell as-needed. He spent years at the same dealer, and most of his customers were repeats and direct referrals. Your ears are your 'story' - let them be the clever ones and draw you away from 'received wisdom' bottled as magic.
>
> Peter Wieck
> Melrose Park, PA

It is because i want the music that i'm trying to understand this. If i can't hear instruments because of the noise or if piano reproduction sounds more like a harpsichord or sounds thin and washed out then i want to know why and what i have to do to improve my listening experience. why is the OP275 regarded as having a good tone. The ears can only tell there is improvement if we are listening and we can't listen to every op amp/cd player/ music combination.

On Tuesday, October 18, 2022 at 2:08:22 PM UTC+1, Peter Wieck wrote:
> > Thanks for this. i see what you mean about "more tone" question and stating the slew value. Re time delays: These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.
> What Dick gave the science for, and what I am suggesting:
>
> Can *you* hear it?
> Does it affect *your* enjoyment of what you hear?
>
> That windmill is calling!
> Peter Wieck
> Melrose Park, PA

i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.

Please let us know what your system includes at this time. And, in all seriousness, and taking you directly at your word, what sort of specific problems are you experiencing such that you feel that you "....can't hear instruments because of the noise or if piano reproduction sounds more like a harpsichord or sounds thin and washed out...." ?

That does seem to indicate severe issues with your system, so knowing what the system includes may be helpful in diagnosing those issues and making suggestions for improvement. I am sitting in my office with my 70 year-old ears listening to baroque harpsichord through a simple vintage system, the newest part of which was made in 1994 (Sony CD changer) and the oldest part in 1963 (Dynaco ST35). I discern no noise, and certainly the harpsichord sounds substantially different from the piano (Mozart) on the previous CD. And the speakers (AR Athena sub-sat) are not at all thin, at least in my small office.

I would posit that what you are experiencing is much more specific that op-amp speed or your particular CD player.

https://cdn.shopify.com/s/files/1/1683/2705/products/Sony-CDP-C215-5-Disc-CD-Player-Changer-Pulse-DA-Converter-Electronics_cfa468a9-2075-4f2b-8945-364a4159662b_750x750.jpg?v=1631614621
http://diyaudioprojects.com/Schematics/images/Dynaco-ST35-Tube-Amplifier-Kit-cage.jpg
http://cdn.shopify.com/s/files/1/0478/4884/9576/products/Dynaco-PAS3X-TubePreamp-FrontRight_1024x.jpg?v=1616770343
https://assets.catawiki.nl/assets/2018/3/28/6/b/3/6b3f34ba-090b-4bfc-886f-88b22fb4ea28.jpg

The Dynaco products have the enhanced power-supplies installed and adjustable bias has been added to the 35 (EFB in both cases). The speakers are as-found, but I have verified that the woofer does not suffer from surround rot.. The CD changer has been cleaned and the laser focus checked. No more.

My point is that there is not a single exotic piece in the system, and to my ears, it does quite well in this environment. As well as providing a source of amusement to colleagues, clients, contractors and vendors passing through.

Peter Wieck
Melrose Park, PA

On Tuesday, October 18, 2022 at 5:27:14 PM UTC+1, Peter Wieck wrote:
> Please let us know what your system includes at this time. And, in all seriousness, and taking you directly at your word, what sort of specific problems are you experiencing such that you feel that you "....can't hear instruments because of the noise or if piano reproduction sounds more like a harpsichord or sounds thin and washed out...." ?
>
> That does seem to indicate severe issues with your system, so knowing what the system includes may be helpful in diagnosing those issues and making suggestions for improvement. I am sitting in my office with my 70 year-old ears listening to baroque harpsichord through a simple vintage system, the newest part of which was made in 1994 (Sony CD changer) and the oldest part in 1963 (Dynaco ST35). I discern no noise, and certainly the harpsichord sounds substantially different from the piano (Mozart) on the previous CD. And the speakers (AR Athena sub-sat) are not at all thin, at least in my small office.
>
> I would posit that what you are experiencing is much more specific that op-amp speed or your particular CD player.
>
> https://cdn.shopify.com/s/files/1/1683/2705/products/Sony-CDP-C215-5-Disc-CD-Player-Changer-Pulse-DA-Converter-Electronics_cfa468a9-2075-4f2b-8945-364a4159662b_750x750.jpg?v=1631614621
> http://diyaudioprojects.com/Schematics/images/Dynaco-ST35-Tube-Amplifier-Kit-cage.jpg
> http://cdn.shopify.com/s/files/1/0478/4884/9576/products/Dynaco-PAS3X-TubePreamp-FrontRight_1024x.jpg?v=1616770343
> https://assets.catawiki.nl/assets/2018/3/28/6/b/3/6b3f34ba-090b-4bfc-886f-88b22fb4ea28.jpg
>
> The Dynaco products have the enhanced power-supplies installed and adjustable bias has been added to the 35 (EFB in both cases). The speakers are as-found, but I have verified that the woofer does not suffer from surround rot. The CD changer has been cleaned and the laser focus checked. No more.
>
> My point is that there is not a single exotic piece in the system, and to my ears, it does quite well in this environment. As well as providing a source of amusement to colleagues, clients, contractors and vendors passing through.
> Peter Wieck
> Melrose Park, PA

Thanks for this. i've soughted out the harpsichord and thin and washed out sound. I agree you don't need exotic. And thanks for sharing your details. I'll do a new conversation post on what i am playing.

What I find interesting is that you really don't necessarily need good electronics to like music.

For example, I have my grandparent's RCA Model 224 console radio, AM and shortwave. I stream period music to it using a Bluetooth AM transmitter and 40s Junction on SiriusXM.

Modern music sounds like crap... but older music? The elaborate tone filtering makes the old stuff sound really nice.

My other grandfather's Victrola sounds pretty nice too, of course the reproducer had to be rebuilt, but the thing is a hundred years old!

I do not doubt that in some instances a faster slew rate op amp might sound better... but I wouldn't necessarily shotgun replace them, either.

I've gotten instant improvements by cleaning the interconnects. If you're not doing that at least once a year, what's the point of changing op amps?

Tom

On Tuesday, October 18, 2022 at 2:51:03 PM UTC-4, t...@gentledarkness.com wrote:
> What I find interesting is that you really don't necessarily need good electronics to like music.

Tom:

My only quibble is with the term "good" here. I would use the term "expensive" to be more accurate.

I keep a Zenith 9S262 with a 15" speaker. I feed it from an SSTRAN AMT5000, uncompressed, it broadcasts 20/20K (better than standard FM) and does very nicely. That, for the record is c. 1938.

Horses for courses, of course. I expect that there is much more going hon here than an op-amp or three. Starting with something as simple as one-or-more compromised driver transistor(s) (if solid-state) or driver tube (if not). Or something equally silly.

Peter Wieck
Melrose Park, PA

On Tuesday, October 18, 2022 at 7:51:03 PM UTC+1, t...@gentledarkness.com wrote:
> What I find interesting is that you really don't necessarily need good electronics to like music.
>
> For example, I have my grandparent's RCA Model 224 console radio, AM and shortwave. I stream period music to it using a Bluetooth AM transmitter and 40s Junction on SiriusXM.
>
> Modern music sounds like crap... but older music? The elaborate tone filtering makes the old stuff sound really nice.
>
> My other grandfather's Victrola sounds pretty nice too, of course the reproducer had to be rebuilt, but the thing is a hundred years old!
>
> I do not doubt that in some instances a faster slew rate op amp might sound better... but I wouldn't necessarily shotgun replace them, either.
>
> I've gotten instant improvements by cleaning the interconnects. If you're not doing that at least once a year, what's the point of changing op amps?
>
> Tom

you've found a system that works for you and gives you the tones you like. and that needs to be respected. it's probable a mono Class A valve, with a single crossoverless 10 inch speaker or am i looking at a different model. it's fairly big. but it must produce quite a sound.

yes interconnects are an issue and need cleaning.

my initial post here is "not" about slew and op amp speed. i never used/mentioned the term speed.

thanks for the post.

On Monday, October 17, 2022 at 11:34:08 AM UTC-5, oben...@gmail.com wrote:
> Slew, Tone and Bullard Laws of Harmonics - is there a link?
>
> I want to try out the following sequence of arguments on readers to see if it makes sense and has legs.
>
> 1. Low slew rate CD player op amps have a wider output to input time delays compared to high slew op amp/players.
>
> 2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.
>
> 3. these time-related added odd-harmonic error differences result "partly" in the differences in what is heard between op amps with different slew values.
>
> 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD replay or call it less tone-full. High slew op amps will have less odd harmonics and sound less edgy and less clean and will be perceived as having more tone.
>
> I suppose i wanted to find a reason why high slew op amps are associated with more tone. And from my reading of Bullard Laws of Harminics, this seems to unlock some of this question. Op amp tone is clearly a function of a number of things. Lower op amp noise will increase tone but others might say that colouration distortion can add to tone. Tone is a pretty nebulous concept anyway but it is an audio attribute we strive for. Bullard Laws link odd harmonics to slew value. What we are hearing is different amounts of odd harmonics and this is interpreted as tone.
>
> do the sequence of arguments work? or am i barking up the wrong tree.
Thanks for the replies.

Yes, everything matters… the only question is, how much?

Where are you going to put your attention? My anecdote of the LF351 instead of 741 made a difference for me and also my random listeners. Easy change. Cleaning the interconnect connectors, easy change. Using star-quad with a shield, easy change, as long as you can solder. :)

Another anecdote. I have a Stax DAC Talent that I got decades ago. I wanted a good DAC and headphone amp for work, so I bought a Z-DAC from Parasound. Note: all home audio now is Parasound.

Richard is proud of his components for a reason. The Z-DAC just barely edged out the Stax… until I bought an upgrade for the Stax from someone in Germany, updated the digital filter chip. Woo! Edged out the Z-DAC.

So many things easy to do. Clean your connectors. Replace the speaker cables. Move your speakers… I once moved a speaker about an inch over and it went from “something is wrong” to “holy crap what just happened?” and I wasn’t the listener. :)

I am beyond happy to see some old friends and this group still survive. Thanks to all of you for that. Don’t have much in terms of legacy, but this one I am certainly proud of.

Also glad RDP is still with us.

Tom

On Tuesday, October 18, 2022 at 10:28:12 AM UTC-4, oben...@gmail.com wrote:
> If i can't hear instruments because of the noise or if piano reproduction sounds more
> like a harpsichord or sounds thin and washed out then i want to know why and what i
> have to do to improve my listening experience.

Well, to be VERY blunt, if you can't tell the difference between a piano and a harpsichord,
then your are wasting time, money and intellectual effort tring to find the best slewing op-amp.
Your system (including your choice of CDs, your speaker, abd, perhaps, even youself have some
serious, fundamental problems that NONE of these windmills at which you tilt have ANY influence.

I have NEVER heard ANY music reproduction system from any time where a piane and harpsichord
sounded even remotely alike. To be certain, there are system which do a terrible job of reproducing
pianos and/or harpsichords, but even on such systems, it is trivially easy for me (at any rate) to
unambiguously tell the difference between terrible reproction of a piane and terrible reproduction
of a harpsichord.

> By whom? Under what conditions and prejudices? For what reasons?

--
Dick Pierce
Diverse Pursuits
Technical Engineering/Development
cartchunk.org
Boston - Spruce Head

On Tuesday, October 18, 2022 at 10:28:38 AM UTC-4, oben...@gmail.com wrote:
> i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.

I'm sorry, but your original post WAS about op amp speed. Here are some quotes from YOUR
posts in this threead:

From your first post on Oct17:

> 1. Low slew rate CD player op amps have a wider output to input time delays compared
> to high slew op amp/players.
> ...
> 3. these time-related added odd-harmonic error differences result "partly" in the differences
> in what is heard between op amps with different slew values.
> 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD
> replay or call it less tone-full. High slew op amps will have less odd harmonics and sound
> less edgy and less clean and will be perceived as having more tone.
> I suppose i wanted to find a reason why high slew op amps are associated with more tone.

Now, just in this partial quote from YOUR post, "op-amp" and "slew" is mention in direct context
6 times.

But, then you say: "my original post is not about op amp speed".

which is it?

On Tuesday, October 18, 2022 at 4:08:25 PM UTC-4, t...@gentledarkness.com wrote:
>
> Also glad RDP is still with us.
>

Yeah, but it's threads like this one that gives me pause.

My own windmills, perhaps.
--
Dick Pierce
Diverse Pursuits
Technical Engineering/Development
cartchunk.org
Boston - Spruce Head

On Wednesday, October 19, 2022 at 8:23:04 PM UTC+1, Dick Pierce wrote:
> On Tuesday, October 18, 2022 at 10:28:38 AM UTC-4, oben...@gmail.com wrote:
> > i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.
> I'm sorry, but your original post WAS about op amp speed. Here are some quotes from YOUR
> posts in this threead:
>
> From your first post on Oct17:
> > 1. Low slew rate CD player op amps have a wider output to input time delays compared
> > to high slew op amp/players.
> > ...
> > 3. these time-related added odd-harmonic error differences result "partly" in the differences
> > in what is heard between op amps with different slew values.
> > 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD
> > replay or call it less tone-full. High slew op amps will have less odd harmonics and sound
> > less edgy and less clean and will be perceived as having more tone.
> > I suppose i wanted to find a reason why high slew op amps are associated with more tone.
> Now, just in this partial quote from YOUR post, "op-amp" and "slew" is mention in direct context
> 6 times.
>
> But, then you say: "my original post is not about op amp speed".
>
> which is it?
thanks for your response

1. Low slew rate CD player op amps have a wider output to input time delays compared to high slew op amp/players.

2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.

the linkedin link gives more info.

[ rare insert from the mod: if you are asked a direct question and you
avoid answering it, I am inclined to think you are trying to troll.
-- dsr the last remaining moderator ]

On Wednesday, October 19, 2022 at 9:03:27 PM UTC+1, oben...@gmail.com wrote:
> On Wednesday, October 19, 2022 at 8:23:04 PM UTC+1, Dick Pierce wrote:
> > On Tuesday, October 18, 2022 at 10:28:38 AM UTC-4, oben...@gmail.com wrote:
> > > i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.
> > I'm sorry, but your original post WAS about op amp speed. Here are some quotes from YOUR
> > posts in this threead:
> >
> > From your first post on Oct17:
> > > 1. Low slew rate CD player op amps have a wider output to input time delays compared
> > > to high slew op amp/players.
> > > ...
> > > 3. these time-related added odd-harmonic error differences result "partly" in the differences
> > > in what is heard between op amps with different slew values.
> > > 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD
> > > replay or call it less tone-full. High slew op amps will have less odd harmonics and sound
> > > less edgy and less clean and will be perceived as having more tone.
> > > I suppose i wanted to find a reason why high slew op amps are associated with more tone.
> > Now, just in this partial quote from YOUR post, "op-amp" and "slew" is mention in direct context
> > 6 times.
> >
> > But, then you say: "my original post is not about op amp speed".
> >
> > which is it?
> thanks for your response
> 1. Low slew rate CD player op amps have a wider output to input time delays compared to high slew op amp/players.
> 2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.
>
> the linkedin link gives more info.
>
>
> [ rare insert from the mod: if you are asked a direct question and you
> avoid answering it, I am inclined to think you are trying to troll.
> -- dsr the last remaining moderator ]

As i understand it Dan Bullard is using the term slew as a measure of errors. and not as a measure of speed. Dan Bullard outlines his position in the link given.

it was not my intention to cause offence and i apologise if i have offended Dick or anyone else.

On Wednesday, October 19, 2022 at 4:03:27 PM UTC-4, oben...@gmail.com wrote:
> On Wednesday, October 19, 2022 at 8:23:04 PM UTC+1, Dick Pierce wrote:
> > On Tuesday, October 18, 2022 at 10:28:38 AM UTC-4, oben...@gmail.com wrote:
> > > i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.
> > I'm sorry, but your original post WAS about op amp speed. Here are some quotes from YOUR
> > posts in this threead:
> >
> > From your first post on Oct17:
> > > 1. Low slew rate CD player op amps have a wider output to input time delays compared
> > > to high slew op amp/players.
> > > ...
> > > 3. these time-related added odd-harmonic error differences result "partly" in the differences
> > > in what is heard between op amps with different slew values.
> > > 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD
> > > replay or call it less tone-full. High slew op amps will have less odd harmonics and sound
> > > less edgy and less clean and will be perceived as having more tone.
> > > I suppose i wanted to find a reason why high slew op amps are associated with more tone.
> > Now, just in this partial quote from YOUR post, "op-amp" and "slew" is mention in direct context
> > 6 times.
> >
> > But, then you say: "my original post is not about op amp speed".
> >
> > which is it?
> thanks for your response
> 1. Low slew rate CD player op amps have a wider output to input time delays compared
> to high slew op amp/players.
> 2. These time delays add error odd-harmonics not present in the original signal according to
> https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of
> Harmonics. The harmonic errors are defined by the slew rate value.

Okay, I just took the opportunity to read this "Dan Bullard's Law of Harmonics."
Several comments:

1. Unlike someone like Isaac Newton, Dan Bullard has neither the stature nor
acceptance nor technical and scientific underpinnings (at least in his article
get to call what he writes as a Law of Anything.

2. I have no idea what Bullard does for a living, but it's clear that he suffers
from a fundamental misunderstanding of the topic.

For example, he claims:
"Look at that! Odd harmonics galore! Why? most people believe that harmonics
come from discontinuities in voltage, in fact, discontinuities can be created by
discontinuites in time too."

I'm sorry, but this is so much BS and gobbledygook.

I can create harmonic distortion simply by LINEARLY summing the right collection
of completely LINEAR sine functions. Indeed, I can duplicate Bullards sample
slew-limited waveform PRECISELY this way. And not one of those sine functions
is slew-limited. I say so, Fourier says so.

Further, if you have a signal who's first derivative wrt time is non-zero (i.e. it changes
from moment to moment, a discontinuity in time MUST cause a discontinuity in
amplitude. Bullard cannot arbitrarily treat time and amplitude as independent
phenomenon.
3. He states:
"while most people believe..."
You want to risk life and limb by waving that red flag in front of me, do so at your
at your own peril. How on earth do you know what "most people believe?" Statements
like this are the height of high-end audio ignorance and BS.

4. He states:
"this is exactly why we don't have people looking at o'scopes to verify waveform quality"
Really? Is he kidding? I stopped using an oscilloscope for such probably 50+ years ago.
How many people in the real world actually do this?

5. He states:
"the invention of the FFT by Cooley and Tukey is such a watershed event in human history.
It allows us to deduce signal quality very, very quickly (hence the name FAST Fourier
Transform).
This stands out like a sore thumb set on fire then doused with radium in an attempt
to smother the flames.
The Cooley/Tukey alorithm is but one of amny mathematically equivalent transforms
that are computationally efficient in one way or another.
It is NOT "very very" quicker per say, it is computationally efficient ONLY WHEN THE
THE DATA SET IS EXACTLY A POWER OF TWO SAMPLES LONG (more on this below).
And, come on, it's a "watershed event in human history". Really? as significant as say,
Newton's law of gravity? Einstein's theory of general relativity (which under relativistic
situation, where Neton falls apart, bive FAR more accurate results)? Quantum mechanics
(which, after all, does allow us to have this exchange)? Penicillin? Calculus? The internet?

6. He states:
"the Even harmonics (red) are likely due to the fact that my poor sine wave gets one cycle
to run through the "filter" of my slew rate restriction."
Sorry, no. It is as likely due to the the distinct possibly that even though the number of
points passed to the FFT is, indeed, 2018 samples long, the entire waveform does not
complete in it's entirety in that 2048 second. In other words, you're looking at the
discontinuity at the end of the data. In yet other words, you may well have failed
to obey your own rules about ttime discontinuities. Had you roperly windows the data,
those harmonics wouldn't be there. The error thus is not the "filter" whatever that means,
but sloppy technique.

"The DC offset (bin zero) is a clue t what is going on."

It is indeed: it screams "bad, sloppy technique" to me: if my hypotheses above is correct,
the resulting waveform he generated MUST have an offset because the date set does not
integrate to 0 within the FFT bin size.

7. Lastly, his claims suffer the same problem as Obe...s original post: it utterly fails to address
his claims in the light if ACTUAL real-world data. Though it is difficult to read the actual
scale of his graphs, he claims he simulated a slew rate of, to quote him, "6V/ms."

Does he REALLY mean 6V/mS? If so, that mean 0.006 V/us and in all of my career, I have
NEVER ONCE encoutered such a preposterously slow slew rate (unless done deliberately as
an opamp based integrator.

The excercise I did earler whowed clearly that you meed a minimum of
an opamp with a minimum slew-rate spec of 0.387 V/us. That's 387 V/ms,
using Bullard's odd notation. If course, if you could ever hope to find such
a demonstrably lousy part and it could fit, the CD player would sound like sh*t.

But we can't, we won't, and Bullard's law is a load of crap.

So there.

> [ rare insert from the mod: if you are asked a direct question and you
> avoid answering it, I am inclined to think you are trying to troll.
> -- dsr the last remaining moderator ]

Yeah, you're probably right. But the bait was too large, too juicy and too attractive
to ignore.

--
Dick Pierce
Diverse Pursuits
Technical Engineering/Development
cartchunk.org
Boston - Spruce Head

On Wednesday, October 19, 2022 at 9:03:27 PM UTC+1, oben...@gmail.com wrote:
> On Wednesday, October 19, 2022 at 8:23:04 PM UTC+1, Dick Pierce wrote:
> > On Tuesday, October 18, 2022 at 10:28:38 AM UTC-4, oben...@gmail.com wrote:
> > > i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.
> > I'm sorry, but your original post WAS about op amp speed. Here are some quotes from YOUR
> > posts in this threead:
> >
> > From your first post on Oct17:
> > > 1. Low slew rate CD player op amps have a wider output to input time delays compared
> > > to high slew op amp/players.
> > > ...
> > > 3. these time-related added odd-harmonic error differences result "partly" in the differences
> > > in what is heard between op amps with different slew values.
> > > 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD
> > > replay or call it less tone-full. High slew op amps will have less odd harmonics and sound
> > > less edgy and less clean and will be perceived as having more tone.
> > > I suppose i wanted to find a reason why high slew op amps are associated with more tone.
> > Now, just in this partial quote from YOUR post, "op-amp" and "slew" is mention in direct context
> > 6 times.
> >
> > But, then you say: "my original post is not about op amp speed".
> >
> > which is it?
> thanks for your response
> 1. Low slew rate CD player op amps have a wider output to input time delays compared to high slew op amp/players.
> 2. These time delays add error odd-harmonics not present in the original signal according to https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of Harmonics. The harmonic errors are defined by the slew rate value.
>
> the linkedin link gives more info.
>
>
> [ rare insert from the mod: if you are asked a direct question and you
> avoid answering it, I am inclined to think you are trying to troll.
> -- dsr the last remaining moderator ]

i'm sorry if this action has been interpreted in this way. i am not trying to troll anyone and i apologise if i have given any offence.

I thank Dick for his contribution and i will try and take on board his comments.

thankyou

On Thursday, October 20, 2022 at 2:59:44 AM UTC+1, Dick Pierce wrote:
> On Wednesday, October 19, 2022 at 4:03:27 PM UTC-4, oben...@gmail.com wrote:
> > On Wednesday, October 19, 2022 at 8:23:04 PM UTC+1, Dick Pierce wrote:
> > > On Tuesday, October 18, 2022 at 10:28:38 AM UTC-4, oben...@gmail.com wrote:
> > > > i totally agree with Dicks science. low slew players don't lack pace. my original post is not about op amp speed.
> > > I'm sorry, but your original post WAS about op amp speed. Here are some quotes from YOUR
> > > posts in this threead:
> > >
> > > From your first post on Oct17:
> > > > 1. Low slew rate CD player op amps have a wider output to input time delays compared
> > > > to high slew op amp/players.
> > > > ...
> > > > 3. these time-related added odd-harmonic error differences result "partly" in the differences
> > > > in what is heard between op amps with different slew values.
> > > > 4. The greater odd harmonics of low slew op amps adds an edge and a cleaner sound to CD
> > > > replay or call it less tone-full. High slew op amps will have less odd harmonics and sound
> > > > less edgy and less clean and will be perceived as having more tone.
> > > > I suppose i wanted to find a reason why high slew op amps are associated with more tone.
> > > Now, just in this partial quote from YOUR post, "op-amp" and "slew" is mention in direct context
> > > 6 times.
> > >
> > > But, then you say: "my original post is not about op amp speed".
> > >
> > > which is it?
> > thanks for your response
> > 1. Low slew rate CD player op amps have a wider output to input time delays compared
> > to high slew op amp/players.
> > 2. These time delays add error odd-harmonics not present in the original signal according to
> > https://www.linkedin.com/pulse/slew-rate-harmonics-dan-bullard Bullard Laws of
> > Harmonics. The harmonic errors are defined by the slew rate value.
> Okay, I just took the opportunity to read this "Dan Bullard's Law of Harmonics."
> Several comments:
>
> 1. Unlike someone like Isaac Newton, Dan Bullard has neither the stature nor
> acceptance nor technical and scientific underpinnings (at least in his article
> get to call what he writes as a Law of Anything.
>
> 2. I have no idea what Bullard does for a living, but it's clear that he suffers
> from a fundamental misunderstanding of the topic.
>
> For example, he claims:
> "Look at that! Odd harmonics galore! Why? most people believe that harmonics
> come from discontinuities in voltage, in fact, discontinuities can be created by
> discontinuites in time too."
>
> I'm sorry, but this is so much BS and gobbledygook.
>
> I can create harmonic distortion simply by LINEARLY summing the right collection
> of completely LINEAR sine functions. Indeed, I can duplicate Bullards sample
> slew-limited waveform PRECISELY this way. And not one of those sine functions
> is slew-limited. I say so, Fourier says so.
>
> Further, if you have a signal who's first derivative wrt time is non-zero (i.e. it changes
> from moment to moment, a discontinuity in time MUST cause a discontinuity in
> amplitude. Bullard cannot arbitrarily treat time and amplitude as independent
> phenomenon.
>
> 3. He states:
> "while most people believe..."
> You want to risk life and limb by waving that red flag in front of me, do so at your
> at your own peril. How on earth do you know what "most people believe?" Statements
> like this are the height of high-end audio ignorance and BS.
>
> 4. He states:
> "this is exactly why we don't have people looking at o'scopes to verify waveform quality"
> Really? Is he kidding? I stopped using an oscilloscope for such probably 50+ years ago.
> How many people in the real world actually do this?
>
> 5. He states:
> "the invention of the FFT by Cooley and Tukey is such a watershed event in human history.
> It allows us to deduce signal quality very, very quickly (hence the name FAST Fourier
> Transform).
> This stands out like a sore thumb set on fire then doused with radium in an attempt
> to smother the flames.
> The Cooley/Tukey alorithm is but one of amny mathematically equivalent transforms
> that are computationally efficient in one way or another.
> It is NOT "very very" quicker per say, it is computationally efficient ONLY WHEN THE
> THE DATA SET IS EXACTLY A POWER OF TWO SAMPLES LONG (more on this below).
> And, come on, it's a "watershed event in human history". Really? as significant as say,
> Newton's law of gravity? Einstein's theory of general relativity (which under relativistic
> situation, where Neton falls apart, bive FAR more accurate results)? Quantum mechanics
> (which, after all, does allow us to have this exchange)? Penicillin? Calculus? The internet?
>
> 6. He states:
> "the Even harmonics (red) are likely due to the fact that my poor sine wave gets one cycle
> to run through the "filter" of my slew rate restriction."
> Sorry, no. It is as likely due to the the distinct possibly that even though the number of
> points passed to the FFT is, indeed, 2018 samples long, the entire waveform does not
> complete in it's entirety in that 2048 second. In other words, you're looking at the
> discontinuity at the end of the data. In yet other words, you may well have failed
> to obey your own rules about ttime discontinuities. Had you roperly windows the data,
> those harmonics wouldn't be there. The error thus is not the "filter" whatever that means,
> but sloppy technique.
>
> "The DC offset (bin zero) is a clue t what is going on."
>
> It is indeed: it screams "bad, sloppy technique" to me: if my hypotheses above is correct,
> the resulting waveform he generated MUST have an offset because the date set does not
> integrate to 0 within the FFT bin size.
>
> 7. Lastly, his claims suffer the same problem as Obe...s original post: it utterly fails to address
> his claims in the light if ACTUAL real-world data. Though it is difficult to read the actual
> scale of his graphs, he claims he simulated a slew rate of, to quote him, "6V/ms."
>
> Does he REALLY mean 6V/mS? If so, that mean 0.006 V/us and in all of my career, I have
> NEVER ONCE encoutered such a preposterously slow slew rate (unless done deliberately as
> an opamp based integrator.
>
> The excercise I did earler whowed clearly that you meed a minimum of
> an opamp with a minimum slew-rate spec of 0.387 V/us. That's 387 V/ms,
> using Bullard's odd notation. If course, if you could ever hope to find such
> a demonstrably lousy part and it could fit, the CD player would sound like sh*t.
>
> But we can't, we won't, and Bullard's law is a load of crap.
>
> So there.
> > [ rare insert from the mod: if you are asked a direct question and you
> > avoid answering it, I am inclined to think you are trying to troll.
> > -- dsr the last remaining moderator ]
> Yeah, you're probably right. But the bait was too large, too juicy and too attractive
> to ignore.
> --
> Dick Pierce
> Diverse Pursuits
> Technical Engineering/Development
> cartchunk.org
> Boston - Spruce Head

Thankyou for this. Much to think about and digest. Thankyou for your contribution. very worthwhile.

On Wednesday, October 19, 2022 at 9:57:52 PM UTC-4, oben...@gmail.com wrote:
>
> As i understand it Dan Bullard is using the term slew as a measure of errors.
> and not as a measure of speed. Dan Bullard outlines his position in the link given.

Well, in Bullard's tome, he states:

"slew rate to 4 Volts per millisecond (4V/ms)"

" increasing the slew rate (allowing the wave to move faster) should change
the harmonic signature."

"I increased the slew rate to 6V/ms"

"slew rate restriction"

In every example, Bullard SEEMS to be using the term "slew rate" by it's conventional
and widely widely adopted and (in essence) standard usage: a measure of the change
in voltage WRT change in time, the first derivativ of voltage vs time or, in layments terms,
the SPEED at which the signal changes.

Unless, of course, the usage here is done in the high-end audio's propensity to co-opt
such a well defined term to mean something entirely different without telling anyone
what this new defintion is. The high-end audio is drowning in suchm and it's most often
done for two reasons: the co-opter is either largely clueless about what they're talking
about or the co-opter is being deliberately obfuscatious about what they're talking about.

> it was not my intention to cause offence and i apologise if i have offended Dick or anyone else.

It's not an "offence" issue, rather, it's the fact that, sincerely or not, you've chosen to
wander off following one person's nutcase theory or another, and end up wandering
down a path that leads to absolutely nowhere but to a state of utter confusion
and inevitably wrong conclusions.

Cn slew rate limiting lead to audible consequences? Absolutely, it can.

But until the point where Bullard, yourself or anyone else can demonstrably who
that it has ANY relevance at all in CD players, and that relevance is that if the
slew rate caabilities of any part of the CD reproduction chain limits the final output
to less that 0.387V/us, you're wasting your time. And NO ONE, most especially
Bullard, has come even remotely close to demonstrating such.

If I sound "offended", it's not becase I am offended, it's because you're wasting my
time, the other's participatinjg in this threads time,and, most importantly, your own
time. You seem to want to pursue this nonsense until you get the answer you already
expect.

It's not there, whether you want it to be or not.

If I sound abrupt, let me simply quote something a man said in this or one of the
other rec.audio newsgroups in reply to several people's insistence at on to a
fundamental misunsertanding that was just plaai wrong:

"Let us retract the foreskin of misconception and apply
the wirebrush of enlightenment." -- Geoff Miller.

--
Dick Pierce
Diverse Pursuits
Technical Engineering/Development
cartchunk.org
Boston - Spruce Head