PRaT - please explain

[Firebottle]

I have never been a fan of the term PRaT. Surely pace, rhythm and timing are all associated with the flow of the music so what's the distinction?

Please explain succinctly.
No Naim bullshit in other words.

[AJSki2fly]

I have never been a fan of the term PRaT. Surely pace, rhythm and timing are all associated with the flow of the music so what's the distinction?

Please explain succinctly.
No Naim bullshit in other words.

Well I will try and come to this question from a purely musical background, having been an amateur musician and played in a number of bands I can relate to it, but only to an extent.

When you play a piece of music you want to perform it at a tempo(beats per minute) this reflects the feeling embodied by the piece, now this may sound like arty party bullshit but it really isn't, for example if you were to play the wedding march at half is scored tempo at least it would sound dour at worst a dirge, something a bride would not appreciate. So this is pace.

Now for rhythm, this is not as straight forward to define, well at least not for me, rhythm is how the piece is construction in terms of beats to a bar or measure, so for example in nearly all pop and rock music it is 4 beats to the bar, so called 4/4 time, in a waltz it is 3/4 time or 3 beats to a bar. So in 4/4 time we can count 1, 2, 3, 4 very often emphasise by a hi-hat or snare drum in rock/pop music. Now what needs to be understood is that the rhythm is obviously closely tied to the tempo, so if the tempo or how quickly or slowly you count 1,2,3,4 effectively speeds up or slow down the music or PACE. Got there in the end.

So what does PRaT have to do with a hifi system, well some cynics would say absolutely nothing, the system used of whatever quality should just reproduce what has been recorded which in itself where the PRaT is, by definition it is what is part of the musical structure, the rest is musical notes played on a selection of instruments and with gaps between them, or silences, put all together and you get a musical piece. However others would argue differently, and this is really I believe from a technical point of view, and I am not sure anyone has proved this to be true scientifically, what other would say is that the act of reproducing the music recorded require it to go through various electrical and even mechanical processes(think turntable and cartridges) so if any of these elements, electrical circuits for example cause delay or modification to the signal previously transcribed be it on a record, tape or on a digital medium then any aspect of PRaT maybe be changed. I hope that makes some sense.

Well I can see some sense to this argument, but you also have to consider the recording process as well, from microphones, amps, mixing desk, digital or analog through to recording master and then onto the pressing process(and I do not differentiate between digital and analogue) because in theory the PRaT could be modified during any of these stages if we agree with the above statement.

So I suspect when we see commentary from reviewers saying "the system has a great sense PRaT" what they really mean is that they think it is reproducing the music as they would expect it to sound or in fact in the case of a live recording it sounds like it did when they were at the concert. Whether this is actually true or just wishful thinking is another matter. IMHO if you took the best possible live recording you could think of then the only way you could get close to actually replicating in the real sense aurally would be to replay in in the original venue with the same number of people present and a system capable of replaying it as recorded. But even then it might not be accurate because of what happened in the record process but I suspect the PRaT would pretty good.:lol:

I apologise if some of you think this is a load of guff, you are probably right.:eyebrows:

[walpurgis]

I can simplify this a bit. A rubbish system sounds shit! ;)

[AJSki2fly]

I can simplify this a bit. A rubbish system sounds shit! ;)

True,:D but it still might have PRaT.

[walpurgis]

PRaT was a bit of hype from the glory days of the Linn/Naim Flat Earthers. Pace, rhythm and timing are (amongst others) worthwhile and desirable attributes in a system. But of course, any decent Hi-Fi will have them. There's no mystique about this.

[Macca]

A way to sell the new, smaller breed of speakers appearing at the time, like Kans and Acoustic Energy? Not much body to the sound but you handle that objection by suggesting that they are more exciting to listen to.

[Firebottle]

Adrian thanks for a comprehensive reply. I understand the construct of music even though I am not a musician.

However what I have always though when PRaT is mentioned is as you have said, it is part of the musical structure. What I can't grasp is why any kit might vary the relationship between the elements in PRaT, so why was this term invented (if not as a marketing 'tool') when in my mind these things can't be separated.

When people rave about the benefits of PRaT or otherwise are they mistaking transient attack (or speed if you like) and possibly a less than crisp bass line for failings in Timing or Rhythm respectively?

[tapid]

Perhaps more of an emphasis on leading edge ?, rather than a phater type of sound

[walpurgis]

In reply to Martin.

That sort of leaves the Linn Saras out on a limb. They may not have been very big and were decidedly odd tonally and pretty coloured, but they were definitely an exciting listen. The problem was pumping enough watts into them to shift air without blowing them up. It was a thin line.

[RMutt]

Just imagine if you’d put together a system that slowed down the music, altered the rhythm and stuff happened at the wrong time.

[walpurgis]

Just imagine if you’d put together a system that slowed down the music, altered the rhythm and stuff happened at the wrong time.

Just use a Rega Planar 3 with a tired belt. :)

[Macca]

Just imagine if you’d put together a system that slowed down the music, altered the rhythm and stuff happened at the wrong time.

I don't have to imagine, I've done that a few times.

[AJSki2fly]

Adrian thanks for a comprehensive reply. I understand the construct of music even though I am not a musician.

However what I have always though when PRaT is mentioned is as you have said, it is part of the musical structure. What I can't grasp is why any kit might vary the relationship between the elements in PRaT, so why was this term invented (if not as a marketing 'tool') when in my mind these things can't be separated.

When people rave about the benefits of PRaT or otherwise are they mistaking transient attack (or speed if you like) and possibly a less than crisp bass line for failings in Timing or Rhythm respectively?

Well my reply was partially serious and some tongue in PRaT.

A system could alter timing, for example a turntable with a belt that flexed too easily and caused wow, you would here modulation of long notes. Also if the motors speed varied badly if would have similar effect. Same with tape machines. Electronics can cause delay at differ frequencies I believe, but I doubt most people would hear it.

Anyway most gear nowadays even the cheaper end of the market is pretty good.


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[Mr. C]

A marketing term Naim coined to fool the middle class and Freemasons into parting with the funds form the late 70's onward.

Or possible to disguise the fact the 80hz lift in the lower bass naim amps gave to generate the 'toe tapping' effect to overlook the fact their amps were in 'old skool slang' piss poor so in order to over come this slight drawback, St Julian of Vereker decided (he who made 'exceeding good amps lol' ) to kick start the (occ)cult of naim which 'Naimee's' staunchly defend this to hilt under the delusion they own world class audio.

Who can forget those immotal words "Your no one without a Naim' :lolsign:

So to quantize then naim amps delivered a two dimension but up front powerful sound that majored on 'leading' (Bleeding) edge musical (lol) depiction had virtually zero trailing edge or note decay, had the tonal quality of a punch drunk Aardvark on speed and the timing of a 140Mph misfiring two stroke wheeze bag trying to achieve a land speed record down Budleigh Salterton high street on a wind sweep Monday afternoon.

The PRaT is a two fold anachronism for we can't really make real sounding amplifiers that music lovers would appreciate so we will 'invent' the toe tapping bang, bang throb that we can market as Pace Rhythm and Timing to the mass as they don't know squat. Or the people that purchased the equipment.

Its an artificially induced bass hump that agrees with the brain to feel its bouncing along in time with the music problem is all music is very different and applying the same Naim algorithm to all forms of music is like to trying to go to the moon and back on a Vespa.

I have an old email that was sent out to dealers nearly two decades ago on how to 'Tune dem' a customer into submission by strategic use of a open frame chair and liberal applications of the side of the foot in time to the music. You really could not make it up.

Thankfully the later generations have discovered real music making equipment from many other brands can deliver a far more satisfying PRaT than anything that Salisbury can muster. IMHO

One last item for the piece the self affirmation of the cult of Salisbury, even when faced with the overwhelming realization their precious naim system is utterly and totally out classed. A quiet skulk home followed by a alcohol fueled ear syringing via number 11 on the naim volume dial to 'confirm' to themselves their have the best possible. The crux here is not so much the total amount spent on their equipment BUT the physiology of them questioning their own choices, after all how could a dedicated follower of two dimensional, non involving bleeding sound could possibly be wrong? Surely not Carruthers?

Turning Naimie's from the (undead) soundscape sound be an Olympic sport time to canvas Bojo :lol:

Of Course YMMV and IMHO

[Puffin]

Just imagine if you’d put together a system that slowed down the music, altered the rhythm and stuff happened at the wrong time.

Ahh, you've heard my system then!:lol:

[Shovel_Knight]

I mostly think of PRaT as a bullshit term, however last year I auditioned some headphones and one pair made everything sound a touch slower :scratch:

After listening to them some more I decided that it was a slightly "warm" tonal balance combined with some lack of "snap" in the midrange that was responsible for this sleep-inducing quality.

[Firebottle]

had the tonal quality of a punch drunk Aardvark on speed and the timing of a 140Mph misfiring two stroke wheeze bag trying to achieve a land speed record down Budleigh Salterton high street on a wind sweep Monday afternoon.

Quality Tony :eyebrows:

Possible Refuse and Trash then?

[Barry]

I thought 'PRaT' referred to any follower of the Flat Earth school of audio, as promulgated during the mid '70s to the early '80s by the Glasgow-Salisbury axis.

[Mikeandvan]

It appears to focus on the movement of the music, with no mentions at all about tone, melody, air, etc. In other words its bollocks.

[Pharos]

As an objectivist, (hides prepared in nuclear shelter), I have never understood what it has referred to, let alone meant.

Adrian is right on the music, but how can it extend to technical stuff to any significant degree, the timings of it all are much in excess of human perception, and the rhythm is indexed to the tempo, they cannot be separated.

Certainly perception of SQ can be affected by frequency response abnormalities, and a change in emphasis my produce exaggerated aspects of timpani, but individual parts in a musical piece cannot be separated and their time relationship be altered.

The Linn/Naim school did start this BS, made a lot of money, and corrupted the minds of so many.

[Lawrence001]

Did I read a while ago that Naim took an earlier (US?) amp design that had fallen out of favour, and basically reinforced the attack at the expense of the decay of a wave in order to make the music more exciting? I didn't know about the peak at 80hz but that would help in a demo I suspect.

Presumably Naim fans will tend to listen to the sort of music that would benefit from this effect, rock, pop etc over unamplified instruments, although I can see acoustic guitar and maybe brass sounding more exciting as well. Nor sure about strings and woodwind sections though, so orchestral/chamber music may fare less well.

[anthonyTD]

I think the term is more akin to describing the person, more than anything associated with musical interpretation! :eek:

[Light Dependant Resistor]

PRaT was a bit of hype from the glory days of the Linn/Naim Flat Earthers. Pace, rhythm and timing are (amongst others) worthwhile and desirable attributes in a system. But of course, any decent Hi-Fi will have them. There's no mystique about this.

Sadly no, the majority of audio systems fail to address what is possible with timing in a audio system.

If we consider some circuitry and look at the way DC is used in audio systems, what we see is very lazy, abysmally lowest cost, implementation.

My specialist area, is the relationship - (which sounds extremely boring ) of the anodes of a shunt pair , cathodes of a shunt pair, the anodes of a series pair, and the cathodes of a series pair
of LDR's I have been investigating and improving this circuitry for over 11 years, and without reservation there is more in audio improvement to be found here, then any other part of a audio system.

This assumes the other parts of a audio system are very good, but not overtly so, My system is modest compared to some, it comprises good sources of Pioneer stable platter CD player, a suite of 5 Yamaha
CDR HD1500 recorders/ players, a stereo coffee attenuator, two quad 306 power amps, and various loudspeakers comprising ESL57, JR149 ( which i use the most ) and Gale GS401a. I use one pair of speakers
at any given time.

The work I have done finds what is missing in other audio systems principally aligning timing from the source component to the power amp, using akin to current drive -the load of the cathode to readdress the anode.
a thread where the circuit is discussed is here. https://www.stereo.net.au/forums/topic/301377-2020-stereocoffee-ldr-passive-preamp-redesign/

[anthonyTD]

Chris, with all due respect, what your describing here will just go over most folks head, why not just show how linear your system is with say; a 50k to 200k Square wave from a 50 ohm source, comparison in and out of your Stereo Coffee LDR preamp, at diffrent volume settings, that may give a better understanding of what your trying to say about your design as far linearity, and its ability to reproduce signals as close to the original, in real time.
Sadly no, the majority of audio systems fail to address what is possible with timing in a audio system.

If we consider some circuitry and look at the way DC is used in audio systems, what we see is very lazy, abysmally lowest cost, implementation.

My specialist area, is the relationship - (which sounds extremely boring ) of the anodes of a shunt pair , cathodes of a shunt pair, the anodes of a series pair, and the cathodes of a series pair
of LDR's I have been investigating and improving this circuitry for over 11 years, and without reservation there is more in audio improvement to be found here, then any other part of a audio system.

This assumes the other parts of a audio system are very good, but not overtly so, My system is modest compared to some, it comprises good sources of Pioneer stable platter CD player, a suite of 5 Yamaha
CDR HD1500 recorders/ players, a stereo coffee attenuator, two quad 306 power amps, and various loudspeakers comprising ESL57, JR149 ( which i use the most ) and Gale GS401a. I use one pair of speakers
at any given time.

The work I have done finds what is missing in other audio systems principally aligning timing from the source component to the power amp, using akin to current drive -the load of the cathode to readdress the anode.
a thread where the circuit is discussed is here. https://www.stereo.net.au/forums/topic/301377-2020-stereocoffee-ldr-passive-preamp-redesign/

[Macca]

a thread where the circuit is discussed is here. https://www.stereo.net.au/forums/topic/301377-2020-stereocoffee-ldr-passive-preamp-redesign/

There's no discussion of the circuit on that thread, are you sure it is the right one?

[Pharos]

I don't doubt that there are timing errors in Hi-Fi, but their significance, or even detectability needs verifying, and the PRaT people I have talked to over the years do not indicate seriously better perceptive ability sensitivity or subtlety in their personalities, often quite the reverse IME.

I would Chris, like the science at least outlined, and preferably explained, or the desired changes and the objectives it achieves described.

[Light Dependant Resistor]

I don't doubt that there are timing errors in Hi-Fi, but their significance, or even detectability needs verifying, and the PRaT people I have talked to over the years do not indicate seriously better perceptive ability sensitivity or subtlety in their personalities, often quite the reverse IME.

I would Chris, like the science at least outlined, and preferably explained, or the desired changes and the objectives it achieves described.

Hi Dennis
The best way of demonstrating this, is for you to start just like I did 11 years ago, and see this for yourself. It will become apparent that LDR's are somewhat better than
other passives straight away, but can be far better still, reproducing music if we spend some time investigating, and NEVER giving up on saying - it cannot get any better,
because it can. I think though what I have done is at the mountain top so to speak, of LDR's being used in audio circuits.

You will need

10 x NSL32SR3 , of those you should be able to get a L pad comprising 3 inputs, the other two might be able to be used at a later date. The NSL32SR3 is not totally consistent with manufacture, so some just will not match.
4 x 2k ten turn trimpots
A circuit board for mounting the LDR's. I can send you a LDR board which will make mounting them very easy
a 50k Bourns Single gang Linear potentiometer

Now the next part is where we begin to see there are differences with how the LDR is powered. So I am not just writing ad infinitum ,
how do you think the LDR should be powered ? .... it gets as interesting as you can possibly imagine ..

The requirements you need to meet are current cannot exceed 20ma per device, you need to head for no more than 4.5ma per LDR
The LDR is quite capable of being a switch and a variable resistor, so we will plan to make the series pairs switches when OFF as well as
variable resistors when ON

We need to have some method of altering that resistance, so we do this via the LDR cathodes, placing the 50k Vol up to the Series cathodes
and Vol Down to the shunt pair cathodes, and we will use a lower potential for the Wiper, but NOT ground.

We will continue once you have some parts ready, and are in dialogue about possible methods to power.

[Pharos]

At my position in life, after many years of building equipment in a period in which major gains in performance against cost were possible, I do not work on anything other than speaker design.

My contention is that largely, electronics has conquered its aims, and is very near perfect, but that speakers are still very much more flawed.

I do not know what an LDR is BTW, but I would need well documented evidence, from reliable and respected sources stating that preamps can be improved on to a significant extent before considering the new implementations.

If passives were a 'new breakthrough', surely some of the well known and scientifically established 'gurus' would be touting their benefits.

[Light Dependant Resistor]

At my position in life, after many years of building equipment in a period in which major gains in performance against cost were possible, I do not work on anything other than speaker design.

My contention is that largely, electronics has conquered its aims, and is very near perfect, but that speakers are still very much more flawed.

I do not know what an LDR is BTW, but I would need well documented evidence, from reliable and respected sources stating that preamps can be improved on to a significant extent before considering the new implementations.

If passives were a 'new breakthrough', surely some of the well known and scientifically established 'gurus' would be touting their benefits.

Actually what you have to contend with, rather than reaching nirvana instantly with LDR's is manufacturing enjoying making money and offering parts that are the worst of the worst
as people just continue paying. There is objection at many levels ( - yes hifi has politics ) when someone creates something better.

The history of the rheostat designed in the 1800's but patented by Mary Hallock Greenewalt in 1919 is testament to what then became the potentiometer, being originally designed
for entirely different purpose, namely a visual music she called Nourathar. Early forms of the potentiometer were stepped attenuators, and most manufacturers closed their eyes
when the asian equivalent the carbon track pot was released, and those in the know haven't opened them yet.

I can point you to review of LDR's as passive attenuators https://www.stereo.net.au/forums/topic/301377-2020-stereocoffee-ldr-passive-preamp-redesign/
You can also follow some technical information here: https://lunainc.com/product/optocouplers/


Actually the other way around, we tend not to notice loudspeaker imperfections if speakers are good already, but electronics imperfections ( Yes the T word ) are obvious.
The link here is David Blackmer discussing how we tend to mask loudspeaker errors and the importance of time. On one hand he says
Loudspeakers turn time into a pretzel, alluding that planar speakers are relatively free of these errors, but is referring to other errors prior to loudspeakers.
https://www.youtube.com/watch?v=j71NrNMx2rU

[Blueflash]

If you play a CD like Elton John "Don't Shoot Me I`m Only The Piano Player" on some of the tracks the drum kit has been recorded with a tiny amount of echo.
It was not until I built the DDDAC that I noticed it. Some systems can miss either the leading or following echo if they do not have the resolution to show it up. My earlier system was missing some of the edges and it did give the impression of something out of sync, only slightly, but it was there.
So I thing the lack of PRAT is a resolution problem somewhere along the reproduction chain. In my case it was the DAC, with someone else it could be the pre or power amp, or the speakers and room interaction.
It is worth pursuing because it will also flatten or artificially bloat the sound stage and depth.

[Pharos]

In principle I agree Alex that errors, wherever they come from, can mask detail as you describe above, and this is surely, (at least with objectivists), what we are all trying to do.

As the resolution increases so we hear more, and clutter gives way to clarity of sound and easy distinction of separate events, and this is what I mean by 'more forensic'.

Which part of the chain is limiting must vary, and there must be so many combinations of equipment that there must also be numerous weak points, and which differ greatly. I suppose eventually with discussion a consensus develops and an establishment occurs that certain equipment is relatively flawed.

I am still after 2 and 1/2 years struggling with what I am hearing with new speakers, and like you am getting revelations, but also some 'oddness' which may be a factor of the speakers, or previously unheard oddities on recordings, this being particularly noticeable on vocals.

However I have difficulty in associating PRaT with any really establishable scientific factors, as alluded to previously my experience has been with these as rather more vaguely touted notions, often from more sales orientated people.

[Barry]

As an aside, the rheostat was invented by Charles Wheatstone around 1843. Considerably earlier than 1919, for Mary Greenewalt's non-linear device.

[zzag]

Great thread this good reading.

What I do remember about 'PRaT' systems 10 -20 years ago is i used to get listening fatigue after 1/2 hour, making them useless to me.

[Barry]

I remember in the '80s, the Flat Earthers would have you believe that unless an audio system had you tapping your foot, then it was a failure as regards PRaT.

To that end, at demonstrations of audio gear designed to follow the Flat Earth school of philosophy, the demonstrator would often be there tapping his foot with the expectation that listeners in the audience would pick up on the visual clue and tap their feet as well.

Well once when I attended an audio fair in London, in the early '80s, I looked in at one such demonstration (by an audio manufacturer whose name I'll not disclose), and yes there was a guy up there jiggling away and tapping his foot - completely out of time with the music! So much for 'pace, rhythm and timing'. :doh:

[Firebottle]

:lol:

[AJSki2fly]

Once a PRaT always a PRaT[emoji23]


Sent from my iPhone using Tapatalk

[Light Dependant Resistor]

As an aside, the rheostat was invented by Charles Wheatstone around 1843. Considerably earlier than 1919, for Mary Greenewalt's non-linear device.

Mary however patented the rheostat, securing her as the recognized inventor patent 1,357,773 Application filed Dec 12 1919, and patented Nov 2 1920
https://patents.google.com/patent/US1357773A/en

Another patent that of Thomas Edison 131,334 differed, called a rheotome it used negative current and is described here as a switch for telegraph equipment
http://www.edisonmuckers.org/wp-content/uploads/2012/06/00131334.pdf

The point being the device was never designed to pass audio signals, rather - one could argue heavily borrowed, but not in sympathy with the actual requirements of audio circuits.
Hence we find 90 years later: https://www.pinkfishmedia.net/forum/threads/alps-potentiometers-gain-and-distortion.68076/

[DavefromDorset]

I'm a bit of a hifi outlier in that I understand only a fraction of what has been discussed, so I can't bring much to this topic. However, I've been listening to music with good-ish kit for most of my adult life (I'm 70). A few years ago I reinstated my 401/3009/V15 analogue set up, and to my ears the major advantage over my digital CD set up was an improvement in what I perceived to be timing. Whether that was caused by better PRaT, better leading edge or some other audio esoterica I have no idea, but the phenomenon was, to me, real.

As a postscript, I recently changed to 2.1 stereo after years of 5.1 multichannel, sold my analogue gear (little used, I had remained with CD) and bought into streaming via an NAD M10 and Qobuz. That sense of better timing has returned, so presumably the culprit was my Arcam AVR350/DV137 gear.

[Pharos]

I remember in the '80s, the Flat Earthers would have you believe that unless an audio system had you tapping your foot, then it was a failure as regards PRaT.

To that end, at demonstrations of audio gear designed to follow the Flat Earth school of philosophy, the demonstrator would often be there tapping his foot with the expectation that listeners in the audience would pick up on the visual clue and tap their feet as well.

Well once when I attended an audio fair in London, in the early '80s, I looked in at one such demonstration (by an audio manufacturer whose name I'll not disclose), and yes there was a guy up there jiggling away and tapping his foot - completely out of time with the music! So much for 'pace, rhythm and timing'. :doh:

That is entirely consistent with the sought of people I encountered and referred to earlier, a type ham fisted and radiating insensitivity, and whom I seem never to encounter now.

The last one was a man from Vintage Wireless who bought my Tannoy Gold 152 Lancs, and on taking them away put one on top of the other tearing my lavishingly waxed cabinets to shreds. He reeked of cigars, and on paying me pulled out a fat wad from his jacket wrapped in a band. This represented to me a dissonance.

[Pharos]

I'm a bit of a hifi outlier in that I understand only a fraction of what has been discussed, so I can't bring much to this topic. However, I've been listening to music with good-ish kit for most of my adult life (I'm 70). A few years ago I reinstated my 401/3009/V15 analogue set up, and to my ears the major advantage over my digital CD set up was an improvement in what I perceived to be timing. Whether that was caused by better PRaT, better leading edge or some other audio esoterica I have no idea, but the phenomenon was, to me, real.

As a postscript, I recently changed to 2.1 stereo after years of 5.1 multichannel, sold my analogue gear (little used, I had remained with CD) and bought into streaming via an NAD M10 and Qobuz. That sense of better timing has returned, so presumably the culprit was my Arcam AVR350/DV137 gear.

That sequence would need some scrutiny IMO.

[Barry]

Mary however patented the rheostat, securing her as the recognized inventor patent 1,357,773 Application filed Dec 12 1919, and patented Nov 2 1920
https://patents.google.com/patent/US1357773A/en

Another patent that of Thomas Edison 131,334 differed, called a rheotome it used negative current and is described here as a switch for telegraph equipment
http://www.edisonmuckers.org/wp-content/uploads/2012/06/00131334.pdf

The point being the device was never designed to pass audio signals, rather - one could argue heavily borrowed, but not in sympathy with the actual requirements of audio circuits.
Hence we find 90 years later: https://www.pinkfishmedia.net/forum/threads/alps-potentiometers-gain-and-distortion.68076/


Greenewalt's patent was for a rheostat/potentiometer having a non-linear law, it was not for the rheostat per se, the latter of which having been in the public domain cannot be patented.

[Light Dependant Resistor]

Greenewalt's patent was for a rheostat/potentiometer having a non-linear law, it was not for the rheostat per se, the latter of which having been in the public domain cannot be patented.

Sorry Barry but her patent was clearly for the rheostat. here's an excerpt of the patent text. https://patents.google.com/patent/US1357773A/en

M. H. GREENEWALT.

RHEOSTAT.

APPLICATION FILED 05c. 10, 1919.

1,357,773. Patented Nov. 2, 1920.

2 SHEETSSHEET 2- UNITED STATES PATENT OFFICE.

RHEOSTAT.

Specification of Letters Patent.

PatentedNov. 2, 1920.

Application filed December 10, 1919. Serial No. 343,826.

To all whom it may concern Be it known that I, MARY HALLOCK GnnnNnwALr, a citizen of the United States, residing in Philadelphia,Pennsylvania, have invented Rheostats, of which the following is a specification.

It has been found that forv a light capable of giving forth thirty two thousand six hundred and ninety seven milli-lamberts of brightness as many as two hundred and sixty seven perceptible gradations, and in a light having a capacity of nine hundred and eighty seven and ninety four hundredth milli-lamberts of brightness, as many as eighty-six perceptible gradations in the full intensity of the lightemitted, may be produced by properly varying the intensity of said light from that value existing when the lamp is operated at its rated capacity or full candle power, to that value which is just sufiicient to cause it to pass from a condition ofabs olute darkness to one in which it begins to give forth light; and my invention is to provide means especially designed to vary the brightness of a lamp or the light it gives forth by amounts capable of causing the minimum perceptible variations in the intensity of such light between the limits of operation above-noted.

The invention further contemplates a rheostat including a resistance element of that form and construction which shall primarily accomplish the above ends; be compact and substantial of a commercially practicable design; relatively simple as regards the aggregate number and arrangement of its parts, and at the same time include a series of contact blocks and a movable contact member adapted for operation by human, mechanical or automatic power.

It is also desired to provide novel means for portably or permanently mounting a resistance element and its movable contact, together with a convenient mechanism whereby said contact may be actuated by the movement of any suitable part of an operators body to vary the current flow in a light circuit, in such manner that the intensity of a lamp connected in such circuit shall be caused to vary by the least perceptible increments, between the limits of its full candle power and absolute darkness; the invention further contemplating the provision of means for indicating to the operator the relative intensity of the light emitted from the lamp when the movable one object of contact member occupies any particular position.

Another object of my invention is to provide a novel foot operated mechanism for actuating the. movable contact or slider of a rheostat primarily designed to vary the current in a light circuit, in such a manner that the intensity of the light emitted by a lamp in said circuit may be increased or decreased at will by the least perceptible increments, in the manner required, or in obedience to a light score such as forms the subject of my invention set forth in patent application Serial No. 318,393, filed August 18, 1919.

[Barry]

I disagree, the patent covers the use of an optically controlled rheostat, or the use of a foot operated rheostat to control the brightness of a lamp.


One cannot retrospectively patent an idea which is already in the public domain: rheostats have been around since c. 1843 and were obviously in use long before 1919.

[Pharos]

Well this really must be sorted out, the whole of mankind's future depends on it.

[Light Dependant Resistor]

Well this really must be sorted out, the whole of mankind's future depends on it.

Its actually quite interesting, Mary as i gather successfully defended the rheostat patent against some true giants of industry. i have her patent book here, she had 11 patents, but there is extensive history about her.
I will spend some time following her defence of her rheostat patent, and create a thread about it.

... and we can follow the potentiometer today is the direct descendant, see historical references at the foot of the article. http://taggedwiki.zubiaga.org/new_content/7a80278530bcfd2124bf55874ac1ca12

As I said, it was never designed for audio purpose to pass audio signals at all, and ironically was intended to vary resistance to alter light intensity for her visual music called Nourathar .
Interesting to reflect upon The LDR does the exact opposite using variation of light intensity to vary resistance.... just as all volume controls should :)

[Pharos]

I meant no offence, but the politics is interesting, and also parallel to the lady who developed the sapphire stylus, and was ripped off by two corporations - cannot recall her name.

[Mr. C]

Once a PRaT always a PRaT[emoji23]

Careful Adrian a lot of Salisbury worshipers will be on the defensive.

Anyhow, back to PRaT its very simple.

The Musicians themselves control PRaT if you like, they alone control the speed, intensity, pitch, loudness and rhythmic content long before any mixing engineer gets his grubby mits on the sliders :lol:

Think of a busker playing a tune on the street, both the so called big two PRaT purveyors have are almost an oxymoron as some of the most rhythmically satisfying engaging music has certainly not emanated from either Salisbury or Glasgow.

[anthonyTD]

:)

The Musicians themselves control PRaT if you like, they alone control the speed, intensity, pitch, loudness and rhythmic content long before any mixing engineer gets his grubby mits on the sliders :lol:

[walpurgis]

The Musicians themselves control PRaT if you like, they alone control the speed, intensity, pitch, loudness and rhythmic content long before any mixing engineer gets his grubby mits on the sliders :lol:

One only has to listen to the Portsmouth Sinfonia to hear that this is true :).

https://www.youtube.com/watch?v=hpJ6anurfuw&list=RDhpJ6anurfuw&start_radio=1&t=32

[anthonyTD]

Aye, plenty of prat going on there, :eek: made me laugh hearing that again, :D
One only has to listen to the Portsmouth Sinfonia to hear that this is true :).

https://www.youtube.com/watch?v=hpJ6anurfuw&list=RDhpJ6anurfuw&start_radio=1&t=32

[AJSki2fly]

Careful Adrian a lot of Salisbury worshipers will be on the defensive.

Anyhow, back to PRaT its very simple.



Of course mustn’t forget TWaT, more commonly known and most important factors in a proper HiFi system

Tone, WOW and Timbre

[emoji41]


Sent from my iPhone using Tapatalk

[Firebottle]

TEMBRE - Urban Dictionary.
Tembre is pretty much the most amazing girl around always looking wonderful never shy outspoken and loves to be active ! Loves hanging out with her bff's.

I guess you mean Timbre, but I'll take the Tembre for a spin.

[AJSki2fly]

Of course mustn’t forget TWaT, more commonly known and most important factors in a proper HiFi system

Tone, WOW and Timbre

[emoji41]


Sent from my iPhone using Tapatalk

Timbre it is[emoji41]


Sent from my iPhone using Tapatalk

[Mr. C]

Adrian indeed :lol:

Mind you TWoNE is very apt as well

Tis Worse on Naim Equipment

Its that bleached two dimensional poor tonal quality zero stage depth and eye syringing capabilities that's sets Naim apart from the rest

[Yomanze]

"Pace", "Rhythm" and "Timing" all refer to the same thing.

It could just be called "Timing".

There are things that dictate how good a system is at timing. These are things like speaker phase distortion, driver overhang, resonant modes (standing waves), enough damping factor, proper turntable setup, filtering etc. that can all influence this.

[AJSki2fly]

"Pace", "Rhythm" and "Timing" all refer to the same thing.

It could just be called "Timing".

There are things that dictate how good a system is at timing. These are things like speaker phase distortion, driver overhang, resonant modes (standing waves), enough damping factor, proper turntable setup, filtering etc. that can all influence this.

Yes true, but do not forget room acoustics, if you live in and echo chamber it will sound wrong and conversely if you room is approaching a anechoic chamber it will sound as dead as a Dodo.

[Pharos]

I hadn't anticipated the extent of antipathy towards Naim, and I have an experienced friend who loved the 250, but I have never liked it aprat from the green/black colouring.

[Light Dependant Resistor]

Expressing the need of timing in audio equipment, we know its needed, can we draw a slightly occasional wavy line in the sand, and arrive to say, very few manufacturers presently market products
that have this much needed attribute ?

We then need to find what it is, that makes this attribute appear. Perhaps its a combination of attributes, Could we say the complete combination of parts should work to preserve timing more so than
worrying needlessly about other parameters.

Key to this is measuring equipment, or better still can it be found collectively subjectively, ie when its right, its just right, I think the latter, as measuring equipment cannot presently get even close
to what we hear.

[Pharos]

OK, so you give validity to PRaT, and allude to a quality which is often in deficiency, so I ask you please to define this/those parameters and a method for measuring them.

It must be possible with current very accurate measuring methods to show these errors.

[anthonyTD]

Hi Dennis,
Of course there are ways of testing whether one has the fundamental basics right, when designing audio equipment, some of which i sugested to Chris earliar on in this thread, when he was atempting by way of tech talk, at explaining the virtues of his LDR preamp, but it seems my sugestions were completely ignored! :doh:
And this post is not meant as a dig, but if one continualy keeps bringing almost every thread one contributes to back around to one's own product, then one has to be prepared to at least explain, or provide evidence as to the superiority of the product one is continually adverstising!
OK, so you give validity to PRaT, and allude to a quality which is often in deficiency, so I ask you please to define this/those parameters and a method for measuring them.

It must be possible with current very accurate measuring methods to show these errors.

[Light Dependant Resistor]

Hi Anthony
As I recall you asked me to do a square wave frequency sweep for linearity, Square waves as readers might or might not know, are the furthest
one can go from reality as representing music , its as alien to our ability of hearing, as you can possibly get.

To show this on the left in the first image is a graphical display of a piece of music, and on the right a square wave generated at 20 hz

Testing with music, Yes always valid, as it reveals the relationship of the musician and equipment to preserve the discussion topic - timing
in direct relationship with our hearing ability

As example the next image shows a square wave at 1000 hz and 17000, can the reader see any difference from 20 hz to 17000 hz ?
yet these same range of frequencies are seen contained in the graphical display of music.

Your assertion is as I understand that i test with a dual trace oscilloscope using a frequency generator providing a square wave to see any deviation with a square wave generated and then following
is that right ?

To further explain how alien graphical displays are, can anyone identify the artists playing in the music... ? and no cheating looking up the title Crawl Space:)
and ask yourself can you see the interplay between musicians, the acoustic of the drum sound, the reverberation of the trumpet and is the topic timing revealed
that makes the music so special to hear ?

[anthonyTD]

Some clever side stepping there Chris, ;)
A simple test using a dual scope would give an indication of whether the equipment in question was at least capable of reproducing the most basic of test parameters, ie; a square wave comparison of the signal before; and after the piece of equipment, would indicate any frequency discrepancies, phase shift, and any non linear amplitude activity at diffrent volume positions etc.
This would be a good starting point. :)
Hi Anthony
As I recall you asked me to do a square wave frequency sweep for linearity, Square waves as readers might or might not know, are the furthest
one can go from reality as representing music , its as alien to our ability of hearing, as you can possibly get.

To show this on the left in the first image is a graphical display of a piece of music, and on the right a square wave generated at 20 hz

Testing with music, Yes always valid, as it reveals the relationship of the musician and equipment to preserve the discussion topic - timing
in direct relationship with our hearing ability

As example the next image shows a square wave at 1000 hz and 17000, can the reader see any difference from 20 hz to 17000 hz ?
yet these same range of frequencies are seen contained in the graphical display of music.

Your assertion is as I understand that i test with a dual trace oscilloscope using a frequency generator providing a square wave to see any deviation with a square wave generated and then following
is that right ?

To further explain how alien graphical displays are, can anyone identify the artists playing in the music... ? and no cheating looking up the title Crawl Space:)
and ask yourself can you see the interplay between musicians, the acoustic of the drum sound, the reverberation of the trumpet and is the topic timing revealed
that makes the music so special to hear ?

[DavefromDorset]

That sequence would need some scrutiny IMO.

Hi Dennis, you're absolutely right: reading my post back I can see that it made no sense. What I was trying to say was that record player and the streamer seem to my ears to be better at timing than the CD player. I guess that's no big revelation.

[Pharos]

Hi Anthony
As I recall you asked me to do a square wave frequency sweep for linearity, Square waves as readers might or might not know, are the furthest
one can go from reality as representing music , its as alien to our ability of hearing, as you can possibly get.

To show this on the left in the first image is a graphical display of a piece of music, and on the right a square wave generated at 20 hz

Testing with music, Yes always valid, as it reveals the relationship of the musician and equipment to preserve the discussion topic - timing
in direct relationship with our hearing ability

As example the next image shows a square wave at 1000 hz and 17000, can the reader see any difference from 20 hz to 17000 hz ?
yet these same range of frequencies are seen contained in the graphical display of music.

Your assertion is as I understand that i test with a dual trace oscilloscope using a frequency generator providing a square wave to see any deviation with a square wave generated and then following
is that right ?

To further explain how alien graphical displays are, can anyone identify the artists playing in the music... ? and no cheating looking up the title Crawl Space:)
and ask yourself can you see the interplay between musicians, the acoustic of the drum sound, the reverberation of the trumpet and is the topic timing revealed
that makes the music so special to hear ?

Ignoring your wording, which is obscure, looking at waveforms in a comparative way cannot reveal anything, but a square wave should be reproduced accurately; it has known amplitudes of all harmonics, and the phase of each of these has to be preserved in order for the wave to be accurately square.

No we don't listen to square waves, but they are a very good model with which to measure failings in several parameters.

[anthonyTD]

Indeed!
The main concern i have, and i would guess anyone contemplating the use of a paticular product is; if the product in question is being promoted on its superior accuracy, in comparison with a conventional potentiometer, then as a starting point, it should at least test as well, using the method described, if on the other hand; the designer of said product is promoting said design soley on its perceived superior musicality, ie; the way it performs in conjunction within a specific system, then i would argue that that's not the same as promoting a product on its known superior accuracy.
Ignoring your wording, which is obscure, looking at waveforms in a comparative way cannot reveal anything, but a square wave should be reproduced accurately; it has known amplitudes of all harmonics, and the phase of each of these has to be preserved in order for the wave to be accurately square.

No we don't listen to square waves, but they are a very good model with which to measure failings in several parameters.

[Light Dependant Resistor]

Indeed!
The main concern i have, and i would guess anyone contemplating the use of a paticular product is; if the product in question is being promoted on its superior accuracy, in comparison with a conventional potentiometer, then as a starting point, it should at least test as well, using the method described, if on the other hand; the designer of said product is promoting said design soley on its perceived superior musicality, ie; the way it performs in conjunction within a specific system, then i would argue that that's not the same as promoting a product on its known superior accuracy.

It suits all audio systems where power amp sensitivity is 1.5 v for full output or preferably less, and fixed resistance loading is below 20k. Its circuit form to partnering equipment is a L pad

Subjectively using music, it has been compared to conventional potentiometers here: https://www.stereo.net.au/forums/topic/113297-comparison-lightspeed-diy-ldr-pre-vs-stereo-coffee-diy/

"I was actually cynical about the whole LDR idea. I did try a stepped attenuator but it wasn't any better than my ALPS it was cleaner but it was also harsh. A bit disappointing.

That's when I decided to give LDR's a go. Wow!

I have had some nice valve amps and I have to say that the LDR is an amazing alternative if you running a solid state. I would imagine it would nice with a valve amp as well.

I have heard an autoformer/transformer but it didn't have the magic."

[anthonyTD]

:doh::brickwall:
It suits all audio systems where power amp sensitivity is 1.5 v for full output or preferably less, and fixed resistance loading is below 20k. Its circuit form to partnering equipment is a L pad

Subjectively using music, it has been compared to conventional potentiometers here: https://www.stereo.net.au/forums/topic/113297-comparison-lightspeed-diy-ldr-pre-vs-stereo-coffee-diy/

"I was actually cynical about the whole LDR idea. I did try a stepped attenuator but it wasn't any better than my ALPS it was cleaner but it was also harsh. A bit disappointing.

That's when I decided to give LDR's a go. Wow!

I have had some nice valve amps and I have to say that the LDR is an amazing alternative if you running a solid state. I would imagine it would nice with a valve amp as well.

I have heard an autoformer/transformer but it didn't have the magic."

[Pharos]

Indeed!
The main concern i have, and i would guess anyone contemplating the use of a paticular product is; if the product in question is being promoted on its superior accuracy, in comparison with a conventional potentiometer, then as a starting point, it should at least test as well, using the method described, if on the other hand; the designer of said product is promoting said design soley on its perceived superior musicality, ie; the way it performs in conjunction within a specific system, then i would argue that that's not the same as promoting a product on its known superior accuracy.

In essence my view on the subjectivist supposition of matching, is that it is based on amelioration of errors by countering and offsetting one with another; this may give a sound more acceptable or pleasing, but does not increase accuracy.

[Mr. C]

The ideal harmonic content observer would be a spectral FFT, a lot of the modern digital scopes have a half respectable one fitted these days (1m points) though ideally a real time spectral analyzer is most useful for this.

I have always found that passive pre's 'ring like a bell' at 4 and 10Khz with a square waveform (which after all is just made up from various sine waves and their harmonic components) which means an awful lot of overshoot on the top half of the wave form.

Happy to do some experiments for you Tony so we can illustrate this.


I have attached some screen shots from our R&D scope, first is of a rather good 10Mhz world clock we have been working on for a new customer project.
This has all of the basic meas horizontally below the wave form.

Below this is the spectral content on this particular clock measured up to 200Mhz this give an indication of how HN is present in a square wave form of this type, granted we are talking lower orders of magnitude but the principle is the same and in some cases the lower frequency SW can produce more detrimental harmonic noise due to their poss poor formation on some crappy PC dac and not a respectable function generator.

The next image is the basic wave form showing the eye pattern and RJ jitter histogram plus on the LeCroy oscilloscopes we have a X-stream eye which is an extrapolated software model of the actual real time data stream.

Final image shows a full serial decode of the word clock data transmission including trend/bath-tub/PJ/RJ/DJ etc.

https://i.ibb.co/MfZDB7K/new-clock-base-waveform-all-meas-00000.jpg

https://i.ibb.co/vXX53vv/new-clock-base-waveform-spectrum-analyser-mode-00003.jpg

https://i.ibb.co/fDtqks7/new-clock-base-waveform-SDA-eye-etc-00003.jpg

https://i.ibb.co/Hg214T9/new-clock-base-waveform-SDA-eye-etc-00004.jpg

[Pharos]

One of the hardest things to do, and which has become evident to me, is to accept the volatility and vulnerability of what we hold to be true.
The adhesion to ideas and concepts which are not valid or true may provide a comfort zone, but inevitably they separate us from reality, stifle or dealing with it, and sabotage our own growth and development.

There is IME a great freedom facilitated when we stop hanging on to dogmas, and I welcome any dissent because it to have my beliefs challenged helps me grow.

Blake; "A man convinced against hi will is of the same opinion still"

Dylan; "The naked truth is still taboo wherever it can be seen."

[Light Dependant Resistor]

In essence my view on the subjectivist supposition of matching, is that it is based on amelioration of errors by countering and offsetting one with another; this may give a sound more acceptable or pleasing, but does not increase accuracy.

The subjectivist usually though is way in front, as the end result is not a specification, but far more meaningful, namely what is heard.

[Mr. C]

One of the hardest things to do, and which has become evident to me, is to accept the volatility and vulnerability of what we hold to be true.
The adhesion to ideas and concepts which are not valid or true may provide a comfort zone, but inevitably they separate us from reality, stifle or dealing with it, and sabotage our own growth and development.

There is IME a great freedom facilitated when we stop hanging on to dogmas, and I welcome any dissent because it to have my beliefs challenged helps me grow.

Blake; "A man convinced against hi will is of the same opinion still"

Dylan; "The naked truth is still taboo wherever it can be seen."

Dennis

A good reply :)

One naimies should take heed of instead of burying their head in the sand (or sounds of mediocrity) and stop deluding themselves with the home self affirmation test :lol: They cannot reconcile their OWN inability to recognize quality music reproduction instead of following the crowd to Freemason land or Salisbury imho. Its the self doubt and thought of all that time spent researching and auditioning so realise their have gone down the wrong path

It is good to challenge one's beliefs as it keep your sense sharp and your mind keen to explore all avenues.

[Light Dependant Resistor]

Dennis

A good reply :)

One naimies should take heed of instead of burying their head in the sand (or sounds of mediocrity) and stop deluding themselves with the home self affirmation test :lol: They cannot reconcile their OWN inability to recognize quality music reproduction instead of following the crowd to Freemason land or Salisbury imho. Its the self doubt and thought of all that time spent researching and auditioning so realise their have gone down the wrong path

It is good to challenge one's beliefs as it keep your sense sharp and your mind keen to explore all avenues.

Most on the forum I would think appreciate when audio is reproduced well, better to include everyone, as we all enjoy music reproduction, and discussion about it.

[anthonyTD]

:)
The adhesion to ideas and concepts which are not valid or true may provide a comfort zone, but inevitably they separate us from reality, stifle or dealing with it, and sabotage our own growth and development.

[Shovel_Knight]

It seems every other thread on this forum eventually turns into a thread about the bloody LDRs.

[Macca]

It seems every other thread on this forum eventually turns into a thread about the bloody LDRs.

Except for the coronavirus thread which is ironically the only thread that might be improved by such a digression...

[Lawrence001]

It seems every other thread on this forum eventually turns into a thread about the bloody LDRs.Brilliant [emoji38]

[Joe]

Except for the coronavirus thread which is ironically the only thread that might be improved by such a digression...

Let's start a rumour that LDRs spread the virus, like what 5G phone masts do.

[walpurgis]

Let's start a rumour that LDRs spread the virus, like what 5G phone masts do.

Nothing wrong with 5G, apart from the premature hair and tooth loss, sterility and tendency to senility.

[Shovel_Knight]

Let's start a rumour that LDRs spread the virus, like what 5G phone masts do.

Actually LDRs contain cadmium, and cadmium exposure leads to respiratory and eventually pulmonary symptoms.

It hasn't been proven that COVID-19 is not caused by LDRs!

[Joe]

Nothing wrong with 5G, apart from the premature hair and tooth loss, sterility and tendency to senility.

You forgot the tendency to senility.

[Joe]

Actually LDRs contain cadmium, and cadmium exposure leads to respiratory and eventually pulmonary symptoms.

It hasn't been proven that COVID-19 is not caused by LDRs!

Clearly we need some blind testing of this. Group A will be asked to swallow LDRs, whilst Group B will be asked to listen to some Placebo.

[Pigmy Pony]

Except for the coronavirus thread which is ironically the only thread that might be improved by such a digression...

I wouldn't know, I've abandoned that bloody thread... I'm over here reading posts about things that make no sense to me, that's how bad it's got :(

[Light Dependant Resistor]

It seems every other thread on this forum eventually turns into a thread about the bloody LDRs.

No problem with that, as I see, :)

[anthonyTD]

:brickwall::brickwall::brickwall::brickwall:
No problem with that, as I see, :)

[Pharos]

The subjectivist usually though is way in front, as the end result is not a specification, but far more meaningful, namely what is heard.

The end result is the arrival at truth, not a spurious sophism.

[Pharos]

Nothing wrong with 5G, apart from the premature hair and tooth loss, sterility and tendency to senility.

Are you joking?

I have wondered about the threat to health of the general spread and increase in RF around.

When one considers blue tooth, Wi-Fi, mobiles, walkie talkies, mobile repeaters, radio and TV transmitters as so on, and the principles of constructive interference, I bet there are very high electric field strengths occurring.

[Light Dependant Resistor]

The end result is the arrival at truth, not a spurious sophism.

Measurements are useful, some though Yes I would agree, might be classed as a spurious sophism, as they have zero relationship, to our ability with hearing.
Acoustic Research sorted this out, with provision of being able to hear their product http://edgarvillchur.com/acoustic-research/

"the company established locations called “Music Rooms” or “Listening Rooms,” where the public could listen to music through AR components and could ask questions of knowledgeable hosts, but where no selling took place. The most famous of the Music Rooms was in Grand Central Station, and became known as a quiet haven in the middle of the noisy terminal. During one year, the Music Room counted one-hundred-thousand visitors."

[AJSki2fly]

Very interesting site and a great read, I was unaware of Villchur and his huge impact.

[Pharos]

What a wonderfully solid person, contrasting that biography with much of what we have to contend with today, we now have so much BS, and the L/N axis seems in retrospect to have been very full of venomous negativity towards others' products.

[zzag]

Whats happened to this thread:scratch:

[Pharos]

Its a hanging loose end.