FM Acoustics Lineariser

ok... can we really
As drawn in post #14, you have a voltage follower, a rather complicated impedance network and another voltage follower. The second voltage follower ensures there will be no signal current flowing through the rather complicated impedance, so the signal voltage drop across it will be zero, so you might as well leave it out. When you do, you have a cascade of two voltage followers, which can be further simplified to just one voltage follower.
sir... it's obviously a conceptual circuit... of course you want the network to be terminated into a impedance [aka a resistor} to earth to facilitate proper real world operation ...cmon guys lets be real here. lets NOT just bash the concept.. lets really flesh this out
 
does anyone out there have a block diagram or any idea of the circuit configuration in a fm acoustics linearizer...? regardless of model i suspect they are the same.. i would REALLY like to see how to achieve frequency manipulation without destroying frequency phase relations in an analog circuit...
this was done using gyrators, both passive and active. A high quality factor of the circuit has a phase change in a small octave interval, so it is believed that phase disturbances do not occur.

Here is a block diagram of the innovative “breakthrough” of modern “engineering”:
RT FM.jpg
but here are real working diagrams from my childhood, i.e. more than 40 years ago))))
RT FM 1982 yar.jpg
 
I had the impression Fig. A and Fig. B were prior art diagrams, showing how they do not do it.
Yes, you are right that they don’t do this and don’t say why, but I will add that they stopped doing this because gyrators or inductor circuits for compensation circuits must be connected between low-impedance levels, the inputs of the operational amplifier or transistor circuits in the attachment in my post from the middle 80s of the last century, have a high input impedance, so this adds noise and was subsequently abandoned, but the principle itself cannot be different, and based on the fact that they can place this block both in parallel with the preamplifier and in series - in the gap between the preamp and the amplifier, I think that we can only talk about low-impedance inputs circuits.
 
JUST IMAGING no phase difference no group delay if i'm saying it correctly... or at least minimal group delay...

Except when all controls are set to a flat magnitude response, an equalizer cannot have zero phase shift. If it did, it would have to be non-causal, that is, predict the future.

It can have the minimum phase shift possible for a given magnitude response without needing to predict the future, a so-called minimum-phase response. That's not an unusual feature, most analogue equalizers are minimum phase.

It could also have a linear phase response, that is, delay all frequency components by the same amount. That is easy to implement digitally, not so easy to implement or approximate analoguely. For an additive/subtractive set-up, the path with flat response then also needs to be delayed.

It could also be somewhere in between, although there is no obvious advantage to that.
 
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im
this was done using gyrators, both passive and active. A high quality factor of the circuit has a phase change in a small octave interval, so it is believed that phase disturbances do not occur.

Here is a block diagram of the innovative “breakthrough” of modern “engineering”:
View attachment 1286382
but here are real working diagrams from my childhood, i.e. more than 40 years ago))))
View attachment 1286383
yes... and thanks... i am aware that these circuits exist... but i cant remember seeing MEASURMENTS for phase response ...

and by the way, those two circuits in the first pic you provided sir are NOT the circuits used... the actual circuit is laid out like the conceptual one i provided
 
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all i know is EQs sound VERY different ..and i mean just the basic circuit, not counting all the support circuits... this is why SOME mixing boards - some old ones too - are revered.... And if you doubt design implementation matters to sound check out reviews for the cello palatte... I would hope the reviews for the fm lin were true to the experience of the reviewers.... With that said. .im attempting a design ..
 
Thanks for all the tips and suggestions....
I have found similar circuit concepts using non global feedback in the design of two other brands and they both complement and boast the superiority in sound quality using this method..
One of them is the Sony SE-P900
The second doesn't come to mind at the moment but it was used in their top tier products ...
... the CELLO palatte is also rather close ..
Again..it is an additive /subtracive design not using global feedback..
I dare say this concept seems to provide superior SOUND quality..
I have simmed a design in lt spice and it works as intended, but have yet to actually build it and listen...
 
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The best audiophile eq ive heard so far is the type found on the McIntosh top of the line integrated amps and preamps.... they do a very good job of not messing up the sound... I know what eq can do to your music if its of good quality...
i was one of two guys -one with over 5 years my senior, im literally 6 months in, and we both got 5 out of 5 stars from a group of 15... Ten of them have over 3 years in that company ...needlless to say they were flabbergasted... No one gets 5 stars for presentation - well except for that guy.. of course now you know what my secret weapon was. I never told anyone what i did... i even used rhe overplayed house cd ,no new music! Everyone is taught flat /bypass is the best -yes because most eqs sound eh terrible.. but not the McIntosh...
That McIntosh setup _mono amps and preamp -their top of the line 6 years ago paired with b&w 801 series 3...with Rel subs .. Brought tears to the eyes..
I'm saying all this to encourage you the reader if you may want to pursue this project also..

It just dawned on me that i never looked up a review for the sony... So i did... Guess what ..


"The most elusive ESPRIT unit but arguably, undisputedly, the best analog parametric EQ ever produced - by anyone.

Absolutely transparent, the SE-P900 does its job without ruining the basics of the signal it is fed with :"...

So... Substitute opamps with top tier, perhaps discrete stuff, and there you go..the Fm acoustic lin..
Im convinced, for me ..that is ENOUGH SAID..

We need to get youtube's/Jay's audio Lab to get an FM AC Lin in house ...
 
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he already knows "I dare say this concept seems to provide superior SOUND quality..".
In general I've heard years ago that you can make an OK amplifier, use a ton of feedback to make it better - or - you can make a really good amplifier design and use just a little feedback to make it better. Supposedly (and intuitively makes sense) the good amp with little feedback sound better than the just OK amp with a lot of feedback. Even though they measure FR and THD similarly.

So the "lean" is toward not using feedback so much for better sound. One would think a linear circuit with no feedback technique at all to make it work properly would sound best. Perhaps so. Anyway I think this is the thinking embodied in these particular products.

Now why they have to market so desperately? Because if they didnt, everyone would just fly right past like their driving down the highway with side blinders on - and they'd starve, instead of making a living at this. You have to sink that hook deep, just to get a potential customer to consider for even a moment what you're doing, how it works, why it's better in your perception.
 
Successful marketing is all about tapping into basic human psychology.

Most advertising uses envy, guilt, greed, sentimentality, lust and other basic emotions to suck you in. That triggers a big rush of dopamine in your brain to make it feel like the advertised item is connected only with great feelings of a reward and satisfaction.

So they're basically advertising to the small inner child in each of us, that we can't do without something even though its obviously not an absolute necessity. This is why they banned targeted advertising to children with toys and disgustingly sugar laden cereal. They even managed to get rid of cigarette commercials.

Companies like Bose wouldn't exist of it wasn't for skillful marketing. They manage to sell their overpriced, horrible sounding little surround sound systems to rich, ignorant consumers who don't have a clue what real live instruments and acoustic music should sound like. Its almost like selling snow to Eskimos and not far from the political propaganda pumped into social media to influence elections.

Usually the biggest indicator of bad marketing is generalized absolute statements using words like great, sensational, amazing or "the best"... Americans are unfortunately some of the most ignorant and gullible consumers in existence. I wish there were more logical guidelines to advertising, protecting the people from targeted manipulation and deceit which often rides the fine line of legality.
 
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In general I've heard years ago that you can make an OK amplifier, use a ton of feedback to make it better - or - you can make a really good amplifier design and use just a little feedback to make it better. Supposedly (and intuitively makes sense) the good amp with little feedback sound better than the just OK amp with a lot of feedback. Even though they measure FR and THD similarly.
Yet, it has been proven again and again that the worst thing you can do is use a little feedback. That increases high order harmonics and not decrease low orderr harmonics significantly. They definitely do NOT measure THD similarly.
As Bruno Putzeys said, if you want to use feedback, use a ton of it!
People believe all kind of stuff they read on the 'net from someone who who read on the 'net - ad infinitum.
Only a few really research it, and they build awesome amps.

Jan
 

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People believe all kind of stuff they read on the 'net from someone who who read on the 'net - ad infinitum.
Problem is that they don't read enough, as in proper literature ;)

With always the default excuse; "Yeah but my math isn't so great" or "yeah but it's so many pages".

It's ironic how much time some people spend on just chatting in circles.
If you would spend AAAAALLL that time in reading proper literature, you basically have a degree of engineering in your hands. (well, more or less)
 
Yet, it has been proven again and again that the worst thing you can do is use a little feedback.
Well if no distortion is the goal obviously :)
There are some situations when people actually enjoy a bit of it.

But yes, this stuff has been around for many many many decades.
The horse isn't dead anymore, it has been dissolved by now.

Happy parroting everyone! :) :)
 
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Wow ... I'm sorry if i offend anyone but what a lot of nothing to contribute....
I just made it known that at least 3 seperate companies have touted the design and said it was better.. in fact who wants to argue against the cello palette ...please go ahead, make yourself known.. give us your technical understand of why it is no better than any other eq...
this dialog is for us to make a judgement based on the concept simply because NONE of us have heard it yet..... My experience with the McIntosh taught me that PLAYBACK eq can be made to sound good...
Please step up and tell us if anyone of you have any LISTENING experience with the aforementioned eqs...

I have heard literally THOUSANDS of pieces of equipment, listened to and repaired.. from studio to high end....30 years in the repair business... Every circuit has a SOUND... even my clients came to know the SOUND of certain equipment... dudes... contribute technical stuff rather than negative no where talk...
If you dont believe it...walk away...there are people out there that still believe we came from apes .. we are not debating a religion here... We are debating a concept that OTHER intelligent Engineers have made a claim in... Lets stick to the science and leave psychology out...
Now...i KNOW eqs can sound awful.. ive heard too many.- even those digital domain ones....and VERY few that id keep in a rack... As i mentioned before the top tier McIntosh do just that..

Please contribute your experience here with EQS ... im coming from outdoor pa in the tens of thousands of watts to high end audio....

My one regret in memory is not getting an eq setting on the martin logan neolith before they left ...had too many toys in the Shop