FM Acoustics Linearizer

wizard

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View attachment 7442

View attachment 7443

The FM 133 Harmonic Linearizer allow precise correction and linearization of non-optimal recordings. They do this in an absolutely unique way.
For the first time bad resonances, colouration, noise, obnoxious sound and other limitations are improved without affecting the balance of the audio signal.
While the characteristics and transparency of the original signal is kept pristine, attenuated parts of the music spectrum can be strengthened.

The method of operation is rather intriguing as the entire audio signal takes a direct path from input to output.
The improvement is achieved by a unique additive/subtractive Linearizer bank that corrects aberrations.
Using just five controls, any frequency (or group of frequencies) in the entire audio band can be optimized without negative influence inflicted on the original audio signal.
Furthermore, the signal always remains purely in the analogue domain.

When looking at the front panel one could be reminded of an equalizer. However, the Harmonic Linearizer's mode of operation is different and avoids all limitations.
The FM 133 are not used like an equalizer as every control is dynamically interacting with the others in a unique linear multi-parameter process.
There is no ripple in the pass band and no phase shift/discontinuity, both of which are unsolved problems of equalizers.
 
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trponhunter

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Description sure sounds like an eq to me - maybe a very good or unique one. Don't get me wrong - I think most systems can be improved with good, and proper eq.
 

ack

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The linear circuit is placed in parallel with the signal path, instead of in series like normal equalizers.

This looks very much like those MIT cables with the "articulation poles" to me.
 

rockitman

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A pro parametric eq (think "Q" and shelf eq control) with offer much more control over the sound than the fixed only frequencies offered by this linearizer, imo. Think Millennia NESQ-4 or other Class A discrete eq. ($4,500)
 

rockitman

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The Milennia looks ugly.

I don't buy on vanity

The technology used is still with filters in the signal path.

Once again you are stuck with set frequency adjustments. I have adjustibility for the entire frequecy range. The technology is first rate (discrete) Pretty bold to insult a component you have zero listening experience with. Carrry on with your FM love affair. My comment was directed at the fact of the limited frequency adjustment of the FM unit versus a top of the line "Professional" Parametric eq.

These specs probably surpass those of the FM, even though it's the sound that matters...not necesarily specs.

Full Timbral Control, Total Signal Integrity

World's first (and only) all-discrete, true differential Class-A input buffer/amplifier.

Selectable balanced or unbalanced input.

Greatly improved 3rd generation FSA-03 all-discrete EQ amplifier

Improved output stage, no muting required (as with Twin Topology)

True hard-wire bypass when EQ not selected

Upgraded power supply leading to improved sonic performance
Fully parametric stereo EQ with unprecedented sonic purity
& integrity

All discrete J-FET solid state signal path

Minimalist design: only one active stage in the audio path

Four EQ bands: 20 Hz to 20 kHz center frequency, 0.4 to
4.0 Q

Extremely low noise: -106 dBu

Constructed for demanding professional applications

Ultra-Premium components throughout

Gold relays, connectors, switches,

Silver Teflon power wiring

Mogami Neglex OFC audio wiring

Specs:
“Q” Range Q = 0.4 to 4.0 Adjustable on middle ranges
Q = 1.0 Fixed on low & high ranges
Maximum Output Level > + 28 dBu (VT)
Maximum Input Level (EQ Flat)
+ 28 dBu (VT)
Maximum Input Level (EQ Full Boost) + 17 dBu (VT)
Frequency Response

+0 / -3 dB sub 2 Hz to beyond 300 kHz
Frequency Response, Stereo Deviation < .15 dB
Noise (All EQ Stages In, Controls Flat) -106 dBu (SS), -94 dBu (VT)
Maximum Boost (21 Step Detented)
+20 dB (+10 dB with range switch in)
Maximum Cut (21 Step Detented) -20 dB (-10 dB with range switch in)
EQ Frequencies

Low Range Switch (Centers - Peak/Shelf Selectable): 20, 34, 56, 100, 180, 270
Low Mid Sweep: 20 Hz - 220 Hz or 200 Hz - 2.2 kHz.
10X Range switch selectable.
Hi Mid Sweep: 250 Hz - 2.5 kHz or 2.5 kHz - 25 kHz.
10X Range switch selectable.
High Range Switch (Centers - Peak/Shelf Selectable) 4.8 k, 5.8 k, 8.0 k, 10 k, 16 k, 21 k
THD + Noise
20 Hz - 30 kHz, All EQ Bands Switched In < .009%, typ < .003 % (VT or SS)
Common Mode Rejection Ratio (With Balanced Option)
10 Hz - 20 KHz, 100 mV C.M. > 60 dB, Typ > 80 dB
Slew Rate, +27 dBu Out > 50 volts per microsecond
Main Hard-wire Bypass Switch For Each Channel? Yes
Peak/Shelf Selection On High & Low Range? Yes
Hard-wire Bypass Switching On Individual EQ Bands? Yes
Input Impedance 25 kilohms
Minimum Output Load Impedance 1 kilohm (VT), 150 ohms (SS)
Recommended Load > 3 kilohms (VT)
Output Impedance < 300 ohms (VT), < 5 ohms (SS)
Twin Topology EQ Amplifiers Switch In: Pure Class-A Discrete J-FETs
Switch Out: Pure Class-A Triode Tubes
Power Consumption 40 watts maximum
Power Requirements Selectable: 100-120, 200-240 V ac, 50/60 Hz
Dimensions/Shipping Weight 19” W x 3.5” H x 12.5”, 26 lbs.
 

Kal Rubinson

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The linear circuit is placed in parallel with the signal path, instead of in series like normal equalizers.
It is in the signal path although in one parallel to the main one. They are bandying semantics.
 

Kal Rubinson

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Yes it has many frequencies with many choices, but are they selected with human hearing in mind?
FMA linearizers uses crititcal frequencies that has most effect on the human hearing.
That may make it an effective tone control but much less so as a "linearizer." I do not mean to dump on it as it is undoubtedly superbly made but the touted advantages are dubious and it is less effective than a more flexible PEQ (which can also be used at those same "crititcal frequencies that has most effect on the human hearing."
 

Kal Rubinson

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Yes the five frequency controls are just starters.
When used together the entire audio band can be optimized.
Not unless there are more center frequencies.

Of course the riser circuit must be in the signal path, but it has no filters like normal eq uses.
Semantics. Looking at the circuit, there are 2 parallel signal paths, one with filters and one without.
 

FrantzM

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That may make it an effective tone control but much less so as a "linearizer." I do not mean to dump on it as it is undoubtedly superbly made but the touted advantages are dubious and it is less effective than a more flexible PEQ (which can also be used at those same "crititcal frequencies that has most effect on the human hearing."

I was about to state the same thing. I am with Kal let's call it an EQ and be done, there are more flexible unit and some of them go above simply boosting or cutting frequencies... IF one want the FM Acoustic way of doing thing fine but the claims need to be cleaned out ...
Back to lurk mode ...
 

FrantzM

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Wizard

There has to be filters if you can selectively adjust a frequency, a band of frequency anything. Call it part of the music if you will. You must filter, that is take something out , filtering.
I understand it is a FM Acoustics forum and my experience with the brand is very thin.. WBF is foremost a discussion forum where we learn a great deal about Audio and Audio brands with a healthy (I hope) and strong emphasis on the best gear available regardless of price, thus claims need to and will be challenged. I am here to learn so , yes, sometime, I will challenge claims to better understand. My purpose is not to derail your thread but to understand and here I don't see how one can modify a Frequency Response without filter. It is to me an impossibility.
 

trponhunter

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what I find most interesting about the arguments going on here about the semantics of this eq, is that everyone is so afraid of eq - like it is some sort of invention created by the devil. Some of the very best systems I've ever heard had eq in them - either analogue or digital. Remember, even the $225k wilson WAMM had an eq in it and Mark Levinson used one for years in his top systems. It seems most audiophiles would rather live with in room frequency response of plus or minus 8 db (which can be a 16db swing) rather than correct it and introduce a little more circuitry in the system.
 

Kal Rubinson

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what I find most interesting about the arguments going on here about the semantics of this eq, is that everyone is so afraid of eq - like it is some sort of invention created by the devil. Some of the very best systems I've ever heard had eq in them - either analogue or digital. Remember, even the $225k wilson WAMM had an eq in it and Mark Levinson used one for years in his top systems. It seems most audiophiles would rather live with in room frequency response of plus or minus 8 db (which can be a 16db swing) rather than correct it and introduce a little more circuitry in the system.
Quite so but this takes the thread in another direction. What is more to the point is that the OP seems to accept an "EQ" but is in denial about the obligatory filters being in the signal path.
 

bblue

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Why not everyone just chill and try to learn something? Many of you are talking out of school and overly biased against anything you don't understand. I'll just bet if you were to listen to it you'd realize it's different than a conventional equalizer.

In studios (mostly digital, but some analog) there are devices that manipulate audio bands in specific ways and they have center frequencies just like an equalizer. But they don't do what an equalizer does! Sometimes, there is a type of phase manipulation, other times harmonics in that particular target range are being manipulated/created/removed in specific ways for effect. That this device is targeting the correction of problem recordings it is likely applying techniques that correct anomalies associated with problem sounds. Things that a standard equalizer CAN NOT do!

I haven't heard this as of yet, so I'm speculating what it might be doing. But there is so much that can be done now with advanced processors it isn't much of a stretch (if at all) to think this is much more than a conventional equalizer.

--Bill
 

FrantzM

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blue

Last stab at this ... The point is not so much that it is an EQ or not.. I objected to the point of the linearizer not having a filter.. that's all. However ways it accomplishes its "linearization" and I can guarantee you we won't learn it in this thread ... There must be filters that's all...

Out for now
 

microstrip

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(...) My purpose is not to derail your thread but to understand and here I don't see how one can modify a Frequency Response without filter. It is to me an impossibility.

Some people consider that when an element is used in shunt mode it is not the signal path - e.g. having a single fixed resistor in a attenuator in a fixed configuration and the variable elements in the shunt, outside the direct signal path between input and output.

It seems to me that FM Acoustics claim something similar - the attenuation is achieved without serial elements with a behavior depending on the frequency in series with the signal path. Surely there is always at less a resistor, usually of high quality, in the signal path.
 

Kal Rubinson

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Do you have an example of an digital advanced processor which can do the job like an regular analog eq?
Once you explicitly describe what you mean by "do the job," it may be possible to answer the question. In terms of filter/EQ possibilities, digital filters are way ahead.

Some people consider that when an element is used in shunt mode it is not the signal path - e.g. having a single fixed resistor in a attenuator in a fixed configuration and the variable elements in the shunt, outside the direct signal path between input and output.

It seems to me that FM Acoustics claim something similar - the attenuation is achieved without serial elements with a behavior depending on the frequency in series with the signal path. Surely there is always at less a resistor, usually of high quality, in the signal path.

Some people do consider that a shunt device is not "in the signal path" but some have argued otherwise. Nonetheless, I did not see any indication in the statements or in the cursory schematics to indicate a shunt circuit. The filters are in the parallel signal paths according to what was offered.

The direction of this thread is disturbing.
 

wgerman

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Kal, why doesn't Stereophile review FM Acoustics? Aren't you curious about the FM Acoustics mystique?
 

bblue

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Some people consider that when an element is used in shunt mode it is not the signal path - e.g. having a single fixed resistor in a attenuator in a fixed configuration and the variable elements in the shunt, outside the direct signal path between input and output.

It seems to me that FM Acoustics claim something similar - the attenuation is achieved without serial elements with a behavior depending on the frequency in series with the signal path. Surely there is always at less a resistor, usually of high quality, in the signal path.
I think what you're describing is mixing the modified signal with the original signal, which is a frequently used technique in modern recording. Most DAW plug-ins (or the DAW itself) include that facility for every type of signal processor; eq, compression, de-essing, spacial modifications, special effects, reverb, echo, you name it. There are some sounds and characteristics that can only be achieved by mixing the effect in with the original sound.

Certain plugin processors produce an output that is designed to mix with the source (in that it contains only elements that cause a certain amount of modification (additive or subtractive) to the original signal. I'm not sure you'd call that filtering, though if the source was completely processed internally and output modified, it might be called a type of filtering. I think that may be in part a distinction that is being made in the Linearizer. It seems to be performing certain modifications to the source (not achievable by just filtering, like eq) and then adjustably mixing them back in to the source, producing a far more neutral yet complex change in the result. Not a new concept at all, but new to consumer audio processing AFAIK.

--Bill
 

bblue

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Do you have an example of an digital advanced processor which can do the job like an regular analog eq?
Just about every plug-in processor you would find in a Digital Audio Workstation (DAW). Waves plug-ins, for example, are one of many plug-in eq's that are designed to emulate to every detail the characteristics of an external analog 'box' or mixing console channel. Famous EQ's like SSL, Neve, API, and many many others, compressor limiters and other analog processors, heck, even tape machines like Studers, Ampex, have emulating plugins which simulate most all of their characteristics. And any of those can be parallel mixed with the source to control degree of effect in a DAW.

--Bill
 

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