FM Acoustics 268 preamp - the debate around its Linearizer

[MylesBAstor]

Well the way I see things going, why not? After all we have very expensive, thus well respected cables with "Articulation Poles' so why not change the sound before the amp? Tone Control by any other names? Will we see a return of the graphic EQ of the 70's?

Have you read about the purpose of the articulation poles? That's like saying impedance matching-which is clearly audible with MIT and Transparent cables-is a tone control. Hell, who's to say changing a preamp isn't a tone control?

It's like saying we should ban all supplements. How far do you want to dig? Practically every food we eat is supplemented if you read the food labels.

Oh and might I add our Charlie King is working on a version of the Cello Audio Pallette.

 

[FrantzM]

Have you read about the purpose of the articulation poles? That's like saying impedance matching-which is clearly audible with MIT and Transparent cables-is a tone control. Hell, who's to say changing a preamp isn't a tone control?

It's like saying we should ban all supplements. How far do you want to dig? Practically every food we eat is supplemented if you read the food labels.

Oh and might I add our Charlie King is working on a version of the Cello Audio Pallette.

Myles

Relax man. No I haven't heard them but what do they do if not change the sound? (Well if they really do anyway another debate) ... They change what ? The sound? Right? And do not call these "Impedance Matching" please. I am not seeing how they match the imp of the amp to the speakers ...but you can always educate me.

Now I never said to ban anything. I asked :I am quoting me "Why Not?" So to me that is a very valid approach, not one that I favor personally but I am one of those who think DRC is a great solution, remember, so aside from steroids and artificial and health-destroying supplements .. I am all for I take my Whey protein and Selenium every day

The Cello Palette is a tone control. Or if you want to put it in other terms a graphic EQ with knobs rather than sliders. Tone control the same. Whomever works on it.

 

[MylesBAstor]

Myles

Relax man. No I haven't heard them but what do they do if not change the sound? (Well if they really do anyway another debate) ... They change what ? The sound? Right? And do not call these "Impedance Matching" please. I am not seeing how they match the imp of the amp to the speakers ...but you can always educate me.

Now I never said to ban anything. I asked :I am quoting me "Why Not?" So to me that is a very valid approach, not one that I favor personally but I am one of those who think DRC is a great solution, remember, so aside from steroids and artificial and health-destroying supplements .. I am all for I take my Whey protein and Selenium every day

The Cello Palette is a tone control. Or if you want to put it in other terms a graphic EQ with knobs rather than sliders. Tone control the same. Whomever works on it.

Frantz, the MIT Oracle ICs for example can adjust for both impedance and number of poles (that is probably changing where the cable goes from resistive to inductive). I find the former far more obvious than the latter.

 

[FrantzM]

Myles

That's is not impedance matching and what are those "poles"?


P.S. I read MIT explanation for "Poles of Articulation". .. This is not about Cables .. sooooo I'll leave it at that ... Back to the FM Acoustics Linearizer. A different name for Tone Control in my book, remember the Title of the Thread:
"FM Acoustics 268 preamp - the debate around its Linearizer"

 

[ack]

See this thread on down http://www.whatsbestforum.com/showthread.php?8737-The-cable-conundrum&p=151692&viewfull=1#post151692 about what I think the MIT articulation poles are all about, with important feedback from Don - in short, an attempt (right or wrong) at addressing inherent voltage/current phase relationships in a cable ('inherent' as in manifested in physics and electronics books, with appropriate references included); though anything can be construed a tone control - because part of equipment design is voicing - in my mind the MIT cables do not meet the strict definition we usually use. Back to FMA.

 

[LL21]

A 268 FS - this unit is brand new, and with no discount - it can be only bought together with a 1811 as a set.
If you have $125' + $155' this set can be yours, not every day this set is FS, as there is 6 months waiting time.

Hi Wizard...have you ever heard these with Wilson speakers by any chance? Not a buyer...just curious to learn.

 

[LL21]

A new version 268-C is coming soon.

268-C now has a new feature - a acoustic resonance compensation (ARC) circuit.

OK...what is an acoustic resonance compensation circuit?

 

[LL21]

The ARC minimizes room modes and other resonances. Room modes occur when parallel surfaces create one or more pronounced resonances (a sharp Sound Pressure Level (SPL) increase at specific frequencies).

In a typical rectangular room the 1st principal resonance is occurring at 1/2 wavelength of opposite walls (this is why it is not a good idea to listen while sitting close to walls) - in above graph this is "P1" (graph is smoothed to only show the two principal resonances). The 2nd resonance is at double this frequency ("P2").

Depending on room size the 1st and 2nd resonances can occur anywhere from around 100 Hz down to below 20 Hz. Such a resonant peak is superimposing itself on the actual music mainly resulting in boominess and poor low frequency definition.

Professional studios can ameliorate such room modes but size, construction limits and cost preclude this for home environments. Usual "hi-fi" absorbers work relatively well for middle and higher frequencies but with reasonably sized domestic absorbers such low frequencies room modes cannot be attenuated efficiently.

The ARC circuits are also ideal if there are resonances from other sources in the room, e.g. air conditioning or any other resonating surface or room component.
These circuits are unique to the FM 268-C. They are pure analogue circuits and do not interfere with the music.

No A/D and D/A conversion is done. The integrity of the existing systems signal reproduction remains.

Interesting...that actually would be great in my room around 32hz or so in one particular problem area. The question is how does this work with the FM? Is it an equalizer-type setup where you can lower the output of that particular frequency?

 

[LL21]

FMA released some preliminary information yesterday, so I don't know how ARC works or how to set it up yet.
Only know that ARC is located at the back of the unit.

Very interesting...thanks, Wizard.

 

[mep]

I don't know if it's just me, but your last two paragraphs seem to contradict each other. "You will realize that when turning the 800 Hz control there is no negative effect in the other frequency range! Only the one frequency range that is subtracted or added is changing while the signal remains pristine and totally transparent, exactly like the original signal!" Reconcile that statement with this one: "On the FM 268-C Linearizer section every control is dynamic, every movement of one control influences the other."

 

[LL21]

From tomorrow's Linearizer - how it works - part 1

View attachment 9356

"While looking at the control panel of the FM 268-C linearizer section one could be reminded of an equalizer. However, the FM 268-C Harmonic Linearizer's mode of operation is rather different and avoids all the problems of equalizers. It's singular characteristics allow linearization of any source by only adding or subtracting critical areas of the audio signal to/from the direct-through signal.
The result: in the FM 268-C there is no ripple in the pass band and no phase shift / discontinuity, which results in pristine signal coherence and superb transient response.

A further unique characteristic is that when all level controls are in full boost position there is no change in frequency response; a linear gain over the entire frequency range is achieved; this is unique, the sign of perfect linearization."

"Thanks to the unique characteristics of the FM 268-C it is now possible to linearize audio signals with the assurance of only positive effects on the direct through audio signal. A good demonstration of the inherent transparency of the FM 268-C is to first listen to the standard signal having all controls in the center detent position. Listen carefully to all frequency ranges. Then turn one of the control, say the 800Hz control and while turning the control, concentrate on another frequency band, say the lower range of voices and low/mid based instruments. You will realize that when turning the 800 Hz control there is no negative effect in the other frequency range! Only the one frequency range that is subtracted or added is changing while the signal remains pristine and totally transparent, exactly like the original signal!

However, do not try to work with the FM 268-C like with an equalizer. It does not work that way. On the FM 268-C Linearizer section every control is dynamic, every movement of one control influences the other. So it is best to control the individual Linearizers dynamically: move one control until you hear it is too much addition or subtraction, then move it back to the point where it becomes a realistic correction. Next, move the control adjacent to it (say the next lower frequency) by turning that control until again it becomes excessive. Turn it back until the setting becomes correct, then readjust the previously set control mildly until the optimum setting between these two controls is found. Then move to the next higher control and repeat the procedure."

Have you tried this? Sounds interesting though in the end, its about how well it works. Thanks for doing this...always great to read your posts!

 

[hahayan]

can i say it is a FIX Q parametric eq? i had some FMA in the past.., but never had this Piece of FMA.., i lived with a some Cello MIV SIV n the past.., very effective n easy tone control, good as it never shift the sound stage ,but tonal control

FMA, too rich for me..tonally, my POV the strength of FMA.. it just sound a bit REAL ..real life atmosphere for acoustic and live music , however does not feel their power

 

[Matej Isak]

Hi Guys,

Just got FM 133 on my hands:



FM ACOUSTICS FM 133 and FM 233 Harmonic Linearizers created quite some stir and interest across the high-end audio society. Is it just a regular EQ or something beyond simple equalisation? I'll go in depth soon, but I love what I hear so far. This is something I hankered for quite some time and a safe cure for bad or mediocre recorded albums. I did't tried with vinyl yet, but with digital audio signal boost is stressless and impressive. With both my favourite preamplifiers Robert Koda Takumi K-10 and Arte Forma Peral results is instant. I have similar sound harmoniser created in my Mac Os X, but prefer hardware unit.

Stay tuned for in depth review and more listening impression.

http://www.monoandstereo.com/2013/05...inearizer.html

 

[Dave_A]

There was a 268 on Audiogon for $60000 US.

It's gone now...

 

[djanggo]

Yup saw 'em just yesterday! Quickly alerted a friend whom I know for years been looking for a used one. He called just to scold me today thinking I was just teasing him! In that pristine condition (the photo), quite a bargain if true.

 

[djanggo]

View attachment 8055

A 268 FS - this unit is brand new, and with no discount - it can be only bought together with a 1811 as a set.
If you have $125' + $155' this set can be yours, not every day this set is FS, as there is 6 months waiting time.

1811
View attachment 8056

Hi Wizard,
I recognize this (top pic. of 268) was the same exact photo up on Agon yesterday. Do you happen to know the owner? If still up for grabs I'm interested.
Also, has price of the new 268-C made known yet? Thank-you.

 

[djanggo]

I didn't saw that ad - the 268 + 1811 is still FS as a set only.
The seller on Agon did borrow the pic I think.

Don't know the price of 268-C because it's not released.
No units has been delivered yet.

But I think around CHF 120,000.

Hi Wizard, thanks..
Too much for the set, especially buying new.

Was interested at the asking price in Agon though, and one in that minty new condition as shown, hmm tempting..

So new 268-C will be around CHF10,000 (or 10%) more than current 268? Curious to know if running them both straight-bypass (sans ARC nor Linearizer) how they'd compare/differ.

 

[Dave_A]

Yup saw 'em just yesterday! Quickly alerted a friend whom I know for years been looking for a used one. He called just to scold me today thinking I was just teasing him! In that pristine condition (the photo), quite a bargain if true.

There's an ad right now for an original 811! Not a bad price?

http://app.audiogon.com/listings/solid-state-fm-acoustics-811-2013-06-09-amplifiers-98370

 

[LL21]

Thanks, Wizard. As a total non-techie, it certainly 'looks' like a Boulder layout inside. I have no idea about parts or anything else. just reminds me of what Boulders tend to look like inside.

 

[LL21]

Thanks, Wizard. I do not have the technical experience to appreciate what these differences mean. Nevertheless, I do look forward to hearing FMA at some point in the future.