Tuesday, April 23, 2013

FM Acoustics 268-C Linearizer - How it works part 2

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.

After an hour of practice or so users get rather comfortable with the controls and often adjust two controls simultaneously. This way they are able to control dynamically and find the optimum setting in seconds. Listeners "come to grips" rapidly with the Harmonic Linearizer's controls. An initial hesitation quickly reverses to enthusiasm as soon as a few recordings have been linearized.

Sometimes one needs to adjust the linearizer controls during playing of a CD, LP, SACD, DVD or other sources. The reason is that titles or movements of works were recorded on different dates, by different engineers and sometimes even in a different location. So it is not uncommon to hear some quite drastic changes in sound from one title / movement to another.

The linearizer controls are special level accurate controls that have a center position. This center position is not just a center detent like e.g. found in usual balance controls: here, the center position employs a separate additional contact that guarantees a 100% true bypass when the control is in the center position, a solution unique to FM ACOUSTICS.

While some great recordings will not need much of the linearizer function, others will become even greater; mediocre recordings will become very nice and some downright unlistenable recordings will become quite listenable; an absolutely amazing feat for any music enthusiast.

Unexpected is the astounding increase in dynamics despite the fact that no signal processing at all is done. When analyzing why this is possible one comes to a somewhat unexpected but logical explanation: as for the human hearing the apparent loudness is not a linear function, even a small subtraction or addition can have a noticeable effect on the audible dynamic range.
As it depends on the contents of the musical signal - which is continuously changing - no currently established measurement can give any indication of this increase, but its effect are instantly audible.

In any function the entire circuitry remains non-inverting but in case the source signal itself is phase inverted, the "Phase" switch on the front panel allows instant 180° phase inversion.

Another priceless feature is the signal routing function on the output of the Linearizer section. Thanks to this it is now for the first time possible to record one's own music selection with the linearizer function in action. This means that standard recordings can be improved / re-mastered and then be transferred to a new media! A huge advantage and the base to build one's own linearized and improved music collection.

From the linear output amplifier stage it is possible to either route the linearized signal to the main output or also switch it to the "tape" outputs. This is a great feature as it allows recording of the linearized signal onto whatever is connected to the tape outputs: tapes machines, blue rays, DVD's, CDR's and the like. This way the source signal can be re-mastered and allows the creation of one's own collection of improved and linearized recordings to whatever media is connected to the "tape" outputs!

The FM 268-C is absolutely unique as it allows any critical frequency in the audio band to be optimally linearized with just five dynamically interacting and easy to adjust controls, all of this with FM ACOUSTICS pure discrete class A analogue circuitry.

The ultimate goal of correcting errors without negatively affecting the audio signal and literally let the signal pass through directly without negative influence has finally become reality.

Now it is possible to achieve huge improvements in the weakest part of the audio reproduction chain: the source signal.

It must be noted that the Linearizer section of the FM 268-C is not designed for compensation of room acoustic problems, although sometimes improvements are possible. The task of the Harmonic Linearizer section of FM 268-C is the linearization of the source signal.