B.M.C. CS2 Stereo Amplifier
B.M.C.'s CS2 is a Load-Effect Free (LEF) Amplifier with an option to upgrade it to a LEF Stereo Power Amplifier. The crucial secret of the CS2's sound is that it avoids distortion, instead of compensating for it through a negative feedback loop.
LEF = Load Effect Free
The CS2 is a power amplifier without a preamplifier for a short, pure signal path. It features a Volume Control using our exclusive Discrete Intelligent Gain Management (DIGM) system, and an input selector. The lossless DIGM volume adjustment eliminates unnecessary signal attenuation at the input, as well as unnecessary high amplification.
Combining the CS2 with a B.M.C. Digital-to-Analog Converter (DAC) transforms it into a LEF stereo power amplifier that offers DIGM gain adjustment set by the DAC's volume control. In addition, B.M.C.'s balanced Current Injection (CI) input enhances the immediacy of reproduced music by processing the signal current of the source until it reaches the speaker's output voltage. B.M.C.'s LEF output stage avoids distortion before it occurs by relieving the sound-critical LEF single-ended Class-A transistor of all duties other than providing perfect signal reproduction.
Unlike other amplifiers, a LEF amplifier handles a speaker's current demand separately from the voltage demand. The result is an unparalleled mastery of musical complexity that brings to startling life delicate details, rock-shaking power, high dynamics, sonic vitality, and accurate imaging — all on a three-dimensional soundstage.
Load-Effect Free amplification is a new experience that must be heard to be fully appreciated.
The CS2 also boasts solid output power: 2 x 200 watts into 8 ohms, and 2 x 350 watts into 4 ohms.
A fully regulated power supply with a 2kW toroidal transformer and balanced current capacitors provide the muscle behind the music.
Outstanding Special Features of the B.M.C. Amplifier
The human sense of hearing is surprisingly unimpressed by the
perfect test results of customary measuring methods.
This is why traditional transistor amplifiers come under fire
again and again, although tube amplifiers are not real
alternative as they have clearly audible characteristics.
Several innovations were needed to build an amplifier that does
not impose its own sound on the music. These innovations go
way beyond the standard circuits and may be not easily
understood, even by technologists.
Current Injection (CI), Discrete Intelligent Gain Management (DIGM), and Load-Effect Free (LEF) circuits are our own, original designs. Used together and consistently executed, they lead listeners into a new world of tonal experience.
Current Injection
Low impedance current input lets the original current of a signal source flow through the amplifier circuit until the desired loudspeaker output voltage is attained.
Discrete Intelligent Gain Management
Precise alignment of the amplifier to the desired volume occurs
only on the level of the output voltage. This avoids unnecessary
input signal attenuation, as well as excessive amplification.
Less amplification = less distortion and noise, which in turn =
more natural musical quality.
Load Effect Free
The LEF output stage takes over the task of adapting the output voltage to the load (the loudspeaker). The signal transistor responsible for the sound is freed from driving the load to avoid distortions at the beginning. LEF makes it possible to use single-ended mode for high power, a mode that exceeds the classic Class-A by its natural lack of distortion.
Overall Negative Feedback is Obsolete
The B.M.C. amplifier's natural lack of distortion facilitates the
intended renunciation of tonally suspect overall negative
feedback.
The Current Injection input and Discrete Intelligent Gain
Management would not be possible without the distortion-free
LEF output stage and the absent negative feedback loop it
induces.
Stabilized 2kW Power Supply
The power supply has nothing to do with the actual amplifier
circuit, but determines the extent to which the potential of the
amplifier really comes into effect.
A 2kW toroidal core transformer forms the solid basis for a very
powerful, dynamic, and stable source of energy.
The storage in a whole battery of specially designed and
produced Balanced Current capacitors is the basis for an
exceptional musical evolvement and transparency.
An innovative electronic stabilization circuit especially for the
power section filters mains voltage ripples and other
disturbances out of the supply voltage, ensuring exceptional
tranquility and dynamic stability.
All About the Music
The consequences of designing an amplifier for consistent,
exceptional musical reproduction also lead to test results right
out of the textbooks. But the essential thing is the musical
experience. The expression "neutral amplifier" makes one think
of an amplifier without a character of its own. But it's this lack of
characteristics that makes describing the B.M.C. amplifier so
difficult, since it can sometimes be brutally dynamic, sometimes
highly expressive and full of detail, sometimes raw and
discordant, sometimes bewitching and seductively beautiful,
detailed and enveloped by its spatial presentation.
In the end, the result is a musical transparency that has never
before been heard.
"More of the music and less of everything else."
- Mark Mickelson, Editor, The Audio Beat -
