B.M.C. Mono Power Amplifier M1

B.M.C.'s advanced circuit design

B.M.C.'s many advances are making audiophile sound exciting again, and leading to amplifiers being built in a completely new way. B.M.C. realized that if overall feedback worked as intended, all amplifiers would sound exactly the same. After considerable research, B.M.C. co-founder Carlos Candeias devised a brilliant solution for avoiding distortions at the source, and making a feedback loop obsolete. This revolutionary circuit was named Load-Effect Free (LEF), because the single-ended Class-A transistor that defines the sound was relieved of all duties other than providing perfect signal reproduction.

This enabled lossless volume control through our Discrete Intelligent Gain Management (DIGM), which offered two additional advantages: the input signal would not be needlessly attenuated, and the amplifier would only need to provide the actual required gain.

The last step was to build the balanced Current Injection (CI) input. In typical circuits, the input signal modulates current flow and creates a copy of the original. B.M.C. power amplifiers lead with the input current, using the Current Injection input, until it generates the speaker output voltage. A crucial step in reproducing a truly musical experience.

A giant power supply with a 2kW toroidal transformer, an army of Balanced Current capacitors, and electronic stabilization provide the foundation for a rock-solid energy supply and noiseless background.

The result is an amplifier whose presence recedes behind the music so listeners can hear the true power of their music as well as all the fine details. Quietness combines with a powerful dynamic vitality, richness of detail combines with warmth. The amplifier's only sonic footprint is the purity of the music itself.

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 -