B.M.C. - Balanced Music Concept
All B.M.C. analogue circuitry is designed with a balanced signal path - a true Balanced Music Circuit. Such a design is not only basically different from its unbalanced counterpart, but also from circuits with balanced in- and output but unbalanced internal signal path.
A circuit which is basically unbalanced modulates the power supply voltage by the music signal. Certainly not on full scale but with reduced amplitude and most certainly not linear in frequency range, depending on the power supply‘s quality. Those modulations might be small but not without influence on the overall quality.
Modern high-end DAC ICs with 24Bit are generally designed balanced for achieving their specifications, regardless of whether or not a manufacturer applies an unbalanced circuit afterwards. Otherwise such delicate low-level resolution is hard to achieve.
Most modern circuits have a high power supply noise rejection, but when examined closely look the rejection ability is not the same for positive and negative voltages and also not for different frequencies. Generally there is no clear idea how this rejection performs under dynamically changing conditions, i.e. music signals.
From our point of view this means: Don‘t rely on power supply noise rejection, rather use circuitry not depending so much on the power supply.
A truly class-A balanced design is a constant non-moving load for the power supply. However much energy one signal requires, the balanced mirror signal requires the same amount less. In theory this way there would be no modulation of the power supply by the music signal at all any more. And in existing applications the power supply modulation is significantly smaller compared to an unbalanced circuit.
Furthermore balanced designs have a natural rejection of common-mode power supply disturbances. This results in a remarkably improved “inner quietness” of the music reproduction. In consequence there is more space left for sound details, colours and 3-dimensional sound-stage.
Analogue to the above described DAC ICs balanced designs offer dramatic advantages for phono amplifiers as well. Just imagine while the output of a phono amplifier delivers some few volts the input signals are in the range of micro-volts! It should be obvious that any influence of the power supply by noise or modulation would have a clear impact to the sound quality. But if there is neither modulation nor power supply noise there is more room for in-depth listening.
This short essay just describes the advantages of balanced circuitry within a component. The advantages of balanced interconnections are widely known and of course also apply to B.M.C.‘s components.