With analogue pulse width modulation (PWM), we use a relatively new operating principle in our pow-amp. As it makes it possible to build powerful yet compact amplifiers, it only found its way into large-scale industrial production. However, if this operating principle is used to achieve the highest transmission quality without compromise, the process can achieve results that would be very difficult or impossible to achieve with conventional technology: It combines the speed and finesse of the tube with the power and low distortion of transistors.
The key to success is the sophisticated output filter, which can be individually adapted to the respective loudspeaker. The final output signal is only generated in the filter. This is why this stage is crucial to the sound of such an amplifier. The bandwidth for the useful signal must be large enough to transmit all the tonal subtleties. At the same time, unwanted effects from the process must be kept away from the wanted signal. Our multi-stage filter fulfils both of these requirements perfectly.
Another advantage of this working principle is its high energy efficiency. It breaks the paradigm of conventional amplifier designs, according to which good devices are large and heavy and produce a lot of heat in order to serve the “power-hungry” loudspeakers. We measured it ourselves: One hour of listening to music with the pow-amp consumed only 60W/h even with the most power-hungry 3-ohm speakers at a deafening volume. Yes, even if pulse power of up to 1000 watts is possible, music is very dynamic and on average only a fraction of this is actually required over time. In comparison, a 35 Watt Class A power amplifier can “burn” 200W/h just through quiescent current, i.e. without any music at all.
