Martin Audio's MA12K power amp.Kitchener, Canada (September 12, 2007)--Martin Audio has added three models to its MA Series of amplifiers. The MA18K, MA12K and MA9.6K reportedly deliver 95 percent of the input power into the speakers with a 5 percent loss dissipated as heat. The technology is said to enable a reduction in size and weight. According to Martin, “one particular feature of this efficiency is that the amps are virtually independent of output level compared to conventional designs, which typically achieve their best efficiency only at full-rated output power.”
The three new MA Series models utilize Pulse Width Modulation (PWM) technology to achieve higher efficiency. A PWM converter works as a high-frequency sampler, converting the variable amplitude of the input signal into a digital pulse at the output. This is then converted into an analog signal with a patented output filter, which is how the low THD and inter-modulation figures are achieved.
The Switch-Mode power supply incorporates Power Factor Correction that maintains a steady current draw on the mains supply. The new MA models can handle mains voltage variations and can be used directly on any worldwide mains voltage standard without adjustment.
The new MA Series models also feature DSP functionality accessed via the front-panel controls and LCD display. Limiting, mains current draw, level and routing can all be controlled, and the amplifier can be remotely controlled and monitored by a PC via an RS485 interface. An optional DSP card can be fitted to give additional DSP functionality thanks to onboard Sharc processing. A smart card can be used to store and load parameters between amplifiers.