Previewed at the 2010 Pro Light & Sound Show, the four-channel E100 amplifier is the flagship of the MC2 E series. Its official launch marks not only the company’s most powerful four-channel amplifier, but also the first four-channel proprietary class-D switch mode amplifier to be developed by MC².
Designed to run cool even in the most difficult working environments, the E100 can deliver 2.8kW into 4Ω with all channels driven from a 2U-high, 11.8kg chassis.
Various proprietary technologies have been used in the design. These include a Hybrid Dual Loop Feedback system (HDLF) for load independent, accurate audio reproduction, a high performance Active Energy Steering Circuit (AESC), custom drive circuitry and magnetic components to ensure highly efficient, high power, low impedance operation without compromise.
From the outset, the E100 was designed to run 2Ω loads, giving power in excess of 3.5kW from each of the four channels. This allows the amplifier to run bass applications and allows bridging of a pair of channels down to 4Ω. As such, bridging a pair of channels via the rear panel switches turns the E100 into a very powerful bass amplifier offering 7.4kW at 4Ω and over 5.3kW into 8Ω. Outstanding distortion and noise figures are claimed right up to maximum output.
In order to achieve high sonic quality, full range, from a class-D amplifier, MC² developed a Hybrid Dual Loop Feedback system (HDLF) to correct errors generated in the switching amplifier stages and the output reconstruction filters, minimising distortion and maximising Signal To Noise ratio. As such, this also ensures the E100 will faithfully reproduce audio signals – completely load independent. In addition, the HDLF is part of MC²’s class-D modulator technology. Each section of the Modulator and Feedback circuit’s design is carefully analysed to ensure that minimal errors are introduced into the audio signal chain.
As part of the extensive R&D process, MC² also studied and modelled individual components and the behaviour of the switching circuitry employed. The results of this work included a high-performance Active Energy Steering Circuit (AESC), custom drive circuitry and magnetic components. The AESC is designed to cut output device stress by orders of magnitude, allowing almost continuous duty at full power into extremely low impedances, with high switching speeds maintained and without accelerated output device temperatures.
This results in output stage efficiencies in excess of >91 per cent typically and means that the E100 will carry on delivering maximum power into 2Ω (all channels driven with a very low crest factor of approximately 3), where other amplifiers would have begun to limit considerably, or self protect.
The E100 also achieves a maximum Plug-to-Plug conversion of 86 per cent of the power consumed, as each Power converter within the E100 has been optimised for maximum efficiency while a resonant PSU dramatically cuts power semiconductor losses within the main power supply.
Also featured is a new Power Reduction Circuit (PRC), which acts as a power control limiter on each channel and main power supply. The function of these circuits is to distribute the available capacity of the main power supply across the four channels. Each channel has a timed current limit and an immediate current limit – allowing each channel to deliver maximum power within a defined ‘window’. Should the demand of all four channels exceed the maximum capacity of the main power supply (or mains feed) then timed limits or immediate power limits are applied to all channels by the main power supply.
Not normally actuated by audio signals, external control of the amplifier’s limiters are provided for each channel on the rear panel – allowing very flexible power limiting up to 6dB of limiting in 2dB steps.
The E100 is equipped with protection systems to cope with the usual fault conditions such as a shorted load, DC on outputs and Thermal Overload.
Common to the current E90 model, thermal limiting is included – which reduces the output power of the amplifier gradually to compensate for very high internal temperatures, rather than shutting the amplifier down into protection mode.
The front panel display, which has been designed specifically for the E100, incorporates indication of the channel’s Power Reduction Circuit, Protection, Bridge and Channel link modes. Each channel’s limiter also features a five-bar LED graph. These represent the amplifier’s relative output to the selected limiter threshold, and are accurate to within 0.25dB completely independent of load.
The feature set is completed with optional gain settings of 26dB, 32dB and 36dB on each channel – user selectable by an internal jumper setting - rear panel Channel Link switches, Neutrik XLR female connector inputs and Neutrik Speakon 4-pole outputs and a captive mains cable. An optional EQ/X-over Board is available (common to the E-475).
More: www.mc2-audio.co.uk
