General Information - MC2 Audio E45 Owner's Manual

General Information

Your E45 power amplifier utilises a proprietary designed progressive switching rail output, which
enables the extremely high voltage swings and peak power without compromising the sonic quality.
Fan speed is varied as required to keep the amplifier within its temperature limits. Signal limiters are
included to protect speakers from clipped signals.
The amplifiers include full DC and short circuit protection to ensure trouble-free service even in 'harsher'
environments.
The E SERIES introduces three user-controlled features previously not seen on MC
amplifiers:
-3dB indicators
Power reduction control (PRC)
User-settable gain/sensitivity (internal)
The latest version now also has improved signal level indication with 3 green LEDs in a 'bar chart'
format. This gives a much clearer indication of level to the operator. The -3dB and Limit LEDs continue
the bar format.
-3dB INDICATORS
Part of the front panel signal level display, they will light up when the signal is approximately 3dB below
the limiting point. The limiting point is set during production to be at the onset of clipping. The response
times of the -3dB indicators (YELLOW) are faster than those of the limit indicators (ORANGE).
Power Reduction Circuit (PRC)
This enables the user to set a maximum output power level below the rated output of the amplifier. This
reduction is controlled by switches on the rear panel, 2 per channel. Each channel has an LED indicator
(GREEN) active when either PRC switch is selected. A full table of PRC settings and the resulting outputs
are given in the Appendix. The possible settings are: -2dB, -4dB, -6dB. This relates to the maximum
output of the amplifier. (See the chart in the Appendix section at the end of this manual.)
In bridged mode the Channel A PRC circuit operates over both Channel A and B. In this mode Channel
B PRC is not used and is out of circuit.
The E45 is the very latest example of a 'dynamic amplifier'. This new 'breed' of power amplifiers
provide very high peak power levels in a much smaller, and lighter, package than previously possible
with conventional amplifiers. They are designed specifically for today's high power audio installations,
which use multiple speakers with electronic crossovers or speaker controllers. These systems can handle
very high transient signals which far exceed their RMS power rating. The E Series amplifiers have
been designed to match this requirement and can deliver huge levels of power for short durations (just
under a second). In order to protect themselves and the loudspeakers that they are driving, continuous
signals, such as sine waves, are automatically detected and reduced (ramped down) to a safe level.
When trying to measure the power output however, continuous signals will give totally incorrect
results. A dynamic signal, such as a tone burst, should be used and the levels measured by monitoring
the waveform on an oscilloscope. The power envelope can then be accurately measured.
Notes on Dynamic Amplifiers
9
2
Audio