Rane MA 6 1988 version - Manual (Page 8)

OPERATION
USING THE BUILT-IN LIMITERS
The built-in limiters in the MA 6 allow a significant increase in usable volume levels without
clipping The limiters DO NOT effect dynamic response, distortion or noise level of any
material below about 90 watts output level. They simply “watch” the input level of each
channel, and whenever the input tries to go beyond .775V, (which is the input level required
for 100 watts output power), the limiter ‘jumps in’ (out of hiding as it were) and literally turns
down the input level to prevent clipping. It does this very quickly (in about 1/100th of a
second) so that only the peaks of the music are affected.
What this means is that when ever a yellow LED flashes, a musical peak has been quickly turned
down to avoid clipping. This allows you to run the amplifier at a higher continuous level,
typically about 4dB SPL higher than without a limiter. And that 4dB of increased SPL is the
equivalent of a 250 watt amplifier without a limiter.
Keep an eye on the LEDs on the MA 6 front panel. Consistent flashing of the YELLOW LEDs
without any of the RED ones lighting up means that you are getting the most SPL out of the
amplifier. If a RED LED flashes on, however, it means that the input signal was so great that it
has gone beyond the 15dB limiting capability and the MA 6 is near or actually clipping.
Consistent flashing of any red LED is NOT recommended: both the clipping and the limiting
can become audible and undesirable, AND there is a danger of damaging compression driver
voice coils with excessive and prolonged clipping as is the case with ANY amplifier.
Ask your dealer, or write to us at the factory, for RAN E NOTE 103, which gives a very detailed
discussion of the workings of the MA 6 limiters.
ADAPTING THE MA 6 TO YOUR CHANGING NEEDS
With six channels to choose from and built-in bridging there are a number of different
combinations available to suit your present and growing needs. The nice thing about the MA6
is that you can reconnect it and keep using it instead of losing money on an obsolete, used
piece of gear you no longer need.
Basically, you can start out with 6 channels at 100 watts or three channels at 300 watts. When
the time comes, you can step up to six channels at 300 watts by obtaining another MA 6 and
keeping the original. Upgrading to biamped monitors or tri-amped mains becomes easy as
well, by simply adding another MA 6 and keeping the original, both taking up only 10.5" rack
space.
ABOUT THE MA 6 AND CIRCUIT BREAKERS...
The MA 6 will easily deliver over 900 watts of audio power, which requires as much as 15 amps
of current from the AC outlet 15 amps is not an uncommon value for household and some
institutional circuitbreakers, though 20-amp versions are becoming more common. The
bottom line of all this is that the MA 6 is capable of tripping a 15 amp circuit breaker UNDER
NORMAL OPERATION. An amp that delivers a lot of power drinks a lot of power to do so.
It is not likely that you will blow many breakers at all, if any, but it is wise to be aware of the
possibility so that you don’t panic if it happens.