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M-Series

M-Series

M-Series Features

Front Panel

Much of the front panel of the M-Series ampliﬁers is

comprised of ventilation slots for expelling warm air from
the inside of the ampliﬁer. Be sure to leave space in front
of the ampliﬁer for proper ventilation to occur.

1. Gain Control

These knobs control the levels to the output section of

the M-Series ampliﬁers. You’ll notice that their travel is
detented, meaning there are 21 built-in “resting points”
so you can easily set both controls to the same level.
Usually, these controls are set all the way up.

The gain structure of the ampliﬁer is designed so that

a +4 dBu (1.23V rms) input signal drives the ampliﬁer
to full power into 4 ohms.
M•2000 = 525 watts/channel into 4 ohms
M•3000 = 800 watts/channel into 4 ohms
M•4000 = 1050 watts/channel into 4 ohms

This is how the sensitivity of an ampliﬁer is deﬁned

(the input voltage required to attain maximum output
power into a speciﬁed load impedance). In this case,
it equates to a voltage gain of 31.4 dB for the M•2000,
33.3 dB for the M•3000, and 34.4 dB for the M•4000).

With the Gain control all the way up (fully clockwise),

the input sensitivity is 1.23V, which works well with
professional equipment operating at a n4 dBu
level.

On the other hand, you may want your listening level

to be quieter than the M-Series ampliﬁer’s maximum
level. For instance, if you’re using the ampliﬁer as a
control room amp, and your control room is the size of a
telephone booth, you’ll probably never want to hear the
amp at its maximum level.

You can set the Gain controls as low as you like. How-

ever, reducing the Gain controls requires an increased
input level to reach full power at the ampliﬁer’s output.

Like all ampliﬁer controls, you’ll typically determine

the optimal settings during installation or sound check,
then leave them alone, using your signal source (usually
a mixer) to control listening levels as you work. Or play.

2. Meters

The M-Series ampliﬁer’s meters indicate the relative

output level of the ampliﬁer referenced to full power.
The numbers next to the meter’s LEDs are in dB below
full power.

Ideally, the –20, –9, –6, and –3 LEDs will light and

blink at normal signal levels, while the OL LED may
ﬂicker occasionally during peak moments.

OL is short for Overload. Overloading, or clipping,

occurs when the output voltage no longer linearly fol-
lows the input voltage and simply stops. This causes a
sine wave to “square off,” or get “clipped off.” Thus, the
term clipping. Fear not — this scenario is quite unlike-
ly. Even with the Gain controls fully up, the M-Series
ampliﬁer easily accepts professional “+4 dBu” operat-
ing levels.

If the OL (Overload) LED is blink-
ing frequently or continuously, turn
down the ampliﬁer’s Gain control or
the source signal (i.e., the mixer’s
master faders).

-3

-6

-9

-20

SIG

-3

-6

-9

-20

SIG

INTERNAL

STATUS