Mackie M2000 Owner'S Manual Download Page 17

Page: 17 / 28

Owner’s Manual

Owner’

s Manual

AC Power Distribution

In order to minimize ground loops, the safety grounds

for all the outlets should be connected to a common
(“star”) grounding point, and the distance between the
outlets and the common grounding point should be as
short as possible.

If lighting is used in a show, it is preferable to power

the lights from a different AC circuit than the one
powering the audio equipment. This will help minimize
noise from the lights coupling into the audio (particu-
larly if SCRs are used).

Input Wiring

Use a high-quality 3-conductor shielded cable to

connect the signal between the signal source (mixing
console, equalizer, etc.) and the balanced inputs to the
ampliﬁer. If you’re making an unbalanced connection,
use a high-quality 2-conductor shielded cable. Your
Mackie Dealer can recommend a suitable cable for your
application.

Refer to “Inputs” [9] on page 13 for more information

about making the input connections.

When connecting a balanced line-level signal using

XLR plugs, they’re wired thusly, per AES (Audio Engi-
neering Society) standards:

Pin 2 = Hot (+)

Pin 3 = Cold (–)

Pin 1 = Shield (Ground)

SHIELD

COLD

HOT

SHIELD

COLD

HOT

SHIELD

COLD

HOT

Balanced XLR Connectors

Balanced TRS (tip-ring-sleeve) plugs can be con-

nected to the combination jacks as well. They are wired
as follows:

Tip = Hot (+)

Ring = Cold (–)

Sleeve = Shield (Ground)

SLEEVE

TIP

SLEEVE

TIP

RING

TIP

SLEEVE

RING

Balanced TRS Connectors

It is recommended that a stiff supply of AC power be

used because the ampliﬁer places high current demands
on the AC line. The more power that is available on the
line, the louder the ampliﬁer will play and the more
peak output power will be available for cleaner, punch-
ier bass.

Under typical conditions, reproducing rock music

where musical peaks are just below the clipping point,
you can safely connect one or more ampliﬁers to an AC
service. Use the table below as a guideline:

The M-Series ampliﬁers are equipped with an in-rush

limiting circuit to minimize startup current and pre-
vent tripping the breakers when two or more ampliﬁers
are turned on at the same time, on the same breaker.
Sequencing is not required.

If you use an extension cord to supply power to the

“amp rack,” it should have a third wire safety ground to
avoid presenting a safety hazard. We also recommend
using a cord that has conductors large enough to avoid
severely limiting the ampliﬁer’s ability to supply high
currents on transients.

Power ampliﬁers can have momentary peak current

requirements many times above the nominal average
current draw. According to Ohm’s Law, the greater the
resistance of the linecord, the more input power is lost
between the AC outlet and the power ampliﬁer (across
the linecord). And to further aggravate the matter,
this relationship is nonlinear. The amount of power
lost across the linecord increases exponentially as the
current demand increases. So if the current demand
doubles momentarily because of an exceptionally loud
bass note, the amount of AC input power lost across
the linecord increases four times. You can see that it
is very important to keep the resistance of the line-
cord to a minimum. That’s why we recommend using a
heavy gauge extension cord (like 14 gauge or bigger).
Remember, wire gets thicker as the gauge number gets
smaller (10 gauge is thicker than 14 gauge).