Mackie M2600 INPUT WIRING, OUTPUT WIRING, Load, Wire, Gauge of, Impedance, Wire Length, AC Power Distribution

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, punchier bass. A suspected problem of “poor bass perfor- mance” is often caused by a weak AC supply to the amplifier.

The M•2600 has an in-rush limiting circuit and relay that will prevent popping the house circuit breakers during turn-on. You should still avoid turning on all of your amplifiers at the same time. Rather, turn them on one at a time.

AC Power Distribution

The majority of AC outlets encountered in homes and clubs (in the U.S.) are served by a 240VAC center-tapped service entrance trans- former. This provides two phases of AC power on either side of the center tap, at 120V each.

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 one leg of the service, and power the audio equipment from the other leg. This will help minimize noise from the lights coupling into the audio (particularly if SCRs are used).

When setting up for a show, oftentimes you are plugging into an AC power distribution system you know nothing about. You may even be faced with 2-wire outlets that are missing the third safety ground pin. It’s a good idea to have a three-wire AC outlet tester in your toolbox so you can check the outlets yourself to make sure they are wired correctly. These testers will tell you if the polarity of the hot and neutral wires is reversed and if the safety ground is disconnected. Don’t use an outlet if it is wired improperly! This is to protect yourself as well as your equipment.

HIGH VOLTAGE POWER LINE

	120V
PRIMARY	240V	SECONDARY
WINDING		WINDING
	120V

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 using the unbalanced inputs, use a high-quality 2-conductor shielded cable. Your Mackie Dealer can recommend a suitable cable for your application.

If you want to roll your own, refer to the “Connectors” section in Appendix B.

OUTPUT WIRING

Use heavy gauge, CLASS 1, stranded wire for connecting speakers to the M•2600 amplifier’s SPEAKER OUTPUT terminals. As the distance between the amplifier and the speakers increases, the thickness of the wire should also increase. Speaker wire has resis- tance, and when electricity passes through a resistor, power is lost. The thicker the wire, the less resistance it offers and the more power actually gets to the speakers.

The wire thickness is rated in gauges. Use the chart below to determine the correct gauge of wire to use according to the distance between the speakers and the amplifier, and the impedance of the load the amplifier is driving. This ensures that the power lost across the speaker wire is less than 0.5 dB.

	Load	Gauge of
Wire Length	Impedance	Wire
Up to 25 ft.	2Ω	14 gauge
	4Ω	14 gauge
	8Ω	14 gauge
Up to 40 ft.	2Ω	12 gauge
	4Ω	12 gauge
	8Ω	14 gauge
Up to 60 ft.	2Ω	10 gauge
	4Ω	12 gauge
	8Ω	14 gauge
Up to 100 ft.	2Ω	8 gauge
	4Ω	10 gauge
	8Ω	14 gauge
Up to 150 ft.	2Ω	6 gauge
	4Ω	8 gauge
	8Ω	12 gauge
Up to 250 ft.	2Ω	4 gauge
	4Ω	6 gauge
	8Ω	10 gauge

TRANSFORMER	EARTH
240V Center-Tapped Secondary	GROUND
	(NEUTRAL)

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