Martin Audio Never disconnect lift the mains safety earth, Martin Audio - MA200Q Amplifier

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Once connected to a suitable AC supply, the amplifier can be started with the power switch. When you power up the amplifier it takes a couple of seconds to self check (this is known as the "soft start" or "slow start" sequence), the fans then blow at high speed before going into "idle". The four bottom green LED’s then illuminate to show the amplifier is operational.

6.4Grounding

There is no ground lift switch or terminal on this amplifier. The signal ground is always floating (lifted), with respect to chassis ground via a ground lift resistor. If a potential difference above 0.6V is detected between signal ground and chassis earth, a short circuit is automatically introduced between the two, ensuring electrical protection. If other equipment or amplifiers within a system should develop an electrical fault to earth, the mains fuse on that equipment should rupture due to this automatic system allowing an earth current to flow for protection purposes.

If however you wish to permanently connect the signal ground to chassis earth, connect the XLR- connector’s shell lug to pin 1. In the interest of safety never disconnect the earth pin on the mains cable. To comply with CE approval (radio interference), there is an AC mains filter. This filter needs the chassis ground for reference, otherwise a current loop is formed via the signal ground.

Never disconnect (lift) the mains safety earth.

6.5Power consumption

There are three ways to determine the power/current consumption of the amplifier:

First, the peak current draw at full power output. Under this condition the amplifier will operate for less than 2 minutes before thermally limiting or blowing the mains fuse, and is an unrealistic ‘normal’ use condition. To design a mains distribution system based on the current draw at full power would result in an over specified system. No music program material requires the full steady state continuous power of an amplifier, this operating condition is only valid during amplifier bench testing.

Second, the maximum expected average current under worst case program material, which is 1/3 of full power according to the FTC-standard. At this level normal program music will be in a state of constant clip and is therefore the highest power level that can be achieved without completely obliterating the program material.

Lastly, the "normal operating power", as defined by EN 60065 as a measurement level for approval and testing to this standard. The normal operating power is measured using pink noise, with an average output power equal to 1/8 of full power. The one-eighth power is the maximum level program music can be re-played without continuous amplifier clipping, this corresponds to a headroom of only 9dB's, which is very low for normal program material.

	MAX OUTPUT POWER			MAINS INPUT POWER
			Power	1/3 Power	1/8 Power	Idle
			[W]	note 1	note 2
MA200Q	8 ohms	4x	130	480	300	85
	4 ohms	4x	200	720	470	85
	2 ohms	4x	270	1065	740	85

note 1 Average power with music as program source. The amplifier driven to clip level.

note 2 Normal musicpower with 9dB headroom,IEC standard power rating.

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Martin Audio – MA200Q Amplifier