Krell Industries MDA-300/500 manual Amplifier Operation

E. AMPLIFIER OPERATION

1.Pushthe black button on the front of both amplifiers to turn themon. The blue LEDon the front panels above each switch will illuminate.

Whenturning on the system, the amplifiers should al-

waysbe last.-The MDA-300/50.0sOn/Off switch is part of a multi-level turn-on circuit that goes throughseveral

steps of protection. Uponturn-on, the amplifier's outputs are not connectedto the.speak.ers. After ttie protect!on circuits have determinedthat the unit has completely stabilized, the speaker relays will be engaged.-Youwill hear a click at this point. Theamplifiers are nowready to use. Theamplifiers will be at temperatureand soundtheir best after approximately30 minutes.

2.Withthe preamplifier in the Muteposition, or volume control fully attenuated, select a source. Turnthe volume control up to yourdesired listening level.

3.Understandingthe operation of these amplifiers is very e.asy. Equallyimportantis an understandingof the care that should be exercised whenoperating the system as a whole, in relation to the enormouspoweroutput of the MDA-300/500sSimple. mistakes, such as switching betweenactive sources without muting the preampfifier

9utput, or bumping/miscuinga cartridge, can generate large transients at lowfrequencies. Withthis type of transient the MDA-300/500scan generate enough power to damagemost loudspeakers. AII switching of sources should be donewith the preamplifier level e~ther muted or fully attenuated. Inputs to the amplifier shouldnot be changedwhile the amplifier is on.

NOTE:Care must be taken whensetting high playback levels. Becauseof their tremendousreserve of-clean power, KRELLamplifiers safely drive speakers to higher soundpressure levels than other amplifiers. This also . meansdriving the speakers to their fimit. Alwaysturn the level downat the first sign of distortion.

Whenturning the system off, the amplifiers should ALWAYSbefirst. This avoids the possibility of a turn- off transient fromsomeother componentgetting to the speakers.

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