QSC Audio PL230A, PL218A, PL236A, PL224A user manual Block diagram of audio path in a PL2A amplifier

TECHNICAL OVERVIEW: BLOCK DIAGRAM & OPERATIONAL DETAILS

An impressive amount of technology is packed "under the hood" of a PL2A amplifier. Thousands of watts of power flow inches away from state- of-the-art low noise inputs. Precise circuit layout and thorough protection assure that all of this activity occurs smoothly and safely. So, what actually happens when you turn on the power switch?

Soft Start Sequence. The first task is to charge the primary energy reservoir without drawing a large surge current. A special inrush limiter allows just enough current to charge the energy bank in three seconds. Meanwhile, a low-power switching supply provides power to start up the main supply. After three seconds, a relay bypasses the inrush limiting and full power operation is enabled. The audio circuitry mutes for one second to eliminate start-up thumps. When the red CLIP lights go out, the amplifier is ready for action.

PowerLight™ Technology. High current switching devices draw over 10,000 watts of peak power from the main energy reservoir, which is replenished directly from the AC line for maximum stiffness. Conventional amplifiers must isolate the energy bank with a large AC transformer, which weakens the flow of current, allows greater sag under load, and produces hum. The PowerLight supply performs voltage conversion at a very high frequency, allowing better coupling through a much smaller isolation transformer.

Block diagram of audio path in a PL2A amplifier

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