The lunchbox gives an engineer the flexibility to bring along specialized EQ effects to any situation: 550A, 550b or 560. The lunchbox is self-powered. API makes several modules for the 500-6B, including the 512c Mic Preamplifier, the 525 Compressor, the 527 Compressor, the 550A 3-band EQ, the 550b 4-band EQ and the 560 Graphic EQ.
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