The 500-8B is the successor of API's famous 500-6B lunchbox.
The new 8-slot unit includes all of the features that have made the 6-slot lunchbox so well regarded in the industry, including DB-25 (D-Sub) connectors for easy I/O, universal power supply (100 or 250V, 47 to 63Hz), phantom power, and easy rack-mounting with optional rack-ear kit. Built for robust performance, with new toggle switches for channel linking.
The lunchbox gives an engineer the flexibility to bring along specialized EQ effects to any situation: 550A, 550b or 560. The lunchbox utilizes an external power supply. API makes several modules for the lunchbox, 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. Combinations of these modules make perfect stereo recording packages (two 512cs and two 550bs) or vocalist's box (one 512c, two EQs and one 527)