API 550B


 7 switched frequency centres per band, fully discrete, click détente in 2 dB steps with 12 dB boost or cut, hi and lo shelf switches, unique proportional Q, high headroom, silent bypass. This is the EQ fitted to all large format API consoles. 
+4 balanced XLR I/O. 

“I can see why these eqs should be so highly prized, the sound is quite special”, Dave Foister. Studio Sound, February 1996.