From the Presonus site.
Uh, the Central Station has talkback as well.
PURELY PASSIVE SIGNAL PATH
The Central Station features a PURELY PASSIVE SIGNAL PATH for ultimate sonic performance. The main audio path of the Central Station uses no amplifier stages including op amps or active IC's (integrated circuits) that add noise, color, distortion, and give that "pinched" sound. Distortion produced by op amps and IC's also gives added ear fatigue.
Signal routing in the Central Station is acheived utilzing 34 sealed mechanical relays (instead of active IC's) maintaining a minimal signal path design wherein extraneous electronics are hard-wire bypassed. Using relays ensures the most transparent signal path maximizing dynamic range, frequency range, and headroom, while minimizing noise and coloration. The Central Station uses the highest quality passive components including military grade 1% tolerance metal film resistors, multi-element potentiometers and ultra-durable connectors to deliver the highest sonic performance.