How to use Ensemble Thunderbolt with Quartet to expand inputs

Quartet’s optical connections offer 8 additional ADAT/SMUX digital inputs. With Apogee’s Ensemble Thunderbolt interface connected via optical, it’s possible to record up to 12 mics at a time (4 inputs on Quartet + 8 inputs on Ensemble Thunderbolt).

To setup Quartet and Ensemble Thunderbolt (or any ADAT/SMUX equipped 8 channel interface) for this application:

1. Connect optical Toslink cables between the interface’s ADAT/SMUX outputs and Quartet’s Optical inputs. At sample rates of 44.1-48kHz, all eight channels are transmitted over one Toslink cable – one cable between the interface and the Optical IN 1 is sufficient. At sample rates of 88.2-96kHz, channels 1-4 are transmitted over one cable (connected to Optical IN 1) and channels 5-8 are transmitted over a second cable (connected to Optical IN 2).
2. Connect a BNC cable between Quartet’s WC Out and the Ensemble Thunderbolt’s word clock input.
3. Setup Ensemble Thunderbolt's routing for direct analog to digital routing, 

The gain of the Ensemble's mic pres may be controlled from the front panel by pressing the appropriate input select button and then adjusting the left-hand input encoder to the desired gain setting. To adjust other input parameters for the Ensemble, press and hold on an input select button to enter the input parameter menu where you can adjust things like engaging 48v phantom power, soft limit, group, insert, hi-pass filter, and polarity reversal.

To check input levels for Quartet, open Apogee Maestro 2 or Apogee Control 2 (depending on which version of the installer you used), and click the Input tab and check the ADAT (SMUX) meters.