Sound Performance Lab 2489 Operation, Volume Control, Source Buttons Surround A/B and Stereo C/D

Operation

Volume Control

The volume is centrally controlled for all channels via a discrete six-level potentiometer with an extremely linear curve. The potentiometer controls the audio signals directly without any signal-degenerating circuitry such as VCAs or DACs, which tend to create tolerances between channels as well as distortion. The white circle with the potency scale can be easily marked using a pencil.

Source Buttons Surround A/B and Stereo C/D

The source buttons Surround A/B and Stereo C/D allow easy switching between surround and stereo sources (inputs). Two surround and two stereo sources are available.

The middle button selects between surround and stereo sources. When depressed (in), the stereo sources are active; when not depressed (out) the surround sources are selected.

The left button selects either surround source A (out) and B (in), while the right button selects either stereo source C (out) or D (in).

Monitor Mode Buttons (Mono, Dim, Mute All)

The Monitor Mode buttons provide various monitoring functions: MONO L/R, MONO LS/RS, DIM -20 and MUTE ALL.

MONO L/R and MONO LS/RS switches the front L and R channels and the rear LS and RS channels to mono, respectively, and can be used to check phase correlation. The MONO LS/RS mode has no effect when a stereo speaker pair is selected.

DIM lowers the monitor volume by -20 dB without changing the volume pot setting, for example to control a mix at low volume (or to answer the phone…).

MUTE ALL does exactly what it says: it mutes all speaker outputs.

8 Surround Monitor Controller 2489