User guide

664 User Guide and Technical Information

v. 1.0 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Headphone Peak LED

The Headphone Peak LED is located just left of the Headphone Encoder.

This LED will illuminate red to indicate clipping in the headphone ampliﬁ er.

Monitoring without a visual indication of headphone clipping can mislead the

sound mixer into thinking that the output or return feeds are distorted.

Headphone Monitoring

Headphone Gain

Headphone output level is controlled by turning the Headphone Encoder while viewing the Main

Screen or Input Se ings Screen. When adjusting the headphone gain, the gain value (in dB) is dis-

played in the lower right corner of the LCD (Near the Headphone Encoder). This space displays the

currently selected headphone source when the headphone gain is not being adjusted.

Headphone Encoder

Headphone gain during adjustment

The 664 can drive headphones to dangerously high volumes. Turn down the headphone gain before

selecting a headphone source to prevent accidental signal extremes.

Headphone Source Selection

To select the monitor source, push the Headphone Encoder while viewing the Main Screen to display

the Monitor Source List. This will display a list of available monitor sources. Turn the Headphone

Encoder to highlight a source, and press the Headphone Encoder to select that source. The signal to

the headphone outputs will immediately change to the selected program.

Monitor Source Description

LR ST Master Bus in stereo.

LR Mono Master Bus summed mono to both ears.

L Mono Left channel of Master Bus sent to both ears.

R Mono Right channel of Master Bus sent to both ears.

LR MS ST Mid-Side Stereo - Master Bus decoded MS stereo to headphones, this is not to be used if the inputs

are already linked as an MS pair.

X1X2 Aux Bus in stereo.

HP Preset HP Presets 1-6 are customizable monitor sources.

See Headphone Presets