Atlas Hardware; Signal Path Architecture; Analogue Inputs - Prism Sound Atlas Operation Manual

Prism Sound Atlas
5

Atlas hardware

This section describes in detail the capabilities of the Atlas hardware.
5.1

Signal path architecture

The figure above is a simplified block diagram of the Atlas audio signal paths.
Atlas is basically a sound card, with all inputs made available to the host computer via the USB host
bus, and all outputs likewise driven from the USB host bus. However, Atlas's signal paths contain a
range of enhanced processing and mixing functions, which are described in the following sections.
5.1.1

Analogue inputs

All eight analogue input channels feature balanced line inputs on TRS jacks, with dual switchable
sensitivity to allow connection to professional or consumer line-level sources. The '+4dBu' setting
accommodates professional signals with a nominal level of +4dBu and allows a maximum level of
+18dBu (0dBFS). The '-10dBV' setting accommodates consumer signals with a nominal level of
-10dBV and allows a maximum level of +6dBu (0dBFS). Unbalanced sources are automatically
accommodated.
All of the input channels also have balanced XLR microphone inputs, with gains variable from 10dB to
65dB in accurate 1dB steps, and with individually switchable phantom power. A -20dB pad is also
selectable for each microphone input individually.
Input channels 1 and 2 also have high-impedance front-panel unbalanced instrument jacks, also with
fine and accurate gain control.
Selection of input modes is automatic: line input mode is automatically selected whenever a TRS jack
is inserted into the rear-panel combo connector, otherwise mic input mode is selected. On channels 1
and 2, mic input mode is automatically over-ridden whenever a mono plug is inserted in the
front-panel instrument jack.
© 2014 Prism Media Products Ltd
Operation Manual Revision 1.00
1.22