dCS 974 User Manual

Manual for Software Version 1.0x

dCS Ltd

May 2001

 

 

Test Submenu

Generator Overview

The dCS 974 includes a high quality digital signal test generator, with both sine or square wave outputs, and displays its settings on the Test Mode screen. When invoked, the generator adjusts its output format to that currently operating, and substitutes the generated output for any input signal. The generator operates at the output sample rate. In PCM modes, it is a PCM generator (in the appropriate mode), in DSD mode it is a DSD generator10.

If the unit is sync’d to an input when it goes into Generator mode, then the generator stays sync’d to that input (so the output will be synchronous and locked).

IMPORTANT! If the unit is not sync’d to anything, set the Sync Source to Internal. Otherwise, the equipment you are trying to drive may be unable to lock to the Generator outputs because the sample rate has drifted out of lock range.

The Sample Rate Conversion menu is still active in Generator mode, so it can enter Generator mode with no external syncing, the Generator can be set up, a sync input can be selected from the Sample Rate Conversion menu and the unit will sync to that. Noise shaping and other features available in the Sample Rate Conversion menu can still be used, as long as these operate at the

output rate. Filters, for example, do not affect the generator output, because they operate on the input signal. Dither operates at the output rate, so it can be used.

Controlling the Generator

To view the Test Mode screen, go to the top level menu, select Test and press Status to get the display below (assumes 96kS/s sync source):

If the unit is set to Internal sync, the screen will show Int beside the input sample rate as follows:

10in DSD mode it is a PCM generator, operating at a sample rate of 705.6 kS/s, and then converted to DSD. This means that the maximum frequency that it can produce is 352.8 kHz.

Manual part no: DOC1241121A1

Page 53

Document No: OS-MA-A0124-112.1A1

Contact dCS on + 44 1799 531 999

email to: more@dcsltd.co.uk

(inside the UK replace + 44 with 0)

web site: www.dcsltd.co.uk