dCS 974 User Manual

Manual for Software Version 1.0x

dCS Ltd

May 2001

 

 

Step 5 – Reducing the Output Wordlength

If you are using Pure Format Conversion or DSD output modes, the Output Wordlength cannot be changed. Proceed to Other Settings.

If you are performing a sample rate conversion with PCM outputs, the destination equipment can handle 24 bit data and you do not want to reduce the wordlength then leave the Output Wordlength set to the default of 24 bits and set Dither to Off. Proceed to Other Settings.

The dCS 974 generates 24 bit data, regardless of the input word length. If the destination equipment cannot handle 24 bit data, the Output Wordlength MUST be set to match. Noise Shaping and/or Dither MUST be applied to smooth the transitions. If the extra bits are just ignored, the audio outputs may sound grainy and unpleasant low effects will result. For more information, see Word Length Reduction on page 104.

do this: Check the maximum input wordlength specification in the manual for the destination equipment. You must set the dCS 974 to match this.

TOP LEVEL

 

 

 

 

 

 

 

 

 

 

 

 

 

Sample Rate Conversion

 

 

 

 

 

 

 

 

 

 

 

 

 

Audio Input Select

 

 

 

 

 

Sync Source

 

 

 

 

 

Multi-Channel Sync

 

 

 

 

Default

Input Sample Rate

 

 

 

24

 

 

 

Output Sample Rate

 

 

 

23

 

Output Mode

 

 

 

...

 

Filter

 

 

 

8

 

Output Wordlength

 

 

 

 

Default

 

 

 

 

Noise Shaping

 

 

 

Off

 

 

 

Dither

 

 

 

1st Order

 

 

 

 

 

AES Message Edit

 

 

 

...

 

 

 

 

 

 

 

10th Order

Default

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Off

 

 

 

 

 

 

Top Hat

 

 

 

 

 

 

 

Triangular

 

 

 

 

 

 

 

NS Triangular

 

Figure 5 – Setting Wordlength, Noise Shaping and Dither

do this: Scroll down the Sample Rate Conversion menu to Output Wordlength and press the button. Scroll down the list to the required number of output bits and press Set.

do this: Scroll down the Sample Rate Conversion menu to Noise Shaping and press the button. From the list below, choose a suitable setting to match the Output Wordlength:

for 22 or 23 bits, scroll to 2nd order and press Set.

for 20 or 21 bits, scroll to 3rd order and press Set.

for 16, 17, 18 or 19 bits, scroll to 9th order and press Set.

do this: For 16 or 17 bits, scroll down the Sample Rate Conversion menu to Dither and press the button. Scroll down to NS Triangular and press Set.

Manual part no: DOC1241121A1

Page 19

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