dCS 904 User Manual | Manual for Software Version 1.5x and 1.36 |
dCS Ltd | June 2000 |
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Pressing the Word Length button repeatedly cycles the word length through the sequence:
24, 23, 22, 21, 20, 19, 18, 17, 16, 24, etc.
The Word Length is briefly shown on the main display, and if a setting other than the maximum is set, the word length LED (above the button) lights.
Noise Shaping is a technique which improves the noise performance of the ADC in the audio band by moving the quantisation noise energy (introduced by reducing the word length) from one part of the spectrum to another. It keeps it out of the middle of the band, where the ear is most sensitive, and places it at the top end or ultrasonic region, where the ear is less sensitive or insensitive. See section “Word Length Reduction” on page 64 for more background.
Pressing the Noise Shaping button repeatedly cycles the unit through 5 noise Shaping characteristics. The characteristic is shown briefly on the main display.
Auto | Unit sets noise shaping automatically, depending |
| on word length: |
| 24 bits – no noise shaping |
| 20 to 23 bits – 1st order noise shaping |
| 16 to 19 bits – 3rd order noise shaping |
Off | No noise shaping |
1st | 1st order noise shaping |
3rd | 3rd order noise shaping |
9th | 9th order noise shaping |
The noise shaping LED (above the button) lights when the setting is other than Auto.
For Menu operation as the Back button, see the section “The Software – the Menu” on page 18.
| Overload Level | Menu | Step |
The Overload Level button is dual function – on its own (blue type on the front panel) it sets the level at which overloads are detected by the unit. With the other menu buttons ( white type on the front panel) it is the menu Step button.
Overload detection is normally set to full scale. The detection level may be reduced in 0.1dB steps down to
For Menu operation as the Step button, see the section “The Software – the Menu” on page 18.
| Overload Indicator | (Overload LED) |
This overload LED lights for a few seconds when the set overload level is exceeded by a signal peak. The detection circuitry monitors both input and digital filtering circuitry for overload conditions. The analogue input sensitivity trims mounted on the rear panel should be set so that the overload indicator does not light on signal peaks.
Manual part no: DOC135904 iss 2B2 | Page 13 | 135904ma2b2.pdf file available from website |
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 |