User's Guide HDSP AES-32 - RME

19.2 Settings dialog - DDS
Usually soundcards and audio interfaces generate their internal clock (master mode) by a
quartz. Therefore the internal clock can be set to 44.1 kHz or 48 kHz, but not to a value in between.
SteadyClock, RME's sensational Low Jitter Clock System, is based on a Direct Digital
Synthesizer (DDS). This superior circuitry can generate nearly any frequency with highest precision.
DDS has been implemented into the HDSP AES-32 with regard to the needs of professional
video applications, as well as to maximum flexibility. The dialog DDS includes both a list of typical
video frequencies (so called pull up/pull down at 0.1% and 4%) and two faders, which allow
to freely change the basic sample rate in steps of 1 Hz (!).
The DDS dialog requires the HDSP AES-32 to be in clock mode Master! The frequency
setting will only be applied to this one specific card!
Changing the sample rate in bigger steps during record/playback often results in a loss of
audio, or brings up warning messages of the audio software. Therefore the desired sample
rate should be set at least coarsely before starting the software.
DDS
Activates all settings of this
dialog.
Value
Shows the sample rate as
adjusted in this dialog. The
sample rate is defined by the
basic setting (Frequency), the
multiplier, and the position of
the activated fader.
Frequency
Sets a fixed basic sample
rate, which can be modified
by multiplier and fader.
Freq. Multiplier
Changes the basic sample
rate into Single, Double oder
Quad Speed mode.
Coarse
Fader for coarse modification of the basic sample rate. Click Active to activate it. Minimum step
size 1 Hz.
Fine
Fader for fine modification of the basic sample rate. Click Active to activate it. Minimum step
size 1 Hz.
Notes on the faders
A mouse click within the fader area, above or below the fader know, will move the fader with the
smallest step size up or down. Holding the Ctrl key while clicking will cause the fader to jump to
its center (0).
User's Guide HDSP AES-32 © RME 31