10
The 740C has a custom-made display on the front of the unit showing
the current status and allowing access to the 740C System
Configuration menus. The 740C features some advanced settings that
allow its use to be customised to user preference.
Menu structure
Press the Menu button to scroll through the menus, then use the Select
button to scroll through the options/sub menus of that menu. Press the
Menu button again to move to the next menu, or after a few seconds the
display will return to the default main menu.
Digital outputs
The digital outputs can be set to two options:
1. Output the raw data from the CD (or digital input) with no processing.
2. Upsampled data processing by the DSP to greater resolution.
Press Select to switch between DSP Upsample or Pass Through.
For DSP upsampling the sample frequency, word width and dither are
set by the next three available menus.
Digital out sample frequency
The digital output sample frequency (note this is different to the main
audio output sample frequency which is fixed at 384kHz for best sound
quality) can be set to 48, 96 or 192kHz (the maximum frequency
supported by SPDIF/Toslink):
Press Select to switch between the frequency options.
Digital out word width
The digital output word width can be set to 16, 20 or 24 bit (note this is
different to the main audio output word width which is fixed at 24 bit for
best sound quality):
Press Select to switch between the word width options.
CD player setup
Default screen
Digital output
Digital out sample frequency
Digital out word width
Digital out dither on/off
Input 1 naming
Input 2 naming
Software version
(Note: If Pass Through is selected here,
the next three menus are bypassed.)
Digital out dither
Dithering is a process where pseudo random noise is added to a signal
to remove quantisation effects that cause harmonic distortion and
replace them with a slightly increased noise floor. The process can
improve the perceived quality of digitised audio signals as a small
decrease in signal to noise ration (especially where the noise is random)
is much preferably to harmonic distortion to the human ear.
The 740C is able to add what is called Triangular Probability Density
Function dither to the upsampled Digital Output signals. Normally, dither
will have already been added to any CD or source material during its
mastering process so the default for this option is off. However if a
source with no dither is used (perhaps an off board A/D converter etc)
TPDF dither can be turned on:
Press Select to switch between Dither On and Dither Off.
Changing input names / source naming
The 2 digital inputs can be renamed to reflect the actual source units
you have connected to the 740C. Press the Menu button to scroll to
either the Digital Input 1 or Digital Input 2 naming menus:
Press Select to start changing the name of the input. The first editable
character will begin to flash. Use the Stop button to go up through the
alphabet/available characters, and Play/Pause to scroll down. To accept
your character selection, move to the next character by using the
Skip/Scan buttons:
To save and exit, press Select. To cancel and exit, press Menu.
Software version
Displays the currently loaded software version:
