40
The "An.input" setup is used to adjust the analog input level before the Analog to Digital conversion required to decode
a two channel signal into a surround effect. No change to “An. Input” is required if the input is only to be used for a
digital source. (
NOTE:
No A to D conversion is done if a two channel signal is to stay two channel when selected in
“Analog Bypass”). The analog input level is adjusted to the highest possible level without clipping. The adjustment is
done using the level LEDs beside the display. The three LEDs per channel are labeled as REF, OVER and CLIP. The
REF LED will light at -20 dB of full scale signal, the OVER at -19 dB, and the CLIP at 0 dB. This is according to the
Dolby/THX procedure to ensure there is enough signal to noise ratio but not so much signal that clipping is occurring
at the input.
The best way to adjust the “An(alog). Input” level is to feed a -20 dB analog test signal from the particular source
player for the source under adjustment, then adjust the input level until the REF LEDs are turned on, but the OVER
LED is still off. Merely increase the level until the OVER LEDs just light, then back off 1 dB at a time. When the OVER
LED is no longer lit you have set the correct input level for analog. Another possible way to adjust the level is to feed a
full-scale (0 dB) test signal from the source player, and adjust the input level so that the CLIP LED just turns off.
If test signals aren't available, the level may be adjusted so that the REF and OVER LEDs are mostly on with normal
music material, but the CLIP LED never lights. If you don’t have access to a CD test disc simply use a CD you believe
has little dynamic range and adjust the “An. Input” level with it instead. With the CD playing adjust the “An. Input” up
until the CLIP LED begins to flicker, than adjust it back down 1 dB at a time until the OVER LED is always lit, but the
CLIP does not flicker at all. We advise that if you are using this ‘unscientific’ (but still effective) method that you check
this level setting by playing a couple more CDs to ensure the CLIP indicator does not light.
There are other sources that are two channel but would benefit from having their surround content decoded. Network
television has several shows with surround effects, most sports are broadcast in surround and virtually all movies
made these days are encoded in some format of surround. To appreciate this content you need to run the output from
your television to the
SSP-25
, and/or you need to send the analog stereo signal from your DSS receiver to the
SSP-25
.
(Digital audio output from satellite receivers is only just now beginning to reach the marketplace). These sources don’t
really have any test signals you can use, and you have to use the actual analog device that will be feeding the
SSP-25
to set it up properly. Use a similar method to that outlined in the paragraph above: play a music channel from the DSS
feed, play a TV feed that has relatively consistent level.
Adjusting the input level will not affect overall volume. As you attenuate or increase the input signal, the output signal is
at the same time amplified or reduced to compensate for the level change. So you won't hear a level change.
To engage the “An. Input” level LED display, you must have the source selected that you are adjusting, and also the
mode must be "STEREO.” In normal operation (menus are off, or you are somewhere else than in that particular
analog input setup menu) the level LEDs are not used at all, not even the clipping LED. You can still adjust the level,
but you won’t see or hear what the change is doing
.
5.4.7
ANALOG INPUT LEVEL SETUP
Select the “An(alog). input:” level control by pressing the “
MENU
” key, to reach the “Main menu – Mode setup” display.
Next, press the “
>
” key one time to reach the “Main menu – Source setup” display. Press “
ENTER
” to select “Source
setup.” “Source setup –
AV1
setup” will be displayed. Still using the “
>
” key cycle through the inputs until you reach the
input which will have an analog input on it. Press the “
ENTER
” key to select the input. Press the “
>
” key three times to
cycle through to the “An. Input” display.
Press the direct access key that corresponds to the input you have selected. If your system is set up and playing you
should now hear it through your speakers. Press the direct access key again and notice in the brief display whether
you are in Analog Stereo mode. If you are not in Stereo mode use the “
< MODE >
” keys to change the mode until you
reach “Analog Stereo.” No other mode of play will enable you to set up the correct levels for “An. Input”
While playing a Test CD, or, if a Test CD is not available, a music CD, use the “
/\
” and the “
\/
” keys to increase or
decrease the level while watching the response of the LEDs to the left and right of the display window. As mentioned
above, the setting for the test CD is different from that for a music CD.
