Sound Performance Lab 2272 Stereo Amplifier User Manual


 
18
GainStation 1
POWER-LED
This LED indicates that the GainStation 1 is connected to the
proper AC current and switched on. If the tube stage is active
when the unit is switched on, it can take several seconds before
a signal can be heard—this time is necessary for the tube to
reach operating temperature.
LED Level Display
The level display shows the peak level before output level
control. A special circuit allows the LED‘s to vary in brightness
to display in-between values. The -30 LED illuminates weakly at
-30 dB and reaches full brightness at 0 dB. The 0 dB LED illumi-
nates weakly at 0 dB and reaches full brightness at +9 dB and so
on.
The CLIP LED operates post-CLEAN GAIN stage and displays
clipping at this point in the signal path. It will not react to tube
saturation in the tube stage, since this can be a desired effect.
AD OVL
This LED displays clipping in the internal AD converter and
illuminates at approximately 0.5 dB before 0 dBfs. This LED
should never illuminate when using the internal or an external
converter—if it does, the output level must be reduced accord-
ingly.
If the converter is not being used or not installed, the AD IN 1
MUTE switch should be activated, so that the output signal is no
longer routed to the converter and the AD OVL circuit. Signals
connected to AD IN 2 are also displayed by the AD OVL LED and
cannot be switched off (they can only be disconnected).
Control elements
Powe
r
Clip
-30 0 dB 9
18
A
D OVL