Ground Zero GZPA Reference 4 SYM Anleitung Seite 10

Adjusting the BIAS
The BIAS-Setting controls the operation mode of the amplifier.
It is continuously adjustable from MIN > Class AB to MAX > nearly Class A.
The sound is warmer at ~Class A mode and more firm and direct at Class AB mode. Please note that the current
consumption and the heating is higher at ~Class A mode. The power rating will not change.
Bypass-Function
To bypass all filters you can switch them all off separately. If you choose the OFF –position of all the filter switches, all
functions are out of function except the BIAS SETTING and LEVEL.
That allows the maximum pure sound quality.
LED Illumination
All Reference amplifiers have a two-piece LED interior illumination. In case the illumination must be switched off, you
have to remove the jumpers from the main board.
Therefore, you need to remove the Plexiglas bottom plate by using a screwdriver. The two "LED-Switch" jumpers are
located on the left and right part of the main board. Once the jumpers have been removed, the LED illumination is
disabled.
Sound Quality Competition
The Reference amplifiers are using integrated cooling fans to avoid overheating and keep a constant temperature at daily
use. As a matter of the construction, the operating noise of the fans might affect the performance at low volumes during
professional sound quality competition judging. For this reason it is possible to switch off the cooling fans by removing a
jumper on the main board.
Therefore, you need to remove the Plexiglas bottom plate by using a screwdriver.
Once the "FAN-Switch"-jumper have been removed, the cooling fans are disabled.
Please note that we just recommend to switch off the fan if the amplifier is used with low and medium volume.
Permanent high power use could cause an overheating of the amplifier. Even a defect of the unit might be possible.
The warranty expires after removing the fan-jumper.
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