Sleep Mode; Replacing The Fuse - QSC ABX Comparator User Manual

LINE-LEVEL EQUIPMENT COMPARISONS
The ABX Comparator is useful for comparing line-level
equipment such as CD players, preamplifiers, and other
equipment, too. The setup is a little different and varied with
this form of testing. For example, testing signal sources such
as CD players and DAT recorders requires only the ABX's LINE
IN and LINE OUT connectors, but connected with the device
inputs going to the connectors labeled LINE OUT. Use a setup
as shown at right. Be sure to match levels as accurately as possible, and use
identical listening program material.
For line-level devices such as processors, preamps, and other units having inputs and outputs, use a setup as
shown at below right. While Calibrate mode is largely intended for amplifier gain alignment, it can serve as a
tone generator for matching other equipment.

SLEEP MODE

The useful life of the LCD display may be extended by
enabling the sleep mode function. Jumper J103 on the main
PCB enables (J103 shorted) or disables (J103 open) this
function. Sleep mode is factory enabled and will engage 60
minutes after the last key is pressed.
ADJUSTMENTS
The upward or downward viewing angle of the LCD display may be adjusted by trimpot XXX.
The backdrop light intensity of the LCD is adjusted by trimpot VR101.
If a different calibration signal level is needed, adjust trimpot VR201. The factory default is 1 Vrms.

REPLACING THE FUSE

To replace the fuse, first detach the AC power cord from the ABX Comparator. Then use a screwdriver to gently
pry the fuseholder out of the combination fuseholder/IEC connector, as shown. The fuseholder contains two fuses;
replace them with the same type: 2 amp, 250V.
12
Disconnect the AC cord
before opening the cover of the ABX Compara-
tor.
Speakers
Speakers
CH1 out
CH2 out
AMP
CH2—LINE OUT—CH1
B
B CH1 CH1 A
A A
INPUT OUTPUT INPUT
M M
P P
B CH2 CH2 A
P 1=G
P 2=+
P 3=-
B
CD PLAYER, DAT, ETC.
Speakers
Speakers
CH1 out
CH2 out
AMP CH 2 in CH 1 in
CH2—LINE OUT—CH1
B
B CH1 CH1 A
A A
INPUT OUTPUT INPUT
M M
P P
B CH2 CH2 A
P 1=G
P 2=+
P 3=-
B
CH2 CH1
IN
LINE-LEVEL DEVICE
OUT
CH 2 in CH 1 in
CH2—LINE IN—CH1 CH2—LINE OUT—CH1
A
RS232
REPLACE
FUSE WITH
QSC AUDIO SAME TYPE.
PRODUCTS INC.
SEE USER'S
MANUAL FOR
SLAVE
RATING.
MADE IN
U.S.A.
A
CD PLAYER, DAT, ETC.
CD PLAYER, DAT, ETC.
CH2—LINE IN—CH1 CH2—LINE OUT—CH1
A RS232
REPLACE
FUSE WITH
QSC AUDIO SAME TYPE.
PRODUCTS INC. SEE USER'S
MANUAL FOR
SLAVE
RATING.
MADE IN
U.S.A.
A
CH2 CH1
IN
LINE-LEVEL DEVICE
OUT
Computer (optional)
Computer (optional)