QSC ABX Comparator User Manual
  1. Manuals
  2. Brands
  3. QSC Manuals
  4. Test Equipment
  5. ABX Comparator
  6. User manual
QSC ABX Comparator User Manual

QSC ABX Comparator User Manual

Double-blind listening test switcher
Hide thumbs
Table of Contents

Advertisement

Quick Links

ABX Comparator
U S E R M A N U A L
ABX Comparator
O N
Double-blind listening test switcher
U N I T A
X
U N I T B
E N T E R
A B X 1
R C
P O W E R
D A T A
C A L I B R A T E
T R I A L
R E V I E W
S C R O L L
A B X C O M P A R A T O R
1

Advertisement

Table of Contents
loading

Summary of Contents for QSC ABX Comparator

  • Page 1 ABX Comparator U S E R M A N U A L ABX Comparator Double-blind listening test switcher U N I T A U N I T B E N T E R A B X 1 P O W E R...
  • Page 3 “B,” and the two have been set up so that they put out precisely the same output levels. “X” designates the unknown factor—is it A or is it B? Thus, every time the ABX Comparator randomly selects “X,” which could be either A or B, the person judging the amps will compare it to amp A and amp B (all the while paying attention to detect audible differences between the two).
  • Page 4 The ABX Comparator not only automatically and randomly selects the amplifiers, but also tracks the choices the listening judge makes in each trial. After a sequence of trials, the ABX will report how many trials and how many correct answers the judge made.

  • Page 5: The Remote Control

    The ABX can also operate without the remote control. III. SETTING UP AN AMPLIFIER TEST The diagram on the following page shows how to wire the ABX Comparator and the other components needed for a listening test of two 2-channel amplifiers.
  • Page 6 Speakers Speakers CD PLAYER CH2—LINE OUT—CH1 CH2—LINE IN—CH1 CH2—LINE OUT—CH1 RS232 REPLACE FUSE WITH QSC AUDIO SAME TYPE. INPUT OUTPUT INPUT PRODUCTS INC. SEE USER'S MANUAL FOR SLAVE RATING. P 1=G MADE IN P 2=+ P 3=- U.S.A. CH1 out...

  • Page 7: Operation

    CONNECTING TO “COMBO” CONNECTORS The six Neutrik “Combo™” connectors accept either 3-pin male XLR or ¼-inch (6.3 mm) male TRS connectors. Pin 2 and tip are +; pin 3 and ring are -; pin 1 and sleeve are shield. CONNECTING TO BINDING POST TERMINALS When setting up the ABX for amp testing, it is vitally important for safety reasons that you connect the cabling between the amplifier outputs, the ABX, and the speakers correctly.
  • Page 8 In the calibration mode, the ABX Comparator will produce a 1 volt RMS, 1 kHz tone and send it to both channels of both amplifiers in place of the audio signal input. At the same time, the digital voltmeter display will show the output level from each amplifier channel, starting with Channel 1 of Amplifier A.
  • Page 9 B, and Amp X as much as you’d like before you enter your choice. Listen carefully. Does X sound like A, or like B? To register your choice with the ABX Comparator, press the button—either A or B—of the amplifier that you believe is X, the unknown. Then press ENTER.
  • Page 10 but over an increasing number of trials will almost certainly tend to approach 50%. For example, the chances of a coin coming up heads on two successive tosses is 1 in 4; on three successive tosses, 1 in 8; on four successive tosses, 1 in 16.
  • Page 11 AMP INPUT A Both channel outputs of amplifier A return to the ABX comparator at the two pairs of AMP A input binding posts. One pair is for Channel 1, the other for Channel 2, and they are fully balanced and isolated.

  • Page 12: Sleep Mode

    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;...

  • Page 13: Specifications

    SPECIFICATIONS SPECIFICATIONS Functionality: Calibration Mode Amplifier A selectable; Channels 1 and 2 individually selectable Amplifier B selectable; Channels 1 and 2 individually selectable Calibrating Signal selected automatically Trim control: 100 mV per step. Up to 2 Vrms max. Calibrating Signal Display Range: 00.0 to 99.9 Vrms ±0.1 Vrms tolerance Trial Mode Audio signal “X”...

  • Page 14: Power Requirements

    Dimensions: 19" (48.26 cm) W × 1.75" (4.44 cm) H × 12" (30.48 cm) D © Copyright 1998 QSC Audio Products, Inc. All rights reserved. “QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office. QSC Audio Products, Inc.,...

Table of Contents