AURORA AUDIO INTERNATIONAL
1520 NORTH CAHUENGA BOULEVARD
HOLLYWOOD, CA90028
EMAIL:
Telephone: 323 462 6136
Web Site: http://www.auroraaudio.net
Fax :
323 462 6137
GTQ2 Mark 3 Instruction Sheet
Introduction:
Well done for purchasing a hand-built, all discrete class A circuitry GTQ2 stereo microphone pre-
amplifier! It is designed to give you years of superb sounds and service. Improvements on the Mark 3
include an extra mid frequency (1600Hz) to provide choices of 400, 1600 and 3200Hz, and impedance
switching (300Ω and 1200Ω) on the XLR inputs.
Unpacking Instructions:
Carefully remove the unit from the custom foam packing and fit the fuse into the fuse-holder. The
GTQ2 uses a power supply that automatically senses the local voltage so no setting is required. For best
noise performance always use a grounded 3 core / 3 pin a.c. cord. If you connect the GTQ2 to an
unbalanced destination, either use the ¼” rear jack or wire to the XLR pins 2 and 3 only. Leave pin 1
high. This will help prevent ground loops.
The rear jack sockets are mono and should be connected with a mono jack. If a balanced TRS jack is
plugged in, there will be a 6dB loss as there would be no signal on the ring contact.
Operating Guide:
The GTQ2 front panel is shown above. In order for the equalizer to work, the “EQL” button must be
selected and the high pass filter, which rolls off frequencies below 80Hz, is selected when both “EQL”
and “HPF” buttons are pressed.
The “48v” button applies 48 volts dc to the mic input XLR in order to power condenser microphones.
Despite urban legends to the contrary, 48v does not harm ribbon or dynamic microphones but damaged
microphone cables might... so always check that your cables are in good condition!
The “PH” button inverts the phase 180 degrees and should be used to correct any phase issues created
by the mic position or any outboard equipment. Press the button and, if the stereo image sounds weird
with it pressed, you know the phasing is OK and to leave the switch off!