Buzz Audio qsp-20studio mic preamplifier - Manual (Page 3)

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1] Installation Precautions
The QSP-20 preamplifier uses Class A amplifiers and these plus the power
supply do generate a fair amount of heat. Normally the QSP can be mounted
into a rack without any special ventilation needs unless there are other units in
the rack that also run hot.
Avoid mounting the QSP in close proximity to other units that have unshielded
power transformers or switching power supplies. Pickup of noise from these
devices may be a problem at high gain settings.
2] The Mains Input
The QSP-20 mains input can be set to run from 110V or 230V. On the rear
panel you will find a circular voltage selector switch to set this. Generally the
QSP mains voltage is set for the country to which it has been sent, but before
powering up the unit, please check the voltage selector.
POWERING UP THE QSP WITH THE WRONG VOLTAGE SETTING MAY CAUSE
BURN OUT OF THE POWER TRANSFORMER!
It is also important to fit the correct mains fuse. Below the IEC inlet you will see
the fuse draw. Using a small flat blade screwdriver, you can flick open the
draw and change the fuse if required. The fuse draw also has a place to hold
a spare fuse (the square tube).
The correct fuses are;
110V = 2 amp slow blow
230V = 1 amp slow blow
These fuses will either be fitted in the fuse draw, and/or supplied in an
accessory bag with the QSP.
3] Audio Connections
On the rear panel of the QSP you will find the XLR Mic input and Line output
connectors. On the front panel you will see four ¼” jack sockets for the high
impedance inputs. These connectors are wired as follows;
Mic In XLR
Pin 1 = Signal ground (shield)
Pin 2 = Signal + (hot)
Pin 3 = Signal – (cold)
Line Out XLR
Pin 1 = Chassis ground (shield)
Pin 2 = Signal + (hot)
Pin 3 = Signal – (cold)