GP2 GP2-QPA-01 User manual

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
BL-99 EDITION
GP2-QPA-01
PREAMP
FOUR CHANNEL
Version 4.5 Decem er 2012- English

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
CONTENTS
1. IMPORTANT SAFETY INSTRUCTIONS
2. INTRODUCTION
3. INSTALLATION
a. AC MAINS SUPPLY
b. AUDIO OPERATION LEVEL
c. MICROPHONE INPUTS
d. INSTRUMENT INPUTS
e. BALANCED OUTPUTS
f. VENTILATION
g. REAR PANEL
h. MOUNTING RACK
4. OPERATION
a. FRONT PANEL
b. MICROPHONE INPUTS
c. 20DB PAD SWITCH
d. PHANTOM POWER
e. INPUT GAIN
f. DRIVE AND PEAK LAMPS
g. PHASE REVERSE
5. BLOCK DIAGRAM
6. GETTING STARTED
7. SPECIFICATIONS
8. WARRANTY

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
1. IMPORTANT SAFETY INSTRUCTIONS
1. Read all these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with dry cloth.
. Do not block ventilation openings, install in accordance with manufacturer‘s instructions.
8. Do not install near any heat sources such as radiators heat registers, stoves, or other apparatus
(including amplifiers) that produce heat.
9. Do not defeat the safety purpose of the polarized grounding type plug. A polarized plug has two
blades with one wider than the other. A grounding type plug has two blades and a third grounding
prong. The wide blade or third prong is provided for your safety. If the provided plug does not fit
into your outlet, consult an electrician for replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched particularly at the plugs, convenience
receptacles, and at the point where they exit from the apparatus.
11. Only use attachments/accessories specified by the Manufacturer.
12. Unplug the apparatus during lightning storms or when unused for long periods of time.
13. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has
been damaged in any way, such as power supply plug has been damaged. Liquid has been spilled
or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture,
does not operate normally, or has been dropped.
Warning: To Reduce the Risk of Fire or Electric Shock, Do Not Expose
This Apparatus to Rain or Moisture

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
2. INTRODUCTION
Congratulations on purchasing the GP2-QPA-01 4-channel Preamp by
Gp2 Inc.
The GP2 Pre-amp is designed with the knowledgea le user in mind.
It picks up where the standard pre-amp leaves off.
Basically, hiss free and harmonic distortion almost too low to measure.
The sound is very ro ust and holds up under wild equalization.
No mid range fog or harshness, as with other pre-amps.
The entire mid-range is well defined and allows for a whole new
experience in the studio.
The top end is smooth with ‘air’ ut no roughness
Extends easily eyond hearing range. (No umping at around 8k or lack
of air)
Headroom is exceptional
Almost impossi le to get distortion.
For the user who doesn’t want the classic English ‘processed’ sound or
the American ‘harshness’
.

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
3. INSTALLATION
AC MAINS SUPPLY
The unit is fitted with an internationally approved 3 pin IEC connector. Earth connection must e
used.
Before connecting the unit to the supply check that the unit is set for the correct mains
voltage. The unit is externally set for 115V 60Hz or 230V 50 Hz operations , y removing the
fuse drawer and removing the voltage selector jumper, reinstall the jumper with the desired
115V or 230V showing through the window in the fuse drawer ,once it is installed. All mains
wiring should e performed with all power switched off.
The mains fuse required is 20mm anti-surge, 1A rated at 250V. If it is ever necessary to replace
the fuse only the same type and rating must e used. The power consumption of the equipment is
20VA.
The appliance coupler is used as main disconnect device.
Warning: Attempting to operate on the wrong voltage setting or with an incorrect fuse will
invalidate the warranty.

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
Instrument and Mi rophone Instrument Combo Ja k Inputs
Each channel has a Stereo 0.025” jack connector on the front panel suita le for low level
instruments such as guitars, and key oards. The impedance of this input is 1M ohm making it
suita le for a wide range of instruments.
Each channel has a female, 3 pin XLR connector, suita le for alanced low impedance (150 to
600 ohm) microphones. The BL99 also has an additional XLR connector at the rear of the chassis
wired in parallel for ease of connection. (Only one XLR input connection can e used per
channel at once).
The mating connector should be wired as follows:
Pin 1 = Ground Pin
2 = Signal Phase (hot) Pin
3 = Signal Non-Phase (cold)

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
Balan ed Outputs
The output is via a alanced 3 pin male XLR connector. The mating connector should e wired
same as a ove.
Ventilation
The unit generates a small amount of heat internally. This heat should e allowed to dissipate y
convection through the grills in the side panels. This must not e o structed. Do not locate near
any external heating sources. If used free standing ensure that the equipment is protected against
rain and other liquid. The BL99 is designed for free standing or rack mounting.
Ra k mounting

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
4. OPERATION
Front Panel
The front panel controls are identified in Section 6. Each of the four sections is identical.
When connecting instruments or microphones, always have the output gain set to the min
position i.e. Fully anticlockwise to avoid sudden “thumps” that could damage speakers.
Mi rophone Inputs
The 4 XLR microphone inputs are at the rear of the BL99. Virtually any low impedance
professional microphone can e used. Condenser microphones will require the 48V phantom power
to e engaged for correct operation, ut efore using Dynamic and Ri on microphones ensure
that the phantom is off.
There are also 4 microphone inputs are at the front of the BL99. Connecting a Microphone to
this com o input will require pushing the Line/Mic. Switch out to ena le the microphone input
on that particular channel. The Line/Mic switch will not e illuminated to indicate Mic function is
selected.
20dB Pad swit h
Occasionally when using sensitive condenser microphones the source signal may e too large for
the input preamp. In this situation to avoid any overloading or distortion of the microphone
preamp stage the 20dB pad can e used to reduce the input gain to a more managea le level.
The 20dB pad only applies to the microphone input.
Ena ling the pad will require pushing the PAD Switch in to ena le the 20 d pad on that
particular channel. The PAD Switch will illuminate to indicate PAD is selected

GP2 INC, BURLINGTON, ONTARIO CANADA
Email: [email protected] We : www.gp2inc.com
Phantom Power
Phantom power may e applied to the microphone socket y depressing the + 48V switch. Do
not attempt to connect any microphone that does not require phantom power, or any other
equipment to an input socket that has phantom power switched on as damage may result.
Selecting Phantom Power to this input will require pushing the +48V Switch in to ena le
Phantom power on that particular channel. +48V Switch will illuminate to indicate Phantom Power is
selected.
CAUTION: Never switch phantom power on or off or plug /unplug A microphone with
phantom power applied unless the output level Control is turned down. Failure to do so may
result in a thump in your monitor or loudspeakers or PA system.
Input Gain
The gain of the preamp stage is varia le from +11 to 26. This is a very wide range to cater for
all types of microphone and recording situations, ut care must e taken not to apply large
sudden changes in gain which may result in unexpectedly large output signals. It is quite normal
to have to apply larger amounts of gain for less sensitive microphones, such as dynamic types
and similarly apply much less input gain for high output condenser microphones.
Drive and Peak Lamps
The white lamp provides a visual indication of the signal level. The drive lamp will gradually
illuminate as the input level or gain is increased over the range.