GEMINI P-700 Service Manual
SERVICE MANUAL
P-700
PR PR
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Features, Operating Instructions…………… .. Page 2
Specifications……………………………………. Page 4
Troubleshooting…………………………………. Page 5
Diagrams………………………………………….. Page 6
Parts List………………………………………….. Page 8
Schematics……………………………………….. Page 11
OFESSIONOFESSION
OFESSION
OFESSIONOFESSION
AL AL
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AMPLIFIERAMPLIFIER
AMPLIFIER
AMPLIFIERAMPLIFIER
introduction
Congratulations
P-700 Power Amplifier! You’ve made a really
wise choice because this state-of-the-art amplifier
has the latest features and technolo gy a nd is
backed by a three-year warranty! We know
you’re anxious to hook everything up and start
mixing beats and cranking up the volume on
those hot dance tracks, but we suggest reading
this instruction manual first as there are some
really cool features on this amplifier that we
wouldn’t want you to miss!
on purchasing this Gemini
features
State-of-the-art circuitry for the finest sound
•
quality and reliability
High output power to drive professional
•
speakers without clipping but also tame
enough for home use
Protection Circuitry (short circuit, thermal cut-
•
off, sub/ultrasonic freq uency fil ter s, tur n -on
delay, main fuse, secondary fuses)
Unbalanced stereo inputs with RCA type jacks
•
Ground lift switch for achieving the quietest
•
possible operation
Large blue-light illuminated VU meters to
•
give you greater control… and they look really
cool
Ultra-modern design with professional 19”
•
rack mounts.
Front-to-rear airflow with variable speed fan
•
control for maximum cooling and quietest
possible operation.
Variable speed fan for quieter operation with
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softer music and home use.
Compact 2U well balanced enclosure
•
Steel reinforced chassis construction for
•
durability and longevity.
Common sense
Some of these things go without saying, but we’re
going to say them anyway!
Read all operating instructions before
•
using this equipment.
To reduce the risk of electrical shock,
•
do not open the unit. There are NO USER
REPLACEABLE PARTS INSIDE. For all repairs
or service questions please contact the Gemini
Service Department or your authorized dealer to
speak to a qualified Gemini Sound Products
technician.
Be sure to allow adequate front and
•
rear ventilation to avoid possible heat damage to
your equipment.
Be sure that AC power is OFF and all
•
level controls are set to MINIMUM before making
connections. This will eliminate any chance of
unexpected loud buzzes, pops or clicks that could
damage your speakers.
DO NOT EXPOSE THIS UNIT TO RAIN
•
OR MOISTURE.
Operators of electronic equipment should
•
never be in contact with water
Keep your power amplifier grounded for
•
maximum safety by always using a 3-prong plug.
If you are using an extension cord, always use a
3-prong cord as well.
DO NOT USE ANY SPRAY CLEANER OR
•
LUBRICANT ON ANY CONTROLS OR
SWITCHES.
hook it up
Okay, let’s get connected!
REAR PANEL
Input Section:
Input Jacks
stereo RCA type jacks, with the tip of the jack
being positive (+) and the sleeve part being
negative (-)/ground.
Connect the output of your mixer here.
Output Section:
Disconnect unit from the AC power source before
making any connections. Pay close attention to
polarity when connecting your speakers.
(Connect the positive wire to the red terminal and
the negative wire to the black terminal).
Connecting your speakers using the wrong
polarity will not damage your speakers, but
will impact the quality of the sound (lack of bass
and incorrect stereo image).
Speaker Outputs
connectors are terminals that will accept a
standard banana plug, or bare wire.
Make sure that all the connections are clean
when using bare wire connections. If any strands
of wire from one connector touch the connector
next to it, the sound will distort, and your amplifier
will overheat.
✰
NOTE:
be lower than 4Ω (Ohm) per channel
AC Power Section:
Fuse
•
AC Inlet
•
the unit.
AC line voltage switch
•
amplifier for either 110-120 V or 220-240 V AC
lines.
Ground Lift Switch
•
from the chassis. (See the Ground Lift Switch
Instructions for more detail.)
(4):
Your amplifier has unbal ance d
(1)
the speaker output
(3):
Total speaker impedance must not
replace with proper type and rating.
is used to attach the power cord to
(6)
allows reconfiguring
(5)
is used to lift the ground
(2)
FRONT PANEL
Power Switch
•
Power LED
•
power is on. If the power LED does not light, refer
to the trouble-shooting guide.
Level Controls
•
each channel.
Large blue-light illuminated VU meters
•
display the output level of each channel.
Stereo Operation
The unit has two channels for stereo operation.
Each channel provides a separate signal at the
speaker outputs. The following instructions are
for use with 4Ω or 8Ω speakers of matched
power ratings.
1. With the power OFF, connect your input
cables to the Channel A and Channel B inputs
using the RCA INPUT JACKS
2. Connect your speakers to the Channel A and
Channel B SPEAKER OUTPUTS
speaker load must be at least 4Ω per channel.)
3. With the LEVEL CONTROLS
channels set to zero (fully counterclockwise), turn
the POWER SWITCH
playing some music and/or talking into your
microphone, and set the level of your input as
high as you think you’ll need it. This way it will be
as high above the amplifier’s noise floor as
possible so you’ll get the best possible sound
with the least amount of noise.
4. Now adjust your LEVEL CONTROLS for each
channel to your desired listening level. You also
have the choice of keeping the volume of both
speakers equal, or for certain situations you can
adjust the volume so one side will be louder than
the other.
turns the unit on and off.
(10):
the power LED lights when the
(9):
control the input levels for
(7):
operation
(1)
(3).
of both
(7)
ON. Okay, now try
(10)
(8)
(The total
Using the Ground Lift Switch
Depending on how your sound system is hooked
up, sometimes applying the ground will create a
quieter signal path. Sometimes lifting the ground
can eliminate ground loops and that annoying
hum to give you quieter and cleaner overall
sound.
1. With the power amp ON, listen to the system in
idle mode (no music or signal) with the ground
ON. The GROUND LIFT SWITCH
will be in
(3)
the left position.
2. Turn the power OFF before moving the
GROUND LIFT SWITCH
Now lift the ground
(3).
by moving the GROUND LIFT SWITCH to the
right. Turn the power back ON and listen to
determine which position makes the overall
sound quieter with the least amount of noise and
hum.
✰
CAUTION
: DO NOT DISCONNECT THE AC
GROUND ON THE POWER AMPLIFIER IN ANY
WAY. THIS CAN BE VERY HAZARDOUS!!
Should you experience any difficulties or
problems, you can first refer to the
TROUBLESHOOTING GUIDE located on the
following page. If you still cannot fix the problem,
please call
Service.
1 (732) 738-9003 for Gemini Customer
That’s it !
Okay, that just about covers everything! NOW
you’re ready to grab a couple of great CD’s or
records, crank it up and get the party started!
specifications
Output Power EIA: 1kHz @ 1% THD, Wrms
Both Channels Driven 8Ω: ………….………………………………70
Both Channels Driven 4Ω: ………….………………………………90
Dynamic Headroom, dB:
At 8Ω:…………………………………………………………………1.5
At 4Ω:…………………………………………………………………3.3
Frequency Response:………………………………..30 Hz – 50 kHz
Total Harmonic Distortion: …………………………..less than 0.1%,
typical 0.05% at 1 kHz
Signal to Noise ratio:………………90 dB below rated power @ 8Ω
Damping factor: ……………………………..greater than 150 @ 8Ω
Slew rate:……………………………………………………….10 V/µS
Voltage gain, dB:……………………………………………………..27
Input Sensitivity (for rated power at 8Ω):…………….……….1Vrms
Input Impedance (unbalanced):...………………………………10 kΩ
Power consumption (at rated power at 4Ω,
both channels driven): ………………………………..……..…400 W
AC Power Requirements: ……………..….110-120 V or 220-240 V
60 / 50 Hz.
Indicators:……………………………………1VU-meter per Channel
1 Power LED
Cooling: ……………Variable Speed Fan, Front-to-Rear Forced Air
Protection: ……………………………Short Circuit, Thermal Cut-off,
Sub/Ultrasonic Frequency Filters,
Turn-on Delay, Main Fuse,
Secondary DC Fuses
Connectors:
Inputs:……………………………………………………….RCA Jacks
Speaker Outputs:……………………………………….Binding Posts
Dimensions:……………………………………..19”W x 11”D x 3.5”H
(483 x 280 x 89 mm)
Weight :……………………………………………..12.9 lbs (5.85 kg)
✰
Specifications and design are subject to
change without notice for purpose of
improvement
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