Gemini X1 Service Manual page 3

INTRODUCTION
Congratulations on purchasing a Gemini Power Amplifier. This state
of the art power arnplifier includes the latest features and is backed
by a three year limited warranty. Prior to use, we suggest that you
carefully read all the instructions.
FEATURES
• State of the art bi-polar output stage technology for the finest sound
quality and reliability
• High output power to drive professional loudspeakers without clipping
• Comprehensive protection circuity (Short Circuit, DC, Thermal Cut-off,
Sub/Ultrasonic Frequency Filters, Turn-on Delay, Main Fuse,
Secondary DC Fuses)
• Three modes of operation - stereo, parallel mono and mono bridge
• Active 1/4" Jack balanced/unbalanced inputs
• Ground lift switch for flexibility in installations
• Signal LEDs and Clip LEDs for better control on X1, X2, X3 amplifers
• Large VU-meters and Clip LEDs for better control on X4 amplifier
• Efficient dual aluminum extrusion heatsink design with directly
mounted output transistors for no-fault operation
• Efficient air guide with front-to-rear airflow for thermal stability and
reliability
• Compact 2U well balanced enclosure (3U for X4 model)
• Steel reinforced chassis construction for durability and longevity
WORDS TO THE WISE
1. Read all operating instructions before using this equipment.
2. To reduce the risk of electrical shock, do not open the unit. There
are NO USER REPLACEABLE PARTS INSIDE. Please contact the
Gemini Service Department or your authorized dealer to speak to a
qualified Gemini Sound Products technician.
3. Be sure to allow adequate front and rear ventilation to avoid
possible heat damage to your equipment.
4. 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 audio transients that could damage your
speaker systems.
In the USA: If you experience problems with this unit,
please call 1 (732) 738-9003 for Gemini Customer Service.
Do not attempt to return this equipment to your dealer.
5. Be sure that AC power is OFF when changing modes of operation
and when changing the position of the ground lift switch.
6. DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. Operators of
electronic equipment should in no way be in contact with water.
7. When connecting to AC power line be sure you haven't lost the
ground connection by using an adapter or extension cord without a
3 prong plug.
8. DO NOT USE ANY SPRAY CLEANER OR LUBRICANT ON ANY
CONTROLS OR SWITCHES.
CONNECTION, CONTROLS
AND INDICATORS
Rear panel
Input Section:
1/4" Phone lnput Jacks (1, 2): accept a balanced as well as an
unbalanced line level signal. The unbalanced line uses a
standard tip-sleeve connection. The tip is positive and the sleeve
is negative or ground. The balanced line uses a tip-ring-sleeve
connection. Tip is hot or positive (+), ring is cold or negative (-),
and sleeve is shield or ground.
Operation Mode Switch (3): switch is used to set the unit for Stereo
mode, Parallel Mono mode or Mono Bridge mode.
AC Power Section:
Fuse (8): replace fuse with those of proper type and rating.
Ground Lift Switch (4) is used to lift the ground from the chassis, see
the Ground Lift Switch Instructions for more detail.
AC Inlet (16) is used to attach the power cord to the unit.
AC line voltage switch (17) allows reconfiguring amplifier for either
110-120V or 220-240V AC lines.
Output Section:
Disconnect unit from the AC power source before making any
connections. Pay close attention to polarity (shown on the back of the
unit) when connecting your speakers. Connecting your speaker
systems 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 (5,6,7): the speaker output connectors are 3-way
binding posts that will accept a standard banana plug, spade lugs,
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 adjacent connector, the sound will distort, and
your amplifier will overheat and go into protection mode.
NOTE: Total speaker impedance must not be lower than
4 Ohm per channel for Stereo and Parallel Mono modes,
and 8 Ohm for Mono Bridge mode.
Front Panel
Power Switch (9) : turns the unit on and off.
Power LED (10): the power LED lights when the power is on. If the
power LED does not light, refer to the troubleshooting guide.
Signal LED (13): the signal LEDs for each channel show when a signal
is present. In Mono Bridge mode, both the channel 1 LED and the
channel 2 LED will light in unison.
Clip LED (14): the amplifier has true clip LEDs to help you properly
control the amplifier's output and achieve undistorted sound. The
clip LEDs for each channel light when your signal level is so strong
that the distortion occurs. The clip LED should not remain
constantly on or flash repeatedly during operation. For clean sound
reproduction, the clip LED should only light occasionally for an
instant. If the LED remains on or flashes repeatedly, you will hear
distorted sound that can be damaging to your speaker systems. If
this occurs, reduce the signal level by lowering the input level
control for the channel that is clipping or reduce the level at the
source. If the clip LED lights when no signal is present, it may
indicate an RF signal on the output which may cause damage to
speakers (the RF signal will not be audible). Please note that when
you are using the amplifier in the Mono Bridge mode, both clip LEDs
of the bridged channels will operate simultaneously.
Protect LED (11): when you first turn on the amplifier, the protect LEDs
light briefly during a turn-on delay which indicates that the outputs
are disconnected internally. There will be an audible click when the
outputs reconnect and the protect LED will turn off. Otherwise, the
protect LED indicates that there is a problem either in the amplifier's
external connections, load or temperature conditions or its internal
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