INTRODUCTION:
Congratulations on purchasing your Gemini GXA power amplifier. This state of the art power amplifier 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 technology provides exceptional reliability when working with difficult speakers.
•Stable down to 2 ohm impedence
•Excellent handling of low frequencies as well as clear mids and flawless highs
•High output power to drive professional loudspeakers without distortion
•Oversized toroidal transformer, filter and heatsinks for better low end, transparency and stability
•Comprehensive protection circuitry (short, overheat, DC, subsonic and RF filters,
•Three modes of operation - stereo, parallel mono and mono bridge with mode status indication LED on front panel
•Flexible input configuration with active balanced inputs; additional input connectors to chain amps
•True clip LED for better control
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•Efficient dual aluminum extrusion heatsink design for thermal stability and reliability
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•Compact 2U well balanced enclosure
•Steel reinforced chassis construction for durability and longevity
CAUTIONS:
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. Please contact the Customer Gemini Service Department or your authorized dealer to speak to a qualified service 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 audio transients that could damage your speaker systems. Be sure that AC power is OFF when changing modes of operation and when changing the position of the ground lift switch. DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. Operators of electronic equipment should in no way be in contact with water. 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. DO NOT USE ANY SPRAY CLEANER OR LUBRICANT ON ANY CONTROLS OR SWITCHES.
CONNECTIONS, CONTROLS AND INDICATORS:
AC POWER SECTION:
FUSE: Replace FUSE (1) with those of proper type and rating.
SIGNAL GROUND LIFT SWITCH: SIGNAL GROUND LIFT SWITCH (2) is used to lift the balanced input connectors’ ground/shield from the amplifier’s ground. When the signal ground lifted, the sound source disconnects from the amplifier’s ground preventing ground loops which can generate hum and noise. See the Signal Ground Lift Switch Instructions for more detail.
AC CORD OUTLET: AC CORD OUTLET (3) is used to attach the power cord to the unit.
REAR PANEL:
INPUT SECTION:
There are two parallel input connectors (one female XLR and one 1/4” TRS jack) per channel. Either can be used as an input or as a link to chain amplifiers.
XLR INPUT JACKS: XLR INPUT JACKS (4, 5) electronically balanced inputs accept a standard XLR male connector. Pin 1 = shield/ground, pin 2 = hot or positive (+) and pin 3 = cold or negative
1/4" TRS INPUT JACKS: 1/4" TRS INPUT JACKS (6, 7) accept a balanced as well as an unbalanced line level signal. The unbalanced line uses a standard
OPERATION MODE SWITCH: OPERATION MODE SWITCH (8) is used to set the unit for STEREO mode, PARALLEL MONO mode, and MONO BRIDGE mode.
OUTPUT SECTION:
Disconnect the 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 it will impact the quality of the sound (lack of bass and incorrect stereo image).
SPEAKER OUTPUTS (9, 10, 11): SPEAKON connectors are provided to connect speakers to the amplifier quickly and easily. They are high current rated and provide very stable and durable contacts. A third SPEAKON connector in the center is provided to be used if the amplifier is in the MONO BRIDGE mode. Every SPEAKON connector has (PIN
NOTE: TOTAL SPEAKER IMPEDANCE MUST NOT BE LOWER THAN 2 OHM PER CHANNEL FOR STEREO AND PARALLEL MONO MODES, OR 4 OHM FOR MONO BRIDGE MODE. THE GXA AMPLIFIER IS DESIGNED TO HANDLE LOW IMPEDENCE LOADS AND WILL OPERATE NORMALLY WITH MOST 2 OHM SPEAKERS/PARALLEL SPEAKER COMBINATIONS. HOWEVER, FOR OPTIMAL PERFORMANCE AND RELIABILITY WE RECOMMEND USING SPEAKERS WITH HIGHER IMPEDENCE.
FRONT PANEL:
POWER SWITCH: The POWER SWITCH (12) turns the unit on and off.
POWER LED: The POWER LED (13) lights when the power is on. If the POWER LED (13) does not light, refer to the trouble shooting guide.
MONO LED: The MONO LED (14) will light when you have set the rear panel OPERATION MODE SWITCH (8) for PARALLEL MONO operation always make sure that this switch is in the correct position and that all speaker connections have been made correctly for the mode of operation you wish to use before powering up the amplifier.
BRIDGE LED: The BRIDGE LED (15) will light when you have set the rear panel OPERATION MODE SWITCH (8) for MONO BRIDGE operation. Always make sure that this switch is in the correct position and that all speaker connections have been made correctly for the mode of operation you wish to use before powering up the amplifier.
SIGNAL LED: The SIGNAL LED (16) for each channel show when a signal is present. In MONO BRIDGE mode, both the CHANNEL A LED and the CHANNEL B LED will light in unison.
CLIP LED: The amplifier has true CLIP LED (17) to help you properly control the amplifier’s output and achieve undistorted sound. The CLIP LED (17) for each channel light when your signal level is so strong that the distortion reaches 1% THD. The CLIP LED (17) should not remain constantly on or flash repeatedly during operation. For clean sound reproduction, the CLIP LED (17) 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 (17) lights when no signal is present, it may indicate a DC level on the output which may cause damage to speakers (the DC level will not be audible). Please note that when you are using the amplifier in the MONO BRIDGE mode, both CLIP LED (17) of the bridged channels will operate simultaneously.
PROTECT LED: PROTECT LED (18) when you first turn on the amplifier, the PROTECT LED light briefly during a
LEVEL CONTROLS: LEVEL CONTROLS (19, 20) establish the input levels required for each channel. Only the CHANNEL A LEVEL CONTROL (19) works in MONO BRIDGE mode.
OPERATING INSTRUCTIONS:
THE AMPLIFIER’S POWER MUST BE TURNED OFF WHEN CHANGING MODES OF OPERATION.
STEREO OPERATION:
The unit has two channels for stereo operation. Each channel provides a separate and discrete signal at the speaker outputs according to the signal received at the inputs. The following instructions are for applications with 8 Ohm, 4 Ohm or 2 Ohm speakers of matched power ratings.
1.With the power off, set the OPERATION MODE SWITCH (8) to the STEREO position. When the power is on, the MONO LED (14) and BRIDGE LED (15) on the front panel will not light. If these LED illuminate, you have the switch in the wrong position. Correct before continuing.
2.With the power off, connect your input cables to the CHANNEL A and B inputs using either the XLR INPUT JACKS (4, 5) or 1/4" TRS INPUT JACKS (6, 7) of each channel. The other CHANNEL A and CHANNEL B inputs can be used to link to an additional amplifier.
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