GEMINI XPM-600, XPM-900, XPM-1200 Schematic

SERVICE MANUAL

XPM-600 XPM-900

XPM-1200

Power Amplifers

CONTENT’S:

Connections & Operations:.......................................................Page 2-5

Specifications:..............................................................................Page 6

Parts Lists:...............................................................................Page 8-20

PCBs:......................................................................................Page 21-22

Schematics:.................................................................................Page 23

Gemini Sound Products Corp.

120 Clover Place P.O. Box 6928

Edison, NJ 08818-6928

732-738-9003 (Phone) • 732-738-9006 (Fax)

Page 1

3 4

2 3 4

14 15

19 20

Stereo

Parallel Mono

Mono Bridge

Connections, Controls and Indicators

Rear Panel

Note: 120V and 230V units have different types of output connectors on the rear panel.

Input Section:

There are two parallel input connectors (one female XLR and one 1/4” jack) per channel. Either can be used as an input or as a link to chain amplifiers.

XLR Input Jacks (1, 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" Phone Input Jacks (2, 4): 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/

ground. The balanced line uses a tip-ring-sleeve connection. Tip =

hot or positive (+), ring = cold or negative (-), and sleeve = shield/

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 (7): replace fuse with those of proper type and rating. Ground Lift Switch (8) is used to lift the ground from the chassis. See

the Ground Lift Switch Instructions for more detail.

AC Cord Outlet (6) is used to attach the power cord to the unit.

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 it will impact the quality of the sound (lack of bass and incorrect stereo image).

Speaker Outputs for 120V Unit (9, 10, 11): the speaker output jacks

are 5-way binding posts that will accept a standard banana plugs,

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 be distorted,

and your amplifier will overheat and go into protection mode. Speaker Outputs for 230V Unit (9, 10, 11): Neutrik 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 1- as negative and pin 1+ as positive.

NOTE: Total speaker impedance must not be lower than 4 Ohm per channel for Stereo and Parallel Mono modes, or 8 Ohm for Mono Bridge mode.

Front Panel

Power Switch (20): turns the unit on and off. Power LED (19): the power LED lights when the power is on. If the

power LED does not light, refer to the trouble shooting guide. Mono LED (12): the mono LED will light when you have set the rear

panel Operation Mode Switch (3) 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 (13): the bridge LED will light when you have set the rear

panel Operation Mode Switch (3) 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 (14): the signal LEDs 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 (15): 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 reaches 1% THD. The clip LED should not remain constantly on or flash repeatedly during operation. For clean sound reproduction, the clip 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 a 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 (16): 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 LEDs 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 functions. If one of these situations occur, the amplifier senses the problem and automatically switches into protection mode. The LED will light to warn you of the trouble and the amplifier will stop working. If this occurs, switch off the amplifier and refer to the Trouble Shooting Guide. If the protect LED remains lit when resuming amplifier operation, do not use the amplifier and contact an authorized service technician.

Level Controls (17, 18): establish the input levels required for each

channel. Only the Channel A Level Control (17) 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 4 Ohm or 8 Ohm speakers of matched power ratings.

1. With the power off, set the OPERATION MODE SWITCH (3) to the

STEREO position. When the power is on, the Mono and Bridge LEDs

on the front panel will not light. If these LEDs 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 (1, 5) or 1/4" INPUT

JACKS (2, 4) of each channel. The other channel A and channel B

inputs can be used to link to an additional amplifier.

3. Connect the loudspeakers to the channel A and channel B SPEAKER

OUTPUTS (9, 11). THE TOTAL SPEAKER LOAD MUST BE AT

LEAST 4 OHMS PER CHANNEL. If you try to operate at a lower

impedance, the amplifier will go into protection mode and stop

operation until you correct the load conditions.

4. With the LEVEL CONTROLS (17, 18) of both channels set to zero

(fully counterclockwise), turn the POWER SWITCH (20) on. Apply a

signal to the input of the amplifier. The level of the input signal should

be as high as you will ever need it to be. This way, it will be as high

above the amplifier’s noise floor as possible, ensuring an excellent

performance and signal to noise ratio. Adjust the LEVEL CONTROLS

for each channel to achieve the desired maximum listening level.

Note, when the clip LEDs light, there is distortion present in the

amplifier’s output section. If a clip LED remains on or flashes

repeatedly, reduce the signal level by lowering the input level control

for the channel that is clipping or reduce the level at the source.

Page 4

Parallel Mono Operation

Follow these instructions for Parallel Mono Operation using a single input cable, and you will have the same monophonic signal on both the channel A and the channel B outputs. Each channel’s output is controlled independently by that channel’s level control.

1. With the power off, set the OPERATION MODE SWITCH (3) to the

PARALLEL MONO position. When the power is on, the MONO LED

(12) on the front panel will light. If the LED does not 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 input

only using the either the XLR INPUT JACK (5) or 1/4" INPUT JACK

(4) of channel A. The other channel A input can be used to link to an

additional amplifier.

3. Connect the loudspeakers to the channel A and channel B SPEAKER

OUTPUTS (9, 11). THE TOTAL SPEAKER LOAD MUST BE AT

LEAST 4 OHMS PER CHANNEL. If you try to operate at less than 4

Ohms per channel, the amplifier will go into the protection mode and

stop operation until you correct the load conditions.

4. With the LEVEL CONTROLS (17, 18) set to zero (fully

counterclockwise), switch the power on. Apply a signal to the input.

The level of the input signal should be as high as you will ever need it

to be. This way, it will be as high above the amplifier’s noise floor as

possible, ensuring an excellent performance and signal to noise ratio.

Adjust the LEVEL CONTROLS for each channel to achieve the

desired maximum listening level. Note, when the clip LEDs light,

there is distortion present in the amplifier’s output section. If a clip

LED remains on or flashes repeatedly, reduce the signal level by

lowering the input level control for the channel that is clipping or

reduce the level at the source.

Using the Ground Lift Switch

Depending on your system configuration, sometimes applying the ground will create a quieter signal path. Sometimes lifting the ground can eliminate ground loops and hum to create a quieter signal path.

1. With the power amp on, listen to the system in idle mode (no signal

present) with the ground applied (the GROUND LIFT SWITCH (8) in

the left position).

2. Then turn the power off before moving the GROUND LIFT

SWITCH (8). Lift the ground by moving the GROUND LIFT SWITCH

to the right, turn the power back on and listen to determine which

position will provide a signal devoid of background noise and hum.

Keep the GROUND LIFT SWITCH in the ground position if the noise

level remains the same in either position. CAUTION: DO NOT TERMINATE THE AC GROUND ON THE POWER

AMPLIFIER IN ANY WAY. TERMINATION OF THE AC GROUND CAN BE HAZARDOUS.

Mono Bridge Operation

Follow these instructions to bridge the unit’s outputs. Bridging the amplifier converts the unit to a monophonic or single channel. The amplifier can be used with 8 Ohm or higher loads only in Mono Bridge mode. This mode is used to provide a higher voltage with greater headroom to your speaker. Before setting your amplifier for Mono Bridge operation, make sure that your speaker can handle the high power level provided by the amplifier in Mono Bridge mode. CAUTION: VOLTAGE OVER 100 VOLTS MAY BE PRODUCED AT THE BRIDGE OUTPUT TERMINALS IN THIS MODE.

1. With the power off, set the OPERATION MODE SWITCH (3) to the

BRIDGE position. When the power is on, the BRIDGE LED (13) on

the front panel will light. If the LED does not illuminate, you have the

switch in the wrong position. Correct before continuing.

2. With the power off, connect your input cables to channel A input only

using the either the XLR INPUT JACK (5) or 1/4" INPUT JACK (4) of

channel A. The other channel A input can be used to link to an

additional amplifier.

3. Connect the loudspeaker to the BRIDGE SPEAKER OUTPUT (10)

only. With a 230V unit, use the center speakon. With a 120V unit, use

the two innermost red terminals. Be sure the polarity of your

connections is correct. The total speaker load must be at least 8

Ohms or above. If you try to operate at less than 8 Ohms in the Mono

Bridge mode, the amplifier will go into the protection mode and stop

operation until you correct the load conditions.

4. With the CHANNEL A LEVEL CONTROL (17) set to zero (fully

counterclockwise), switch the power on. Apply a signal to the input.

The level of the input signal should be as high as you will ever need it

to be. This way, it will be as high above the amplifier’s noise floor as

possible, ensuring an excellent performance and signal to noise ratio.

Adjust the LEVEL CONTROL (17) for channel A to achieve the

desired maximum listening level. Note, when the clip LEDs light,

there is distortion present in the amplifier’s output section. If a clip

LED remains on or flashes repeatedly, reduce the signal level by

lowering the input level control for channel A or reduce the level at

the source. During Mono Bridge operation, the channel B level is

inactive, however, both channels LEDs will flash simultaneously and

show output conditions.

Page 5

SYMPTOM CAUSE SOLUTION

UNIT DOES NOT PRODUCE SOUND. POWER LED DOES NOT LIGHT .

POWER LED LIGHTS, BUT NO SOUND IS PRODUCED BY AMPLIFIER.

SOUND IS PRESENT BUT VOLUME IS TOO LOW EVEN THOUGH SOURCE DEVICE IS SET TO A HIGH LEVEL.

LOUD 50/60 HZ OR 100/120 HZ HUM IS HEARD AT ALL TIMES THROUGH THE SPEAKER SYSTEMS.

SOUND IS DISTORTED.

PROTECT LED REMAINS LIT OR GOES ON AND OFF INTERMITTENTL Y AFTER USING AMPLIFIER FOR A SHORT TIME.

FUSE BLOWS INTERMITTENTL Y .

PROTECT LED(S) STAY ON WITH NO SPEAKERS CONNECTED AND WITH THE AMPLIFIER COOLED DOWN.

• POWER SWITCH NOT IN ON POSITION.

• POWER CABLE NOT CONNECTED TO AMPLIFIER OR TO OUTLET .

• AC OUTLET NOT ACTIVE.

• MAIN AMPLIFIER FUSE DEFECTIVE.

• NO INPUT SOURCE SIGNAL.

• INPUT SOURCE NOT CONNECTED.

• INPUT CONNECTING CABLE DEFECTIVE.

• SPEAKER(S) NOT CONNECTED.

• SPEAKER CABLE DEFECTIVE.

• SPEAKER SYSTEM(S) INOPERATIVE.

• AMPLIFIER’S LEVEL CONTROLS ARE SET TO ZERO.

• AMPLIFIER INPUT LEVEL CONTROLS ARE SET TOO LOW.

• WRONG PIN CONNECTIONS IN CABLES.

• IMPROPER OR DEFECTIVE GROUND CONNECTION AT INPUTS. IMPROPER OR DEFECTIVE GROUND AT INPUT SOURCE DEVICE(S).

• IMPROPER OR DEFECTIVE GROUND CONNECTION ON AC OUTLET .

• GROUND LOOP THROUGH AC LINE CONNECTION/RACK MOUNTING.

• DISTORTION OCCURRING IN SOURCE DEVICE.

• INPUT LEVEL IS SET TOO HIGH.

• UNIT IS OPERATING AT EXCESSIVELY HIGH TEMPERATURE.

• EXTREMELY LOW SPEAKER IMPEDANCE.

• SHORT IN SPEAKER CONNECTORS, SPEAKER CABLE OR SPEAKER SYSTEM.

• SPEAKER LOAD IMPEDANCE IS TOO LOW.

• TYPE OR RATING OF THE FUSE IS NOT CORRECT .

• FAILED AMPLIFIER.

• MOVE POWER SWITCH TO ON POSITION.

• CONNECT POWER CABLE TO AC SUPPLY.

• CHECK CONDITION OF OUTLET.

• REPLACE AMPLIFIER MAIN POWER FUSE ON REAR PANEL WITH CORRECT TYPE AND RATING.

• CHECK FOR PROPER FUNCTION OF INPUT SOURCE DEVICE.

• CHECK INPUT CABLES AND CONNECTIONS. REPLACE QUESTIONABLE CABLES WITH KNOWN GOOD CABLES.

• CHECK SPEAKER CABLES AND CONNECTIONS. REPLACE QUESTIONABLE CABLES WITH KNOWN GOOD CABLES.

• CHECK OPERATING CONDITION AND STATUS OF SPEAKER SYSTEM(S). BE SURE THE LEVEL CONTROLS ARE PROPERLY S ET.

• ADJUST LEVEL CONTROLS AS PER INSTRUCTIONS.

• USE CORRECT CABLES (AS SHOWN ON BACK OF UNIT).

• CHECK FOR PROPER AC LINE GROUND ON POWER AMP AND ALL INPUT DEVICES.

• CHECK INPUT CABLES FOR ALL SOURCE DEVICES AND SIGNAL PROCESSING AS WELL AS INPUT CABLES TO POWER AMPLIFIER. CHECK POSITION OF GROUND LIFT SWITCH AS PER INSTRUCTIONS FOR LIFTING THE GROUND.

• NEVER LIFT THE AC LINE GROUND ON THE POWER AMPLIFIER. IF YOU ARE NOT TOT ALLY F AMILIAR WITH GROUND LIFTING OR UNIFICATION PROCEDURES, DO NOT ATTEMPT THEM WITHOUT FIRST CONSUL TING YOUR DEALER OR A QUALIFIED SOUND TECHNICIAN FOR MORE INFORMATION ON GROUNDING. IMPROPERLY DONE, SUCH PROCEDURES CAN POSE A SAFETY AND/OR FIRE HAZARD.

• CHECK CLIP INDICATORS ON INPUT SOURCE DEVICES AND RESET LEVELS IF NECESSARY TO ELIMINATE DISTOR TION.

• ADJUST LEVEL CONTROLS AS PER INSTRUCTIONS.

• CHECK THAT AMPLIFIER IS ADEQUATELY VENTILATED ON THE FRONT AND REAR PANELS WHERE THE AIR VENTS AND FANS ARE LOCATED. IF OVERHEATED, LET THE AMPLIFIER COOL DOWN BEFORE APPLYING AN INPUT SIGNAL.

• CHECK THE POSITION OF OPERATION MODE SWITCH. BE SURE THAT THE SPEAKER CONNECTIONS ARE MADE IN ACCORDANCE WITH THE SWITCH SETTING.

• VERIFY SPEAKER SYSTEM IMPEDANCES. BE SURE THE TOTAL SPEAKER SYSTEM IMPEDANCE IS AT LEAST 4 OHMS PER CHANNEL WHEN THE OPERATION MODE SWITCH IS IN THE STEREO POSITION OR PARALLEL MONO POSITION. IF THE SWITCH IS IN THE BRIDGE MODE, THE IMPEDANCE MUST BE AT LEAST 8 OHMS. IF YOU ARE NOT SURE OF YOUR TOTAL SPEAKER IMPEDANCE LOAD, CONTACT YOUR DEALER FOR MORE INFORMA TION.

• CHECK CONDITION OF SPEAKER CABLES.

• IF USING BARE WIRE CONNECTIONS ON THE OUTPUTS OF THE AMPLIFIER, BE SURE THAT NO STRANDS FROM ONE CONNECTOR ARE TOUCHING ANY OTHER CONNECTOR.

• CHECK FOR SHORTS ON THE OUTPUTS.

• CHECK YOUR SPEAKER IMPEDANCE (INFO FROM DEALER).

• CHECK THAT THE FUSE TYPE AND RATING IS CORRECT.

• CONTACT THE GEMINI SERVICE DEPARTMENT OR YOUR AUTHORIZED DEALER TO SPEAK TO A QUALIFIED SERVICE TECHNICIAN. IN THE U.S.A. CALL TOLL FREE 1-800-476-8633

Page 6

Specifications

Output Power EIA: 1kHz @ 1% THD Single Channel 8Ω 230 310 400

Both Channels Driven 8Ω 200 280 360 Single Channel 4Ω 300 480 630 Both Channels Driven 4Ω 270 400 530 Mono Bridge 8Ω 550 800 1060

Dynamic Headroom: XPM-600 XPM-900 XPM-1200 8Ω 1.4 1.4 1.3 4Ω 2.2 2.2 2.2

Frequency Response............................................................20 Hz - 60 kHz

Total Harmonic Distortion......less than 0.1%, typical 0.03% at 1 kHz

Intermodulation Distortion.......................less than 0.05% (SMPTE)

Signal to Noise Ratio..........................100 dB below rated power, 8Ω

Damping Factor..............................greater than 200 @ 8Ω

Slew Rate.................................................................................25 V/µS

Voltage Gain....................................................................33 dB

Input Sensitivity (for rated power at 8 Ohm):

Input Impedance Unbalanced....................................................10 kOhms

Input Impedance Balanced.......................................................20 kOhms

Power consumption: XPM-600 XPM-900 XPM-1200

Note: power consumption is given at rated power at 8Ω per channel, both channels driven.

AC Power Requirement:

(power connection is factory configured)............................120V/ 60 Hz

Indicators.......................................................................1 Power Indicator

Cooling....................................2 Speed Dual Fan; Front-to-Rear Forced Air

Protection...........Short Circuit, DC, Thermal Cut-off, Sub/ultrasonic

Frequency Filters, In-rush Current Limiter, Turn-on Delay

Connectors:

Balanced/Unbalanced Inputs....................................1/4" Jack

Balanced Inputs............................................XLR Female Jack

Speaker Outputs (120V unit)..........................................5-way binding posts

Speaker Outputs (230V unit)...........Speakons (ch.A, ch.B and bridge)

Dimensions...................................19" x 13.75" x 3.5" (483 x 350 x 89 mm)

Weight XPM-600 XPM-900 XPM-1200

* Specifications and design are subject to change without notice for purpose of improvement.

XPM-600 XPM-900 XPM-1200

0.9 Vrms 1.1 Vrms 1.2 Vrms

700 VA 900 VA 1100 VA

230V/ 50 Hz

1 Signal LED per channel

1 Clip LED per channel

1 Protect LED per channel

1 Mono LED

1 Bridge LED

25.8 lbs 29 lbs 31.2 lbs

11.7 kg 13.2 kg 14.2 kg

Page 7

XPM-600

1) 102056543301 SPACER XPM-900 PC 2

2) 102119214701 CARTON XPM-600 PC 1

3) 102260018001 EXT.CARTON XPM-600 PC 1

4) 103012005700 SPACER 1200x570m/m PC 1

5) 105011008501 HOLDER XPM-900 PC 2

6) 105032409601 WALL XPM-900 PC 1

7) 105034608501 SILD PANEL XPM-900 PC 2

8) 105242608601 BACK BOARD XPM-600 PC 1

9) 105343431801 TOP COVER XPM-900 PC 1

10) 105443431701 BOTTOM CABI XPM-900 PC 1

11) 107042002501 AIRFILTER 420x25m/m XPM-900 PC 1

12) 107042004001 PVC COVER XPM-600 PC 1

13) 1070ACS03501 ACS-3.5 PVC RED PC 5

14) 1070KG-010— M0VEABLE BUSHING KG-010 CM 2

15) 1070SCB-10— SPACER SUPPORTS SCB-10 XPM-900 PC 4

16) 1070SS-6—— SELF RETATINING SPALERS SS-6 PC 1

17) 1070YJ-98—- NYLON CLAMPER YJ-98 PC 1 2

18) AL201AL50101 AL201/AL501 SJT W-A 14AWG 6FT PC 1

19) AO016D130—- 3P AC INLET AC-016D130 XPM-900 PC 1

20) 105006400001 6.4m/m PIN PC 6

21) 106203003003 RECTIFER HEAT SINK XPB-1600 PC 1

22) 106201302001 HEAT SINK BLACK 13x20 XPM-900 PC 1

23) 1070LED-3.5- LED SPACER SUPPORT LED-3.5 PC 9

24) 700KBP060002 RECTIFIER KBP06 2A 600V PC 1

25) 700MP3504W02 RECTIFIER MP3504W 35A 400V PC 1

26) CCN0A101250K CERAMIC CAP 100P 250V PC 6

27) CCN0A680500J CERAMIC CAP 68P 500V NPO 5% PC 2

28) COIL16115T6L COIL 1.6x10.1x11.5T-6L XPM-900 PC 2

29) ECL04700080M ELEC CAP 4700u80v PC 4

30) ECS00010050M ELEC CAP 10u50v PC 4

31) ECS00100025M ELEC CAP 100u25v PC 4

32) ECS00100100M ELEC CAP 100u100v PC 4

33) ECS00220016M ELEC CAP 220u16v PC 6

34) ECS01000025M ELEC CAP 1000u25v PC 1

35) ECS02200025M ELEC CAP 2200u25v PC 1

36) ICNJM3404AD- IC NJM3404AD PC 2

37) ICTL072CP—- IC TL072CP PC 1

38) JS1001025003 BASE 3P 2.5m/m PC 2

39) JS1001025012 BASE 12P 2.5m/m PC 1

40) JS1001R25002 BASE 2P JS-1001R-02 PC 2

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