Gemini XTR-400 User manual

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SERVICE MANUAL
XTR-400
ACTIVE SPEAKER SYSTEM
SUBWOOFER / SATELLITES
Gemini Sound Products Corp.
120 Clover Place P.O. Box 6928
Edison, NJ 08818-6928
732-738-9003 (Phone) • 732-738-9006 (Fax)
CONTENT’S:
Cautions, Connections, & Operations :....................................Page 2-4
Specifications:..............................................................................Page 4
Parts Lists:....................................................................................Page 5
PCBs:..........................................................................................Page 6-8
Schematics....................................................................................Page 9

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INTRODUCTION:
Congratulations on your purchase of an XTR-400 speaker system
engineered & manufactured by Gemini Sound Products. This state of the
art speaker system is backed up by a three-year warranty. The XTR-400
offers ultimate fidelity, power handling, and an array of features that makes
it a highly versatile, compact, self contained & powered speaker system.
FEATURES:
• Active self-powered 400W rms tri-amp design.
• One 15-inch bandpass subwoofer. Features top-hat hardware for pole mounting of a
satellite speaker and metal corner protectors.
• Two high quality satellite speakers featuring 10-inch woofers and dual piezo horns housed in
trapezoidal cabinets. Satellite speakers are uniquely designed for placement on stands or for use
as floor monitors, and protected by full front metal grill and metal corners.
• Built-in active optimized crossovers.
• Sensitivity/Volume controls.
• Satellites equipped with reliable Speakon™ connectors for exceptional sound.
(cables must be purchased separately)
• Signal Ground Lift Switch for achieving the quietest possible hum-free operation.
• Airflow controlled by variable speed fan for maximum cooling and quietest possible operation.
• Mono or Stereo operation.
• AC line voltage selector switch allows reconfiguring amplifier for either 110-120V or 220-
240V AC lines.
• Compact design featuring large metal handles and casters for ease in transporting.
CAUTIONS:
1. All operating instructions should be read 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 refer servicing to a
qualified Gemini Sound Products service technician.
In the USA: If you experience problems with this unit, please call 1 [phone] for
Gemini Customer Service. Do not attempt to return this equipment to your dealer.
3. Do not expose this unit to direct sunlight or to a heat source such as a
radiator or stove.
4. This unit should be cleaned only with a damp cloth. Avoid solvents or
other cleaning detergents.
5. When moving this equipment, it should be placed in its original carton
and packaging. This will reduce the risk of damage during transit.
6. DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE.
7. DO NOT USE ANY SPRAY CLEANER OR LUBRICANT ON ANY
CONTROLS OR SWITCHES.
CONNECTIONS:
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: XLR INPUT JACKS (1) 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" PHONO INPUT JACKS: 1/4" PHONO INPUT JACKS (2) accept a
balanced as well as an unbalanced line. 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.
SENSITIVITY/VOLUME CONTROLS: SENSITIVITY/VOLUME CONTROLS
(10) control the input levels for each channel of the 2satellite speakers.
The volume level of the subwoofer is controlled automatically to match the
volume levels of the satellite speakers. It will always maintain a perfect
balance to give you incredible sound quality!
SIGNAL GROUND LIFT SWITCH: SIGNAL GROUND LIFT SWITCH (7)
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.
OUTPUT SECTION:
Disconnect unit from the AC power source before making anyconnections.
SPEAKER OUTPUTS (3): The speaker output connectors are Speakon™
connectors that will accept cables with Speakon™ connectors. (These
cables must be purchased separately) The subwoofer is already connected
internally, so you don’t have to worry about connecting it to the amplifier.
AC POWER SECTION:
POWER SWITCH (8): turns the unit on and off.
POWER LED (9): the power LED lights when the power is on.
FUSE (4): replace with proper type and rating.
AC INLET (6) is used to attach the power cord to the unit.
AC LINE VOLTAGE SELECTOR SWITCH (5) allows reconfiguring
amplifier for either 110-120V or 220-240V AC lines.
OPERATION:
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 8W speakers of matched power ratings. We suggest only
using the speakers that come with the unit.
1. With the power OFF, connect your input cables from your music source
(such as your mixer) to the Channel 1 and Channel 2 INPUTS using the
XLR INPUT JACKS (1) or 1/4" PHONO INPUT JACKS (2).
2. Connect your speakers to the Channel 1 and Channel 2 SPEAKER
OUTPUTS (3).
3. With the SENSITIVITY/VOLUME CONTROLS (10) of both channels
set to zero (fully counter clockwise), turn the POWER SWITCH (8), ON.
Okay, now try 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. Now play some
music and listen for audible distortion. If you do hear distortion decrease
the output level using the SENSITIVITY/VOLUME CONTROLS (10).
MONO OPERATION:
Connect your MONO signal to the Channel 1 input (1 or 2). Now create a
link by connecting the remaining Channel 1 input to a Channel 2 input
(1 or 2) using a standard balanced cable (may be purchased separately).
You can adjust the level of each satellite speaker using it’s channel’s
SENSITIVITY/VOLUME CONTROL (10).
USING THE SIGNAL 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 SIGNAL GROUND LIFT SWITCH (7) will
be in the left position.
2. Turn the power OFF before moving the SIGNAL GROUND LIFT SWITCH (7).
Now lift the ground by moving the SIGNAL GROUND LIFT SWITCH (7)
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!!

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SETUP:
There are various ways to set up this system:
BASIC SETUP:
Okay, this is your basic setup, perfect for small parties and venues. The
ideal location for your subwoofer is close to a wall or in a corner. This
will give you the fullest bass response. Your 2 satellite speakers can be
placed up on stands on each side (stands must be purchased separately).
TWO-SYSTEM SETUP:
This setup is perfect for larger venues. This setup requires 2 XTR-400
systems. This will give you a total of 800 watts rms! Place a subwoofer
on each side to the left and right. Using the high-hat hardware and
connecting pole (which can be purchased separately), place the
pole in the high-hat socket on the subwoofer, and a satellite speaker on
top of the pole. The 2 remaining satellite speakers may be used as either
floor monitors, or placed on stands elsewhere in the room giving you a
louder and fuller sound.
Each speaker system in this setup must be used in MONO mode (see
Mono section). Connect the system that is on the left side of the audience
to the LEFT channel of your mixer, and the system that is on the right side
of the audience to the RIGHT channel of your mixer.
ACTIVE SPEAKER SYSTEM SUBWOOFER/SATELLITES
The XTR-400 features a unique design for ease in transporting. The 2
satellite speakers conveniently fit into a special recessed section of the
subwoofer and are securely fastened using a strap that attaches to the
handles (included).
SHOULD YOU EXPERIENCE ANY DIFFICULTIES OR PROBLEMS,
PLEASE CALL: 1 [phone] FOR GEMINI CUSTOMER SERVICE.
SPECIFICATIONS:
Subwoofer XTR-400SUB:
Amplifier’s Output Power:.........................230 Wrms on subwoofer channel
Frequency response:……………………...........................….32 Hz - 100 Hz
Components:………………………...........................……………..15" woofer
Features:
Efficient band-pass cabinet design
Large metal handles
Metal protection corners
Four 2" wheels
Amplifier assembly on the back
35mm standmount cap on top
Black carpet finish
Rubber feet
Dimensions:..............................................................WxDxH: 20"x31"x24.5"
(508 x 788 x 622 mm)
Weight:…………………............................……………………..96 lbs (44 kg)
Satellites GT-1002s:
Amplifier’s Output Power:..........................2x85 Wrms on satellite channels
Frequency response:…………............................………….100 Hz – 20 kHz
Components:….…………...........................……………………….10" woofer
6” dual piezo horn
Features:
Trapezoidal cabinet
Full front protective metal grill
Metal protection corners
35 mm standmount cup on the bottom
Black carpet finish
Rubber feet
Neutrik Speakon connector
Dimensions:……….……..............................…….W x D x H 12.5" x 9" x 18"
(318 x 229 x 458 mm)
Weight:……………………...........................………………18 lbs (8 kg) each
Total System:
Maximum SPL, continuous:……...........................……………………120 dB
Sensitivity………………………...........................……………………. 1 Vrms
Input Impedance………...............10 kOhm unbalanced/20 kOhm balanced
Features:
Balanced XLR and 1/4" Jack inputs
Neutrik Speakons on Satellite Channels’ outputs
Active electronic X-over (Fx=100 Hz)
Variable speed fan
Individual channel Sensitivity/Volume controls
Signal Ground lift switch
110-120 VAC / 220-240 VAC switchable
Total Weight:……………............…...............………………...132 lbs (60 kg)
SPECIFICATIONS AND DESIGN ARE SUBJECT TO CHANGE WITHOUT
NOTICE FOR PURPOSE OF IMPROVEMENT.

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Item # Designators Description Part Number
MAIN PCB:
1 ZD3, ZD2 ZENER DIODE 1/2W 12V (RD12EB2) 079-012
2 D3, D1, D2 SILICON DIODE 1N4148 079-003
3 ZD1 ZENER DIODE 1/2W 24V (RD24EB2) 079-020
4 Q1 SILICON TRANSISTORS 2SC1815 076-003
5 Q2 SILICON TRANSISTOR 2SC4793 076-100
6 C18, C13 ELECTROLYTIC CAPACITORS 6800µµ
µµ
µ/50V 050-198
7 REC1 BRIDGE RECTIFIER KBPC804W 086-019
8 U3, U2, U4, U1 INTEGRATED CIRCUIT TDA7294V 074-189
CROSSOVER PCB:
1 VR1, VR2 ROTARY VR 10KA L:15MM 071-228
2 LD1 LED (GREEN) 5φφ
φφ
φ080-086
3 IC1, IC3, IC2 INTEGRATED CIRCUIT NJM4558DD (BA15218,M5218AP) 074-163
INPUT PCB:
1 SW1 SLIDE SWITCH SV70050 081-030
2 IC1 INTEGRATED CIRCUIT NJM4558DD (BA15218,M5218AP) 074-163
3 X3, X2 PHONE JACK 6.3φφ
φφ
φTRS 1/4" BAL 092-078
4 XLR2, XLR1 XLR XLF-3PH 092-069
OUTPUT PCB:
1 X1, X2 SPEAKON™ CONNECTORS NL4MP 092-149
OTHER:
1 AC CORD 093-369
2 AC INLET 092-105
3 DC FAN 24V 001-613
4 TRANSFORMER 059-247
5 SLIDE SWITCH 081-023
6 POWER SWITCH 083-121
7 FUSE VBS UTE 3.15A 250V 100-068
8 FUSE VBS UTE 6.3A 250V 100-071
PARTS LIST:
In the USA: If you should experience problems with this unit,
please call 1 [phone] for Gemini Customer Service.
Do not attempt to return this equipment to your dealer.

XTR400-3
XTR400-4
SW1
X1
C1
R1
R2
R3
R4
R6
R7
R8
R9
C2
C3
C4
C5
R5
IC1
X2
X3
XLR1
XLR2 G
++
OUTPUT PCB
INPUT PCB
Page 6

XTR400-1
XTR400-2
RED
RED/BLK
BLK
RED
BLK
BLK BLK
RED
RED
C8
R5
LD1
J1
C7
C6
C4C3C2
C12
C5
C11
C1
C10
C9
IC2
IC3
R11
R20
R9
R6
R14
R15
R21
R2
R8
R19
R12
R13
R10
R3 R4
R18
R1
R7
R22
R17
R16
X2
X4
X3
X1
IC1
J2
J3
C13
C14
VR2
VR1
C21
X2
X6X5
X11
X10
X7
X8
X1
X13
Q2
1
R2
X4
C13
R5
C12
AC
AC
+
-
REC1
X9
J6
R12
R6
J5
J8
R34
J1
J2
J9
J10
J7
ZD1
ZD2
ZD3
X12
X3
15
1
U1
115
U4
R37
R3
R36
R10
R7
R28
R29
R1
R24
R33
R19
R20
R16
R15
R30
R8
R21
R22
R18
R17
R35
R23
R9
R31
R26
R11
R38
R27
R32
R14
R25
R4
Q1
L4
L1 L3
L2
D2
D1 D3
C19
C5
C3
C29
C1
C23
C2
C22
C4
C31
C26
C11
C17
C16
C15
C14
C20
C8
C30
C27
C7
C28
C6
C25
C9
C24
C10
J3 J4
115
U2
R13
115
U3
C18
C32
TOP LAYER X-OVERMAIN PCB

XTR400-1
XTR400-2
RED
RED/BLK
BLK
RED
BLK
BLK BLK
RED
RED
C8
R5
LD1
J1
C7
C6
C4C3C2
C12
C5
C11
C1
C10
C9
IC2
IC3
R11
R20
R9
R6
R14
R15
R21
R2
R8
R19
R12
R13
R10
R3 R4
R18
R1
R7
R22
R17
R16
X2
X4
X3
X1
IC1
J2
J3
C13
C14
VR2
VR1
C21
X2
X6X5
X11
X10
X7
X8
X1
X13
Q2
1
R2
X4
C13
R5
C12
AC
AC
+
-
REC1
X9
J6
R12
R6
J5
J8
R34
J1
J2
J9
J10
J7
ZD1
ZD2
ZD3
X12
X3
15
1
U1
115
U4
R37
R3
R36
R10
R7
R28
R29
R1
R24
R33
R19
R20
R16
R15
R30
R8
R21
R22
R18
R17
R35
R23
R9
R31
R26
R11
R38
R27
R32
R14
R25
R4
Q1
L4
L1 L3
L2
D2
D1 D3
C19
C5
C3
C29
C1
C23
C2
C22
C4
C31
C26
C11
C17
C16
C15
C14
C20
C8
C30
C27
C7
C28
C6
C25
C9
C24
C10
J3 J4
115
U2
R13
115
U3
C18
C32
BOTTOM LAYER X-OVERMAIN PCB

T1
SW3
SW4
C101
6.3A / 110-120V
WHT
BLK
ORG
BLU
BRN
F
SW-POWER
VOLTAGE SELECTOR
L
E
N
F
AC INLET
P2
P3
P1
POWER PCB
230v115v FAN1
24Vdc/0.19A
C2
270
R3 10K 1%
R4 10K 1%
R7
10K 1%
R9 10K 1%
C4 270
CH.2 (R)
T
R
S
X3 TRS 1/4" BAL
2 1
3
XLR2
XLF-3PH
C3
270
R1 10K 1%
R2
10K 1%
R8 10K 1%
C5 270
T
R
S
X2 TRS 1/4" BAL
2 1
3
XLR1
XLF-3PH
CH.1 (L)
6
5
7
IC1B
NJM4558DD
2
3
1
4 8
IC1A
NJM4558DD
R6 10K 1%
+ 12V
- 12V
2 5
1
4
3
6
SW1
C1 0.047uF
"Signal ground lift"
R5 510
+ 12V
- 12V
INPUT
INPUT
CH.1 (L) OUTPUT
CH.2 (R) OUTPUT
INPUT PCB
2
3
1
4 8
IC1A
NJM4558DD
6
5
7
IC1B
NJM4558DD
2
3
1
4 8
IC2A
NJM4558DD
2
3
1
4 8
IC3A
NJM4558DD
R9
13K 1%
R10
39.2K 1%
R8
39.2K 1%
R11
22.1K 1%
C4
.047uF5%
R13
60.4K 1%
R18
10K 1%
C3
.047uF5%
R12
60.4K 1%
+ 12V
- 12V
X-OVER PCB
R15
13K 1%
R7
39.2K 1%
R1
39.2K 1%
R14
10K 1%
C8
.1uF 5%
C5
.1uF 5%
R6
13K 1%
R5
39.2K 1%
R19
39.2K 1%
- 12V
+ 12V
R20
22.1K 1%
C2
.047uF 5%
C12
.047uF 5%
6
5
7
IC3B
NJM4558DD
6
5
7
IC2B
NJM4558DD
R22
13K 1%
R17 13K 1%
R2 13K 1%
R4 39.2K 1% R3 39.2K 1%
R21 13K 1%
C11
0.033uF5%
C1 0.033uF5%
1
2
3
4
5
6
7
X2
VR2
10KA
VR1
10KA
+ 12V
- 12V
1
2
3
4
X4
1
2
3
4
X3
1
2
3
X1
C9
0.1
C10
0.1
+ 12V
+ 12V
- 12V- 12V
C7
10uF25V NP
C6
10uF25V NP
LD1
GRN
R16
2.4K
C13
100uF16V
C14
100uF16V
CH.1 (L) INPUT
CH.2 (R) INPUT
CH.1 (L)
CH.2 (R)
CH.1 (L) OUTPUT
SUB OUTPUT (+)
CH.2 (R) OUTPUT
SUB OUTPUT (-)
VOLUME
CONTROL
VOLUME
CONTROL
STBY
9
IN +
3
-Vs 8
IN+MUTE
4
-PWVs 15
+Vs 7
BOOTSTRAP
6
MUTE
10
STBY-GND
1
+PWVs 13 IN -
2
OUT 14
U2
TDA7294V
1
2
3
4
REC1
KBPS10-02
C11 22uF50V
+E
-E
L2 1.0uH
R10 8R2 1W
C2
0.1uF100V
R12 13K 1%
R6 26.7K 1%
R4
1K 1%
C9
22uF25V
C10
2200pF
R9 5.1K
C13
6800uF50V
C18
6800uF50V
X8 RED
X6 BLACK
X7 RED
C6 10pF
C28 10pF
+E
-E
R17
5.1K
R18
5.1K
R34 5.1K
R33 5.1K
R24
8.2K
R23
5.1K
C30
10uF25V
C32
22uF25V
STBY
9
IN +
3
-Vs 8
IN+MUTE
4
-PWVs 15
+Vs 7
BOOTSTRAP
6
MUTE
10
STBY-GND
1
+PWVs 13 IN -
2
OUT 14
U4
TDA7294V
C21 22uF50V
+E
C16
0.1
-E
C14
0.1
L3 1.0uH
R36 8R2 1W
C23
0.1uF100V
R27 13K 1%
R38 26.7K 1%K
R25
1K 1%
C25
22uF25V
C24
2200pF
R35 5.1K
R22
5.1K
R21
5.1K
D3
1N4148
ZD2
12V 0.5W
R1 8.2K
C3
220uF25V
+12V
Q2
2SC4793
X4
STBY
9
IN +
3
-Vs 8
IN+MUTE
4
-PWVs 15
+Vs 7
BOOTSTRAP
6
MUTE
10
STBY-GND
1
+PWVs 13 IN -
2
OUT 14
U1
TDA7294V
C5 10uF50V
+E
-E
L1 1.0uH
R3 8R2 1W
C1
0.1uF100V
R13 13K 1%
R11 26.7K 1%
R14
1K 1%
C8
10uF25V
C4
390pF
R8 5.1K
C7 10pF
C27 10pF
R15
5.1K
R16
5.1K
STBY
9
IN +
3
-Vs 8
IN+MUTE
4
-PWVs 15
+Vs 7
BOOTSTRAP
6
MUTE
10
STBY-GND
1
+PWVs 13 IN -
2
OUT 14
U3
TDA7294V
C19 10uF50V
+E
C15
0.1
-E
C17
0.1
L4 1.0uH
R37 8R2 1W
C29
0.1uF100V
R31 13K 1%
R26 26.7K 1%
R32
1K 1%
C20
10uF25V
C22
390pF
R30 5.1K
R20
5.1K
R19
5.1K
ZD1
24V 0.5W
Q1
2SC1815
R29 1.2K 3W
R28 1.2K 3W
ZD3
12V 0.5W
C31
100uF16V
C26
100uF16V
C12
4.7uF50V
D2
1N4148
D1 1N4148
R7
68
R5
2.4K
R2 2.4K
T
+E
-12V
X11
BLACK
X1
RED
X10
RED/BLACK STRIP
X2
RED
+12V
-12V
1
2
3
X9
1
2
3
4
X3
1
2
3
4
X12
SUB INPUT (-)
CH.2 (R) INPUT
SUB INPUT (+)
CH.1 (L) INPUT
FAN
24 Vdc
CH.1 (L)
OUTPUT
OUTPUT
CH.2 (R)
OUTPUT (+)
SUBWOOFER
SUBWOOFER
OUTPUT (-)
X5 BLACK
X13 BLACK
To CENTER TAP
To POWER
To POWER
To SPEAKER
To CHASSIS
POWER TRANSFORMER
TRANSFORMER
TRANSFORMER
OUTPUTS
MAIN PCB
OUTPUT
1+
1-
2+
2-
X2 NL4MP
1+
1-
2+
2-
X1 NL4MP
P1
RED
P2
BLACK
P3
RED/BLACK STRIP
CH.1 (L)
OUTPUT
CH.2 (R)
3.15A / 220-240V
FUSE
OUTPUT PCB
18AWG RED 45sm
18AWG BLACK 45sm
Ends
striped
15mm
Twisted pair to Subwoofer terminal
18AWG BLACK 18AWG BLACK
18AWG RED
18AWG RED/BLACK STRIP
18AWG BLACK
1
2
3
4
5
6
7
X1
1
2
3
4
5
6
7
1
2
3
4
5
6
7
SCHEMATIC
Page 9