Studiomaster SX225, SX235 User Manual

Professional Power Amplifier

SX ENG V1

SX225
SX235

1

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

IMPORTANT SAFETY SYMBOLS

The symbol is used to indicate that some hazardous live terminals are involved
within this apparatus, even under the normal operating conditions, which maybe
sufficient to constitute the risk of electric shock or death.

The symbol is used in the service documentation to indicate that specific com­ponent shall be replaced only by component specified in that documentation
for safety reasons.

Protective grounding terminal

Alternating current/voltage

Hazardous live terminal

ON: Denotes the apparatus is turned on

OFF: Denotes the apparatus is turned off.

WARNING: Describes precautions that should be observed to prevent the danger of

iInjury or death to the operator.

CAUTION: Describes precautions that should be observed to prevent danger of the
apparatus.

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1. IMPORTANT SAFETY INSTRUCTIONS

Read these instructions.

Keep these instructions.

Heed all warning.

Follow all instructions.

Water & Moisture

The apparatus should be protected from moisture and rain, can not used near

water, for example: near bathtub, kitchen sink or a swimming pool, etc.

Heat

The apparatus should be located away from the heat source such as radiators,

stoves or other appliances that produce heat.

800W 2

450W 2

1000W 2

580W 2

2000W

4 Ohms

8 Ohms

8 Ohms

1600W

10K Unbalanced 20K Balanced

0dB/0.775V

20Hz~20KHz 0.5dB

<0.1% (1KHz)

100dB(A weighted) 88(bandwidth)

300 @8

300 @8

70dB (1KHz) or 45dB (20-20KHz)

1200W 2 1500W 2

2 Ohms

4 Ohms

3000W2600W

220-240V AC 50Hz/60Hz

483 400 88.8mm(W D H)

12.5kg 13kg

F. TECHNICAL SPECIFICATIONS

Stereo mode
(dual channel)
1KHz

Bridge mono
1KHz

Damping coefficient

S/N ratio

THD(SMPTE-1)

Item

Frequency response

(below 10dB rated power)

Protection

Control

Input sensitivity

Input impedance

Crosstalk damping

DC protection, over drive/heat protection,
short-circuit protection, clip protection.

Indicator

Signal: 2 green LED
PEAK: 2 red LED
Power: 1 blue LED
Level: 2 green LED
Bridge: 1 yellow LED

Front panel: AC switch
Each channel volume knob
Rear panel:

1. stereo/bridge/parallel mode selecting switch

2. ground switch

3. Hi-pass selecting switch

Connector

Power supply

Dimension

Weight

Input: electric balanced COMBO,
1/4 inch TRS and terminal block.
Output: speak-on and binding posts.

12

SX235SX225

MODEL

Ventilation

Do not block ventilation areas. Failure to do so could result in fire. Always install

accordance with the manufacturer's instructions.

Object and Liquid Entry

Objects do not fall into and liquids are not spilled into the inside of the apparatus

for safety.

Power Cord and Plug

Protect the power cord from being walked on or pinched particularly at plugs,

convenience receptacles, and the point where they exit from the apparatus.
Do not defeat the safety purpose of the polarized or grounding-type plug.

Power Supply

The apparatus should be connected to the power supply only of the type as

marked on the apparatus or described in the manual. Failure to do so will result
in damage to theproduct and possibly to user.

Unplug this apparatus during lightning storms or when unused for long periods
of time.

Fuse

To prevent the risk of fire and damaging the unit, please use only the recommended

type of fuse as described in the manual. Before replacing the fuse, make sure the

unit is turned off and Type disconnected with AC outlet.

Electrical Connection

Improper electrical wiring may invalidate the product warranty.

Cleaning

Clean only with a dry cloth. Do not use any solvents such as benzol or alcohol.

Maintenance

Do not accept any servicing other than that described in the manual. Consult with

a qualified service personnel only.

Only use accessories or parts recommended by the munufacturer.

2

INPUT

LINK

E.R

30Hz-9dB

LA DIF

PWR AMP

OUTPUT

CH A

CH A

1.15V RMS

+4dB

15Kohm

BALANCED

SUB WOOFER

(OPTION)

+/-

MODE

INPUT

LINK

E.B LA DIF

PWR AMP

OUTPUT

CH BCH B

AUTORAMP

TURN-ON CIRCUIT SHOCK

DC OFFSET

DC SERVO

OVER TEMP

SHORT CIRCUIT

CURRENT LIMITER

TURN-ON/TURN-OFF

TRANSIENTS

BRIDGED

PARALLEL

MONO

ACTIVE

CLIP

CH A

CH B

AMP

SIG

CH-A

CH-B

OPTION

BINDING POST

TERMINALS

AC PWR

DETECTOR

PWR

INDR

2-SPEED

¡Û

FANS

IN-RUSH

CURRENT

POWER

SWITCH

FUSE

AC POWER

120V/220V/230V

/240V 50/60Hz

(OPTION)

:XLR CONNECTOR

:1/4" PHONE JACK

:SPEAKON CONNECTOR

NOTICE

30Hz-9dB

SWITCH

POWER

E. BLOCK DIAGRAM

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3

A. INTRODUCTION

Thanks for purchasing our this series professional power amplifier.
With many years amplifier R&D experience, the product adopts advanced professional
technology, which can guarantee its cost performance is higher than similar products
in market. The internal part of product adopts high effect software switch technology
that makes product be light and stable, and features multiple protect functions: clipping
& limiting protect, overdrive/overheat protect, HF protect and short-circuit protect etc.
apparatus is simple and elegant, operation is convenient and clear. Panel: power switch,
each channel (channel A/B) volume control knobs, clipping indicator, signal indicator,
power indicator and bridge indicator. Rear panel: combo/wiring terminal blocks/TRS
input socket, speak-on/binding-post output socket, parallel/bridge/stereo mode transfer
switch, limit transfer switch etc.
In order to have a good understand of product's features, please read carefully the
manual before operating the apparatus.

B. CONTROLS

Front/rear panel controls

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INPUT

FROM

SOURCE

1+

2-

2+

1-

CH A-

CH A+

1+

2-

2+

1-

CH A+

CH B+

1+

2-

2+

1-

CH B-

CH B+

CH A

Bridged

CH B

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+

INPUT

FROM

SOURCE

SHIELD

CH A

CH A

+

PIN 1+

PIN 1-

How to connect bridge mode?

Under bridge mode, signals that input from CH A, can be output from CH A+ and
CH B+ or bridged output connector. Volume is controlled by volume knob of CH A.
In order to avoid crosstalk, please turn down CH B's volume to lowest. Please set
mode selecting switch to right position (BRIDGE) before bridge mode operating.
For further information, please refer to following diagram:

input connection hint

Balanced Unbalanced

BRIDGE

STEREO

PARALLEL

unavailable

unavailable

(solo channel)

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1

2

3

4

7 7

6

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8. AC input socket

Connect standard 3PIN IEC power connector to main power system through
accessible power cable.
Please confirm if the voltage is correct before connecting power.

Note: to avoid shock or fire damages, please make sure amplifier and related

apparatus all connect to ground.

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1. power switch(ON/OFF)

Power switch, is used for turning on/off amplifier power. When turn on apparatus
power, power indicator illuminates.
Note: to avoid damaging your apparatus, please turn down volume before turning
on amplifier power.

2. peak indicator (PEAK)

Both Channel A and channel B feature a peak indicator. When input signal reach
or pass over peak level (signal distortion 0.5%), corresponding channel indicator
illuminates. Please adjust level control to avoid distortion.

3. bridge indicator (BRIDGE)

When bridges, indicator illuminates.

4. level indicator (-10dB, -20dB)

Indicates signal strength that inputs to power amplifier.

5. signal indicator(SIG)

Each channel feature a signal indicator, when output signal passes 500mV
(or input signal to input path ), indicator of corresponding channel illuminates.

6. power indicator (POWER)

When turn on apparatus power, the blue indicator illuminates.

7. volume control (CHA/CHB)

Both Channel A and channel B feature a volume control knob, turn the knob
to adjust input sensitivity of corresponding channel. The adjustable scope is:

- ~30dB. turn anti-clock to OFF position, at which can protect your loudspeaker
when turn on any system.

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SHIELD

INPUT

FROM

SOURCE

1+

2-

2+

1-

CH A-

CH A+

1+

2-

2+

1-

CH A+

CH B+

1+

2-

2+

1-

CH B-

CH B+

CH A

Bridged

CH B

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INPUT

FROM

SOURCE

SHIELD

+

+

PIN 1+

PIN 1-

PIN 1+

PIN 1-

How to connect parallel mode?

Under parallel mode, signals that input to CH A or CH B, can be output from
CH A and CH B. Volume is controlled by volume knob of each channel.
Please set mode selecting switch to left position (PARALLEL) before parallel
mode operating. For further information, please refer to following diagram:

input connection hint

Unbalanced

Balanced

unavailable

CH A

CH A

CH B

BRIDGE

STEREO

PARALLEL

(solo channel)

9

10. Ground separating switch

ON means connecting apparatus ground with case, OFF means apparatus ground
isn't connecting with case(mainly used for decreasing noise when system allocates).

11. Hi pass selecting switch

Under ON state, can filter infrasonic wave below 30Hz, and protect bass unit effectively.

12. mode selecting switch

The switch supplies three operation modes, parallel, stereo and bridge.
Please select according to requirement.

1) Parallel mode:

Under the mode, there are one solo channel input, and two channels output; that is,
signals that input to CH A or CH B, can be output from CH A and CH B. Volume is
controlled by volume knob of each channel.

2) Stereo mode:
Under the mode, CH A and CH B operate separately. Signals that input from CH A,
outputs from CH A; Signals that input from CH B, outputs from CH B. Volume is
controlled by volume knob of each channel.

3) Bridge mode:

Under the mode, there are one solo channel input, and one solo channel output;
signal that inputs from CH A, and outputs from CH A+, CH B+ or bridge output
socket. The volume is controlled by CH A volume control knob. Turn down CH B
knob to lowest to avoid cross talk. Specific operation, please refer to chapter 4
of the manual.

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9. audio input/output connector

CHA and CHB electric balance COMBO (compliance XLR and 1/4"), terminal
block input connectors, used for connecting external audio signal.
These connectors internal parallel, can receive balanced and unbalanced audio
signal. The amplifier adopts low noise electric balanced circuit, wide dynamic
scope make it can receive signal of any audio level.

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SHIELD

INPUT

FROM

SOURCE

1+

2-

2+

1-

CH A-

CH A+

1+

2-

2+

1-

CH A+

CH B+

1+

2-

2+

1-

CH B-

CH B+

CH A

Bridged

CH B

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INPUT

FROM

SOURCE

SHIELD

+

+

PIN 1+

PIN 1-

PIN 1+

PIN 1-

How to connect stereo mode?

Under stereo mode, CHA and CHB work separately, Signals that input from CHA,
outputs from CHA; Signals that input from CHB, outputs from CHB. Volume is
controlled by volume knob of each channel. Please set mode selecting switch to
the middle position (STEREO) before stereo mode operating.
For further information, please refer to following diagram:

input connection hint

Unbalanced

Balanced

CH B

CH A

CH A

CH B

unavailable

BRIDGE

STEREO

PARALLEL

(solo channel)

8

4) Turn off power after operating.

3) Adjust volume knob of amplifier to the best S/N ratio.

2) Turn on power switch of amplifier.

of speaker, two volume knobs should be turned to lowest before turning on

power amplifier.

volume knob sets on appropriate position. Usually, in order to avoid damaging

operation mode is correct;

all device connect to ground rightly;

AC voltage is correct;

1) Please confirm before connecting,

3) Power connection

Please check if voltage is correct, before connecting amplifier to power. Voltage
and fuss should be the same as indicated at rear panel. please use power cable
recommended by manufacture. It adopts standard IEC plug, which is qualified for
national ISM standard.

2) Audio connection

Power amplifier features COMBO, 1/4" TRS and terminal block input connection,
speaker-on as well as binding post output connector, which is convenient for
different connecting.

1) cabinet equipment

amplifier's height is 19" 2U, is suitable for standard cabinet equipment. In order to
avoid overheat, please make sure that power amplifier have enough room to cool
down, don't block ventilation.

6 7

14. fan

Fan can adjust speed automatically according to internal temperature.
Wind direction: front board rear board

13. audio output connector

Output connector of standard speak-on and biding post connector, which is used
for outputting audio signal amplified to external speaker. in order to avoid damage
of your device, please pay attention to impedance matching, don't make it is pay
attention to impedance matching, don't make it is lower than lowest impedance.

LF: 1+ 1-

HF: 2+ 2-

1+
1-2+2-

SPEAKON

Tip

Ring

Sleeve

+

-

1/4" TRS JACK

XLR

1

2

3

1

2

3

1: GND 2: Hot (+) 3: Cold (-)

COMBO -XLR/JACK

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3

XLR-F :
1: GND 2: Hot (+) 3: Cold (-)

TRS JACK
Tip/Ring/Sleeve

Wiring configuration

D. OPERATION

C. EQUIPMENT AND CONNECTION