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6

Guided Tour - Rear Panel

1:  AC input -  Connect the supplied standard 3-pin “IEC” plug here.

2:  Fuse holder - Insert a 2.5 amp, 125 volt fuse here for 115 volt operation, or a 1.5 amp, 250 volt fuse
for 230 volt operation.  We recommend the use of normal (as opposed to slow-blow) fuses.
WARNING: Fuses should only be replaced with the power cord disconnected.

3:  Bridge switch - For normal operation, place this switch at its left (“OFF”) position.  When placed at
its right (“ON”) position, the two amplifier sections (the left and right channels) are bridged, providing full
120 watt power output into a single output.  For more information, see the “Bridge Mode” section on
page 7 in this manual.  WARNING: Due to the extremely high power output of the Servo 120 when used
in Bridge mode, be sure to use only 8 ohm loudspeakers sufficiently rated to handle the resultant
wattage.

4:  Balanced Inputs* - Connect incoming signal to these electronically balanced 1/4" TRS
(Tip/Ring/Sleeve) jacks, wired as follows: Tip hot, Ring cold, and Sleeve ground.  Use balanced three-
conductor cabling and TRS plugs wherever possible (unbalanced two-conductor plugs can also be
inserted into these inputs, but you’ll get better signal quality and less outside noise and hum if you
use balanced lines).  Stereo signals should be connected to both the left and right input jacks; when
operating the Servo 120 in Bridge mode, use the left input jack only (see page 7 in this manual for more
information).  The Servo 120 accepts input levels of any strength but needs at least +4 dBu to achieve
maximum power.

5:  Unbalanced Inputs* - Connect incoming signal to these unbalanced RCA-type jacks.  Stereo signals
should be connected to both the left and right input jacks; when using the Servo 120 in Bridge mode,
use the left input jack only (see page 7 in this manual for more information).  The Servo 120 accepts
input levels of any strength but needs at least +4 dBu to achieve maximum power.

6:  Push-spring terminal output connectors - Use these to connect each channel of the Servo 120
to loudspeakers.  Be sure to connect the loudspeaker correctly, with the red (+) terminal normally
connected to the positive input of the speaker and the black (ground) terminal normally connected to the
negative input of the speaker.  See the “Bridge Mode” section on page 7 in this manual for speaker
connection instructions when using the Servo 120 in Bridge mode.

* If required, both the balanced and unbalanced inputs can be used simultaneously.

BRIDGE

OFF

ON

F

U

S

E

F

U

S

E

SERVO 120 STEREO AMPLIFIER

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

!

SAMSON

BALANCE

RIGHT

LEFT

M0N0

BALANCE

AC INPUT

USA & CANADA 115V~60HZ 200W

EUROPE & UK 230V ~ 50HZ 300W

USA & CANADA

2.5A/125V (115V)

EUROPE & UK

1.5A/250V (230V)

+RIGHT

GROUND

LEFT+

MONO (8

)

-

+

1

2

3

4

5

6

Summary of Contents for Power Amplifier Servo 120

Page 1: ... OWNERS MANUAL S T U D I O AMPLIFIER S E R V O 1 2 0 ...

Page 2: ...4 Guided Tour 5 Front Panel 5 Rear Panel 6 Setting Up and Using the Servo 120 Amplifier 7 The Servo 120 Protection Circuitry 8 Bridge Mode 9 Appendix A Linearity vs Frequency Sweep 10 Appendix B Power Output vs THD 11 Specifications 12 ...

Page 3: ...dio experience in your own home try connecting your home hi fi amplifier s auxiliary outputs to the Servo 120 s inputs thus using your hi fi amp as a preamplifier and then connect your existing speakers to the Servo 120 s outputs If you fall in love with the sound as we re sure you will you might want to substitute a professional pre amplifier for your existing hi fi amp and from there you may wel...

Page 4: ...h push spring terminal output connectors Convection cooling no fan makes for whisper quiet operation even in critical listening environments such as recording studios Unique bipolar circuit design that continuously keeps DC output during idling at or near 0 volts thus keeping idle speakers at their 0 point This serves to minimize heat overload problems by effectively preventing the Servo 120 from ...

Page 5: ...n on page 7 in this manual for more information 5 Protection LED This goes on for approximately five seconds whenever the Servo120 is powered on and fades slowly when the amp is powered off When lit 0 volts DC are provided to all connected speakers thus muting them and preventing any thump from occurring For a complete description of the conditions under which this light goes on see the section en...

Page 6: ... connected to both the left and right input jacks when operating the Servo 120 in Bridge mode use the left input jack only see page 7 in this manual for more information The Servo 120 accepts input levels of any strength but needs at least 4 dBu to achieve maximum power 5 Unbalanced Inputs Connect incoming signal to these unbalanced RCA type jacks Stereo signals should be connected to both the lef...

Page 7: ... the same power strip that other audio devices such as a mixing console are connected to You can then turn on all devices at once with the single power strip on off switch with no danger of damaging connected speakers by generating thumps 6 Press the front panel Speaker on off switch so that it is in in its down position and then press the front panel Power switch in order to turn on the Servo 120...

Page 8: ...o guard against this problem make sure the Servo 120 receives adequate ventilation on all sides see page 5 for more information in extreme environmental conditions you may also want to consider the use of cooling fans Severe overcurrent conditions This occurs whenever the signal being input to the Servo 120 rises to a level above 20 THD Total Harmonic Distortion Shorted speaker cables This will oc...

Page 9: ...d is thus doubled so that the power output is doubled When using the Servo 120 in Bridge mode be sure to connect each loudspeaker as shown in the illustration below and as silkscreened on the rear panel with the red terminal of the left channel connected to the positive input of the speaker and the red terminal of the right channel connected to the negative input of the speaker Do not use the blac...

Page 10: ...ty vs Frequency Sweep 10 Linearity 0 dB Ref vs frequency sweep 10 Hz 50 kHz 5 0000 4 0000 3 0000 2 0000 1 0000 0 0 1 000 2 000 3 000 4 000 5 000 10 100 1k 10k 50k Ap AUDIO PRECISION Servo 120 LEVEL dBr vs FREQ Hz 0dB ref ...

Page 11: ...60 W vs Total Harmonic Distortion 80 000 73 000 61 000 56 000 48 000 40 000 32 000 21 000 15 000 8 000 200 0u 0 000 1000 2000 3000 4000 5000 6000 7000 8000 9000 1 000 20 100 1k 10k 50k Ap AUDIO PRECISION Servo 120 THD N LEVEL W vs FREQ Hz THD Watts ...

Page 12: ...z 7 kHz rated output power 03 3 Signal To Noise Ratio 22 Hz 22 kHz bandwidth dB below rated output power 105 dB 4 Frequency Response 10 Hz 20 kHz 0 0 5 dB 3 Hz 65 kHz 0 3 0 dB 5 Input Sensitivity 4 dBu to achieve rated power Level control set to maximum 6 Crosstalk adjacent channels 75 dB 1 kHz 7 Output DC Offset Voltage 50 mV DC Servo Controlled 8 Headphone Output Level 15 mW into 8 Ω 1 THD N 9 D...

Page 13: ...avelength for Samson Technologies Corp Copyright 1997 Samson Technologies Corp Printed June 1997 Samson Technologies Corp 575 Underhill Blvd P O Box 9031 Syosset NY 11791 9031 Phone 1 800 3 SAMSON 1 800 372 6766 Fax 516 364 3888 ...

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