Samson Servo 120 User Manual

• Rack-mount stereo power amplifier (1-space).

• 60 watts per channel into 4 ohms (stereo).

• 120 watts into 8 ohms (mono bridge).

• 10 Hz to 100 kHz frequency response.

• Electronically balanced 1/4″ and unbalanced RCA

inputs on gold-plated connectors.

• Push-spring terminal outputs.

• Smart Servo circuitry protection against overheating

and overcurrent.

• High-current output power transistors.

• Unique bipolar circuit design continuously keeps DC

output during idling at or near 0 V (thus keeping idle
speakers at their 0 point).

• Front-panel protection LED, headphone jack, speaker
on/off switch, 3 color LED meters.

• Independent left- and right-channel input controls
with 41-position detent.

• Convection-cooled (No Fan).

• Solid steel chassis with lightweight anodized alu-

minum heat sink.

• Toroidal transformer power supply.

• Front-panel headphone jack with speaker disable

switch.

• 3 Year warranty.

SERVO 120

AMPLIFIER

POWER

The Servo 120 power amplifier is intended for use
in all types of recording applications, live performance
and permanent installs. This easily-installed 1-space rack­mount stereo power amplifier (which can also be used in
mono bridge mode) delivers 60 watts per channel into a 4
ohm load (in mono bridge mode, 120 W into 8 ohms),
over a bandwidth of 20 Hz to 50 kHz. It utilizes high-cur­rent output power transistors and features an efficient
bipolar circuit design that continuously keeps DC output
during idling at or near 0 volts. The Servo 120 also has
balanced 1/4

″ and RCA inputs and push-spring terminal
outputs, a front-panel protection light, headphone jack,
speaker On/Off switch, 3 color LED meters and thermal
and overcurrent protection circuitry. The Servo 120 is con­vection cooled for silent operation, eliminating f an noise
and the need for filter maintenance.

Contact:

Samson Technologies Corp., P.O. Box 9031, Syosset, NY 11791-9031 • Phone: [phone] • Fax: [phone] • www.samsontech.com

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 (8Ω)

-+

Output Power (typical all channels driven):

4 Ω, 1 kHz, 1% THD, 83 W

4 Ω, 1 kHz, .034% THD, 60 W

8 Ω, 1 kHz, 1% THD, 57.5 W

8 Ω, 1 kHz, <.019% THD, 52 W

8 Ω bridged, 1 kHz, 1% THD, 160 W

8 Ω bridged, 1 kHz, < .08% THD, 120W
Frequency Response (-3 dB): <10 Hz to 100 kHz
Frequency Response (1 watt): 20 Hz to 20 kHz, -0.1/-0.2
Crosstalk (adj. channels): 80 dB, 1 kHz @ rated output
Distortion (THD+N, 20 Hz to 20 kHz) (80 kHz LPF):
at rated power: < .05%
at 1 watt: < .05%
Sensitivity (level control at maximum): +4 dBu
Damping Factor (8 Ω): > 150
Dynamic Range: 98 dB below rated output

(20 Hz to 22 kHz B.P.F.)
Headphone Output Level: 240 mW at 8 Ω (1 kHz)
Input Impedance: >10 k Ω balanced/> 10 k Ω unbalanced
Power Consumption: 240 W @ 120 V/60 Hz

270 W @ 220 V/50 Hz

Dimensions: 17.5

″ (w) x 1.75″ (h) x 11.5″ (d)

444 mm (w) x 44 mm (h) x 292 mm (d)

Weight: 15.6 lb / 7 kg

SERVO 120 SPECIFICATIONS

ARCHITECT’S & ENGINEER’S

SPECIFICATION

The power amplifier shall be capable of stereo or
mono bridged operation. In stereo mode, it shall deliver a
minimum of 52 W into loads of 8 ohms each with both chan­nels operating, or 6 0 W into loads of 4 ohms each with both
channels operating. In mono bridge mode, it shall deliver a
minimum of 120 W into an 8 ohm load. It shall be passively
cooled, and shall have internal short-circuit and ther mal pro­tection circuitry. A protection LED indicator shall activate
and the power amplifier shall shut down to protect against
short circuits, overheating, severe overcurrent conditions or
DC offset present at the outputs. The power amplifier shall
have slow start-up and muted inputs on turn-on. Inputs
shall be on balanced 1/4

″ tip-ring-sleeve connectors and

outputs shall be on 1/4

″ phone connectors and on push­spring terminals. The front panel shall have independent level
controls for left and right channels, a master power switch
and LED indicators for clip, idle and amplifier protection.

The power amplifier shall have a frequency response
of less than 10 Hz to 100 kHz, signal-to-noise equal to or
greater than 103 dB and THD less than 0.5%. Total power
consumed at full audio power shall be 240 W (120 Vac)
and 975 W (220 Vac). The dimensions shall allow for stan­dard 19

″ EIA rack mounting. It shall be 1.75″ (44 mm; 1

rack space) high and 11.5

″ (292 mm) deep. Weight shall be

15.6 lb. (7 kg). The power amplifier shall carry a three-year
warranty.

The power amplifier shall be a SAMSON SERVO 120.

Specifications subject to change without notice. ©1998 Samson

FREQUENCY RESPONSE

AUDIO PRECISION Servo 120 LEVEL (dBr) vs FREQ (Hz)

0dB ref

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

Ap

50k