Samson 4060-4120 User Manual

OWNERS MANUAL

Q U A D

AMPLIFIER

SERVO 4060/4120

Introduction 3 Servo Quad Amplifier Features 4 Guided Tour 5

Front Panel 5 Rear Panel 6

Setting Up and Using the Servo Quad Amplifier 7 The Servo Quad Amplifier Protection Circuitry 8 Bridge Stereo Mode 9 Bi-amplification Applications 10 Appendix A: Linearity vs. Frequency Sweep 11 Appendix B: Power Output vs. THD 12 Specifications 13

Congratulations on purchasing the Samson Servo Quad Amplifier! Although designed for easy operation, we suggest you first take some time to go through these pages so you can fully understand how we’ve implemented a number of unique features.

The Servo Quad Amplifier is actually four discrete power amplifiers in a single chassis, optimized for use in live performance, recording studios, and permanent installations. This manual covers two Servo Quad Amplifier models, which differ primarily in terms of their power rating: the Servo 4060, which delivers 60 watts per channel into 4 ohms (or, in bridged mode, 120 watts into 8 ohms) and the Servo 4120, which delivers 120 watts of power per channel into 4 ohms (or, in bridged mode, 240 watts into 8 ohms). Both models operate over the full frequency spectrum (from 20 Hz to 50 kHz) and include dual bridging switches, four sets of binding post (banana jack) outputs, and both electronically balanced 1/4" TRS and unbalanced RCA-type input connectors

Suggested applications for the Servo Quad Amplifier include:

• Bi-amping applications - Because it is actually four amplifiers in one, the Samson Servo Quad Amplifier is particularly well-suited (in conjunction with appropriate crossover circuitry) to power small and medium size bi-amped speaker systems.

• Amplification for main or nearfield monitors in both professional and project studios - Its superb audio specs and whisper-quiet performance (its convection cooling design means there is no fan) make the Servo Quad Amplifier the perfect complement to any recording studio.

• Home Theatre applications - The sheer flexibility offered by the Servo Quad Amplifier (four discrete amplifier sections plus two independent bridging switches) makes it the perfect addition to any home theatre, in conjunction with any DVD player or other surround sound system. For example, use two channels to drive your front left/right speakers and the other two to drive your satellite rear speakers. Or use two channels for your front left/right speakers and bridge the remaining two channels to drive your center channel or subwoofer with power galore—you’re limited only by your imagination!

• As an extension to a home hi-fi system - The Servo Quad Amplifier boasts professional specs which far exceed that of most consumer products. For a real “studio” experience in your own home, try connecting your home hi-fi amplifier’s auxiliary outputs to the Servo Quad Amplifier’s inputs (thus using your hi-fi amp as a preamplifier) and then connect your existing speakers to the Servo Quad Amplifier’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 well end up graduating to higher-level speakers. High quality sound is addicting—don’t say we didn’t warn you!

• Powering public address systems in permanent installations - The Servo Quad Amplifier can be used to effectively drive PA speakers in installations such as classrooms and corporate conference rooms.

• Onstage monitoring - In small and medium-sized onstage areas (such as in clubs, lounges, etc.), the Servo Quad Amplifier can be used to drive stage monitors, allowing the performers to hear themselves without having to rely on onstage equipment amplification.

• MIDI rack monitoring - MIDI musicians can easily incorporate the Servo Quad Amplifier into their existing rack of gear. Combined with a pair of high quality stage or studio monitors, this makes for an excellent monitoring system that can accurately reproduce the broad range of frequencies typically output by devices such as synthesizers, samplers, and digital audio workstations.

In these pages, you’ll find a detailed description of the many features of the Servo Quad Amplifier, as well as a guided tour through its front and rear panels, step-by-step instructions for setting up and using your Servo Quad Power Amplifier, a description of suggested applications, reference appendices, and full specifications. You’ll also find a warranty card enclosed—please don’t forget to fill it out and mail it in so that you can receive online technical support and so we can send you updated information about these and other Samson products in the future.

SPECIAL NOTE: Should your unit ever require servicing, a

Return Authorization number (RA) is necessary. Without this number, the unit will not be accepted. Please call Samson at 1-800-372-6766 for a Return Authorization number prior to shipping your unit. Please retain the original packing materials and, if possible, return the unit in its original carton and packing materials.

Introduction

Servo Quad Amplifier Features

The Samson Servo Quad Amplifier utilizes the latest technology in professional power amplifier design. Here are some of its main features:

• Power to spare - Each channel of the Servo 4060 delivers 60 watts into 4 ohms (or, in bridge stereo mode, 120 watts into 8 ohms). Each channel of the Servo 4120 delivers 120 watts of power into 4 ohms (or, in bridge stereo mode, 240 watts into 8 ohms).

• Clean, crisp sound - Impressive audio specifications such as 0.05% THD, S/N of 95 dB, crosstalk of

-70 dB, and frequency response of 20 Hz to 50 kHz guarantee ultra-clean sound quality in any live or recording environment.

• Independent input controls for all four channels, with 41-position detents showing attenuation in dB.

• Independent five-segment LED meters for each of the four channels continuously display power

output levels and allow you to correct for overloading (clipping) conditions.

• Front-panel Protection lights show you at a glance overheating or faulty wiring conditions.

• Both electronically balanced 1/4" TRS and unbalanced RCA-type input connector jacks are provided.

• Binding post (banana jack) 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 Quad Amplifier from applying power when unnecessary.

• Protection relay circuitry (linked to the DC offset circuitry) that prevents “thumps” when powering on or off. This means that you can use the Servo Quad Amplifier with a single power strip into which a mixer or other audio devices are connected, without danger of damage to connected speakers.

• Rugged construction (an all-steel chassis with a titanium finish and a lightweight anodized aluminum heat sink) makes the Servo Quad Amplifier eminently roadworthy.

• Flexible design allows the Servo Quad Amplifier to be used free-standing or, with the use of included rack ears, mounted in any standard 19" rack (taking just two rack spaces).

• Three-year warranty.

• Last but certainly not least, value. The Samson Servo Quad Amplifier has been designed from the

ground up to deliver excellent yet affordable sound quality.

Guided Tour - Front Panel

1: Power switch - Use this to power the Servo Quad Amplifier on or off. 2: Power LED - Lit whenever the Servo Quad Amplifier is powered on. 3: Channel input controls (Ch 1 - 4) - These four 41-position knobs allow you to adjust the input level

of the signal arriving at the rear-panel input jacks (see #4 and #5 on the following page). At their fully counterclockwise position (labeled “∞”), the signal is infinitely attenuated (completely off). At their fully clockwise position (labeled “0 dB”), the signal is at unity gain (that is, no attenuation). When 0 dBm of signal arrives at the input jacks and the Channel Input controls are set to their “0 dB” position, the Servo Quad Amplifier delivers full power output.

4: LED meters (Ch 1 - 4)- These five-segment LED meters continuously monitor the power output level for that channel. For convenience, the segments are labeled as follows, from left to right: -20 dB / 10%,

-10 dB / 30%, -3 dB / 50%, 0 dB / 70%, and CLIP / 100%. When the left-most (-20 dB / 10%) segment is lit, the Servo Quad Amplifier is operating at 10% of its power capacity. When the right-most (CLIP / 100%) segment is lit, signal is being output at full strength. For the best signal-to-noise ratio, the right-most (CLIP / 100%) segment should light occasionally during peak levels; if it lights frequently, you may be overloading the Servo Quad Amplifier and a distorted (“clipped”) signal is probably being output. If this occurs and backing off the Input Level control delivers too low an output level for your application, consider using bridge stereo mode (see the “Bridge Stereo Mode” section on page 7 in this manual for more information).

5: Protection LEDs (Ch 1/2, Ch 3/4) - These go on for approximately five seconds whenever the Servo Quad Amplifier is powered on and fade 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 entitled “The Servo Quad Amplifier Protection Circuitry” section on page 6 of this manual.

-20 dB -10 dB -3 dB 0 dB CLIP 10

30 50 70 100%

-16

-1

-19

-12

-23

-27

-33

-40

-44

0dB

LEVEL

∞

CHANNEL 1

-9

-5

-3

-0.5

-20 dB -10 dB -3 dB 0 dB CLIP 10

30 50 70 100%

-16

-1

-19

-12

-23

-27

-33

-40

-44

0dB

LEVEL

∞

CHANNEL 2

-9

CH1/2

-5

-3

PROTECTION

-0.5

SAMSON

SERVO 4120 - 120 WATT X 4 AMPLIFIER

CH3/4

PROTECTION

POWER

-20 dB -10 dB -3 dB 0 dB CLIP 10

30 50 70 100%

-16

-1

-19

-12

-23

-27

-33

-40

-44

0dB

LEVEL

∞

CHANNEL 3

-9

-5

-3

-0.5

-20 dB -10 dB -3 dB 0 dB CLIP 10

30 50 70 100%

-16

-1

-19

-12

-23

-27

-33

-40

-44

0dB

LEVEL

∞

CHANNEL 4

-9

-5

-3

-0.5

+ 9 hidden pages