Symetrix 581e User manual

581E Distribution Ampliﬁer (4x4)

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

Safety

581E Distribution Ampliﬁer (4x4)

Safety

GThe lightning ﬂash with arrowhead

symbol within an equilateral triangle is

intended to alert the user of the presence

of uninsulated “dangerous voltage”

within the product’s enclosure that may

be of sufﬁcient magnitude to constitute

a risk of electric shock to persons. The

exclamation point within an equilateral

triangle is intended to alert the user of

the presence of important operating and

maintenance (servicing) instructions in the

literature accompanying the product (i.e.

this Quick Start Guide).

GCAUTION: To prevent electric shock,

do not use the polarized plug supplied

with the unit with any extension cord,

receptacle, or other outlet unless the

prongs can be fully inserted.

GPower Source: This Symetrix hardware

uses a switching power supply that

automatically adjusts to the applied

voltage. Ensure that your AC mains

voltage is somewhere between 100-240

VAC, 50-60 Hz. Use only the power

cord and connector speciﬁed for the

product and your operating locale. A

protective ground connection, by way of

the grounding conductor in the power

cord, is essential for safe operation. The

appliance inlet and coupler shall remain

readily operable once the apparatus has

been installed.

GUser Serviceable Parts: There are no

user serviceable parts inside this Symetrix

product. In case of failure, customers

inside the U.S. should refer all servicing to

the Symetrix factory. Customers outside

the U.S. should refer all servicing to an

authorized Symetrix distributor. Distributor

contact information is available online at:

http://www.SymetrixAudio.com.

AVIS:

NE PAS OUVRIR

Il ne se trouve a l’interieur aucune piece pourvant entre reparée l’usager.

SEE OWNERS MANUAL. VOIR CAHIER D’INSTRUCTIONS.

S’adresser a un reparateur compétent.

RISQUE DE CHOC ELECTRIQUE

No user serviceable parts inside. Refer servicing to qualified service personnel.

CAUTION

WARNING:

TO REDUCE THE RISK OF FIRE OR

ELECTRIC SHOCK DO NOT EXPOSE

THIS EQUIPMENT TO RAIN OR MOISTURE

DO NOT OPEN

RISK OF ELECTRIC SHOCK

Important Safety

Instructions

!Read these instructions.

@Keep these instructions.

#Heed all warnings.

$Follow all instructions.

%Do not use this apparatus near water.

This apparatus shall not be exposed to

dripping or splashing and no objects

ﬁlled with liquids, such as vases, shall be

placed on the apparatus.

^Clean only with dry cloth.

&Do not block any ventilation openings.

Install only in accordance with the

manufacturer’s instructions.

*Do not install near any heat sources such

as radiators, heat registers, stoves, or

other apparatus (including ampliﬁers) that

produce heat.

(This apparatus shall be connected to

a mains socket outlet with a protective

earthing connection. Do not defeat

the safety purpose of the polarized or

grounding-type plug. A polarized plug has

two blades with one wider than the other.

A grounding type plug has two blades

and a third grounding prong. The wide

blade or the third prong are provided for

your safety. If the provided plug does not

ﬁt into your outlet, consult an electrician

for replacement of the obsolete outlet.

BL Protect the power cord from being

walked on or pinched particularly at

plugs, convenience receptacles, and the

point where they exit from the apparatus.

BM Only use attachments/accessories

speciﬁed by the manufacturer.

BN Use only with the cart, stand,

tripod, bracket, or table

speciﬁed by the manufacturer,

or sold with the apparatus.

When a cart is used, use

caution when moving the cart/apparatus

combination to avoid injury from tip-over.

BO Unplug this apparatus during lightning

storms or when unused for long periods

of time.

BP Refer all servicing to qualiﬁed service

personnel. Servicing is required when

the apparatus has been damaged in any

way, such as power-supply cord or plug

cord is damaged, liquid has been spilled

or objects have fallen into the apparatus,

the apparatus has been exposed to rain

or moisture, does not operate normally, or

has been dropped.

What Ships in the Box

• A581Ehardwareunit.

• Adetachablepowercord.

• 20EuroConnectors.

• ThisUser’sGuide.

Getting Help

If you have questions beyond

the scope of this User’s Guide, contact

our Customer Support Group in the

following ways:

Tel: +1 (425) 778-7728

8:00 am to 4:30 pm

Monday through Friday,

Pacific Time

Web: http://www.SymetrixAudio.com

This device complies with part 15 of

the FCC Rules. Operation is subject

to the following two conditions: (1)

This device may not cause harmful

interference, and (2) this device must

accept any interference received,

including interference that may cause

undesired operation.

This Class B Digital apparatus meets

all requirements of the Canadian

Interference-Causing Equipment

Regulations

Cet appariel numerique de la classe

B respecte toutes les Exigences du

Reglement sur le materiel brouilleur

du Canada.

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

Introduction•FirstTimeSetup

Introduction

The Symetrix 581E Distribution Ampliﬁer (4x4) is a

four-input, sixteen-output distribution ampliﬁer. In a typical

conﬁguration the 581E accepts four balanced input signals

and distributes each input to four independent outputs. The

volume of each of the sixteen outputs may be individually

trimmed via its front panel potentiometer. Similarly, the

volume of each of the four inputs may be independently

controlled. Associated with each input is a four LED level

meter to assist the user in setting optimum operating levels.

The balanced input stages are designed for high common

mode rejection and RF immunity. Output line drivers are

stable short-circuit protected and designed around industry

standard 5532 type op amps. The 581E operates from

an internal power supply built around a low magnetic ﬁeld

toroidal transformer, resulting in a very low noise, high

performance product.

The 4x4 architecture of the 581E allows the ampliﬁer to ﬁt

the greatest possible number of conﬁgurations. Each one

input, four output module is independent of the others.

Wiring the 581E’s inputs to four separate audio sources

provides four mono distribution channels with four outputs

each. This conﬁguration also accommodates two stereo

audio feeds.

Stereo audio can be distributed to eight inputs by strapping

the 581E’s inputs together in pairs. Left channel audio is

wired to inputs #1 and #2, while the right channel connects

to inputs #3 and #4.

The 581E distributes a single mono audio source to all 16

outputs when all inputs are strapped together. Regardless

of your audio distribution requirements, the Symetrix 581E

solves the problem with minimum cost and no wasted

outputs.

Fast First Time Setup

Follow these instructions to get your 581E up-and-running

as quickly as possible. The intent of this section is fast

setup. Refer to later chapters for explanation of the 581E’s

controls and functions.

!Connect audio inputs and outputs. If you do not know

how to do this, forget Fast Setup and skip to the Rear

Panel Overview.

@Set INPUT level trim controls straight up (12 o’clock

position).

#Set OUT level trim controls at maximum level (clock-wise

rotation).

$Plug the 581E into an AC outlet using the IEC-type

detachable power cord provided with the unit.

Caution: Failure to connect the 581E to the proper AC

mains voltage may cause ﬁre and/or internal damage.

Warning: Lethal voltages are present inside the chassis.

There are no user serviceable parts inside the chassis.

Refer all service to qualiﬁed service personnel or to the

factory.

%Apply line level audio signal to the input(s). “Line level”

means previously ampliﬁed audio, i.e. not the output of a

microphone or other unampliﬁed audio transducer.

^Turn up the INPUT level pot(s) until the red CLIP LED

just barely lights. Then back the level down just a bit

until the CLIP LED doesn’t come on any more, or only

occasionally ﬂashes.

&Now read the rest of this User’s Guide.

581E Distribution Ampliﬁer (4x4)

Front/Rear Panel

Front Panel

Item Description

Input Level The four input level controls on the 581E are marked INPUT 1, INPUT 2, INPUT 3 and INPUT 4. Each control adjusts it’s correspond-

ing input signal over a 30 dB range. With signal applied to input(s) turn up the INPUT level pot(s) until the red CLIP LED just barely

lights. Then back the level down just a bit until the CLIP LED doesn’t come on any more, or only occasionally flashes. This is the

optimum setting and will provide the greatest signal-to-noise ratio without distortion.

If your incoming signal positions are unpredictable then we suggest a straight up (12 o’clock) setting. Since the 581E’s input has 18

dB of headroom above +4 dBu, this setting should work well under most conditions.

If you find that your input signal is very low (the output of a “-10” consumer level device, such as a CD player, for example), turn the

INPUT level control clockwise to boost the signal. Conversely, if you’re feeding a “+8” broadcast level signal to the 581E then turn the

INPUT level control counterclockwise until the proper LED display is achieved.

Input LEDs Individual LED indicators show input signal levels of -10, 0, +10 and CLIP.

Output Level The sixteen output level controls on the 581E are marked OUTPUT 1A, OUTPUT 1B, OUTPUT 1C, OUTPUT 1D, OUTPUT 2A,

OUTPUT 2B, etc. Use these controls to attenuate the output level over a 20 dB range. Start by turning all controls fully clockwise

(unity gain). This will create equal levels from all outputs. If for some reason you wish to reduce the level of certain outputs then turn

the appropriate control(s) counterclockwise. Otherwise, for better overall system performance it’s best to leave the controls wide open

(full clockwise) for the hottest possible output signals.

Power Red LED indicates power “on”.

REAR Panel

Item Description

IEC Connector Connect the proper IEC power cable supplied for your locale. Connect only to appropriate AC power source. Refer to rear panel

marking for correct AC source voltage.

Inputs/Outputs The 581E is fitted with Euroblock style connectors for both inputs and outputs

NOTE:

Detachable Euroblock connectors are designed for use with bare wire.

Do not tin stranded wires before inserting them into the connectors.

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

Making the Connections

Inputs

The four 581E inputs are balanced. Of course, they may be used in

unbalanced configurations but for optimum system wide performance

(best noise rejection) balanced operation is highly recommended.

Use shielded cable for both input and output connections. The wire

should always be two-conductor plus shield, even for unbalanced

connections.

For balanced input signals:

MConnect the incoming signal “+” (high) to the “+” INPUT terminal of

the 581E.

MConnect the incoming signal “-” (low) to the “-” INPUT terminal of the

581E.

MConnect the incoming signal ground (shield) to the ground terminal of

the 581E. Repeat for all inputs.

MFor unbalanced input signals, using two-conductor shielded cables:

MConnect the incoming signal “+” (high) to the “+” INPUT terminal of

the 581E. Use the red wire.

MConnect the incoming signal ground to the “-” INPUT terminal of the

581E. Use the black wire.

MConnect the cable shield at the ground connection of the 581E only.

If you experience hum or noise, make sure that both the 581E and

the device which you are feeding are grounded on the same AC

mains circuit. If this is not the source of the noise problem, you must

isolate the unbalanced output from the balanced input with an audio

transformer or “matchbox.”

Wiring the 581E in 2x8 or 1x16 conﬁguration

To connect the 581E as a 2 input, 8 output dis-

tribution ampliﬁer proceed as follows:

MConnect the two incoming signals to INPUT 1 and INPUT 2 as per

the instructions above.

MConnect (4) additional short pieces of #20 or #22 gauge wire as

follows:

MINPUT 1 “+” to INPUT 3 “+”

MINPUT 1 “-” to INPUT 3 “-”

MINPUT 2 “+” to INPUT 4 “+”

MINPUT 2 “-” to INPUT 4 “-”

To connect the 581E as a 1 input, 16 output

distribution ampliﬁer proceed as follows:

MConnect the single incoming signal to INPUT 1 as per the instructions

above.

MConnect (6) additional short pieces of #20 or #22 gauge wire as

follows:

MINPUT 1 “+” to INPUT 2 “+”

MINPUT 2 “+” to INPUT 3 “+”

MINPUT 3 “+” to INPUT 4 “+”

MINPUT 1 “-” to INPUT 2 “-”

MINPUT 2 “-” to INPUT 3 “-”

MINPUT 3 “-” to INPUT 4 “-”

Outputs

The 581E’s four outputs are active balanced circuits and should be

used to feed balanced audio inputs. Use two-conductor shielded audio

cable for all connections.

Feeding balanced inputs:

MConnect the “+” (high) OUTPUT terminal of the 581E to the “+” (high)

of the input of the device which you are feeding.

MConnect the “-” (low) OUTPUT terminal of the 581E to the “-” (low) of

the input of the device which you are feeding.

MConnect cable shield to the ground of the 581E and the ground

connection of the device which you are feeding.

Feeding unbalanced inputs:

WE DON’T RECOMMEND IT. If you must feed an unbalanced input

with the 581E, you should isolate the two devices with either an

audio transformer or an interface matching device (a “matchbox”).

The 581E follows the AES standards for balanced audio circuits. The

ground connections of the amplifier are chassis ground.

If you must connect the output of the 581E directly to an unbalanced

input, try this procedure. Use two-conductor shielded audio cable.

MConnect the “+” (high) OUTPUT terminal of the 581E to the “+” (high)

of the unbalanced input.

MMake no connection to the “-” (low) OUTPUT terminal of the 581E.

MConnect the cable shield at the 581E’s ground and at the input

connector of the unbalanced input.

The output signal level of the 581E will be 6 dB lower when driving an

unbalanced input without a transformer or matching interface device.

If you experience hum or noise, make sure that both the 581E and

the device which you are feeding are grounded on the same AC

mains circuit. If this is not the source of the noise problem, you must

isolate the balanced output from the unbalanced input with an audio

transformer or “matchbox.”

581E Distribution Ampliﬁer (4x4)

Connecting to Other Gear

Matching Levels vs Matching Impedances

In any audio equipment application, the question of “matching”

inevitably comes up. Without digging a hole any deeper than absolutely

necessary, we offer the following discussion to (hopefully) clarify your

understanding of the subject.

Over the years, we have all had impedance matching pounded into

our heads. This is important only for vintage audio systems, power

amplifiers, and RF. Technically speaking, the reason is power transfer,

which reaches a maximum when source and load are matched. Modern

audio systems are voltage transmission systems and source and load

matching is not only unnecessary, but undesirable as well.

2Vintage audio systems operate at 600 Ohms (or some other

impedance value), and must be matched, both at their inputs and at

their outputs. Generally speaking, if you are dealing with equipment

that uses vacuum tubes, or was designed prior to 1970, you should

be concerned about matching. These units were designed when

audio systems were based on maximum power transfer, hence the

need for input/output matching.

2Power amplifiers are fussy because an abnormally low load

impedance generally means a visit to the amp hospital. Thus, it’s

important to know what the total impedance of the pile of speakers

connected to the amplifier really is.

2RF systems are matched because we really are concerned with

maximum power transfer and with matching the impedance of the

transmission line (keeps nasty things from happening). Video signals

(composite, baseband, or otherwise) should be treated like RF.

Some folks seem to believe that balanced/unbalanced lines and

impedances are related; or even worse that they are associated

with a particular type of connector. Not so. Unbalanced signals are

not necessarily high-impedance and balanced signals/lines are not

necessarily low-impedance. Similarly, although 1/4 inch jacks are

typically used for things like guitars (which are high-impedance and

unbalanced), this does not predispose them to only this usage. After

all, 1/4 inch jacks are sometimes used for loudspeakers, which are

anything but high-impedance. Therefore, the presence of 3-pin XLR

connectors should not be construed to mean that the input or output

is low-impedance (or high-impedance). The same applies to 1/4 inch

jacks.

So, what is really important? Signal level, and (to a much lesser

degree), the impedance relation between an output (signal source) and

the input that it connects to (signal receiver).

Signal level is very important. Mismatch causes either loss of headroom

or loss of signal-to-noise ratio. Thus, microphone inputs should only

see signals originating from a microphone, a direct (DI) box, or an

output designated microphone-level output. Electrically, this is in the

range of approximately -70 to -20 dBm. Line inputs should only see

signals in the -10 to +24 dBm/dBu range. Guitars, high-impedance

microphones, and many electronic keyboards do not qualify as line-

level sources.

The impedance relation between outputs and inputs needs to be

considered, but only in the following way - Always make sure that a

device’s input impedance is higher than the output source impedance

of the device that drives it.

Some manufacturers state a relatively high-impedance figure as the

output impedance of their equipment. What they really mean is that this

is the minimum load impedance that they would like their gear to see.

In most cases, seeing a output impedance figure of 10,000 (10K) Ohms

or higher from modern equipment that requires power (batteries or AC)

is an instance of this type of rating. If so, then the input impedance

of the succeeding input must be equal to or greater than the output

impedance of the driving device.

Symetrix equipment inputs are designed to bridge the output of

whatever device drives the input (i.e. to be greater than 10 times the

actual source impedance). Symetrix equipment outputs are designed to

drive 600 Ohm or higher loads (600 Ohm loads are an archaic practice

that won’t go away). You don’t need to terminate the output with a

600 Ohm resistor if you aren’t driving a 600 Ohm load. (If you don’t

understand the concept of termination, you probably don’t need to

anyway.)

The two facts that you need to derive from this discussion are:

2Match signal levels for best headroom and signal-to-noise ratio.

2For audio, impedance matching is only needed for vintage equipment

and power amplifier outputs. In all other cases, ensure that your

inputs bridge your outputs (meaning the inputs are in the range of 2

to 200 times the output source impedance).

Signal Levels

The 581E is designed around studio/professional line levels: +4 dBu

or 1.23 volts RMS. The unit is quiet enough to operate at lower signal

levels such as those found in semi-pro or musical instrument (MI)

equipment (-10 dBV or 300 millivolts).

I/O Impedances

The 581E is designed to interface into almost any recording studio or

sound reinforcement application. This includes:

600 Ohm systems where input and output impedances are matched.

Modern bridging systems where inputs bridge and outputs are low

source impedances (voltage transmission systems).

The 581E’s input impedance is greater than 20k Ohms balanced. The

inputs may be driven from any balanced source capable of delivering at

least -10 dBV into the aforementioned impedances.

The 581E’s output impedance is 600 Ohms balanced, 300 Ohms

unbalanced. The output line driver delivers +22 dBm into 600 Ohm

balanced loads or +18 dBm into 600 Ohm unbalanced loads.

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

Input/Output Connections

Input and Output Connections

The illustration to the right shows how to connect the 581E to balanced

and unbalanced sources and loads.

To operate the 581E from unbalanced sources, run a 2-conductor

shielded cable (that’s two conductors plus the shield) from the source

to the 581E. At the source, connect the low/minus side to the shield,

these connect to the source’s ground; connect the high/plus side to the

source’s signal connection. At the 581E, the high/plus wire connects

to pin 2, the low/minus wire connects to pin 3, and the shield (always)

connects to pin 1. This is the preferred method as it makes best use of

the 581E’s balanced input (even though the source is unbalanced). The

other alternative shown in the illustration converts the 581E’s balanced

input into an unbalanced input at the input connector. This works, but

is more susceptible to hum and buzz than the preferred method. There

is no level difference between either method.

You can drive unbalanced loads with the 581E’s outputs by using the

XLR connector with pin 3 left open. In an emergency (the show must go

on), you can ground pin 3, but if you have the choice... leave it open. If

you must ground pin 3, it is must be grounded at the 581E, rather than

at the other end of the cable. The price, regardless of whether or not

pin 3 is grounded is 6 dB less output level. If your system is wired with

pin 3 hot, and you are driving an unbalanced load, pin 2 must float.

Balanced

Terminal Strip

Terminal Strip [balanced]

Euroblock

Connector

Channel Input/Output

Euroblock

Connector

Channel Input

Euroblock

Connector

Channel Output

Euroblock

Connector

Channel Input/Output

Euroblock

Connector

Channel Input

Pin 2 = (+) Plus

Pin 3 = (–) Minus

Pin 1 = Ground

XLR Female Plug [balanced]

Pin 2

Pin 3

Pin 1

Pin 2

Pin 3

Pin 1

Pin 2 = (+) Plus

Pin 3 = (–) Minus

Pin 1 = Ground

XLR Male Plug [balanced]

Tip = (+) Plus

Ring = (–) Minus

Sleeve = Ground

TRS 1/4" Plug [balanced]

Tip = (+) Plus

Sleeve = Ground

TS 1/4" Plug [unbalanced]

Euroblock

Connector

Channel Output

Tip = (+) Plus

Sleeve = Ground

TS 1/4" Plug [unbalanced]

NOTE: Detachable Euroblock

connectors are designed for use

with bare wire. Do not tin stranded

wires before inserting them into

the connectors.

IMPORTANT NOTICE 1

The wiring diagrams on this page are included for

information purposes only.

Symetrix can not anticipate exactly what connection

is needed at the non-581E end of the cable. It is

the user’s responsibilty to determine what

connection is needed.

In addition, Symetrix accepts no responsibilty for

injury or damage caused by user created wiring.

581E Distribution Ampliﬁer (4x4)

Block Diagram

CHANNEL 4

CHANNEL 3

CHANNEL 1

CHANNEL 2

CLIP

+10

OUTPUT

1A LEVEL

INPUT 1

LEVEL

CHANNEL 1

INPUT LED

DISPLAY

CHANNEL 1

INPUT

OUT

OUTPUT

1B LEVEL

OUT

OUTPUT

1C LEVEL

OUT

OUTPUT

1D LEVEL

OUT

CHANNEL 4

CHANNEL 3

CHANNEL 1

CHANNEL 2

CLIP

+10

OUTPUT

1A LEVEL

INPUT 1

LEVEL

CHANNEL 1

INPUT LED

DISPLAY

CHANNEL 1

INPUT

OUT

OUTPUT

1B LEVEL

OUT

OUTPUT

1C LEVEL

OUT

OUTPUT

1D LEVEL

OUT

The 581E Block Diagram

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

Troubleshooting

No output

Check cables and connections. Are inputs driven by

outputs, and outputs driving inputs? Verify cables, source

and load by patching input and output connections together,

at the unit. Check for AC power presence.

Hum or buzz in output

Check input and output connector wiring. Ground loop:

check related system equipment grounding. Are all system

components on the same AC ground?

Distortion

Check the level of the input signal on the 581E’s LED

display(s). Is the CLIP light on all the time? If so, reduce

the incoming signal level by turning the INPUT level

counterclockwise. Is the incoming signal already distorted?

Listen “up stream” from the 581E to make sure you’re

feeding it a clean signal.

Noise (hiss)

Check input signal levels and input level control settings The

input signal may be too low. If so, boost the incoming signal

(if possible). Is the input signal already noisy? Listen “up

stream” from the 581E to determine that you are feeding it a

clean signal.

No LED display

Is the unit plugged in, and turned on? Is the AC outlet OK?

Notes:

581E Distribution Ampliﬁer (4x4)

A&ESpecs•DeclarationofConformity

Architects and Engineers Speciﬁcations

The audio distribution amplifier shall be a four channel unit with each channel

consisting of one electronically balanced input amplifier and four electronically

balanced output amplifiers. Associated with each channel shall be a master gain

adjustment circuit capable of up to 15 dB of gain or 15 dB of loss for the purpose

of optimally matching incoming signal level(s). Also associated with each channel

shall be a four LED array for the indication of the signal levels applied to the output

drive circuits. The LED’s shall be labelled CLIP, +10, 0, and -10 corresponding to

internal signal levels of +18 dBu, +10 dBu, 0 dBu, and -10 dBu.

Each output shall be capable of driving a 600 Ohm balanced load to a level of

+22 dBm. The maximum output level into a balanced bridging load (20k Ohms)

shall be +26 dBu. Each output will offer an individual attenuator with a range of

0 to -20 dB.

Frequency response through the amplifier shall be ±½ dB, measured between 20

Hz and 20 kHz. THD+Noise shall be less than 0.009% measured at unity gain

with a bandwidth of 30 kHz. Residual noise will be >100 dB below a +4 dBu input

signal when measured with an A-weighting filter.

The unit shall occupy one rack space (1U). The physical dimensions shall be

1.72”H x 19”W x 6”D; 4.45cm H x 43.7cm W x 15.24cm D.

The distribution amplifier shall operate by means of its built-in power supply

connected to 115 VAC, nominal, 95-130 VAC, 50-60 Hz; or 230 VAC nominal,

165-255 VAC, 50 Hz. Power consumption shall be 18 watts, maximum. There

shall be a rear panel receptacle for an IEC type detachable power cord. The

distribution amplifier shall carry the CE mark.

The distribution amplifier shall be a Symetrix, Inc. model 581E Distribution

Amplifier (4x4).

Speciﬁcations

Input/Output

Maximum Input Level +26 dBu Balanced

Maximum Output Level +26 dBu Balanced (20k Ohm load)

+22 dBm (600 Ohm load)

Input Impedance 20k Ohms Balanced, 10k Ohms Unbalanced

Output Impedance 200 Ohms Balanced, 100 Ohms Unbalanced

Performance Data

Frequency Response ±½ dB, 20 Hz - 20 kHz

THD+Noise <.009%, unity gain input to output,

30 kHz measurement bandwidth

Signal to Noise Ratio >100 dB, A-weighted, ref. to +4 dBu

Dynamic Range >125 dB, A-weighted

Common Mode Rejection >40 dB, 20 Hz - 20 kHz

Input Gain Range ±15 dB

Output Gain Range 0 to -20 dB

Connections

All Inputs, and Outputs Euroblock

Power In IEC 3-prong jack

Physical

Size (hwd) 1.72 x 19 x 6 in., 4.37 x 48.26 x 15.24 cm.

Shipping Weight 8 lbs.

Electrical

Power Requirements 115 VAC nominal, 95-130 VAC, 50-60 Hz

230 VAC nominal, 165-255 VAC, 50 Hz

Power Consumption 18 watts maximum

Note: The maximum operating ambient temperature is 25 degrees C.

Declaration of Conformity

We, Symetrix Incorporated, 6408 216th St. SW,

Mountlake Terrace, Washington, USA, declare under our

sole responsibility that the product:

581E Distribution Ampliﬁer

to which this declaration relates, is in conformity with

the following standards:

EN 60065

Safety requirements for mains operated electronic and

related apparatus for household and similar general

use.

EN 50081-1

Electromagnetic compatibility - Generic emission

standard

Part 1: Residential, commercial, and light industry.

EN 50082-1

Electromagnetic compatibility - Generic immunity

standard

Part 1: Residential, commercial, and light industry.

The technical construction ﬁle is maintained at:

Symetrix, Inc.

6408 216th St. SW

Mountlake Terrace, WA, 98043 USA

The authorized representative located within the

European Community is:

World Marketing Associates

P.O. Box 100

St. Austell, Cornwall, PL26 6YU, U.K.

Date of issue: January 1, 2001

Place of issue: Lynnwood, Washington, USA

Authorized signature:

Dane Butcher, President, Symetrix Incorporated.

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

Warranty and Service

The Symetrix Limited Warranty

Symetrix, Inc. expressly warrants that the product will be free from

defects in material and workmanship for eighteen (18) months from

the date the product is shipped from the factory. Symetrix’s obligations

under this warranty will be limited to repairing or replacing, at Symetrix’s

option, the part or parts of the product which prove defective in material

or workmanship within eighteen (18) months from the date the product

is shipped from the factory, provided that the Buyer gives Symetrix

prompt notice of any defect or failure and satisfactory proof thereof.

Products may be returned by Buyer only after a Return Authorization

number (RA) has been obtained from Symetrix. Buyer will prepay all

freight charges to return the product to the Symetrix factory. Symetrix

reserves the right to inspect any products which may be the subject of

any warranty claim before repair or replacement is carried out. Symetrix

may, at its option, require proof of the original date of purchase (dated

copy of original retail dealer’s invoice). Final determination of warranty

coverage lies solely with Symetrix. Products repaired under warranty will

be returned freight prepaid via United Parcel Service by Symetrix, to any

location within the Continental United States. Outside the Continental

United States, products will be returned freight collect.

The foregoing warranties are in lieu of all other warranties,

whether oral, written, express, implied or statutory. Symetrix, Inc.

expressly disclaims any IMPLIED warranties, including fitness

for a particular purpose or merchantability. Symetrix’s warranty

obligation and buyer’s remedies hereunder are SOLELY and

exclusively as stated herein.

This Symetrix product is designed and manufactured for use in

professional and studio audio systems and is not intended for

other usage. With respect to products purchased by consumers for

personal, family, or household use, Symetrix expressly disclaims

all implied warranties, including but not limited to warranties of

merchantability and fitness for a particular purpose.

This limited warranty, with all terms, conditions and disclaimers set forth

herein, shall extend to the original purchaser and anyone who purchases

the product within the specified warranty period.

Symetrix does not authorize any third party, including any dealer or

sales representative, to assume any liability or make any additional

warranties or representation regarding this product information on behalf

of Symetrix.

This limited warranty gives the buyer certain rights. You may have

additional rights provided by applicable law.

Note: Some Symetrix products contain embedded software and may

also be accompanied by control software intended to be run on a

personal computer. Said software is specifically excluded from

this warranty.

Limitation of Liability

The total liability of Symetrix on any claim, whether in contract, tort

(including negligence) or otherwise arising out of, connected with, or

resulting from the manufacture, sale, delivery, resale, repair, replacement

or use of any product will not exceed the price allocatable to the

product or any part thereof which gives rise to the claim. In no event will

Symetrix be liable for any incidental or consequential damages including

but not limited to damage for loss of revenue, cost of capital, claims of

customers for service interruptions or failure to supply, and costs and

expenses incurred in connection with labor, overhead, transportation,

installation or removal of products, substitute facilities or supply houses.

Servicing Your Symetrix Product

If you have determined that your Symetrix product requires repair

services and you live outside of the United States please contact your

local Symetrix dealer or distributor for instructions on how to obtain

service. If you reside in the U.S. then proceed as follows:

Return Authorization

At the Symetrix factory, Symetrix will perform in-warranty or out-of-

warranty service on any product it has manufactured for a period of

three (3) years from date of discontinued manufacture.

Before sending anything to Symetrix, please contact our Customer

Service Department for a Return Authorization (RA) number. The

telephone number is +1 (425) 778-7728. Additionally, support is

available via the web site: http://support.SymetrixAudio.com.

In-warranty Repairs

To get your Symetrix product repaired under the terms of the warranty:

1. Call us for an RA number (have the serial number, shipping and contact

information and description of the problem ready).

2. Pack the unit in its original packaging materials.

3. Include your name, address, daytime telephone number, and a brief

statement of the problem.

4. Write the RA number on the outside of the box.

5. Ship the unit to Symetrix, freight prepaid. We do not accept freight

collect shipments.

Just do these five things, and repairs made in-warranty will cost you only

one way freight charges. We’ll pay the return freight.

If you don’t have the factory packaging materials, we recommend using

an oversize box. Wrap the unit in a plastic bag, surround it with bubble-

wrap, and place it in the box surrounded by Styrofoam peanuts. Be sure

there is enough clearance in the box to protect the rack ears. We won’t

return the unit in anything but Symetrix packaging for which we will have

to charge you. If the problem is due to operator misuse or error, you will

have to pay for both parts and labor. In any event, if there are charges

for the repair, you will pay for the return freight. All charges will be COD

unless you have made other arrangements (prepaid, Visa or Mastercard).

Out-of-warranty Repairs

If the warranty period has passed, you’ll be billed for all necessary parts,

labor, packaging materials, and freight charges. Please remember, you

must call for an RA number before sending the unit to Symetrix.

581E Distribution Ampliﬁer (4x4)

User’s Guide

6408 216th Street SW |Mountlake Terrace, WA 98043 USA

T+1.425.778.7728 F+1.425.778.7727 |www.SymetrixAudio.com

581E Distribution Ampliﬁer (4x4)

Item No. 53-0007

581E Distribution Amplifier (4x4) User’s Guide

Symetrix, Inc. shall not be liable for technical or editorial errors or omissions contained herein; nor is it liable for incidental or consequential damages

resulting from the furnishing, performance, or use of this material. Mention of third-party products is for informational purposes only and constitutes

neither an endorsement nor a recommendation. Symetrix assumes no responsibility with regard to the performance or use of these products. Under

copyright laws, no part of this brochure may be reproduced or transmitted in any form or by any means, electronic or mechanical, without permission

in writing from Symetrix, Inc. If, however, your only means of access is electronic, permission to print one copy is hereby granted. The following are