Symetrix 303 User manual

303 Interface Amplifier
(Bi-directional)
Users Guide
303

i
Table of Contents
Chapter 1 Introduction 1
Chapter 2 Operator Safety Summary 2
Chapter 3 Fast Setup 3
Chapter 4 Front & Rear Panel Overview
Chapter 5 Tutorial 5
Chapter 6 Applications 6
Chapter 7 Troubleshooting 7
Chapter 8 Specifications 8
Chapter 9 Warranty and Service 9
Chapter 10 Declaration of Conformity 11
Rev A, 15 June, 1998
Symetrix part number 53303-0A00
Subject to change at our whim and fancy without
notice.
©1998, Symetrix, Inc. All right reserved.
Symetrix is a registered trademark of Symetrix, Inc.
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 manual may be
reproduced or transmitted in any form or by any
means, electronic or mechanical, including photo-
copying, scanning, recording or by any information
storage and retrieval system, without permission, in
writing, from Symetrix, Inc.
6408 216th St. SW
Mountlake Terrace, WA 98043 USA
Tel [phone]
Fax [phone]
Email: [email protected]
303

303
1
IntroductionChapter 1
Front panel
Rear panel
Computer audio recording systems and high-
quality consumer audio equipment provide their
users with efficient and affordable systems.
Unfortunately, they also create a few audio
challenges of their own. Joining consumer audio
gear with professional audio gear in a signal path
requires connecting equipment designed to
operate at different signal levels. A direct wire
connection between them should be avoided.
he Symetrix 303 Interface Amplifier creates a
proper interface between consumer and profes-
sional audio gear. his tool provides bi-direc-
tional level-matching and balanced/unbalanced
conversion between professional (+4 dBu
nominal level, balanced) audio equipment and
consumer (-10 dBV nominal level, unbalanced)
audio components.
he 303 has two completely separate channels of
conversion and level matching in each direction
(from -10dBV to +4dBu, and from +4dBu to
-10dBV). his means that, in each direction, the
303 may be used as a stereo interface amplifier, or
as two mono interface amplifiers. All inputs and
outputs may be used at the same time, allowing
up to four channels of simultaneous level-
matching and conversion.
Level-matching permits the connection of
consumer and pro audio gear, while allowing
both types of units to operate at optimal perfor-
mance levels. A typical use of the 303 would be
to connect a DA , cassette deck or computer
sound card (all of which generally run at -10dBV
nominal level), to a professional audio mixer
(+4dBu nominal level) or vice versa.
he Symetrix 303 also provides conversion from
unbalanced, -10dBV outputs to balanced, +4dBu
inputs and conversion from balanced, +4dBu
outputs to unbalanced, -10dBV inputs. his
conversion can also be used to minimize noise
and hum.
A note about setup: Unbalanced cables are much
more susceptible to induced noise and hum than
balanced cables (when used with balanced inputs
and outputs), and the longer an unbalanced cable
is, the more noise and hum you are likely to pick
up. If you keep the unbalanced cables between
the consumer equipment and the 303 short (under
10 feet), and use the balanced lines between the
professional gear and the 303 for any long cable
runs, you are far less likely to pick up noise and
hum, and you take advantage of the common-
mode rejection of the balanced input.
Low noise operation is also ensured by the
Symetrix 303 s external power supply, which
eliminates the possibility of power supply noise
developing in the 303's circuitry.
We recommend that you read this manual
cover-to-cover. You will find the answers to
most of your questions inside. However, if you
are in a hurry, go directly to Chapter 3 (Fast
Setup). It will get you started quickly. Please
feel free to contact us if you have questions,
comments or suggestions.
Phone:[phone]
Fax:[phone]
Email: [email protected]
Website: www.symetrixaudio.com
PWR
(BI-DIRECTIONAL)
INTERFACE AMP
303
+4dBu IN(L)+4dBu IN(R)
(L)
(R)
-10dBV IN -10dBV OUT
BALANCED TO UNBALANCED
+4dBu OUT(L)+4dBu OUT(R)
INPUT
POWER
RÉFÉREZ TOUTE RÉPARATION À UN TECHNICIEN QUALIFIÉ.
FABRIQUÉ AUX E.-U. PAR SYMETRIX INC., LYNNWOOD, WASHINGTON.
MANUFACTURED BY SYMETRIX INC. LYNNWOOD, WA USA
THIS PRODUCT CONTAINS NO USER SERVICABLE PARTS.
OR PS-3E POWER
SYMETRIX PS-3
CONNECT TO
SUPPLY ONLY.
UNBALANCED TO BALANCED

303
2
he information in this summary is intended
for persons who operate the equipment as well
as repair personnel. Specific warnings and
cautions are found throughout this manual
wherever they may apply.
he notational conventions used in this
manual and on the equipment itself are
described in the following paragraphs.
he 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 per-
sons.
he exclamation point within an equilateral
triangle is intended to alert the user of the
presence of important operating and mainte-
nance (servicing) instructions in the literature
accompanying the 303 (i.e. this manual).
Caution To prevent electric shock, do not
use the polarized plug supplied
with the 303 with any extension
cord, receptacle, or other outlet
unless the blades can be fully
inserted.
Terms
Several notational conventions are used in this
manual. Some paragraphs may use Note,
Caution, or Warning as a heading. Certain
typefaces and capitalization are used to
identify certain words. hese are:
Note Identifies information that needs
extra emphasis. A Note generally
supplies extra information to help
you to better use the 303.
Equipment Markings
Operator Safety Summary Chapter 2
Caution Identifies information that, if not
heeded, may cause damage to the
303 or other e uipment in your
system.
Warning Identifies information that, if
ignored, may be hazardous to
your health or that of others.
CAPI ALS Controls, switches or other
markings on the 303's chassis.
Boldface Strong emphasis.
Power source - his product is intended to
operate from a power source that does not
apply more than 255Vrms between the power
supply conductors or between either power
supply conductor and ground. A protective
ground connection, by way of the grounding
conductor in the power cord, is essential for
safe operation.
Danger from loss of ground - If the protective
ground connection is lost, all accessible
conductive parts, including knobs and
controls that may appear to be insulated, can
render an electric shock.
In-line power supply - his product receives its
operating power from the Symetrix PS-3 or PS-3E
power supply. his is the only power supply
approved for use with the product. Do not
connect the product to any other in-line, or
plug-in, transformer. he use of other power
sources may cause damage to the equipment
or present a shock hazard to the operator.
Operating location - Do not operate this
equipment under any of the following condi-
tions: explosive atmospheres, in wet locations,
in inclement weather, improper or unknown AC
mains voltage, or if improperly fused.
tay out of the box - o avoid personal injury
or injury to others, do not remove the product
covers or panels. Do not operate the product
without the covers and panels properly
installed.
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

303
3
Fast First-Time Setup
Follow these instructions to get your 303 up-and-running as quickly as possible. he intent of this
section is fast setup. Refer to later chapters for explanation of the 303's connections and applications.
1. Connect the 7-pin connector end of the 303's external power supply cable to the 7-pin
power receptacle on the rear of the Symetrix 303.
2. Connect the three-pronged AC plug end of the 303's external power supply cable to an
AC power source of the proper voltage and frequency, as marked on the rear of the unit.
Caution Failure to connect the 303 to the proper 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.
3. o connect the analog output(s) of a consumer (-10dBV) audio device to the analog
input(s) of a professional (+4dBu) audio device:
A.Connect the output(s) of the -10dBV device to the Symetrix 303's RCA input jack(s).
B.Connect the Symetrix 303's XLR output jack(s) to the input(s) of the +4dBu device.
4. o connect the analog output(s) of a professional (+4dBu) audio device to the analog
input(s) of a consumer (-10dBV) audio device:
A.Connect the output(s) of the +4dBu device to the Symetrix 303's XLR input jack(s).
B.Connect the Symetrix 303's RCA output jack(s) to the input(s) of the -10dBV device.
Once you have completed the previous steps, the 303 should pass signal. Fast setup is complete.
Fast Setup
Chapter 3

303
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Front Panel
PWR LED: his is the power LED, which lights to indicate the presence of power at the
303's power input jack.
Front & Rear Panel Overview Chapter 4
PWR
(BI-DIRECTIONAL)
INTERFACE AMP
303
+4dBu IN(L)+4dBu IN(R)
(L)
(R)
-10dBV IN -10dBV OUT
BALANCED TO UNBALANCED
+4dBu OUT(L)+4dBu OUT(R)
INPUT
POWER
RÉFÉREZ TOUTE RÉPARATION ÀUN TECHNICIEN QUALIFIÉ.
FABRIQUÉAUX E.-U. PAR SYMETRIX INC., LYNNWOOD, WASHINGTON.
MANUFACTURED BY SYMETRIX INC. LYNNWOOD, WA USA
THIS PRODUCT CONTAINS NO USER SERVICABLE PARTS.
OR PS-3E POWER
SYMETRIX PS-3
CONNECT TO
SUPPLY ONLY.
UNBALANCED TO BALANCED
Rear Panel
POWER INPU : 7-pin DIN receptacle. Connect this to the 7-pin DIN plug of a
Symetrix PS-3 or PS-3E only. Connect the AC power connector of the
PS-3 or PS-3E to an AC power source that is of the correct voltage and
frequency, as marked on the PS-3 or PS-3E.
NoteThe PS-3 and PS-3E are Symetrix accessories, available from your Symetrix
dealer.
UNBALANCEDhis is the input and output section of the 303's unbalanced -10dBV to
O BALANCED: +4dBu conversion/level-matching circuitry.
+4dBu OU (L) hese balanced XLR outputs will contain the signal applied to the -10dBV
and +4dBu OU (R): inputs, after that signal has been balanced and raised to +4dBu nominal level.
-10dBV IN hese unbalanced RCA inputs accept -10dBV nominal unbalanced signals,
(L) and (R): which are converted to +4dBu balanced signals at the +4dBu outputs.
Note he (L) and (R) inputs and outputs listed above may be used for stereo left
and right signals, or they may be used as two mono inputs and outputs,
because the circuitry for the left and right channels is completely separate.
BALANCED Ohese are the input and output jacks for the 303's balanced +4dBu to -10dBV
UNBALANCED: conversion/level-matching circuitry.
-10dBV OU hese unbalanced RCA outputs will contain the signal applied to the +4dBu
(L) and (R): inputs, after that signal has been unbalanced and lowered to -10dBV nominal
level.
+4dBu IN hese balanced XLR inputs accept +4dBu nominal balanced signals, which
(R) and (L): are converted to -10dBV unbalanced signals at the -10dBV outputs.

303
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TutorialChapter 5
Consumer Audio Equipment
For the purposes of this discussion, consumer audio equipment is defined as equipment that is
designed to operate at -10dBV nominal signal levels. he inputs and outputs of this type of gear
are unbalanced. ypically, the input and output connectors are of the RCA-type.
o operate properly and with the lowest noise performance, the signal level applied to the line
input of a consumer audio device must be -10dBV nominal. If the input signal is too low, the
apparent noise floor will increase as the overall gain is increased downstream , to compensate for
the weak input signal. If the input signal is too weak it may never reach the threshold at which the
consumer device begins to act. If the input signal is too high (i.e. +4dBu), headroom will be greatly
reduced, and the input stage of the audio device may overload and distort.
Consumer audio equipment is unbalanced, and unbalanced wiring is susceptible to RF (radio
frequency) interference, as well as other types of induced noise and hum. he length of intercon-
necting cables for unbalanced equipment must be kept to a minimum (under 10 feet), to minimize the
noise and hum that may be induced in the cables.
Semi-pro audio equipment also falls into this category.
Professional Audio Equipment
For the purposes of this discussion, professional audio equipment is defined as equipment that is
designed to operate at +4dBu nominal signal levels. he inputs and outputs of this type of gear
are balanced. ypically, the input and output connectors are of the XLR-type.
o operate properly and with the lowest noise performance, the signal level applied to the line
input of a professional audio device must be +4dBu nominal. If the input signal is too low (i.e.
-10dBV), the apparent noise floor will increase as the gain is increased downstream , to compen-
sate for the weak input signal. If the input signal is too weak it may never reach the threshold at
which the professional device begins to act. If the input signal is too high, the input stage of the
audio device may overload and distort.
Professional audio equipment is balanced, and balanced wiring is designed to reject RF (radio
frequency) interference, as well as other types of induced noise and hum. Balanced inputs utilize
Common-Mode Rejection to get rid of any noise or hum that may have been picked up by the
interconnecting cables. he relative immunity of balanced wiring to induced noise and hum
permits the interconnecting balanced cables to be very long, sometimes hundreds of feet, without
picking up appreciable noise or hum.
Beware of using unbalanced cables to interconnect balanced equipment. Doing this immediately
changes the operation of your balanced equipment to unbalanced, and destroys the noise immu-
nity advantage of your balanced gear.
Also avoid making a direct-wire connection between unbalanced and balanced gear. his connec-
tion changes the operation of your balanced equipment to unbalanced, and destroys the noise
immunity advantage of your balanced gear. Use your Symetrix 303 instead.
Interconnecting Consumer and Professional Audio Equipment
o properly connect a piece of consumer audio equipment to a piece of professional audio gear,
you must ensure that each type of gear receives the appropriate nominal signal levels. You must
also make sure that the inputs and outputs of your balanced equipment are connected to balanced
cables, which are in turn connected to other balanced equipment. he Symetrix 303, inserted in the
signal path between consumer and professional audio devices, accomplishes both of these
functions, maintaining the integrity of the signal as it passes between the two types of audio
equipment.

303
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Connecting the Output of a Computer Audio Card to +4dBu Gear
he diagram below shows how the 303 should be connected in-line between the audio card's
-10dBV, unbalanced output and the input of a +4dBu, balanced device.
Connecting the Output of a +4dBu Device to -10dBV Gear
he diagram below shows how the 303 should be connected in-line between the balanced outputs
of a +4dBu device, and the unbalanced inputs of a -10dBV unit, such as a DAT machine or cassette
recorder.
Applications Chapter 6
(+4dBu), DESTINATION
PRO LEVEL AUDIO
BALANCED, -10DbV SOURCE
OR OTHER
AUDIO CARD
COMPUTER
CHANNELCHANNEL
INPUTS
ANALOG
LEFT
INPUTS
RIGHT
ANALOG
+4dBu IN(L)+4dBu IN(R)
(L)
(R)
-10dBV IN -10dBV OUT
BALANCED TO UNBALANCED
+4dBu OUT(L)+4dBu OUT(R)
INPUT
POWER
RÉFÉREZ TOUTE RÉPARATION ÀUN TECHNICIEN QUALIFIÉ.
FABRIQUÉAUX E.-U. PAR SYMETRIX INC., LYNNWOOD, WASHINGTON.
MANUFACTURED BY SYMETRIX INC. LYNNWOOD, WA USA
THIS PRODUCT CONTAINS NO USER SERVICABLE PARTS.
OR PS-3E POWER
SYMETRIX PS-3
CONNECT TO
SUPPLY ONLY.
UNBALANCED TO BALANCED
(-10dBV) AUDIO DEVICE
SIGNAL TO CONSUMER
DEVICE
AUDIO (+4dBu)
BALANCED PRO-
SIGNAL FROM
OUTPUT
UNBALANCED/
INPUT XLR PIN 2 = HIGH = 1/4" TIP
XLR PIN 3 = LOW = 1/4" RING
XLR PIN 1 = GND = 1/4" SLEEVE
BALANCED
BALANCED
BALANCED
UNBALANCED
OUTPUT
TIP=RETURN
RING=SEND
SLEEVE=GROUND
IN/OUTUNBALANCED
BALANCED
SIDECHAIN
IN/OUT
SIDECHAIN
+4dBu IN(L)+4dBu IN(R)
(L)
(R)
-10dBV IN -10dBV OUT
BALANCED TO UNBALANCED
+4dBu OUT(L)+4dBu OUT(R)
INPUT
POWER
RÉFÉREZ TOUTE RÉPARATION ÀUN TECHNICIEN QUALIFIÉ.
FABRIQUÉAUX E.-U. PAR SYMETRIX INC., LYNNWOOD, WASHINGTON.
MANUFACTURED BY SYMETRIX INC. LYNNWOOD, WA USA
THIS PRODUCT CONTAINS NO USER SERVICABLE PARTS.
OR PS-3E POWER
SYMETRIX PS-3
CONNECT TO
SUPPLY ONLY.
UNBALANCED TO BALANCED

303
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TroubleshootingChapter 7
TroubleshootingChart
YMPTOM PROBABLE CAU E
No output signal Check cables and connections. Are inputs driven by outputs, and
outputs driving inputs? Check for AC power presence. Is the 303's
power light on?
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 input signal. Is it too hot, or is it already distorted? Check the
output loading. It should be above or equal to 600 ohms. Is the input of
the device following the 303 clipping? Is something else clipping?
Noise (hiss)Check input signal. he 303's unbalanced inputs are designed to run at
-10dBV nominal, and the 303's balanced inputs are designed to run at
+4dBu nominal. Make sure that you are feeding a line level (not mic
level) signal to the 303 at the appropriate nominal level. Check gain
settings on downstream equipment. he system gain structure should
be such that the 303 operates at or near unity gain. Is the input signal
already noisy?
No Power LED Is the 303 plugged in? Is the AC outlet OK?

303
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Specifications
Architects and Engineers Specifications
Specifications Chapter 8
In the interest of continuous product improvement, Symetrix, Inc.
reserves the right to alter, change, or modify these specifications
without prior notice.
©1998,Symetrix,Inc. All rightsreserved.
Input/Output: +4dBu to -10dBV Circuit
Maximum Input Level +28 dBu Balanced, +22dBu Unbalanced
Maximum Output Level +18 dBV Unbalanced
Input Impedance 40kOhmsBalanced,20kOhmsUnbalanced
Output Impedance 100 Ohms Unbalanced
Input Common Mode Rejection >40dB
Performance Data: +4dBu to -10dBV Circuit
Frequency Response 10 Hz to 30 kHz, +0, -1dB
THD+Noise <.005% at +28dBu
Gain -12dB
Input/Output: -10dBV to +4dBu Circuit
Maximum Input Level +8dBV Unbalanced
Maximum Output Level +22 dBm Balanced, 600 Ohm load
+18dBm Unbalanced, 600 Ohm load
Input Impedance 100k Ohms Unbalanced
Output Impedance 200Ohms Balanced,100OhmsUnbalanced
Performance Data: +4dBu to -10dBV Circuit
Frequency Response 10 Hz to 30 kHz, +0, -1dB
THD+Noise <.005% at +8dBV
Gain +12dB
he Symetrix 303 Interface Amplifier (Bi-
directional) shall simultaneously provide the
following: two channels of -10dBV to +4dBu
(nominal) signal level matching, and two
channels of +4dBu to -10dBV (nominal)
signal level matching.
All -10dBV input and output connectors
shall be unbalanced RCA-type phono
connectors. All +4dBu input and output
connectors shall be balanced 3-pin XLR
(AES/IEC standard wiring - pin 2 +).
he unit shall occupy half of the width of one
rack space. he physical dimensions shall be
1.75"H x 8.5"W x 6.5"D; 4.445cm H x 21.59cm
W x 15.875cm D.
he interface amplifier shall operate by
means of a Symetrix PS-3 or PS-3E power
supply connected to 117V AC nominal,
(95-130V AC), 50-60 Hz or 230V AC nominal,
(165-255V AC), 50 Hz.
he interface amplifier shall be a Symetrix,
Inc. model 303 Interface Amplifier (Bi-
directional).
Connections
Input XLR,RCAjacks
Output XLR,RCAjacks
PowerIn 7pinDIN
Physical
Size(hwd) 1.75 x 8.5 x 6.5 in., 4.445 x 21.59 x 15.875 cm.
Shipping Weight 4.5 lbs
Electrical
PowerRequirements 117V AC nominal, 95-130V AC, 50 to 60 Hz
230V AC nominal, 165-255V AC, 50Hz

303
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Warranty and ServiceChapter 9
Symetrix, Inc. expressly warrants that the product
will be free from defects in material and
workmanship for (18) months. 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 (18) months from date
of shipment, 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 by Symetrix via United Parcel
Service (surface), to any location within the
Continental United States. At Buyer's
request the shipment may be returned via
airfreight at Buyer's expense. 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. ymetrix, Inc.
303 Limited Warranty
Limitation of Liability
he total liability of Symetrix on any claim,
whether in contract, tort (including negli-
gence) or otherwise arising out of, con-
nected with, or resulting from the manufac-
ture, sale, delivery, resale, repair, replace-
ment or use of any product will not exceed
the price allocable to the product or any part
thereof which gives rise to the claim. In no
event will Symetrix be liable for any inciden-
expressly disclaims any IMPLIED warran-
ties, including fitness for a particular
purpose or merchantability. ymetrix's
warranty obligation and buyer s remedies
hereunder are OLELY and exclusively as
stated herein.
his 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 merchant-
ability and fitness for a particular purpose.
his limited warranty, with all terms, condi-
tions 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 addi-
tional warranties or representation regarding
this product information on behalf of
Symetrix.
his limited warranty gives the buyer certain
rights. You may have additional rights
provided by applicable law.
tal 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, installa-
tion or removal of products or substitute
facilities or supply houses.

303
10
If you have determined that your 303 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:
Before sending anything to ymetrix, contact our Customer Service Department for a
return authorization (RA) number. he telephone number is [phone] or email:
[email protected]
In-warranty Repairs
o get your 303 repaired under the terms of the warranty:
1. Call us for an RA number.
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.
Repairs made in-warranty will cost you only one-way freight charges. We'll prepay the
return (surface) freight.
If you send us your product in substandard packaging, we will charge you for factory
shipping materials. If you don t have the factory packaging materials, please use an
oversized carton, wrap the unit in a plastic bag, and surround it with bubble-wrap. Pack the
box full of Styrofoam peanuts. Be sure there is enough clearance in the carton to protect
the rack ears (you wouldn't believe how many units are returned with bent ears). We will
return the unit in Symetrix packaging. Of course, if the repair is due to operator error, parts
and labor will be charged. In any event, if there are charges for the repair costs, you will
pay for the return freight. All charges will be COD unless you have made other arrange-
ments (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.
Servicing the 303

303
11
Declaration of ConformityChapter 10
Declaration of Conformity
We, ymetrix Incorporated,
6408 216th St. SW, Mountlake Terrace, Washington, USA,
declare under our sole responsibility that the product:
303InterfaceAmplifier (Bi-directional)
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.
he technical construction file is maintained at:
ymetrix, Inc.
6408 216th St. SW
Mountlake Terrace, WA, 98043
USA
he 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: June 15, 1998
Place of issue:Mountlake Terrace, Washington, USA
Authorized signature:
Dane Butcher, President, ymetrix Incorporated.

303

303

303
16
ymetrix, Inc.
6408 216th St. SW
Mountlake Terrace, WA, 98043
USA
el: [phone]
Fax: [phone]
Website: http://www.symetrixaudio.com
Email: [email protected]