Fender SR-6520PD, SR-8520PD User Manual

Owner’s Manual for
SR-6520PD
SR-8520PD

P/N 049152

TABLE OF CONTENTS

1. OVERVIEW

1-1. BLOCK DIAGRAM
1-2. INTRODUCTION

2. FRONT PANEL CONTROLS, JACKS, AND LEDS

2-1. INPUT JACKS

2-1-1. LINE INPUTS
2-1-2. MICROPHONE INPUTS

2-2. CHANNEL CONTROLS

2-2-1. CHANNEL MAIN CONTROL
2-2-2. CHANNEL TONE CONTROLS
2-2-3. EFF./REV. CONTROL
2-2-4. MONITOR CONTROL

2-3. MASTER SECTION CONTROLS

2-3-1. MAIN MASTER LEVEL CONTROL
2-3-2. MONITOR MASTER LEVEL CONTROL
2-3-3. REVERB RETURN TO MAIN CONTROL
2-3-4. REVERB RETURN TO MONITOR CONTROL
2-3-5. EFF./REV. SEND LEVEL CONTROL
2-3-6. AUX. LEVEL CONTROL
2-3-7. GRAPHIC EQUALIZER
2-3-8. DIGITAL REVERB and EFFECTS CONTROLS
2-3-9. PHANTOM POWER
2-3-10. DELTACOMP
2-3-11. POWER LED

2-4. PATCH BAY

2-4-1. MAIN OUTPUT
2-4-2. MONITOR OUTPUT
2-4-3. EFF. OUTPUT / REVERB FOOTSWITCH
2-4-4. GEQ OUTPUT
2-4-5. GEQ INPUT
2-4-6. AUX. INPUT
2-4-7. TAPE INPUTS
2-4-8. TAPE OUTPUTS
2-4-9. PWR. AMP INPUT

TM

3. REAR PANEL

3-1. SPEAKER OUTPUT JACKS
3-2. POWER SWITCH
3-3. POWER CORD

4. SETUP AND OPERATION

4-1. INITIAL CONTROL SETTINGS

4-1-1. TYPICAL PRESETS
4-1-2. MAIN CONTROL
4-1-3. MON. CONTROLS
4-1-4. CHANNEL TONE CONTROLS
4-1-5. GRAPHIC EQUALIZER

4-2. USING THE THE GRAPHIC EQUALIZER TO ELIMINATE ACOUSTIC FEEDBACK

4-2-1. THE CAUSE OF ACOUSTIC FEEDBACK
4-2-2. TYPICAL PROCEDURE FOR ROOM EQUALIZATION

4-3. CORDS AND CABLES

4-3-1. MICROPHONE CORDS

4-3-2. SPEAKER CABLES
4-4. INPUT PADS
4-5. PATCHING

5. UPKEEP AND SERVICE

6. TROUBLESHOOTER'S CHECKLIST

7. SPECIFICATIONS

1-1 Block Diagram

MAIN

MONITOR

PHANTOM

EFFECTS/REVERB

MAIN

MASTER

EFF./REV.

SEND LEVEL

OUTPUT

MONITOR

MASTER

MAIN

GEQ

INPUT

REVERB RETURN

TO MONITOR

L

TAPE

OUTPUTS

R

GRAPHIC EQ

DIGITAL SIGNAL

PROCESSER

GEQ

OUTPUT

POWER

AMP INPUT

PEAK

PILOT LAMP

POWER

AMP

DELTACOMP

SWITCH

SPEAKER
OUTPUT

2 OHM

MINIMUM

TM

EFFECTS
OUTPUT

REVERB

FT. SW.

MONITOR

OUTPUT

MICROPHONE

+

21

LINE

PHANTOM

POWER

SWITCH

3

_

REVERB RETURN

TO MAIN

+15 VDC

AUX

INPUT

TAPE

INPUTS

L

R

MAIN

CHANNEL EQ

_

+

HIGH

MID

LOW

Signal path exclusive
of individual channel

AUX.

LEVEL

TO PHANTOM BUSS

TO MAIN BUSS

TO EFFECTS/

REVERB BUSS

EFF./REV.

Signal path typical

for each channel

TO MONITOR BUSS

MON.

1. OVERVIEW.

1-2. INTRODUCTION.
The SR series integrated mixer/amplifiers have been

designed for easy setup and simple but versatile oper­ation. Requiring only the addition of microphones and
speakers, the SR powered mixers are self-contained
sound reinforcement systems, with features and per­formance generally found only in units costing much
more.

not exceed 0.8 VRMS. Higher amplitude signals, such
as balanced line levels signals, may also be patched
into these jacks if an input pad is used (see Section 4-

4). The XLR jack is wired according to the following
standard:

Pin 1 is ground.
Pin 2 is the non-inverting (+) input.
Pin 3 is the inverting (-) input.

Signals at the XLR jacks experience 20 dB more gain
than those at the 1/4” channel input jacks.

Each input preamp channel provides a balanced XLR
MICROPHONE input with switchable phantom power
for condenser microphones, a 1/4’’ phone jack LINE
input, MAIN level control, LOW, MID, and HIGH fre­quency tone controls, MON. send control and an
EFF./REV. send control.

The master section features MAIN MASTER, MON.
MASTER, AUX. LEVEL, and DIGITAL REVERB and
EFFECTS level controls, a GRAPHIC EQUALIZER, and a
versatile patch bay.

The SR series mixers include DELTACOMP
tive compression system. DELTACOMP

TM

, an adap-

TM

is a high per­formance power amp limiter that senses amplifier
error due to clipping, and automatically reduces the
gain until the distortion is minimized. A front panel
yellow PEAK LED indicates power amp input limiting.

To make setup as simple as possible, the mixer,
graphic equalizer, and power amplifier are pre­patched in a standard configuration that requires
plugging in only the microphones and speakers to be
“on the air.” To make the system as versatile as possi­ble, this “normalized” patch may be bypassed by
using the inputs and outputs of the patch bay. These
allow the individual components of the system to be
used in various combinations, and for external equip­ment to be added into the system as the need arises.

2-2. CHANNEL CONTROLS.
2-2-1. CHANNEL MAIN CONTROL. The channel’s

MAIN control determines how much of the channel’s
signal is sent to the Main mixing buss and to the
EFF./REV. control. For best signal to noise ratio, this
control should be set relatively high; usual settings are
around 2 o'clock, except when input signal levels are
great enough to cause clipping. See Section 4-1-2.

2-2-2. CHANNEL TONE CONTROLS. The LOW, MID,
and HIGH controls on each channel may be adjusted
to enhance the qualities of its particular audio signal
and to control excessive boominess or sibilance (“s”
sounds) by using the LOW, MID, and HIGH controls.
When these controls are at 0 (straight up), the channel
is “flat” (no frequencies cut or boosted). The most nat­ural sound is achieved by avoiding extreme tone con­trol settings.

2-2-3. EFF./REV. CONTROL. This control determines
how much signal from each channel goes onto the
Effects/Reverb buss. All signals on this buss are com­bined in the master mixer section, and sent both to the
EFF. OUTPUT jack and to the internal reverb system.
The EFF./REV. control is wired post MAIN control and
post-EQ; thus, the level and tone of the EFF./REV. sig­nal are altered by the settings of the MAIN, LOW,
MID, and HIGH controls.

The SR Series has been designed to meet the needs of
professionals, and can be counted on to provide reli­able service in the most demanding situations.

1-1. BLOCK DIAGRAM. The block diagram illustrates
the typical signal path for the SR series.

2. FRONT PANEL CONTROLS, JACKS AND LEDs.

2-1-1. LINE INPUTS. The 1/4” phone jacks are
intended for high impedance balanced or unbalanced
inputs whose amplitude is under 8 VRMS. This would
include instrument and line level signals. When used
as a balanced input, the tip connection of the 1/4”
jack is the non-inverting (+) input and the ring con­nection is the inverting (-) input.

2-1-2. MICROPHONE INPUTS. The three-pin audio
connectors (often called “XLR” or “Cannon” connec­tors) on the front panel are intended for balanced
input signals from low impedance microphones. To
avoid clipping in the input stage, signal levels should

2-2-4. MON. CONTROL. The MON. control deter­mines how much of a channel’s signal is sent to the
Monitor buss. This allows a separate mix to be creat­ed for stage monitoring. The control is wired pre­MAIN control and pre-EQ; thus, the monitor signal is
independent of other channel controls.

2-3. MASTER SECTION CONTROLS.
2-3-1. MAIN MASTER LEVEL CONTROL. This is the

master level control for the main mix. It controls the
signal level present at the MAIN OUT jack, if nothing
is patched into the EQ. IN jack or the PWR. AMP
INPUT jack. The MAIN MASTER control also deter­mines the graphic equalizer and power amplifier input
levels.

2-3-2. MONITOR MASTER LEVEL CONTROL. This is
the master level control for the monitor mix. It con­trols the signal level present at the MONITOR OUTPUT
jack.

2-3-3. REVERB RETURN TO MAIN CONTROL. This
control determines how much of the signal from the
reverb system is added or returned to the main mix.

When the LED is illuminated, the phantom power is
on. The 15 volts used for phantom power will run
nearly all condenser microphones.

2-3-4. REVERB RETURN TO MONITOR CONTROL.
Determines how much of the signal from the reverb
system is added to the monitor mix. Many vocalists
like to hear some reverb on their voices in the monitor
system; be aware that reverb in the monitors increases
the likelihood of feedback in the monitor system due
to increased gain.

2-3-5. EFF./REV. SEND LEVEL CONTROL. The mix
created by the settings of the channel EFF./REV. con­trols appears at the EFF. OUPUT jack, as well as being
sent to the reverb system. The signal level at the EFF.
OUTPUT jack is adjusted by the individual channel
EFF./REV. controls, and the EFF./REV. SEND LEVEL
master control.

2-3-6. AUX. LEVEL CONTROL. Signals patched into
the AUX. INPUT jack and / or the TAPE INPUTS are
sent to the Main buss via the AUX. LEVEL control. This
control determines how much of the AUX. INPUT sig­nal appears in the main mix.

2-3-7. GRAPHIC EQUALIZER. The 9 band graphic
equalizer consists of active band pass / band reject fil­ters spaced at octave intervals. The lowest frequency
filter is centered at 63Hz while the highest frequency
filter is centered at 16kHz. All others are centered on
the frequencies indicated below their sliders. Moving
the sliders up or down boosts or cuts the gain at the
indicated frequencies. This allows the sound engineer
to suppress feedback by compensating for room reso­nances encountered in live sound reinforcement appli­cations. The EQ controls are accurately scaled in dB to
indicate the amount of cut or boost applied at each
frequency.

NOTE: It is possible for distortion to occur in the
Graphic Equalizer if excessive attenuation is used (slid­er well below center) while also trying to achieve sig­nificant level within the attenuated bands.

2-3-8. DIGITAL REVERB AND EFFECTS CONTROLS.
The internal DSP (Digital Signal Processor) system pro­vides 126 different types of reverb and effects. These
are selected by the two rotary switch controls located
in the DIGITAL REVERB and EFFECTS section of the
front pannel. These two controls work together to
select and modify each reverb sound or effect algo­rithm. When the bottom switch chooses one of the
fourteen reverb selections, the top switch chooses the
reverb or delay time. When the bottom switch is in the
SPECIAL EFFECTS setting, the top switch chooses the
special effects algorithm. This is indicated by the pan­nel graphics, which show light and dark colored sec­tions.

2-3-9. PHANTOM POWER (Select Switch and
Indicator LED). Engaging the switch applies 15 volts of
phantom power to all the XLR microphone input con­nectors for powering electret condenser microphones.

PHANTOM POWER LED. The green LED is the “phan­tom power on” indicator.

2-3-10. DELTACOMP

TM

. The yellow DELTACOMP

TM

LED comes on when excessive signal levels are being
sent to the power amp. It illuminates on signal peaks
that cause clipping (distortion) with DELTACOMP
activated, or for signal peaks that cause DELTACOMP
to reduce power amp input level (DELTACOMP

TM

not

TM

active). If the limiter is on for a large percentage of the
time, the dynamic range of the system is reduced and
the overall sound suffers; for this reason, level controls
should be adjusted so that the LIMIT light only flashes
on occasional signal peaks.

DELTACOMP
engaging the DELTACOMP

TM

SWITCH. DELTACOMPTMis activated by

TM

SWITCH.

2-3-11. POWER LED. The red POWER LED is the front
panel “power on” indicator.

2-4. PATCH BAY.
2-4-1. MAIN OUTPUT. Signals from each of the

channels are combined with AUX. and TAPE INPUTS
and the REVERB RETURN TO MAIN signal to form the
final main mix. The overall level of the mix is con­trolled by the MAIN MASTER control and this mix
appears at the MAIN OUTPUT jack. The mix is also
normally passed on to the GRAPHIC EQUALIZER and
to the power amplifier (see Sections 2-4-5 and 2-4-9).
Inserting a plug into the MAIN OUTPUT jack does not
interrupt the normal signal flow. It can be used for
inserting signal processing equipment into the signal
path (see Section 4-5), using the MAIN OUTPUT as a
send, and the GEQ INPUT as a return.

2-4-2. MONITOR OUTPUT. Signals present on the
Monitor buss are combined in the monitor summing
amplifier and sent to the MONITOR OUTPUT jack.
The signal level present at this output is determined by
the MONITOR MASTER control.

2-4-3. EFF. OUTPUT / REVERB FOOTSWITCH. Signals
present on the Effects/Reverb buss are mixed in the
Effects/Reverb summing amplifier. This mix is sent
both to the Reverb driver and to the EFF. OUTPUT
jack. Thus the mix created by the settings of the
EFF./REV. level controls on each of the preamp chan­nels is present at the EFF. OUTPUT jack. The overall
level at this output is determined by the master mix
section EFF./REV. SEND LEVEL control. This output
may be used to drive external effects (echo units,
phase shifters, flangers, digital delays, etc.). The
return signal from the effect may be patched into the
mixer through the AUX. INPUT jack, or by way of a
preamp channel 1/4” input jack. Use of a preamp
channel as a return gives you the ability to shape the
frequency response of the signal; however, care must
be taken to insure that the EFF./REV. control on that

TM