Peavey SMR 821 User Manual

SMRTM821

Stereo Mic/Line

Program Audio Mixer

User Manual

Architectural Acoustics

SMR 821 User Manual

WARNING! To prevent electrical shock or potential fire hazards, do not expose the SMR 821 to moisture or rain. Before using this product, read the user
manuals for further warnings and cautions.

The following cautions should be carefully observed when installing, wiring or using this product:

DO NOT use any other power supply or cable other than the one provided with this unit.
DO NOT remove the top cover of the SMR 821. There are no user serviceable parts inside. Refer service to qualified personnel.
DO NOT use solvents or other cleaners to clean the unit. Basic external care requires only a damp cloth. Disconnect the power supply cord before cleaning.
Read all safety and installation instructions and retain all documentation for further reference.
Installation of the SMR 821 should such that it’s mounting position does not interfere with proper ventilation.
This product should not be installed or placed near a source of heat.
Power supply cords and associated connectors should be unplugged from the power source when the unit is not used for long periods of time, or will be
stored.
If this product is to be mounted in an equipment rack, install rear support if required by the rack manufacturer.
Care should be taken to ensure that the installation is clear of possible sources of contamination. Make sure that the product’s ventilation openings are not
exposed to possible sources of liquid, gases, or other contaminant.
This product should be inspected by a qualified service technician if the power supply cord or connector has been damaged, if the unit has been dropped, or if
a foreign substance has gained access to the interior electronic and electrical components.

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Than k You ! 3

What's In The Box? 3

De sc rip ti on 3

Features 4

Front Panel Features 5

Rear Panel Features 6

Installation 7

Connections

Channel Input 8

Stereo Input 9

Master Bus Link 10

Remote Volume and Channel Select 11

Configuration 12

Applications

Re sta ura nt 14

Hotel Meeting Room 15

Presentation Room 16

Bar 17

Small House of Worship 18

Plant Paging 19

Courtroom 20

Frequently Asked Questions (FAQ) 21

Tech Support 22

W arranty Registrati on 22

Options & Modifications

Microphone Input Transformers 23

Channel 7 & 8 Select Switch Defeat Modification 25

Functional Block Diagram 26

Equalizer Frequency Response Chart 27

Specifications 28

Warranty Statement 31

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Peavey Electronics Corp.

Welcome

Thank You!

Thank you for purchasing the SMR 821 Mic/Line Program Mixer. This prod­uct is designed to provide years of trouble-free operation, and high quality
audio performance. We sincerely hope that you enjoy your new SMR 821,
and will find other products in the Peavey Architectural Acoustics product
line to supplement your new mixer. We are confident that you will find the
SMR 821, as well as other Architectural Acoustics products to be of the
highest quality available.

This manual was written to provide as much information as possible for
your new Peavey Architectural Acoustics product. It is our sincere desire
that you enjoy your purchase. We feel that the best way to fully enjoy any
purchase is to have an in-depth understanding of the product’s features,
functionality and performance characteristics. We hope that this manual,
along with the manuals of our other products will provide this. If you
require additional information that this manual does not provide, please let
us know. We are always looking for better ways to provide information
about our products, and your input is always appreciated. If you have a
comment about this manual, or would like to make a suggestion, please
write to: Peavey Electronics Corp., Architectural Acoustics Division, 711 A
St., Meridian MS, 39301. Thank you again for using Peavey!

What’s In The Box?

The SMR 821 is packaged in a single container. This container includes the
following items:

1- SMR 821 Mic/Line Program Audio Mixer
1- IEC removable power supply line cord

(120VAC Domestic, 230VAC Export)
2- 5-screw Euro connectors*
9- 3-screw Euro connectors*
1- Plastic Security Cover for EQ controls*
1- User Manual/Literature Package
4- Rubber feet

* Asterisk indicates that these items are shipped installed on the SMR 821.

If any of these items are missing, please contact your Authorized Peavey
Architectural Acoustics contractor/dealer.

Description

The SMR 821 is a professional Microphone and Line level audio program
mixer intended for fixed installation applications. This single rack-mount
package is designed to provide high quality audio performance, versatile
control options and simple, easy to use controls. Engineered from the
ground up with the commercial sound systems contractor in mind, the SMR
821 includes removable screw connectors for easy installation and cost effec­tive servicing, as well as limited front panel user control.

With three independent audio output buses, the SMR 821 is perfect for
applications where stereo output and simple monitoring is required. Six of
the eight inputs include high quality microphone pre-amplifiers and separate
gain controls. Additional rear panel controls provide even more flexibility
for proper gain setup, output assign and remote control features.

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SMR 821 User Manual

Features

- Single rack space package

- Eight total inputs (6 balanced Mic/Line, 2 un-balanced stereo)

- LED Level/Clip status indicator on each channel

- Mic inputs include selectable 48 volt phantom power

- Two selectable stereo line inputs (mono or stereo switchable)

- Three assignable electronically balanced outputs (Left, Right, Aux)

- Master level controls for each output bus

- Three 5 LED meter arrays

- 4-band EQ (low, low mid, high mid, high)

- Integral Ducking/Muting system

- Audio and mute bus linking

- Left, Right, Aux and Mute bus links for stacking multiple SMR 821’s

- Rear panel Master/Slave linking mode switch

- Remote stereo input select

- Remote Master L/R level control port

- Rear panel 20 dB pad switch on each microphone input

- Front panel continuously variable preamp gain control

- Rear panel bus assign switches for each microphone channel

- Rear panel global 100 Hz low cut filter switch for all mic inputs

- Mute bus with Channel 1 rear panel threshold control

- Select switch for routing microphone mix bus post remote control

- All audio I/O on removable connectors

In stand alone applications, the SMR 821 is a very powerful tool. Ease
of use, external control options and a simple interface make it perfect
for many applications where the end user must have access to the audio
system. The SMR 821’s ability to link multiple units provides even
more flexibility for a wide range of applications. Among the many
applications the SMR 821 was designed for include:

- Presentation Rooms

- Board Rooms

- Courtrooms

- Auditorium/Cafetorium

- Lecture Hall Sound Reinforcement

- Meeting Rooms

- Convention Centers

- Paging

- Background Music

- Retail Spaces

- Restaurant/Bar Sound

The SMR 821 is a prefect choice for many audio applications. This man­ual will show how some of these applications fit into the SMR 821’s
feature set, and how you can maximize your system designs.

To fully grasp all of the functionality and possible uses of the SMR 821,
please refer to the Applications section later in this manual.

Panel Features

Pag e 5Peavey Electronics Corp

Front Panel Features

1. GAIN CONTROL This can also be referred to as a “trim” control. It varies the
amount of mic preamp gain at the first gain stage.

2. STATUS LED This bi-color LED illuminates green when a signal at -20dBm is pres­ent, and red when the signal level is near clipping.

3. LEVEL The Level control adjusts the channel signal level sent to the mix buses.

4. CHANNEL 7 & 8 LEVEL The Level control adjusts the channels’ stereo signal level
sent to the mix buses.

5. SELECT The Select switch is a momentary switch that selects the stereo input sig­nal from either Channel 7 or 8. When power is applied to the SMR821, Channel 7 is
selected by default.

6. SELECT LED The Select LEDs indicate which stereo input channel is feeding the
mix buses.

7. LOW EQ The Low EQ control is a shelving type active tone control. (±15 dB at 70
Hz).

8. LOW MID EQ The Low Mid EQ control is a bandpass (peak/notch) type of active
tone control. (±15 dB at 250 Hz).

9. HI MID EQ The Hi Mid EQ control is a bandpass (peak/notch) type of active tone
control. (±15 dB at 3.1 kHz).

10. HI EQ The Hi EQ control is a shelving type of active tone control. (±15 dB at 10
kHz).

11. LEVEL METERS The three 5-segment LED Level Meters monitor the levels of the
Left, Right, and Aux outputs. The 0 dB reference level corresponds to +4 dBu at its
respective output connector.

12. LEFT/RIGHT LEVEL The Left/Right Level control adjusts the level of the Left
and Right outputs.

13. AUX LEVEL The Aux Level control adjusts the output of the Auxiliary output.

14. POWER LED This LED indicates that AC power is applied to the SMR 821.

1 2 3 4 10 11 12 137 8 965 14

SMR 821 User Manual

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Rear Panel Features

1. CHANNEL 1 MUTE THRESHOLD Adjusts the level of signal needed to trigger the muting
circuitry in Channel 1.

2. PAD The Pad switch attenuates the input signal by 20 dB.

3. CHANNELS 1-6 INPUT Balanced microphone or line input on removable connector.

4. ASSIGNMENT SWITCHES Assigns the input channel to the Left, Right, or Aux mix buses
and enables the 48 volt phantom power for channels 1-6.

5. LOW CUT Low Cut filter with a corner frequency of 100 Hz Enabling this switch will
affect Channels 1-6 only.

6. MIC MIX Allows the summed signal of Channels 1-6 to be routed before or after the remote
L/R volume control.

7. RIGHT OUT MUTE Controls the muting of the right mix bus. When this switch is
enabled, the left and right mix buses are affected by the activity of the muting circuit. When
this switch is defeated, only the left bus is affected by the muting circuit.

8. MODE Selects either Stereo mode or Mono mode for Channel 7 or 8.

9. CHANNELS 7 AND 8 INPUT Dual RCA connector for stereo input sources (nominally -10
dBV).

10. EQ Places the 4-band equalizer in or out of the Left and Right signal paths. In the OUT
position the equalizer is completely bypassed.

11. BUS LINK SWITCH For use with multiple SMR 821’s, this switch places the mixer in the
master or slave mode of operation.

12. LEFT OUT, RIGHT OUT, AUX OUT Main mix bus balanced outputs.

13. BUS LINKS “Stacking” connector for multiple SMR 821 mixers.

14. REMOTE CONNECTOR Used to control the Left/Right Master Volume Control and
Stereo Input Select from a remote location.

15. POWER SWITCH Applies power to the SMR821.

16. A/C POWER RECEPTACLE For standard IEC power cable (included).

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Installation

Pag e 7Peavey Electronics Corp

Installation

The SMR 821 is designed to be installed in a standard EIA equipment rack.
Since the depth of the unit is only 8-3/4”, you can use practically any size
rack. Using only a single EIA rack space, the SMR 821 includes integral rack
mounting ears and does not require any additional hardware for rack mount-

ing.......other than the rack screws!

All connections for the SMR 821 are made on the rear panel. It is recom­mended that you provide an additional 4” of clearance between the rear of
the chassis and the interior rear of your equipment rack for wiring harnesses.
Since every connection to the SMR 821 is easy to disconnect, the unit can be
removed from an equipment rack easily, without have to disturb fixed
wiring harnesses.

Although the SMR 821 does not generate enough heat to warrant forced air
or convection cooling, it is recommended that you provide a single rack
space vent above, and below the unit when rack mounting. Using common
sense when installing this unit will ensure that it will provide years of trou­ble free service. In installations where there are multiple power amplifiers, it
is further recommended that the SMR 821 be located more toward the top of
the rack, while power amplifiers remain near the bottom. This is generally
considered to be standard rack design in the commercial audio industry.
Following this convention will ensure adequate rack cooling and reliable
operation from the SMR 821.

SMR 821 User Manual

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Connections

Connecting the SMR 821 is not much different than any other analog audio
product. There are inputs and outputs, but there are also additional connec­tions that you need to be aware of . These include the external control ports
and the Bus Link connectors. All cables for these connections should be
shielded.

Refer to the following illustrations for each type of connection.

Audio Input

The inputs to the SMR 821 are balanced. This means that there are three wires for each connection, a positive, negative and
shield. These should be connected to each pin accordingly.

Shield
Audio Negative
Audio Positive

Balanced Microphone or Line Level Input

Figure 1. Balanced Audio Input Connections

Shield

Insert jumper wire between the negative
and shield pins for un-balanced circuits.

Audio “Hot” or Positive

Un-Balanced Microphone or Line Level Input

Figure 2. Un-Balanced Audio Input Connections

Connections

Pag e 9Peavey Electronics Corp

Stereo Inputs

Left Shield
Left “Hot” Audio
Right Shield

Unbalanced RCA connections

Right “Hot” Audio

Channels 7 and 8 provide two individual inputs for each channel. These are intended for stereo use, as each input (Left, Right)
has a fixed assignment to the Left and Right output buses. Additionally, a sum of both inputs is fed simultaneously to the Aux
output bus. Although you cannot change the distribution of these inputs, you can determine if they are stereo or mono. The
Mode Switch, when enabled, will sum both connectors, feeding both to the Left and Right outputs simultaneously. These con­nectors accept nominal levels of -10dBV.

The Mode switch selects either Stereo mode or Mono mode individ­ually for Channel 7 or 8. In the Stereo mode, the Left input signal
feeds the Left mix bus and the Right input signal feeds the Right
mix bus via the front panel Level Control. In the Mono mode, the
summed Left and Right input signals feed both Left and Right mix
buses. This allows for only one input to be used to feed the stereo
mix buses. Additionally, it allows for Left and Right outputs of the
source to be summed without a Y-cable. In either mode, a summed
mono signal feeds the Aux mix bus.

Figure 3. RCA Input Connections

The cabling for these connectors should be of
the standard, consumer un-balanced shielded
type. If you are using a 2-conductor shielded
cable, make sure to connect the negative side of
the signal to the shield. NOTE: Unbalanced
signal sources should be located within approx­imately 6’ of the SMR-821.

Slave Mixer 2

Slave Mixer 1

SMR 821 User Manual

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Audio Positive
Audio Negative
Shield

Audio Bus Outputs, Typical For Each Bus

Left Audio Link (L)

Right Audio Link (R)
Link Shield (SHD)

Master Bus & Mute Link Connections

Aux Audio Link (A)

Mute Bus Link (M)

Master Bus Output & Link Connections

These connectors allow you to expand your SMR 821. The Bus Links connector has 5 pins for combining multiple SMR 821’s.
Using a 4-conductor, shielded cable, you can easily connect between 2 or more units wiring pin-to-pin across multiple SMR 821
mixers. NOTE: Use only shielded cable!

Refer to the illustrations below.

The Bus Link switch is used to place the mixer in the master
or slave mode of operation. A stand-alone unit should

always

be in the master mode.

The EQ switch places the 4-band equalizer in or out of the
Left and Right signal paths. In the OUT position the equal­izer is completely bypassed.

To increase the number of inputs available, multiple mixers may
be linked together. Linking mixers is a very simple process. Wire
the

Bus Links

connections between each mixer. Select the mixer

to be used as the master and place its

Bus Link Switch

in the
MASTER position. All other mixers in the system should have
their link switches in the SLAVE position. The EQ and master
level controls of the unit chosen as MASTER should be used to
control the system. NOTE: Slave mixer outputs are still active,
and will output any channels assigned to them.

Master Mixer

In a linked system, the Master mixer’s
outputs would be the primary system
outputs.

Figure 4. Master Output & Bus Link Connections