Plantronics S12 Fascicule

S12

The S12 Telephone Headset System is designed to add a 
headset to an existing telephone.

The S12 System provides precise levels of listening and talking
comfort and crystal clear voice quality.  

The S12 System is not designed to work on telephones that
have the dial pad in the handset or on cordless telephones.

This user guide provides the following steps to quickly set up
and use your headset system.

Identify the Components

Attach to Telephone

Set Amplifier Compatibility Switch

Make a Test Call

The other side has more details:

Examine other features

Troubleshooting

Technical Support Center Information

FCC Information

Parts and Accessories

Warranty and Service

Read and follow all instructions and warnings prior to using the
product. 

When using your telephone equipment, these instructions and
warnings should be followed to reduce the risk of fire, electric
shock, injury to persons, and damage to property.

For your comfort, health, and safety, do not exceed moderate
listening levels.

Use only the Listed AC power adapter supplied by Plantronics.

Unplug this product from the wall outlet before cleaning. Do not
use liquid cleaners or aerosol cleaners.

Avoid contact with liquids. Do not locate this product near water,
for example, near a bath-tub or sink, in a wet basement, or near a
swimming pool.

This product should never be placed near or over a radiator or
heat register. This product should not be placed in a built-in
installation unless proper ventilation is provided.

Do not allow anything to rest on the power cord. Do not locate
this product near operating machinery or in areas where the
power cord is likely to be damaged by furniture or foot traffic.

Discontinue use of product and contact Plantronics if the product
overheats, has a damaged cord or plug, has been dropped or
damaged, or if the product has been dropped in water.

Do not overload outlets and extension cords as this can result in
the risk of fire or electric shock.

Never disassemble or push objects of any kind into this product as
this may short out parts that could result in a fire or electric shock.

Use caution when installing or modifying telephone lines.

Do not use the telephone equipment to report a gas leak in the
vicinity of the leak.

 Unplug your telephone 

handset cord from the 
telephone base.

 Plug your telephone 

handset cord into the S12 
amplifier handset jack.

 Connect the cord     

between the telephone base 
jack on the S12 amplifier and 
your telephone base. 

 Plug the headset plug into 

the headset jack. 

 Route the headset cord through the cable management 

channel on the bottom of the amplifier (not shown). 

 Snap in the headset holder     (not shown).

 Plug the AC power adapter into the AC power adapter jack 

and plug into a standard 
AC wall output.

 Verify that the mute button is off.

The mute indicator should not be illuminated

 Remove the phone handset from the 

cradle and place on your desk. 

If you do not hear a dial tone in the 

headset, press the headset button.

The headset indicator is on.  

 Use your telephone keypad to call a 

friend or colleague. 

Adjust the listen volume using the listen 

volume control. 

 If your friend cannot hear you, or you 

hear a buzz or hum, try changing the 
compatibility slide switch.

 Adjust how loud you sound to the other 

party by adjusting the speak volume control.   

 If you sound too loud, move the speak 

volume master switch to its lower setting and 
adjust the speak volume control. 

 After completing the call, return the 

handset to its cradle. 

 Put on headset and press the 

headset button. 

The headset indicator      should be 
on (green). 

 Lift the telephone’s handset off 

the cradle and place it on your 
desk.

 If you hear a clear dial tone, 

you can proceed to Step 4.

 If you don’t hear a dial tone, 

adjust the compatibility slide switch      
following this process:

Slide the compatibility slide 

switch until you hear a clear dial 
tone. 

There may be multiple settings 
with a dial tone. Select the one 
that sounds most like the handset 
of your phone.  

Experimenting with various switch 
settings will not harm the amplifier 
or your telephone.

 

Adjustable 

Headband

 

Headset 

Assembly

 

Clothing Clip

 

Headset Plug

 

Microphone 
Boom

 

Ear Cushion 
Assembly

 

Earloop

 

Pivot Ball Ring

 

Firefly

®

In-Use 

Indicator

Over-the-Head............converts to............Over-the-Ear

2

3

4

1

 

Q

UICK 

S

TART 

G

UIDE

  Headset Holder

  

  Compatibility Slide 

Switch

  

  S12 Amplifier

  

  Headset Indicator 

(Green)

  

  Power Indicator 

(Green)

  

  Mute Indicator (Red)

  

  Listen Volume Control

  

  Mute Button

  

  Headset/Handset 

Button

  

  Speak Volume Control

  

  Speak Volume Master 

(Hi, Low) Switch

  

  Cord (Phone to 

Amplifier)

  

  AC Power Adapter

 

 

  AC Power 

Adapter Jack

  

  Headset Jack

  

  Handset Jack

  

  Telephone Base Jack 

Over-the-Head

Over-the-Ear