Shure FP12 Schematic
222 HARTREY AVE., EVANSTON, IL 60202-3696 U.S.A.
AREA CODE
312/866-2200·
CABLE: SHUREMICRO
THE SOUND OF THE PROFESSIONALS®
PROFESSIONAL PRODUCTS
GENERAL l
The FP12 is an in-line, battery-powered amplifier
designed to accept a microphone- or line-level signal,
bridge it, and produce a signal sufficient to drive headphones at very loud levels. The FP12 is ideal for anyone
in the broadcasting, sound reinforcement or audio recording fields who has a need for headphone monitoring or checking microphone- or line-level cable runs.
In addition, the FP12 can be used to provide multiple
headphone feeds, a two-station intercom, extra power
for existing headphone circuits, or a means of
ing
electronic instruments through headphones.
FEATURES
0
Wide-range frequency response
0
Low input noise and harmonic distortion
0
High-impedance bridging input does not load signal
source
0
Switchable microphone- and line-level inputs
0
Switchable low- and high-impedance headphone outputs
0
Parallel 3-circuit phone and miniature (3.5 mm) head-
phone jacks
Balanced loop-through locking XLR connectors and
phone jacks
0
Powered by easily obtainable 9V alkaline battery
0
Low current drain for extended battery life
0
Rugged construction, with durable belt clip for field
use
0
Low susceptibility to radio-frequency interference
SPECIFICATIONS
Frequency Response
40 Hz to 15
kHz,
Equivalent Input Noise
-118
dBV
(maximum gain; source resistance 150
ohms; 300 Hz to 20
(ref 1
+ 1, - 3
kHz)
kHz)
dB
practic-
Voltage Gain (ref 1
Headphone
Input Impedance
Mic
Line
Mic
Line
Lo-Z
Hi-Z
kHz)
Impedance
4 ohms total (8 ohms
per earphone, parallel)
1 k total (2k per
phone driver, parallel)
ear-
Gain
70
20
96dB
46
Total Harmonic Distortion
Less than 1% (40 Hz to 15
kHz;
measured at 10
below clipping point)
Input Clipping Levels
Mic Input: 200 mV (-14
Line Input:
60V (
(at 1
kHz)
dBV)
+35 dBV)
Output Clipping Levels
Lo-Z: 750 mV ( -2.5
dBV)
(load resistance 4 ohms
total; 8 ohms per earphone driver, parallel)
Hi-Z:
15V ( +
23
dBV)
(load resistance 1 k total; 2k
per earphone driver, parallel)
Input Impedance (ref 1 kHz)
Mic:
7.5 kilohms
Line: 66 kilohms
Output Impedance
Lo-Z: 16 ohms
Hi-Z: 440 ohms
±10%
±10%
(ref
1
±10%
±10%
kHz)
Phase
Input in phase with output. Pin 2
of Mic Input in phase
with Phones (both phone jacks and mini jacks) tip
and ring
Protection
Protected against damage from
to 5V [ + 14
dBV]
input signals)
shorted outputs, (up
Power
Type: 9V alkaline battery
Battery Life: Approximately 10 hours under normal
operating conditions
mAdc
Current Drain (typical): 6
(idle); 72
(clipping)
Temperature Range
Operating:
Storage:
-29° to
49°C (32°
74°C ( -20°
to
to
120°F)
165°
F)
0° to
Connectors
Input/Output
Locking
3-socket
XLR, Locking
3-pin
XLR,
3-circuit
phone jacks (2)
dB
dB
dB
dB
mAdc
Copyright 1985,
27A8072
(EH)
Shure
Brothers Inc.
Headphones Output:
Phone jack (2)
Mini Jack (2)
Battery Test
Insulated tip jacks;
(
negative)
red (positive) and black
Case
Die-cast zinc; matte black enamel
Overall Dimensions
mm x 150 mm x 55.5 mm
80.9
(3-3/16
x
5-11/16
x
2-3/16
in.)
Net Weight
501 grams (1 lb
2-1/2
oz)
CONTROLS, CONNECTORS, INDICATOR
Level
Control
:
applies power to FP12 circuitry and
sets headphone output level. Knob position also indicates when power is applied.
Mic-Line
Switch:
selects microphone- or line-level sig-
nal source.
Hi-Z/Lo-Z Switch:
selects operation with
highimpedance (greater than 600 ohms) or low-impedance
(less than 600 ohms) headphones.
In/Out
XLR and Phone Jacks:
provide loop-through in-
put and output connections for balanced microphone-or
line-level signal sources.
Phones A, B
Jacks:
provide for connection to high- or
low-impedance headphones. Note that A and B headphone jacks can be used simultaneously. Each output
can accept a headphone phone plug
Batt Test
Jacks:
can be used to check condition of
or
mini plug.
9V
battery.
Connections
Connect the signal source (microphone- or line-level)
to the appropriate
jack), and set the
signal
In/Out
connector (XLR or phone jack) to the input
In/Out
Mic-Line
connector (XLR or phone
switch. Connect the parallel
of mixer, tape recorder or amplifier. Connect the head-
phones (one or two units) to the
set the Hi-Z/Lo-Z switch to the proper position for
Phones A, B
jacks, and
high-
or low-impedance headphones.
Operation
Position the FP12 for operation. Note that the belt
clip can be used to secure the unit to a belt, trousertops,
or D-rings on other equipment. The belt clip can easily
be removed if desired.
Rotate the Level control from the Off position to the
desired listening level. Note that the exposed color dot
on the
Level
control knob serves as a reminder that the
unit is on.
Battery voltage can be checked at any time without
removing the battery or turning the unit on. Inserting
voltmeter leads in the Batt Test jacks (observe proper
polarity) will indicate battery condition.
GUARANTEE
This Shure product is guaranteed in normal use to be
free from electrical and mechanical defects for a period
of one year from date of purchase. Please retain proof
of purchase date. This guarantee includes all parts and
labor. This guarantee is in lieu of any and all other
guarantees or warranties, express or implied, and there
shall be no recovery for any consequential or incidental
damages.
OPERATION
Battery Replacement
Use a coin or screwdriver, turning one-quarter turn in
either direction, to open the battery compartment door.
Insert a fresh 9V alkaline battery
(NEDA 1604A,
Duracell
MN1604, Eveready 522, or equivalent) in the compartment. Note that the battery contacts are polarized, and
the battery cannot be inserted improperly. The compartment door can be closed by pressing shut with the
fastener properly aligned.
SHIPPING INSTRUCTIONS
Carefully repack the unit, have it insured, and return it
prepaid to:
Shure Brothers Incorporated
Attention: Service Department
222 Hartrey Avenue
Evanston, Illinois 60202-3696
If outside the United States, return the unit to your
dealer or Authorized Shure Service Center for repair.
The unit will be returned to you prepaid.