Shure FP31 User guide

Shure FP31 User guide
[email protected]
THE SOUND OF THE PROFESSIONALS'~
222 HARTREY AVENUE
EVANSTON, ILLINOIS 6 0 2 0 2 - 3 6 9 6 V.S.A.
PROFESSIONAL PRODUCTS
Controls and Indicators
Active, feedback-type input gain controls permit
direct input of high-level sources without input attenuators
Built-in Limiter with adjustable threshold - prevents
output clipping of mixer or input overload o f
amplifier, telephone line or tape recorder
LED indicator flashes with Limiter operation or to
signal overload with Limiter defeated
w Lo-Cut filters available at each input to reduce ex-
.
traneous low-frequency interference
f o r 'Ondenser
(Phantom) simplex O r A - B
microphones available at each microphone input
Built-in tone oscillator for level checks or line tests
Slate microphone with automatic gain control (AGC)
for take identification or for emergency use
Slate tone for identifying take locations during
editing
Outputs
Two transformer-coupled, 3-pin XLR-connector outputs, each switchable either to low-impedance
balanced microphone or to 600-ohm balanced line
level
rn Tape output to feed tape recorder input or other unbalanced Aux-level input
rn Front and side panel stereo headphone jacks (8 to
2,000 ohms, %-inch and 3.5 mm jacks) with separate
Phones level control. Either or both jacks can drive
Aux or unbalanced line-level inputs. Four separate
sources can be driven from these two headphone
outputs.
Copyr~ght1991, Shure Brothers Inc
27A8080 (KG)
G
3
7
v
2
m
z
VU lamp, stays illuminated while pushbutton is
depressed, automatic 5-second turnoff after button
is released.
X
Phones level control adjusts output at both headphone jacks
Inputs
Three transformer-coupled, 3-socket XLR-connector
inputs; each switchable t o low-impedance
microphone or line level
1
C)
Master gain controls level at LinelMic and Tape outputs as well as tone oscillator level
FEATURES
z
Professional VU meter, factory set for 0 VU = + 4
dBm, internally adjustable for other VU levels
Battery check function with readout on VU meter
GENERAL
The FP31 is a portable electronic news gathering
(ENG) electronic field production (EFP), or film production, mixer that provides the quality and features needed for remotes.
H
.
Power
Mixer is powered by two standard 9V alkaline batteries that also supply simplex power for condenser
microphones
w extreme!^ low battery d r a i n provides 8-hour
minimum battery life under normal conditions
Separate 9V alkaline battery supplies A-B power for
condenser microphones; third battery is not required
if A-Q power is not used
3
m
a
4
2
I
I
(D
2
5
o
1.
Z
(D
d
V)
C)
%
3
2.
3
0
IZo
I
!
Spring-loaded battery compartment prevents incorrect insertion of batteries; batteries available for
replacement instantly when compartment door is
opened
=
!
Mixer can be powered from any 11 to 18 Vdc source
such as: standard belt pack, automotive electrical
system, video tape recorder. or ac power converter
C
.
Q
?
0
Q
2
-.
0
3
Mechanical characteristics
Extremely rugged and durable construction
Very small size and light weight
Carrying case and detachable shoulder strap supplied
.
.
.
A ~ Iinput and output connectors are professional
standard types
Performance
Reliable Operation u n d e r w i d e e x t r e m e s
temperature and humidity
Extremely low noise and low RF susceptibility permits use near microwave transmitters and in strong
hum fields
Wide, flat response, extremely low distortion, and up
to + 18 dBm output level provide studio-quality performance in a portable mixer
Pr~ntedn U S A
=I
rn
0
x
z
-
0
D
I
0
D
-I
D
SPECIFICATIONS
Frequency Response
30 Hz to 20 kHz + 2 dB
Distortion
Less than 0.25O/0 total harmonic distortion at + 4
dBm, 50 Hz to 20 kHz
Noise
Less than
Control Interaction
Less than 1 dB with any control combination
- 129 dBV equivalent input noise
Common Mode Rejection
65 dB minimum at 100 Hz, -30 dBV input
Output Isolation
Shorting one output shall cause no more than 8 dB
level drop at 1 kHz at other output
Inputs
19 to 6003*
Less than 10 k3
Line
i
lnput Clipping
Level
IMPEDANCE
66 k3
-47 to -17 dBV
(4.5 to 141 mV)
+ 3 to +33 dBV
(1.4 to 44V)
'Including simplex or A-B powered, and dynamic or ribbon microphones
Tone Oscillator
1 kHz nominal at + 4 dBm, Master at approx. 7
Slate Tone
400 Hz, 1 sec, each time button is depressed
Slate Microphone
Electret condenser, omnidirectional, with AGC, activated while slate button is depressed
Outputs
IMPEDANCE
For Use With 1 Actual
Mic
Line
Output Clipping
Level
- 34 dBV (20 mV)
Any low-Z mic
input
6003
minimum into 1503
+ 18 dBm minimum
into 6003
- 6 dBV (0.5V RMS)
into 47 k3
+ 4 dBV (1.6V RMS
Max)
into 2003
Tape 18 k0 or greater
high level input
Phone 83 to 2 k3
Phase
3-pin lnput & Output connectors in phase; pin 3 in
phase with tip of phone & mini jacks
Gain (at 1 kHz)
INPUT
Line
Overload and Shorting Protection
Shorting outputs, even for prolonged periods, shall
cause no damage. Microphone inputs will not be
damaged by signals up to 3 volts.
Indicators
POWER ON: Green LED flashes at approximately
I-second repetition rate as long as power switch is
on
PEAKIOVERLOAD: Limiter IN - Red LED flashes to
indicate onset of limiting; Limiter OUT-flashes 6 dB
below output clipping level
BATTERY CHECK: Converts VU Meter to battery
condition or circuit voltage indicator; 0 VU or higher
indicates good batteries or adequate (11 to 18 Vdc)
external power source
VU METER: Factory-set at 0 VU = + 4 dBm; 0 VU
level internally screwdriver adjustable
VU
LAMP:
Illuminates meter while
button is
depressed; automatic shufoff 5 seconds after
release
Power
MIXER AND SIMPLEX (PHANTOM) POWER: SUPplied by two internal 9V standard alkaline batteries
(Duracell MN1604 or equivalent) or external 11 to 18
Vdc supply; &hour battery life under normal operation
SIMPLEX POWER: 11 to 18 Vdc nominal through
6200
A-B POWER: Supplied by additional 9V standard
alkaline battery
Connectors
LlNElMlC INPUTS AND OUTPUTS:
OUTPUT
Line
-10 dB
SIMPLEXIDYNAMICIA-B SELECTORS: Individual
for each input, supplies 11 to 18 Vdc Simplex (phantom) or 9 Vdc A-B power with lnput in MIC position;
supplies no power with Selector in DYN position (for
dynamic or ribbon microphones) or with lnput in LINE
position
3-pin XLR type
TAPE OUT: 3.5 mm mini jack
PHONES: Stereo jacks; one standard %-inch
40 dB
phone and one 3.5 mm mini
Controls
CHANNEL GAIN: Active, feedback type, individual
for each input; Channel 1 control pulls out to activate
tone oscillator
MASTER GAIN: Controls LinelMic and Tape outputs, and tone oscillator and slate levels
LOW-CUT FILTERS: 7 dB rolloff at 100 Hz, - 6
dBloctave slope
PHONES LEVEL: Controls both headphone outputs
+
LIMITER: Controls LinelMic and Tape outputs; 14
dBm factory-set threshold, internally screwdriver adjustable down to + 3 dBm; 3 msec attack, 500 msec
recovery time typical
12 VDC EXTERNAL POWER:
jack
Single-pin dc power
Temperature Range
OPERATING: - 18 to 57OC (0 to 135OF)
STORAGE: -29 to + 7 I 0 C (-20 to + 160°F)
+
Dimensions
48.3 mm H x 160 mm W x 135 mm D (1-718 x 6-5116 x
5-5116 in.)
Net Weight (less batteries)
1 kg (2.2 Ib)
Supplied Accessories
Removable shoulder strap, carrying case
OPERATION
LineIMic Inputs and Outputs
XLR-type 3-pin connectors, transformer-coupled balanced-linecircuits; pins 2 and 3 are signal conductors;
pin 1 is ground. All XLR connectors are in phase with
one another.
Lo-Cut Filters
Activated by Inlout switch above each Channel Gain
Control to provide low-frequency rolloff as shown in
Figure 1. Reduce undesirable low-frequency signals
such as wind noise.
FREQUENCY IN Hz
LO-CUT FILTER ACTION
FIGURE 1
Channel Gain Controls
Determine preamplifier gain and provide preamplifier
output attenuation. As gain is reduced, input clipping
level increases for channel. Optimum signal-to-noise
ratio occurs with Channel controlsset as high as possible (consistent with maintaining adequate control
range and input clipping level).
Tone Oscillator
Activated by pulling out Channel 1 control knob; stable
1 kHz oscillator; level determined by Master gain control. Oscillator signal appears at all outputs. When not
in use, Channel 1 control knob should be pushed in.
Slate
Depressing Slate button activates 1-second 400 Hz
tone and turns on Slate Microphone. Omnidirectional
electret Slate Microphone remains on while button is
depressed, can be used to identify recorded segments
or as emergency field microphone. Slate Tone and
AGC'd microphoneaudio levels are controlled by Master Gain Control.
Master Gain Control
Determines output levels at LineJMic and Tape outputs. Also sets Tone Oscillator level when Channel 1
knob is pulled out, and Slate-tone and -microphone
level when Slate button is pushed.
Headphone Jacks
Two stereo phone jacks: one mini 3.5 mm (front panel)
and one 114-inch phone (side panel). Combined output, including Tone Oscillator, Slate Tone and Slate Microphone, appears at headphone jacks. Can be used
to drive up to four headphones or Aux-level recorder
or amplifier inputs. To wire either connector for two outputs, connect one conductor to tip; connect other conductor to ring; and connect shield(s) to sleeve of appropriate mating stereo plug. Tip and ring of headphone
jacks in-phase with pin 3 of XLR LineJMicinput andoutput connectors.
Phones Control
Sets output level at headphone jacks.
Limiter
Limiter Inlout switch turns on fast-acting, peak-responding limiter circuit to cut overload distortion during
loud program intervals without affecting normal program levels. Limiter switch In (operating) restricts
maximum mixer output to approximately +14 dBm. Increasing individual Channel or Master gain controls increases both average output and amount of limiting. To
change Limiter threshold, see section on Limiter
Threshold Adjustment.
Peak LED
Indicates Limiter operation with Limiter switch In. With
switch Out, flashes at 6dB below output clipping. Peak
indicator responds much faster than meter, activated
by even shortest transient peak, yet remains lit long
enough to provide easy recognition.
VU Meter
Factory calibrated for +4 dBm = 0 VU with 600-ohm
load at Line output. (Microphone output levels are 50
dB below Line output.) Supplied 0 VU level is recommended for normal use to provide approximately 14dB
headroom between operating level and clipping level.
To change 0 VU level, see section on VU Meter Adjustment.
VU Lamp
Illuminates meter while button is depressed; automatically turns off 5 seconds after release to prevent battery drain.
Tape Outputs
3.5 mm jack to feed unbalanced Aux-level input of tape
recorder or amplifier. Tip of connector in phase with pin
3 of XLR connectors.
Telephone Lines
In Line position, output transformer will operate with
dc-biased "dialed up" telephone lines although there
may be slight increase in distortion. When connecting
FP31 to telephone line, use FCC-Registered* interface adapter between mixer and telephone line.
'DOC-Certified in Canada
Condenser Microphone Power
Condenser microphones, either 12 to 18 Vdc phantom
(simplex) powered or 9 Vdc A-B(T) powered, can be
supplied from any Mic input of FP31. Below batteries,
inside battery compartment, are three 3-position
switches. Center position is for dynamic microphones
(no dc power supplied to Mic input); left position is for
9-Vdc A-B power, right position is for 11- to 18-Vdc
phantom power.
NOTE: No power is supplied to any input with LineJMic
switch in Line position. No A-B power is supplied unless right-side battery is present.
Mixer Powering
In ordinary portable use, the FP31 is powered by two
standard 9-Vdc alkaline batteries installed in leftmost
battery compartment positions. Phantom power is also
supplied by these batteries.
The FP31 can also be powered by an 11 to 18 Vdc external source, such as an automotive battery, battery
beltpack, Shure PS20 AC Adapter or other low-ripple
ac power converter (see Figure 2), using the12 Vdc
single-pin coaxial input connector in the left-side panel. To filter possible power-supply hum and noise, install a 100 C2 resistor on the "+" side of the dc output.
The outside barrel of the mating connector is positive.
u
*Wire with white stripe is 12 V+
Coaxial
J
Plug
Cut off molded dc power plug of PS20 and wire new
connector as shown
POWERING FP31 FROM EXTERNAL AC ADAPTER
FIGURE 2
Parts Required:
1 Shure PS20 AC Adapter or equivalent (dc output
= 12 Vdc, 100 mA minimum)
1 100 L2 1 W resistor
1 Coaxial dc power plug to fit FP31 external dc power jack (2.1 or 2.5 rnm I.D.) Radio Shack
#274-1567A
Batteries can be left in place as backup in case of failure of external source. Switchover to internal batteries
is performed by disconnecting external plug.
CAUTION
12 Vdc input circuit is not fused. Any external source
should be provided with in-line fuse, 0.25 A, 250 V,
as safety wecaution.
Battery Check
Depressing BATT button converts VU Meter to readout
of battery condition (two mixer-powering batteries) or
of supply voltage. Readings of 0 VU or higher indicate
good batteries or adequate external supply.
VU METER ADJUSTMENT
To set the VU Meter for a value different from the
supplied 0 VU = +4 dBm, proceed as follows.
1. Connect a 600-ohm load to one of the Line outputs.
2. Connect an acvoltmeter (e.g., HP 400GL) in parallel
with the load.
3. Pull out the Channel 1 knob to activate the Tone Oscillator.
4. Adjust the Tone Oscillator level with the Master gain
control until the ac voltmeter reading is at the level
desired.
5. With a screwdriver, adjust the VU Level trimpot (left
of the A-BIDYNISPLX Selector switches) until the
VU Meter reads 0.
LIMITER THRESHOLD ADJUSTMENT
To adjust the Limiter threshold for a value different from
the supplied +I
4 dBm, proceed as follows.
1. Connect a 600-ohm load and an ac voltmeter to a
Line output as described in steps 1 and 2 above.
2. Pull out the Channel 1 knob to activate the Tone Oscillator.
3. With Limiter switch Out, adjust Master gain control
until the ac voltmeter reading is at the level desired.
4. Move the Limiter switch In, and adjust Limiter
Threshold trimpot (left of the VU Level trimpot) until
the level drops 0.5 dB.
FURNISHED ACCESSORIES
Carrying Case . . . . . . . . . . . . . . . . . . . . . . . 9588066
Shoulder Strap . . . . . . . . . . . . . . . . . . . . . 90BX2600
Rohm SLR34MG3
Rohm SLR340R3
ITT Cannon XLR-3-31-F77
ITT Cannon XLR-3-32-F77
None
None
Diode, Light Emitting, Red
Connector, Three Socket
Connector, Three-Pin
Phone Jack, Miniature, 3.5mm
Phone Jack, 'h in.
Motorola IN4002
RCA 1N48, 1N60
TI IN4148
I.C.C. 108RMR025M
I.C.C. 226RSS016M
I.C.C. 107RMR016M
Marcon CESSMlA470
I.C.C. 227RMR025M
Marcon CESSMIC221
Panasonic ECEBI HKO10
I.C.C. 336RSS010M
Marcon CESSMlC471A
Marcon CESSMlC471
Marcon CESSMI E4R7
Panasonic ECEBI EK4R7
Diode, Light Emitting, Green
I
I
Commercial Alternate
Panasonic ECEBOJK220
Power Jack, Coaxial
None
'arts listed as RKC Kits ihould be order1 d by that kit number. Orders recc red for piece parts where RK(
<it number is shown wi be shipped in IKC quantities.
D118, 0119,
D205
I
Diode, Germanium, 30V
D113, D114,
D302, D303,
D304, D305
Silicon Rectifier. 100V. '%A
Diode, Silicon, Computer,
75v
D101-D112,
D115, D117,
D120, D201,
D202, D203
D306
1
Capacitor, Electrolytic,
1000 pF, 25V
C152
86A404
Capacitor, Electrolytic,
22 IF, 16V
(2149, C157,
C158, C159
4
Capacitor, Electrolytic,
100 pF, 16V
C148
I 1
Capacitor, Electrolytic,
47 pF, 1ov
C145, C146,
C147
C133
Capacitor, Electrolytic,
220 pF, 25V
Capacitor, Electrolytic,
33 pF, 1ov
C144
I
Capacitor, Electrolytic,
470 pF, 16V
Capacitor, Electrolytic,
1 pF, 25V
Capacitor, Electrolytic,
220 pF, 16V
RKC21
868629
C129, C131,
C206
C128
C122, C150,
C211, C154,
C212
1-1
I
86AD629 Capacitor, Electrolytic,
470 pF, 16V
1-1
Capacitor, Electrolytic,
22 pF, 6.3V
C114, C154,
--
I
86AC629 Capacitor, Electrolytic,
4.7 pF, 25V
I
86V628
C112, (2120,
C153
C102, C104,
C106
C107, C109,
C115, C119,
C126, C130,
C205, C302,
C303,C305
Reference Replace. Replacement Kit Consists Of:
Designation ment Kit CIty.l Part No.
Description
U301
SI04. S105,
Sl06
I
--
--
RKC66
Swttch, Pushbutton, SPDT
Sw~tch,Slide, DPDT
Switch, Slide, DPTT
None
Raytheon RC4156N
Opto-Isolator
lntegrated Circuit, Quad Op
lntegrated Circuit, Quad
Comparator
lntegrated Circuit, 10V
Regulator
lntegrated Circuit, Dual
comparator
National Semiconductor
LM386N-4
lntegrated Circuit, Quad Op
Ampl (Selected for NF)
lntegrated Circuit, Audio
Power Amplifier
868808
ved for piece parts where Rlc
Raytheon LM339DB
TI UA78LIOACLP
Motorola LM393N
Raytheon RC4156N
None
Transformer, Output
51A8015
None
None
None
Alcoswitch SLS-230PC
Transformer, Input
I1
I
I
Piher PTIOLh(2.5)50k
51 D243
55A8022
None
Potentiometer, 50k
Alcoswitch MSS4200RG
Piher PTlOLh(2.5)lOOk
Potentiometer, 50k
Switch, Slide, 4PDT
None
Potentiometer, lOOk
1 be ordered by that kit number. Orders re(
lipped in RKC quantities.
I 1
I
None
Potentiometer, 50k
None
TI TI593
Farranti FST185L
Potentiometer, lOOk
Potentiometer, look, with
SPDT Switch
I Transistor, PNP
I
I
Precision Lamp PL7218
Motorola 2N5210
None
Lamp, TI, IOV, .027A
None
Knob, PHONES
Battery Cover
None
Knob, MASTER
Transistor. NPN
86A335
Radio Shack 270-090
None
Knob, MIC 1-3
None
Cartridge, Electret
Stackpole 57-3425
Stackpole 57-0181
Commercial Alternate
VU Meter (Special VU Range)
Ferrite Bead Ring
Ferrite Bead Ring
--
1
80A365
80A250
Transistor, NPN
-
-
-
RKC89
---
--
Parts listed as RKC Kits
Kit number is shown wi
1
R110 & S108
Q302
Q101
Q102, Q103,
(2104, Q301
M P6
PLI
L201, L202
L301
L1-L10
REPLACEMENT PARTS LIST
I
I
PC BOARDS
BOTTOM BOARD - COMPONENT SIDE
BOTTOM BOARD -SOLDER SIDE
TOP BOARD - COMPONENT SIDE
TOP BOARD - SOLDER SIDE
.
METER BOARD - COMPONENT SlDE
-
METER BOARD - SOLDER SlDE
CIRCUIT DIAGRAM
I
TAPE OUT
MINI JACK
I
r----------7
I
I
I
I
I
I
I
PUONE JACK
I #HE TONE OSC
TONE
09C.
R M E TMR
1
. ALL CAPACITORS I N p.F bND 50V OR MDRE WLESS OTHERWISE SHIWN.
ELECTROLYTIC CAPACITORS S
2.
3.
4.
-
BT I 9V 8T2
NOTES
ALL RESISTORS L / W I
6E
W IN
pF
AC VOLTAGES SHOW FOR VL02B OBTAINED WITH LIMITER "IN"
(THRESHOLD AT +Ik ISM) bND WILL VARY DEPENDING U W N CIRCUIT
PARAMETERS AND SETTING OF L I M ADJ CWTROL ( W 3 1 .
8.
AC VOLTAGES SHIWN FOR 930% OBTAINED WITH VU ADJ CONTROL
(~~5.3)SET m IN~ICATE o w AT +4 r n LINE
~ PUT.
X VOLTS.
5% LNLESS OTHERWISE SPECIFIED.
FOLLOWlffi SYP(BOLS DEMTE:
;K;S
7.
E ~ 0
"AD
PCMLTAGE
WlOl
0C
AC
VOLTAGE
I
D
m
ALL VOLTAGES MEASURED WITH 32.5 MLTS DC APPLIED
l w v nett
POWER INPUT CWECTOR. ALL SWITCHES I N WSITIONS S W N I EXCEPT
AS NOTED. MIC 1 INPUT LEVEL -80 DBV (0.1 mV RMSI ACROSS PINS
2 AND 3 OF JLI SUPPLIED BY 1 5 0 MI L KHZ SOURCE. LINE OUTPUT
PHPlES OUTPUTS LOADED WITH
(J4 OR J5) WADED WITH 600 OHMS.
200 O M S FROM T I P AND RING TO SLEEVE. TAPE MIT WADED WITH 47K
OHMS.
INPUT L PJvD WSTER CONTROLS CLOCKWISE. PH3NES KNTROL
SET FOR 0.W RHS ON WIPER (APPROXIMATELY MID POSITION).
VOLTAGES
X bND
ARE MEASURED WITH RESPECT TO GROLND EXCEPT WHERE SHMN.
AC VOLTAGES MEASLRED WITH LO H E W M METERS. VALUES ARE TYPICAL
20%.
LAC VOLTAGES ARE RMS VALUES) bND MAY VARY
+
I
T eot
BOTTOll VIEW
e
E
3
F
4
5
-G
5
H
J
8
C
VE
PK IND. DRIVE
L
MLTAGES SHlWN FOR U r n 6 OBTAINED WITH SLATE SWITCH MPRESSED.
AC VOLTAGES SHOWN FOR SECTIOvS A AND B OF UL06 WILL VARY WITH
ACOUSTICAL INPUT
WL.
VAWES GIVEN PS(E TYPICAL MR AN AC
COUPLED I L p F ) L KHz, 3 mV RMS SIGNAL APPLIED AT THE JLNCTIW OF
RL57 AND R158. THIS MAY RE APPROXIMATED BY A STEADY W I S T L E
WITHIN 6" OF THE FlMNT PANEL. VOLTAGES S M FOR SECTICNS C
bND D OF U L W ARE BEST READ WITH R209 SHORTED C U TO PREVENT THE
SLATE TONE TIMER FROM TIMING OUT THE SLATE TONE OSCILLATOR.
M
N
-P
R
-5
6
C
C
Vcc
PK IND OR
0
E 0------o
E
GND
F MIX U i A N I
F
F
AUX
GMIXCIlAN2
G o-----O
G
IOV
HCaEIMP3OVT
J PREAMP &! WT
L SLATE TMR OUT
WLTAGES SHMN FOR ULOZC PND D OBTAINED WITH TONE OX: SWITCHED ON.
W3Ol A VUDFZ
0 0----9
E U T E TONEPWR
K PREAMP I OUT
6.
A
D MIX CHAN 3
K cr-----O
5.
m
(2-----o
WZG2
Vcc/,
A -WmA
M
VU
OR
N PROG
P
A-0
R A-8
SGND
BATTBArr+
D
A single-pin coaxial 12 Vdc external power,jack.permits the mixer
to be powered froman-11 i o 18 volt source such as a video tape
recorder, automotive electrical system or ac power converter. Such
an external source will also provide simplex power to the
microphone inputs, but a battery is still required for A-B power.
The three &socket professional audio input connectors are individually switchable to balanced 600-ohm
line or low-impedance microphone level. In the MIC
position, either simplex (phantom) or A-B power IS
available at each input for powering condenser
microphones. Each input transformer is Mumetal
shielded for maximum resistance to electrical hum.
The mixer requires 11 to 18 Vdc for operating power. Internal power is supplied by two standard rectangular 9-volt
alkaline-batteries(Duracell
K~1604 ~ r < ~ u ~ v a l e n t ) w ~ c h P
also provlde s~mplex(phantom) power to the microphone
inputs. Battery life IS approximately 8 hours.
IMPORTANT: Use only alkaline batteries.
I
____I
t
A thi~d-91volt-batte~:is used to supply
~ 3 - ~ o w eat
r each microphone input.
When the ~ n p u tselector switch is in the
Line position, the power is automatically
off for that input.
When powering the mixer from an external source, the batteries
may be left in place as backup in case of failure of the source.
Switchover to battery power is performed by removing the plug
from the 12 Vdc jack. To prevent the possibility of damage caused
by leaking batteries, remove the batteries during any prolonged
period of storage or nonuse.
t
--
--
The Slate-pushbutton inserts a 1-second low-frequency
tone (400 Hz) each time it is depressed, and it keeps the
slate microphone on as long as it is depressed.
Using .the.-On10ff-switch to turn the power on
starts the green Power On indicator LED-flashing
.. .- -- .--- !
I
with a repetition rate of a p p r o x i m a ~ l y1 second.
The LED continues to flash so long as the switch
is on.
-..- .
.
-..-.-,
1
Individual Lo-Cut filter switches for each input reduce lowfrequency interference from air-conditioner or fan noise,
wind, strong hum fields, or similar sources. The filters insert a 7 dB rolloff at 100 Hz with a slope of -6 dB per octave.
The VU-Meter is supplied set for 0
VU = + 4 dBm. This level can be
changed by an internal adjustment (see section on VU Meter
Adjustment).
,
,,
The Limiteflhreshold-and-VU-Meter_tfimpots are
located through screwdriver slots below the battery compartment and to the left of the
A-BISimplex switches.
Simplex
or A-B-power is selected by
-- - --means of switches directlybelow the battery
compartment, inside the battery door. In the
DYN position, no power is supplied to the
Mic inputs.
I
Lama bushbutton momentarilv il--- The VU-
On Channel-1,-the. Gain-Control- knobpulls out to activate a 1 kHz tone
oscillator that serves as a level-setting
aid. The oscillator level is set with the
Master control and is indicated on the
VU Meter.
luminates ;he Z i e r dlal:~;
automatic timed
release shuts off the lamp after 5 seconds. The
lamp remains lit while the button is depressed.
7
A13
provides an Aux-level Tape
L
i - 5 mm mini jack
- --
output with minimum clipping level of 0.5V RMS
( - 6 dBV).
The-re<Peal&ED
flashes to indicate the onset
of limiting. When the Limiter is Out, the red LED
acts as an overload indicator and begins
flashing at 6 dB below output clipping level.
--
The Battery check pushbutton converts the VU
~ e c tor a7batterycondition orcircuit voltage indicator while the button is depressed.
L
s
7
i
A built-in pushbutton-operated, electret condenser
-slate-microphone can be used either for identifying
recorded segments
microphone.
Each input-channel-has-its own-gaincontrol. The input clipping- level for
microphones is from -47 to - 17 dBV
depending on the channel control setting. For line inputs, the clipping level
ranges from + 3 to +33 dBV, again
depending on the control setting.
or as an emergency
field,
The Master gain control sets the output level at the
LinelMic a n d ~ a ~ e ~ u tGain
~ u ~iss40
. dB from Mic In to
Mic Out or from Line In t o Line Out; 90 dB from Mic In to
Line Out, 68 dB from Mic In to Tape Out, and 18 dB from
Line In to Tape Out.
;
r
J
s
!
The outputLimiter
has a threshold of + 14 dBm at the
-600-ohm Line output (4 dB below clipping), with comparable levels at the Mic and Tape outputs. The
threshold can be internally adjusted down to + 3 dBm
(see section on Limiter Threshold Adjustment). The
Limiter attack time is 3 msec typical, with 500 msec
typical recovery time, for unobtrusive operation.
A b.5-mm-minijack and a quarjerjnchphonejackprovide two stereo headphone outputs that can
be used simultaneously. They are designed to
drive mono or stereo headsets with impedances
of 8 to 2,000 ohms. They can also be used to drive
up to four Aux-level tape recorder or amplifier inputs.
s
A beparate Phones volume control sets the level
at the T C a ~ ~ e F ~ t p G t ~ ; - m a xoutput
i i ~ mis
1.6V RMS ( + 4 dBV) to 200 ohms.
I
-
-- ---
-
Two
-- 3-pin professional
-- -- audio output
connectors
are
individually switchable to
,
600-ohm Gne level or I&-impedance
microphone level. Minimum clipping levels
are + 18 dBm (Line) and -34 dBV (Mic).
--
-
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