OTARI MX-5050BII Series User manual

Parts No. OS3-038
MX-5050611
SERIES PROFESSIONAL RECORDERS
INSTRUCTION MANUAL
Edition No. 6
Issued : Dec. 1984
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CAUTION
To prevent fire or shock hazard :
Do not expose this appliance to rain or moisture.
Do not remove cover.
No user-serviceable parts inside.
Refer servicing to qualified service personnel.
PLEASE READ THROUGH SAFETY INSTRUCTIONS
ON THE NEXT PAGE.
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SAFETY INSTRUCTIONS
1. Read Instructions All the safety and operating instruc-
tions should be read before the appliance is operated.
2. Retain Instructions The safety and operating instructions
should be retained for future reference.
3. Heed Warnings - All warnings on the appliance and in the
operating instructions should be adhered to.
4. Follow Instructions - All instructions should be followed.
5. Water and Moisture The appliance should not be used near
water - for example, near a bathtub, washbasin, kitchen sink,
laundrytub, in a wet basement, or near a swimming pool, etc.
6. Carts and Stands - The appliance should be used only with
a cart or stand that is recommended by the manufacturer.
7. Ventilation The appliance should be situated so that its
location or position does not interfere with its proper
ventilation.
For example, the appliance should not be situated on a bed,
sofa, rug, or similar surface that may block the ventilation
operatings; or, placed in a built-in installation, such as a
bookcase or cabinet that may impede the flow of air through
the ventilation openings.
8. Heat The appliance should be situated away from near
sources such as radiators, heat registers, stoves, or other
appliances (including amplifiers) that produce heat.
9. Power Sources The appliance should be connected to a
power supply only of the type described in the operating
instructions or as marked on the appliance.
10. Grounding or Polarization Precautions should be taken so
that the grounding or polarization means of an appliance are
not defeated.
11. Power-Cord Protection Power-supply cords should be routed
so that they are not likely to be walked on or pinched by
items placed upon or against them, paying particular atten-
tion to cords at plugs. Convenience receptacles, and the
point where they exit from the appliance.
12. Cleaning The appliance should be cleaned only as recom-
mended by the manufacturer.
13. Nonuse Periods The power cord of the appliance should be
unplugged from the outlet when left unused for a long period
of time.
14. Object and Liquid Entry Care should be taken so that
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objects do not fall into and liquids are not spilled into the
enclosure through openings.
15. Damage Requiring Service -- The appliance should be serv-
iced by qualified service personnel when:
A. The power-supply cord or the plug has been damaged; or
B. Objects have fallen, or liquid has been spilled into the
appliance; or
C. The appliance has been exposed to rain; or
D. The appliance does not appear to operate normally or ex-
hibits marked change in performance; or
E. The appliance has been dropped, or the enclosure damaged.
16. Servicing -- The user should not attempt to service the
appliance beyond that described in the operating instruc-
tions.
All other servicing should be referred to qualified service
personnel.
iv
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WARNING
This equipment generates, uses, and can radiate
radio frequency energy and if not installed and
used in accordance with the instructions manual,
may cause interference to ratio communications.
It has been tested and found to comply with the
limits for a Class A computing device pursuant to
Subpart J of Part 15 of FCC Rules, which are de-
signed to provide reasonable protection against
such interference when operated in a commercial
environment. Operation of this equipment in a re-
sidential area is likely to cause interference in
which case the user at this own expense will be
required to take whatever measures may be re-
quired to correct the interference.
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COMMUNICATION WITH OTARI
FOR SERVICE INFORMATION AND PARTS
The OTARI PRODUCTS are manufactured under strict quality control
and each unit is carefully tested and inspected prior to shipment
from our factory.
If, however, some adjustments or technical support become neces-
sary, replacement parts are required, or technical questions arise,
please contact your nearest Otari dealer or write to:
OTARI ELECTRIC CO., LTD.
4- 29 -18, Minami Ogikubo,
Suginami-ku, Tokyo, 167,
Phone: [phone]
Telex: J26604 OTRDENKI
Fax . [phone]
OTARI CORPORATION
2 Davis Drive, Belmont,
Japan California 94002, U.S.A.
Phone: [phone]
Telex: 25 9103764890
Fax [phone]
OTARI ELECTRIC DEUTSCHLAND GmbH.
Gielenstrasse 9, 4040 Neuss 1
F.R. Germany
Phone: [phone]
Telex: 41 8517691 OTEL D
Fax [phone]
OTARI SINGAPORE PTE., LTD.
Unit 5350, 2nd floor, Woh Hup
Complex, 5001, Beach Road,
Singapore, 0719
Phone: [phone]
Telex: 87 36935 RS36935 OTARI
OTARI ELECTRIC (UK) LTD.
Herschel Industrial Centre, Church Street,
Slough SL1 IEL, Berkshire, United Kingdom
Phone: [phone]
Telex: 849453 OTARI G
Fax [phone]
Another part of Otari's continuous technical support program for
our products, is the continuous revision of manuals as the equip-
ment is improved or modified.
In order for you to receive our information and service applicable
to your requirements, and for the technical support to function
properly, please include the following information, most of which
can be obtained from the name plate on the equipment in all
correspondences.
1. Model Number
2. Serial Number
3. Date of purchase
4. Name and address of dealer from whom machine was
purchased
5. Power requirements (voltage and frequency) of the
machine
6. Manual number to which you are referring
vii
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TABLE OF CONTENTS
PAGE SECTION TOPIC
I GENERAL INFORMATION
1-1 1.1 System Description
1-2 1.1.1 Tape Transport
1-3 1.1.2 Record/Reproduce Electronics
1-3 1.1.3 Head Assemblies
1-4 1.2 Standard Accessories
1-4 1.3 Optional Accessories
1-5 1.4 Service and Replacement Parts
1-5 1.5 Specifications
II INSTALLATION
2-1 2.1 Unpacking and Inspection
2-1 2.2 Location and Environment
2-2 2.3 Dimensions
2-2 2.4 Standard Switch Position on Shipment
2-4 2.5 Power and Signal Connections
2-7 2.5.1 AC Power Connections
2-8 2.5.2 Signal Connections
III OPERATION
3-1 3.1 Controls and Indicators
3-9 3.2 Operating Information
3-9 3.2.1 Use of the Reel Hold Down Knobs
3-10 3.2.2 Pre-operating Procedure
3-11 3.2.3 Reproduction
3-12 3.2.4 Normal Recording
3-13 3.2.5 Recording with Selective Production
3-14 3.2.6 Fast Winding
3-14 3.2.7 Editing and Splicing Tape
IV PREVENTIVE MAINTENANCE AND ADJUSTMENTS
4-1 4.1 Test and Maintenance Equipment
Requirements
4-2 4.2 Preventive Maintenance
ix
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PAGE SECTION TOPIC
4-2 4.2.1 Cleaning
4-3 4.2.2 Demagnetizing
4-4 4.2.3 Lubrication
4-5 4.3 Electronic Trimming
4-5 4.3.1 Record Bias Adjustment
4-5 4.3.2 Record Level Adjustment
4-6 4.3.3 Record Equalization Adjustment
V AMPLIFIER ADJUSTMENTS
5-1 5.1 Access to the Amplifier
5-1 5.2 Amplifier P.C.B. Assembly layout
5-6 5.3 Block Diagram and Circuit Description
5-6 5.3.1 Reproduce Circuit
5-6 5.3.2 Record Circuit
5-9 5.4 Transport Control Timing Chart
5-9 5.5 Amplifier Adjustment
5-9 5.5.1 Test Tape Selection
5-10 5.5.2 Head Alignment
5-12 5.5.3 Reproduce Equalization Adjustment
5-13 5.5.4 Bias Adjustment
5-15 5.5.5 Record Level, Monitor Level Adjustment
5-15 5.5.6 Peak Indicator Trigger Level Adjustment
VI TAPE TRANSPORT MAINTENANCE AND REPLACE-
MENT PROCEDURE
6-1 6.1 Transport Access
6-2 6.2 Brake Adjustment
6-4 6.3 Capstan Pinch Roller Pressure Adjustment
6-6 6.4 Speed Conversion and Speed Adjustment
6-7 6.5 Reel Motor Assembly Replacement
6-7 6.5.1 Reel Table Height Adjustment and
Replacement
6-7 6.5.2 Reel Motor Replacement
6-8 6.5.3 Brake Band and Solenoid Replacement
6-9 6.6 Power Transformer Replacement
6-9 6.7 Capstan Motor Replacement
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PAGE
6-10
6-11
6-11
6-12
SECTION
6.8
6.9
6.9.1
6.9.2
VII
TOPIC
Pinch Roller Replacement
Head Assembly Replacement
Description
Head Stack Replacement
PERFORMANCE TESTING
7-1 7.1 General Notice
7-1 7.2 Test Tapes
7-2 7.3 Test Conditions
7-2 7.4 Performance Tests
7-3 7.4.1 Overall Signal-Noise Ratio
7-4 7.4.2 Overall Distortion Test
7-5 7.4.3 Crosstalk Test
7-6 7.4.4 Erasure Test
7-7 7.4.5 Tape Speed Measurement
7-8 7.4.6 Flutter and Wow Test
VIII P.C.B. ASSEMBLIES AND PARTS LISTS
IX EXPLODED VIEW DRAWINGS AND PARTS LISTS
X CIRCUIT DIAGRAMS
xi
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SECTION I. GENERAL INFORMATION
The MX-5050BII Series Recorders are professional quality two-speed
audio tape recorder/reproducers designed for optimum performance
and long life.
The MX-5050BII units use 1/4-inch tape and are available in 4 dif-
ferent models. The different models, and their application, are
determined by the head format.
Table 1 -1
Model Head Format Speed Tape
BU-2 2-track, 2-channel
*15 and 7 -1/2 IPS 1/4 inch
BII-4 4-track, 2-channel
BII -F Full track, Mono
BII -2E 2-track, 2-channel DIN
* The MX-5050BII is factory set to operate at tape speeds of
15 and 7 -1/2 ips. By users conversion the unit can be
reset to operate at 7 -1/2 and 3-3/4 ips.
Refer to page 5 -1.
1.1 SYSTEM DESCRIPTION
Among the many professional features of the MX -5050BII Series are:
selective reproduction, motion sensing, an edit control that
permits spilling, an adjustable cueing control for audible moni-
toring in the fast-forward and rewind modes, a built-in two
frequency low distortion test and cue-tone oscillator, a com-
puterized elapsed time indicator with a digital LED display,
front adjustable record bias, equalization, and level controls,
active balanced input and output circuits, a reference flux level
indicator on the front amplifier panel, a standard reference
level output switch, separate line and microphone input level
controls for each channel, switches for recording levels, equal-
ization, microphone, and output level attenuators, play-back
equalization pots for each speed, a memory stop for automatically
stopping the tape in the rewind mode at a predetermined position,
ceramic tape guides, big head housing, lower transport noise, and
improved specifications for distortion, erase effect, and signal
and noise ratio.
1 -1
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1.1.1 TAPE TRANSPORT
All components of the tape transport system are mounted on a
rigid aluminum frame for stability. The transport design in-
corporates two 6 -pole induction motors for the reels and a 3-
speed DC servo motor (Direct drive) for the capstan.
Speed selection is made by a front panel push- button switch which
also switches the equalizer.
The transport accommodates tape reels of 10 -1/2 inches, 7 inches,
and 5 inches in diameter with NAB or EIA hub configurations. A
solenoid-actuated tape lifter lifts the tape away from the heads
in the fast forward and rewind modes, in addition to the stop
mode, to increase head and tape life.
In addition to the editing controls, a tape -splicing block (Fig.
3 -3) mounted on the head cover holds the tape for ease of editing.
Momentary contact push-button switches on the transport are used
to select operational modes: record, play, stop, rewind, and
fast forward. These modes may be controlled from a remote loca-
tion by means of an optional remote control unit (page 1 -5).
0 O O 0 0 0 0 0 0 0 0 (p D D
TAPE TRANSPORT
CONTROL PANEL
RECORD/REPRODUCE
ELECTRONICS
Fig. 1 -1 MX- 5050B11 Major Components
1 -2
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1.1.2 RECORD/REPRODUCE ELECTRONICS
FEATURES
(1) The RECORD/REPRODUCE amplifier unit is connected to the
transport unit only by the connectors and therefore can be
easily removed for ease in servicing.
(2) This machine contains a SEL. REP. function for overdubbing:
for example, SOUND WITH SOUND, SOUND ON SOUND, carried out
by the PUNCH -IN and PUNCH -OUT functions of the transport
control.
(3) This machine provides both NAB and IEC equalizers, switchable
on the rear panel. However, when the equalizer position is
changed, fine tuning the record and reproduce equalizer
adjustment controller is necessary.
(4) In order to give optimum performance for different types of
recording tapes, record bias, level, and equalization con-
trols on the front panel can be adjusted to meet any
requirements.
(5) To improve the signal to noise ratio and increase the head
room, the record/reproduce electronics have been designed
with a high-fidelity amplifier.
1.1.3 HEAD ASSEMBLIES
As viewed from the front of the recorder, the configuration of the
head assembly of each model MX-5050BII is shown in Table 1 -2.
Table 1 -2 Head Assembly Configuration
Model No. Head Structure Record
HeadH1
Erase H2
Playback H3 Record H4
Playback
MX-5050B11-2 2T, 2CH 4T, 2CH 2T, 2CH 2T, 2CH 2T, 2CH
Stereo
MX-5050B II -4 4T, 2CH 2T, 2CH 4T, 2CH 4T, 2CH 4T, 2CH
Stereo
MX-50501312 -F FT, MONO 2T, 2CH FT, MONO FT, MONO FT
Monoaural
MX-505013 II-2E 2T, 2CH
DIN 4T, 2CH 2T, 2CH
DIN 2T, 2CH
DIN 2T, 2CH
Stereo
1 -3
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NOTE: The head assemblies of these models contain two
playback head stacks. A head change -over switch
located in the head assembly permits selection of
either head stack.
Fig. 1 -2 Head Arrangement
1.2 STANDARD ACCESSORIES
The MX-5050BII is supplied with the standard accessories
below.
STANDARD ACCESSORIES ( *ZA-12W)
listed
1. NAB Hub Reel Hold Down Knob KWOHO 2 pcs.
2. NAB Empty Reel 10 -1/2 inch ZA -51A 1 pc.
3. Reel Adjusting Disc (Shim) ** KW00005 2 pcs.
4. Instruction Manual 053 -038 1 pc.
5. Power Cord PZ9D003 1 pc.
* This part number includes
numbers 1 through 5. all parts described in
** The reel-adjusting disc (shim) is placed between
a metal reel and the turntable to compensate for
the difference in thickness between metal reels
and plastic reels.
1.3 OPTIONAL ACCESSORIES
Optional accessories available are listed below.
l-4
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OPTIONAL ACCESSORIES
1. Remote Control Unit CB -102
2. Cleaning Kit ZA-51B
3. Balanced Input Transformer Ass'y ZA -53T
4. Balanced Output Transformer Ass'y ZA-53S
1.4 SERVICE AND REPLACEMENT PARTS
For service and replacement parts, or for technical support,
please contact your nearest service center, Otari dealer, or
write directly to Otari. (See page iii for complete addresses.)
1.5 SPECIFICATIONS
The specifications of the MX- 5050BII Series are as listed in Table
1 -3.
NOTE: Specifications are based on tape speeds of 7 -1/2 and 15
ips. Specifications, although obtainable when serviced
by qualified service personnel, are not guaranteed when
using lower tape speeds.
Table 1 -3 Specifications of the MX -5050B Series
Tape Width and Tracks
Tape Speeds
Reel Sizes
1/4 inch (6.3 mm) tape:
2 tracks (0.079 in. or 2.0 mm
track width)
4 tracks (0.040 in. or 1.0 mm
track width)
Full tracks (0.24 in. or 6.1 mm
track width)
7 -1/2 and 15 ips (19 and 38 cm/sec) or
3 -3/4 and 7 -1/2 ips (9.5 and 19 cm/sec)
Maximum deviation: +0.2% measured
with 1.5 mil (0.038 mm) tape.
7 inch or 10 -1/2 inch plastic or metal,
EIA or NAB.
1 -5
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Heads
Motors: Capstan
Reels
Operating Position
Power Requirements
Operating Environment
Storage Environment
Dimensions and Weight
Mounting
Standard Accessories
Model MX-5050BII -2:
Half-track configuration
Model MX-5050BII -4:
Quarter-track configuration
Model MX-5050B11 -F:
Full-track configuration
Model MX-5050BII -2E:
Half-track configuration
Four head stacks:
MX- 5050BI[ -2: 2T erase, 4T reproduce,
2T record, 2T reproduce.
MX- 5050BII -4: 4T erase, 2T reproduce,
4T record, 4T reproduce.
MX- 5050BIr -F: FT erase, 2T reproduce,
FT record, FT reproduce.
MX- 5050BII -2E:
2T DIN erase , 4T reproduce,
2T DIN record, 2T DIN reproduce.
DC servo controlled motor. (Pitch
control limits ± 7 % )
Two induction torque motors.
Vertical or horizontal.
50/60 Hz , 100/117/220/240 V ± 10 %
Single phase AC , 100 W
40° to 104 °F (5° to 40 °C)
20 to 80 % RH
-5° to 113 °F ( -20° to 45 °C)
Height 527 mm (20.7 inch)
Width 430 mm (16.9 inch)
Depth 225 mm ( 8.8 inch)
24 kgs (53 lbs.)
Dark grey leather- finished cabinet.
One empty 10 -1/2 inch NAB reel, two NAB
reel hold down knobs, two NAB reel-
adjusting discs (shims), and one
instruction manual, one power cord.
1 -6
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Remote Control Unit
Connectors
Inputs: Line
Microphone
Outputs: Line
Headphone
Equalization
Frequency Response
Signal to Noise Ratio
An optional remote control unit is used
to control the record, play, stop,
rewind, and fast forward modes.
Line input, line output, and microphone,
standard three -pin XLR.
Minimum -15 dBm, active balanced 10k
ohms. (Floating type). Minimum -15
dBm, balanced 10 k ohms with optional
transformer.
Minimum -70 dBm, active balanced, adapt-
able microphone's impedance: 150 to
10 k ohms. The microphone attenuator
switch may be set to the 0 dB, -20 dB,
or Off position depending on the circum-
stances.
Level: +4 dBm or -10 dBm, rear panel
switch selectable.
Active balanced (Floating type),
Source impedance: 5 ohms.
Load impedance: More than 600 ohms.
Maximum line output: +27 dBs with a
600 ohm load.
Level: -24 dBm with an 8 ohm load.
Load impedance: 8 ohms or greater.
NAB or IEC for 3 -3/4, 7 -1/2, and 15 ips.
Switchable on the rear panel, but
calibration is necessary.
15 ips: 30 Hz to 20 kHz t 2 dB
7 -1/2 ips: 20 Hz to 18 kHz t 2 dB
3 -3/4 ips: 20 Hz to 10 kHz t 2 dB
Specifications refer to a 1 kHz refer-
ence when recorded on 3M 226.
Over-all measured at the level of 520
nWb/m.
1 -7
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NAB Equalization
Tape Speed 2 Track 4 Track Full Track
Weighted Unweighted Weighted Unweighted Weighted Unweighted
15 ips 66 dB 64 dB 62 dB 60 dB 68 dB 66 dB
7 -1/2 ips 68 dB 66 dB 63 dB 61 dB 68 dB 66 dB
3 -3/4 ips 66 dB 64 dB 62 dB 60 dB 66 dB 64 dB
IEC Equalization
Tape Speed 2 Track 4 Track Full Track
Weighted Unweighted Weighted Unweighted Weighted Unweighted
15 ips 66 dB 62 dB 62 dB 58 dB 62 dB 60 dB
7 -1/2 ips 64 dB 62 dB 62 dB 58 dB 62 dB 60 dB
3 -3/4 ips 64 dB 62 dB 62 dB 58 dB 62 dB 60 dB
Crosstalk
Wow and Flutter
Distortion
Erase Efficiency
With a 1 kHz signal on adjacent tracks:
2 tracks: greater than 55 dB
4 tracks: greater than 55 dB
(NAB weighted):
Tape Speed
15 ips less than 0.06 %
7 -1/2 ips less than 0.08 %
3 -3/4 ips less than 0.12 %
Less than 0.5% at 1 kHz at 250 nWb/m.
Greater than 75 dB.
1 -8
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Test Oscillator Frequency
Bias and Erase Frequency
Peak Indicator
Record Level
(SRL)
Nominal 1 kHz and 10 kHz
133 kHz
Trigger level: 1040 nWb/m (15 dB
above Ampex operating level)
recorded flux level.
3-position switchable on the rear
panel.
Position Flux Relative
Level Test Tape Recording tape to be used
Low 185 nWb/m* 0 dB Ampex Operat-
ing Level Scotch 177,
Ampex 641
Medium 250 nWb/m* +2.6 dB MRL NAB
Reference
Flux
Scotch 206,
207, 226, 250
Ampex 406,
407, 456
High 320 nWb/m** +3.8 dB BASF or MRL
IEC Standard IEC Equaliza- tion
* Short circuit flux
** Open circuit flux
NOTES: 1. Signal to noise ratio is measured with respect to a
recorded level of 520 nWb/m to biased tape noise when
using Scotch 226 magnetic tape.
Unweighted: Using a 30 to 18 kHz RC filter to atten-
uate noise outside the audio spectrum.
Weighted Using an NAB or ASA "A" weighting filter
and a 1 kHz reference.
2. Otari reserves the right to change specifications
without notice and/or obligation.
3. IN CASE OF DIN STEREO VERSION (MX-5050BII-2E), 3-
POSITIONS ARE SET AS FOLLOWING.
Low 250 nWb/m
Medium 320 nWb/m
High 520 nWb/m
1 -9
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SECTION II. INSTALLATION
This section of the manual provides information on unpacking and
inspection, location and environment, and power and signal
connections.
2.1 UNPACKING AND INSPECTION
The MX- 5050BII Series system is shipped from the factory in a single
cardboard packing case. Upon receipt, examine the case for any
signs of damage. Unpack the equipment and inspect for any signs
of damage. Use great care when unpacking the equipment and remov-
ing packing materials to prevent damage to critical components
such as the capstan, head assembly, and tension arms.
Referring to the lists in Secs. 1.2 and 1.3 (as applicable), veri-
fy that all items have been received. Report any shortage or
damage to the carrier and your local Otari dealer. Save the
packing case for possible reshipment. Other packaging may cause
damage during transportation and will void the warranty.
Please refer to the illustration which is attached to flap of the
packing box regarding the repacking method.
2.2 LOCATION AND ENVIRONMENT
The area chosen for operation should be adequately ventilated and
dust free. Since recording is by an electromagnetic process, it
is possible that strong electromagnetic fields may affect the
system adversely. Common sources of interference are fluctuating
loads on nearby high-voltage lines, heavy duty transformers, and
transmitting equipment.
It is recommended that the equipment be used in an environment
where the surrounding temperature does not exceed limits of 40°
to 104 °F (5° to 40 °C), with the relative humidity between 20 and
80 %. Allow at least a 4 inch (10 cm) clearance behind the rear -
panel ventilation grill.
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2.3 DIMENSIONS
Equipment dimensions of the MX- 5050BII Series are shown in Fig. 2 -1.
21.3 inch (541 mm) 10.2 inch (258 mm) 0. 7 inch
(18 mm)
o e
E
ruc
=s. 7.,.t..^L_11:iir - Ó
c u o c u o 0 0
11111111 PT PT Il I !MIT I-1
16.9 inch (430 mm)
ü a-
e 3
Fig. 2 -1 Equipment Dimensions
2.4 STANDARD SWITCH POSITION ON SHIPMENT
8. 1 inch
(206 mm)
Either the NAB standard or the IEC standard of equalization,
recording level, etc. may be used with the Otari MX-5050BII series.
These units have been provided with a slide switch on the back
panel which selects one of these two standards; to change stand-
ards, merely slide the switch to the desired position.
2 -2
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