OTARI MTR-10II Series User manual

Parts No. 053-088
lflOfj[j]H
MTR-10II and 1211
SERIES PRODUCTION TAPE RECORDERS
OPERATION AND MAINTENANCE MANUAL
M TR-l O-C Over bridge Model
Edition No.6
Printed: May 1989

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 -- rrhe appliance should not be used near
water - for example, near a bathtub, washbasin, kitchen sink,
laundry tub, 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
III

COMMUNICATION WITH OTARI
FOR SERVICE INFORMATION AND PARTS
All Otari products are manufactured under strict quality control.
Each unit is carefully inspected and tested prior to shipment.
If, however, some adjustment or technical support becomes neces-
sary, replacement parts are required, or technical questions
arise, please contact your Otari dealer or contact Otari at:
OTARI, INC.
OTARI CORPORATION
4-33-3 Kokuryo-Cho, 378 Vintage Park Drive
Chofu-shi, Tokyo 182, Japan Foster City, CA 94404, U.S.A.
Phone: [phone]
Phone: [phone]
Telex: J26604 OTRDENKI
Telex: 650 302 8432 MCI UW
Fax: [phone]
Fax: [phone]
Cable: OTARIDENKI TOKYO
OTARI ELECTRIC DEUTSCHLAND GmbH.
OTARI SINGAPORE PTE., LTD.
Rudolf-Diesel-Str. 12
625 Aljunied Road
D-4005 Meerbusch 2(Osterath)
#07-05 Aljunied Industrial
West Germany
Complex, Singapore 1438
Phone: [phone]
Phone: [phone]
Telex: 8531638 OTEL D
Telex: 87-36935 RS 36935 OTARI
Fax: [phone]
Fax: [phone]
OTARI ELECTRIC (UK) LTD.
22
Church Street Slough
Berkshire SLI IPT
United Kingdom
Phone: [phone]
Telex: 849453 OTARI G
Fax: [phone]
Another part of Otari's continuing technical support program for
our products is the continuous revision of manuals as the
equipment is improved or modified. In order for you to receive
the information and support which is applicable to your equipment,
and for the technical support program to function properly, please
include the following information, most of which can be obtained
from the Serial number label on the machine, in all correspondence
with Otari:
* Model Number:
* Serial Number:
* Date of Purchase:
* Name and address of the dealer where the machine was purchased
and the power requirements (voltage and frequency) of the
machine.
vii

TABLE OF CONTENTS
PAGE
SECTION 1: INTRODUCTION
1.1 USING THIS MANUAL
1-1
1.2 OTARI MTR-10 AND MTR-12 SERIES MASTER PRODUCTION
1-3
RECORDERS
1.3 REFERENCE PHOTOGRAPHS
1-6
SECTION 2: INSTALLATION
2.1 PRELHHNARY
2-1
2.2
INSPECTION
2-1
2.3
FUNCTION SELECTION
ON MASTER CPU P.C.B. ASSEMBLY
2-9
2.4
CONNECTIONS
2-11
2.4.1 LINE INPUT AND LINE OUTPUT
2-11
2.4.2 INTERCONNECT CABLE FOR OPTIONAL AUTO LOCATOR
2-12
2.4.3 INTERCONNECT CABLE FOR OPTIONAL REMOTE CONTROL BOX
2-13
2.4.4 REMOTE MODE SWITCHING FOR NOISE REDUCTION
2-13
EQUIPMENT
2.4.5 PARALLEL I/O CONNECTOR
2-13
2.4.6 AC POWER CONNECTION
2-14
SECTION 3: FUNCTIONAL CHECKOUT AND BASIC OPERATION
3.1 GENERAL
3-1
3.2 MTR-10 CONTROLS AND INDICATORS:
QUICK REFERENCE GUIDE
3-1
3.3 FUNCTIONAL CHECKOUT
3-13
3.3.1 REEL INSTALLATION
3-13
3.3.2 CHECKING TENSION COMPENSATION FOR TAPE WIDTH
3-15
3.3.3 POWERING UP
3-15
3.3.4 LOADING TAPE ON THE TRANSPORT
3-16
3.3.5 THE TAPE SPEED AND RECORD/PLAY EQUALIZATION
3-17
SELECTORS
3.3.6
NORMAL PLAY MODE 3-18
3.3.7
REVERSE PLAY MODE 3-18
3.3.8
FAST WINDING MODES
3-18
3.3.9 SPOOLING MODE
3-19
3.3.10
SHUTTLE CUE HODE
3-19
3.3.11
FAST CUE MODE
3-19
3.3.12 EDIT/UNLOAD
3-20
3.3.13
SPEED MODE SELECTION
3-20
3.3.14 SEARCH TO ZERO
3-21
3.4 REMOTE CONTROL BOX
(REMOTE BOX) FUNCTIONAL CHECKOUT
3-22
3.5
THE AUTO LOCATOR
3-22
3.6
AUDIO/MONITOR CONTROL FUNCTION
(INCLUDING RECORD)
3-22
CHECKOUT
3.6.1
RECORD MODE
3-22
3.6.2
INDIVIDUAL CHANNEL OUTPUT
SELECTION (AUDIO MONITOR)
3-23
3.7 INPUT AND OUTPUT LEVEL CONTROLS
3-24
ix

PAGE
SECTION 4: AUDIO ALIGNMENT
4.1 GENERAL DESCRIPTION 4-1
4.2 DEMAGNETIZING THE HEADS AND TAPE GUIDANCE PATH 4-4
4.3 CLEANING THE TAPE PATH 4-5
4.4 AUDIO CIRCUIT BOARD PRELIMINARY ALIGNMENT (OCCASIONAL) 4-5
4.5 REPRO (AND SEL-REP) ALIGNMENT 4-8
4.6 RECORD ALIGNMENT 4-10
4.6.1 BIAS ADJUSTMENT 4-10
4.6.2 RECORD LEVEL ADJUSTMENT 4-13
4.6.3 RECORD EQUALIZATION ADJUSTMENT 4-13
4.6.4 PHASE COMPENSATION 4-14
4.6.5 LOW FREQUENCY COMPENSATION (LF COMP)
4-15
4.7 TIME CODE MODULE ALIGNMENT
4-15
4.7.1 HEAD ADJUSTMENT
4-15
4.7.2 REPRODUCE ALIGNMENT
4-16
4.7.3 OUTPUT LEVEL ALIGNMENT
4-16
4.7.4 RECORD ALIGNMENT
4-16
SECTION 5: TRANSPORT ALIGNMENT
5.1 GENERAL DESCRIPTION 5-1
5.2 HEAD GEOMETRY 5-1
5.3 ACCESS TO THE UNDERSIDE OF THE MTR-l0 TRANSPORT 5-1
DECK PLATE
5.4 CAPSTAN PINCH ROLLER SOLENOID TRAVEL (& PRESSURE) 5-2
5.5 BRAKE TORQUE 5-4
5.6 REEL TURNTABLE HEIGHT 5-6
5.7 TAPE LIFTERS 5-6
5.8 SUPPLY AND TAKEUP REEL TENSION AND SPEED ADJUSTMENTS 5-7
5.8.1 SUPPLY REEL TENSION 5-7
5.8.2 TAKE UP REEL TENSION 5-8
5.8.3 ZERO SEARCH SLOW SPEED CRAWL 5-9
5.8.4 FAST WIND SPEED 5-9
5.9 TACHOMETER PHASE 5-11
5.10 REVERSE PLAY SPEED AND REEL MOTOR DRIVE 5-13
AMPLIFIER (MDA) GAIN
5.11 CAPSTAN CONTROL BOARD (D) 5-15
5.11.1 CAPSTAN GAIN 5-15
5.11.2 CAPSTAN DAMPING 5-15
5.11.3 EXTERNAL SYNC INPUT CALIBRATION 5-17
5.11.4 CUE LEVER OFFSET AND MAXIMUM SPEED 5-17
x

PAGE
SECTION 6: OPERATION
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
6.14
6.15
6.16
GENERAL
RECORDING INTITIAL TRACKS
PLAYBACK OF INITIAL TRACKS
SEL-REP RECORDING (OVERDUBBING)
SEL-REP RECORDING (PUNCH-INS)
REHEARSAL OF OVERDUBS OR PUNCH-INS
MIXDOWN
REVERSE PLAY FOR TIMING OF EDITED PROGRAM
USE OF THE CUE BUTTON AND CUE LEVER
SPOOLING
MODE
HAND SPOOLING
DUMP EDIT
USE OF VARIABLE SPEED MODE
USE OF AN EXTERNAL SPEED REFERENCE
USING SMPTE SYNCHRONIZATION AND/OR
6.15.1 GENERAL
6.15.2 CONNECTING A SYNCHRONIZER TO
6.15.3 INTERFACE
SHADOW
6.15.4 INTERFACE
KINETICS
6.15.5 INTERFACE
OF THE OTARI
OF
THE OTARI
"Q-LOCK" SMPTE
OF THE OTARI
SMPTE SYNCHRONIZERS
TIME
CODE UNIT DESCRIPTION
6.16.1 TIME CODE UNIT
6.16.2 SPECIFICATION FOR TIME
MTR-I0
MTR-I0
SEGMENTS
LOCATION CONTROL
THE MTR-I0
TO THE BTX
TO AUDIO
SYNCHRONIZERS
MTR-10
TO ADAMS-SMITH 2600
CODE VERSION
SECTION
7: AUTO LOCATOR
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
7.11
7.12
7.13
GENERAL
INSTALLATION
TAPE TIME
LOCATE TIME
KEYBOARD NUMERALS
SHIFT LEFT AND SHIFT RIGHT
LOAD
CONVENTIONAL STORE/RECALL/SEARCH VS. DIRECT STORE/SEARCH
7.8.1 CONVENTIONAL MEMORY STORE
7.8.2 DIRECT MEMORY STORE
7.8.3 CLEARING (ZEROING) A MEMORY
7.8.4 CONVENTIONAL MEMORY RECALL
7.8.5 DIRECT MEMORY SEARCH
SEARCH
ZERO
SHUTTLE
AUTO REWIND
TRANSPORT CONTROLS
EXAMPLES OF AUTO LOCATOR OPERATION
xi
AND SEARCH
6-1
6-1
6-2
6-3
6-4
6-5
6-6
6-6
6-7
6-7
6-8
6-8
6-10
6-10
6-11
6-11
6-11
6-12
6-16
6-17
6-22
6-22
6-24
7-1
7-1
7-2
7-4
7-4
7-4
7-5
7-5
7-5
7-6
7-6
7-7
7-7
7-7
7-8
7-9
7-9
7-9

PAGE
SECTION 8: FIELD CONVERSIONS
8.1 OVERBRIDGE CONVERSION KIT 8-1
8.2 STANDARD CONSOLE CONVERSION KIT 8-1
8.3 FULL TRACK CONVERSION HEAD ASSEMBLY 8-1
8.4 DIN TRACK CONVERSION HEAD ASSEMBLY 8-1
8.5 PARTS KIT FOR MODIFICATION OF 1/2" MODEL INTO 1/4" MODEL 8-2
8.6 MODIFICATION FOR LOW SPEED OPERATION (3.75, 7.5, 15 ips) 8-2
8.7 PARTS KIT FOR CENTER TRACK CONVERSION 8-7
SECTION 9: CIRCUIT DESCRIPTION
9.1 RECORD/REPRODUCE ELECTRONICS -- GENERAL
9-1
9.2 REPRO HEAD AND ELECTRONICS
9-1
9.3 AUDIO OUTPUT STAGE
9-2
9.4 RECORD ELECTRONICS
9-3
9.5 BIAS/ERASE CIRCUITRY AND TIMING
9-3
9.6 MASTER CPU: BOARD "B"
9-4
9.7 TRANSPORT CONTROL: BOARD "A"
9-5
9.8 REEL CONTROL: BOARD "C"
9-5
9.9 CAPSTAN CONTROL: BOARD "D"
9-6
SECTION 10: MAINTENANCE
10.1 GENERAL 10-1
10.2 REMOVING AND REINSERTING PRINTED CIRCUIT BOARDS 10-1
10.3 REEL MOTOR REPLACEMENT 10-2
10.4 BRAKE PAD REPLACEMENT 10-3
10.5 METER OR METER LAMP REPLACEMENT 10-3
10.6 CAPSTAN PINCH ROLLER REMOVAL AND REPLACEMENT 10-4
10.7 TAKEUP ROLLER GUIDE REMOVAL AND REPLACEMENT 10-4
10.8 IMPEDANCE ROLLER (SUPPLY REEL ROLLER) REMOVAL AND 10-5
REPLACEMENT
10.9 TACHOMETER ROLLER REMOVAL AND REPLACEMENT 10-5
10.10 CLEANING AND LUBRICATION 10-6
10.11 REEL MOTOR DRIVE CIRCUIT BOARDS REMOVAL AND REPLACEMENT 10-6
10.12 SAFETY SHUT-OFF SWITCH ASSEMBLY REMOVAL AND REPLACEMENT 10-7
10.13 SWING ARM ASSEMBLY REMOVAL AND REPLACEMENT 10-7
10.14 CAPSTAN MOTOR REMOVAL AND REPLACEMENT 10-8
SECTION 11: SPECIFICATIONS
11.1
TAPE TRANSPORT
11-1
11. 2 ELECTRONICS
11-2
11. 3 PHYSICAL
11-3
11.4
ACCESSORIES
11-4
xii

PAGE
SECTION 12: PARTS LISTS AND P.C.B. ASSEMBLIES
12.1 GENERAL
12-1
12.2 PARTS LISTS (& P.C.B. ASSEMBLIES)
12-1
SECTION 13: PARTS LISTS AND DRAWINGS
13.1 GENERAL
13-1
13.2 PARTS LISTS (& EXPLODED VIEW DRAWINGS) 13-1
SCHEMATICS
xiii

IMPORTANT NOTICE
May 18, 1987
Applies to all MX-SOSO*, MTR-IO, MTR-12, MTR-20, MX-70 and
MX-80 machines.
The Capstan Motors in these machines contain an oilite bear-
ing at the front end, which requires lubrication.
USE ONLY OTARI OIL PiN PZ9E003.
To access the bearing for lubrication, remove the capstan
shaft dust cap. On most machines the dust cap unscrews. On
MTR-20s the dust cap is located under the head assembly base,
and snaps off the top of the motor.
There are two basic types of motors; one which has a foam
ring surrounding the bronze colored oilite bearing, and one
which has a felt pad on top of the bronze colored oilite
bearing.
If the motor has a felt pad on top of the bearing, remove the
pad, and insert three drops of oil in the cavity surrounding
the bear ing •
If the motor has a foam ring surrounding the bearing, apply
three drops of oil to the foam ring.
Apply one drop of oil every 3 to 6 months depending on
machine usage.
Do not over lubricate, and be careful not to apply oil to the
portion of the capstan shaft which contacts the tape.
* NOTE; Early MX-SOSO, BGM-IOOO and ARS-IOOO machines use a
belt-driven Capstan Shaft. The Capstan Shaft as-
sembly contains an oilite bearing in the same
location and the same lubrication procedures should
be followed.
Use MOBILE DTE oil LITE for those machines instead of
PZ9E003.
Dec 87

Switch Function
Factory Setting
SW3-5
Fast Winding
deceleration
tape speed
ON (MTR-lO)
OFF (MTR-12)
ON
OFF
No deceleration at the end
tape
Deceleration at the end of
tape only with
7" reel
of
SW3-6
to
SW3-8
Not
used
SW4-l
Not used on MTR-lO/12 series
OFF
SW4-2 Dump
Edit mode selection
OFF
ON
OFF
Transport will enter Dump Edit
mode when the safety arm switch
is activated by stopping the
take-up reel.
Trasport will stop when the
safety arm switch is activated.
SW4-3
Vari-Pitch in Record mode
ON
ON
OFF
When
Vari-Pitch mode is
selected, the machine can
enter Record mode.
When Vari-Pitch mode is
selected, the machine can
not enter Record mode.
SW4-4
Stop mode priority selection
OFF
ON
OFF
Play mode will continue even
when PLAY and STOP buttons are
pressed.
transport will stop when both
buttons are pressed simulta-
neously.
Jul 88

Switch Function
Factory Setting
SW4-5 and
SW4-6 Punch In selection
OFF, OFF
OFF OFF
Pressing the RECORD button
(ON
ON) during Play mode causes the
machine to enter Record mode.
ON OFF
Pressing
the RECORD and PLAY
buttons
simultaneously during
Play mode causes the machine
to enter Record mode.
OFF ON Pressing the RECORD button
during Stop mode causes the
machine to enter Record mode.
SW4-7
Punch
Out selection OFF
ON Punch Out is inhibited. The
machine does not leave Record
mode by pressing the PLAY
button during Record mode.
OFF Pressing the PLAY button during
Record mode causes the machine
to leave Record mode.
May
89

NEWLY ADDED OPEATION WITH PB-4GEA
MASTER CPU P.C.B. ASSEMBLY
The latest MTR-IO/12 Series machine using PB-4GEA MASTER CPU
P.C.B. assembly has attained following two operations.
1) Reverse Erase operation
Set the proper audio channel to Record mode, then press
the RECORD, REWIND and PLAY buttons simultaneously.
The MTR-IO/12 enters Record mode and the Erase and
Record Bias are activated, but the transport does not
move tape.
By spooling tape backward by hand, Reverse Erase mode
starts.
Press the STOP/LOAD button to leave the Reverse Erase
mode.
2) Reverse Play operation
Press the REWIND and PLAY buttons simultaneously, then
the transport moves backward the tape.
Those two operations are selectable by the switches on CPU
P.C.B. assembly. Refer to the following table.
Add the following description to pages 3-6, 3-7, 3-19, and
6-7 of the MTR-IO n/12 IT manual (OS3-088).
"Press the EDIT/UNLOAD button (instead of the CUE
button) simultaneously with the F.FWD or RWD button to
enter Forward or Reverse Spooling mode."
The new CPU PCB assembly has three DIP switches for user
function selections. Refer to the following table describes
the function of DIP Switches 2, 3 and 4.
May 89

Switch Function Factory Setting
SW2-l
Output muting on entering Stop mode
ON
ON
: Muting
OFF : No Muting
SW2-2
Output muting in Fast Wind mode
ON
ON : Muting
OFF : No Muting
SW2-3
Output muting on entering Play
OFF
ON Muting
OFF No Muting
SW2-4 to SW2-8 Not used
SW3-l
Fast Spool tape speed selection
ON
ON : Standard tape speed
OFF : Lower tape speed
SW3-2
Reel type selection for end-of-tape OFF
sense
ON DIN REEL (See SW3-5)
OFF NAB REEL (See SW3-5)
SW3-3 Reverse Erase mode selection
OFF
*
ON
Reverse Erase Enabled
OFF Reverse Erase Inhibited
*
In order to enter Reverse Erase mode, press REC, RWD and
PLAY buttons at the same time or press PLAY button while
REC (first) and RWD (second) buttons are held. Spool
the tape by hand in the reverse direction only to start
Reverse Erasing.
NOTE: Spooling tape in the forward direction will record
any incoming signals present at the input connectors.
SW3-4
Reverse Play mode selection
ON
ON : Reverse Play Enabled
OFF Reverse Play Inhibited
May 89

KW-4Y-O Brake Stopper Kit
Installation Manual (0S3-285)
KW-4Y-O Brake Stopper Kit
This kit lengthens the life span of the current brake mechanism
of MTR-1 0 and 12 series.
1. Parts List
Name
Stopper Plate L
Stopper Plate R
M3 x 15 Cap Screw
M3 Nut
Otarj PartS No.
KW4Y002
KW4Y003
F22315SB
F50003SN
Quantity
1
1
2
2
Stopper Plate L
Stopper Plate R
(Supply Side)
(Takeup Side)
Figure 1
Stopper Plates
2. Installation (Refer to Figure 2)
1. Raise the Transport Deck Panel.
2. Remove the protect cover which covers the brake
mechanism at the bottom of the Reel Motor.
3. Attach the stopper plate to the brake base with M4 screw
(marked "A" in Figure 2). Set the stopper plate position by
fitting the angle portion to the brake base plate, and tighten
the M4 screw.
4. Referring to Figure 2, attach the Hex Socket Head Bolt (M3 x
15) and Hex Nut (M3) to the stopper plate.
1
January 1990

Hex
Bolt
KW-4Y-D Brake Stopper Kit
I nstallation Manual
B
O.Smm
3. Adjustment
Socket
Head
Figure 2
Installation of Stopper Plate
1. Attach one end of a 6ft (2m) piece of string to the hub of a 7"
large hub reel. Attach the other end of the string to the
spring scale.
2. Place the reel on either Supply Reel Table or Take-up Reel
Table. Wind the string so that the reel rotates
counterclockwise (for Supply Reel) or clockwise (for Take-up
Reel) when the string is pulled.
CAUTION: At this stage, loosen the Hex Socket Head Bolt so that
the end of the bolt does not touch the brake arm when
rotating the reel in Holdback direction.
3. Pull on the spring scale slowly to unwind the string. Write
down the reading of the scale. Repeat the measurement
several times, and average the data. Adjust the position of
the spring hook by loosening the screw B so that the scale
reading becomes 350 - 400g (equivalent to 1.75 - 2.0 kgcm
shaft torque).
4. TIghten the Hex Socket Head Bolt until the gap between the
end of the bolt and the brake arm becomes about 0.5rnm;
5. Adjust the brake torque of Holdback direction by turning the
Hex Socket Head 80ltso that the torque becomes the value
described in the following table.
March 1990
2

1

SECTION 1
INTRODUCTION
1.1 USING THIS MANUAL
OTARI's master production tape recorder MTR-10 and MTR-12
series are available in many variations. The major d ifference be-
tween the MTR-10 series and the MTR-12 series is that the size of
the largest usable reel for the MTR-10 is 10-1/2" (26.7 cm) while
the largest reel size for the MTR-12 is 12-1/2" (31.75 cm). There
are no other functional differences between the two series. Each
series has several variations as shown in the following table.
MTR-10/MTR-12 SERIES MODEL LIST
Type
Tape
Width
Tape
Speed
Catalog
Number
Head
Console
Low
Profile
Over-
bridge
MTR-10
1/4"
*30
ips
15
ips
7.5 ips
MTR-10-2
2T
2CH
0
MTR-10-C
2T
2CH
0
MTR-10-K
MTR-10-M
MTR-10-G
2T DIN
Stereo
0
2T DIN
Stereo
2T 2CH
2T 2CH
0
1/2"
0
MTR-10-H 0
MTR-10-4 4T
4CH
0
MTR-10-I
4T
4CH
0
MTR-12
1/4"
MTR-12-2
2T 2CH
0
MTR-12-C 2T
2CH
0
MTR-12-K 2T DIN
Stereo
0
MTR-12-M 2T DIN Stereo
0
1/2"
MTR-12-G
2T 2CH
0
MTR-12-H 2T 2CH
0
MTR-12-4 4T 4CH
4T 4CH
0
MTR-12-I
0
* Low speed versions (15, 7.5, and 3.75 ips) and center track
versions can be ordered by a d ding an "L" or "T" suffix to each
of the catalog numbers mentione d above. However, some models
are not available in "L" and "T" versions.
Also other models are available, although not l i sted above.
For further details, please contact your nearest OTARI dealer
or OTARI representative.
1-1

This operation and maintenance manual is intended for use with
the MTR-IO and MTR-12 series master production recorders. The de-
scriptions and references refer to the MTR-IO. If a difference
between the series exists, the information specific to the MTR-12
will be found following the information for the MTR-IO.
The various sections of this manual are divided by major topic
(i.e., SECTION 2. INSTALLATION), and by sub topic (i.e., Section
2.2. Inspection). Within a sub section, the steps or topics are
numbered (1, 2, ••• etc.), and within these steps or topics, the
details may be further divided numerically (2.2.1., 2.2.2, etc.)
or alphabetically (A,B, ••• etc.).
Normal parentheses () are used for examples and parenthetic
comments. Square brackets [ ] are used for references to callouts
in certain illustrations. The square brackets in a given sub
section are either all referenced to a particular illustration, as
noted in that sub section, or are individually referenced (i.e.,
[Fig. 1-3, B], meaning callout "B" in Figure 1-3.).
Generally, we have used all upper case type to describe
a particular switch or control when that item is similarly labeled
on the actual equipment (i.e., the PLAY button). Where a switch
or function is not labeled, or the reference is less clear, we
capitalize only the first letter of the item (i.e., the Cue lever
near the CUE button). Machine status or operating modes are
usually described with an upper case first letter (i.e., you press
the PLAY button to place the machine in Play mode).
The functional checkouts in Section 3 should be carefully
performed when the MTR-IO/MTR-12 is first set up. You will proba-
bly learn a great deal about how the machine operates while follow-
ing this procedure, but it is not intended as a guide for recording
and editing; that information is provided in a more useful format
in Section 4. Parts Lists and P.C.B. assemblies are indexed in
Section 12, parts lists and exploded view drawings are indexed in
Section 13, and schematic diagrams are indexed in Section 14.
We encourage you to read this manual carefully now, and
to again review it after you have had a while to become familiar
with the MTR-IO/MTR-12. The more you know about your machine, the
more you can benefit from its many versatile features.
CAUTION
The DC reel motors develop substantial torque. Never place a
hand, clothing or other objects inside, atop, or near a reel or
anywhere along the tape path, when actuating the tape motion
controls. When using the Auto Locator or a Remote Control
Box, always make sure anyone near the transport is aware
of the potential hazard posed by the high torque motors.
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1. 2 OTARI MTR-IO AND MTR-12 SERIES MASTER PRODUCTION RECORDERS
The Otari MTR-IO and MTR-12 series are fully microprocessor-
controlled 1/4" and 1/2" tape recorder/reproducers. Tape movement
is governed by a proven 8680A microprocessor (8085 on all MTR~12
and on MTR-IO with serial number suffix "K" and later) on the
recorder's plug in CPU (central processing unit) board. Enhancing
the CPU are four erasable programmable read-only memories (EPROMS:
only one EPROM on all MTR-12 and on MTR-IO with serial number suf-
fix "K" and later) which furnish the necessary firmware for con-
trolling the machine's operating parameters and production features.
Otari's research has led to the development of the proprietary micro-
processor used in the MTR series, which economi6ally raises the
level of reliability due to the use of fewer electronic and me-
chanical parts -- fewer linkages, fewer relays, and fewer critical
adjustments. Reel motor, capstan and transport control circuits
are each contained on individual, modular plug-in circuit boards.
The MTR-IO/HTR-12 has all the standard transport commands one
would expect of a professional master recorder. The buttons have
dual-level illumination, with the brightest one confirming the
transport mode. In addition, its microprocessor based operation
makes possible a variety of special features, like 3 play/record
speeds, and the ability to run backwards at any of them. Normal
play/record speeds are crystal locked for extreme accuracy, and
there is also a built-in VSO (variable speed oscillator) to adjust
pitch over a ±20% range relative to the selected nominal speed for
re-timing edits or special effects. Additionally, an external fre-
quency reference may be used to control the capstan speed, a feature
used for remote pitch control or synchronizer interface. Interface
to an editing system (i.e., a tape controller or SMPTE code synchro-
nizer) is accomplished with a single rear-panel connector, and
excellent tape slewing characteristics are obtained because the MTR-
10 CPU automatically compensates for a high rate of change in the
9600 Hz input by applying dynamic braking when necessary.
Tape control on the MTR-IO is perhaps the most sophisticated
of any professional tape machine on the market. For example, very
high resolution constant tension is achieved without the use of
tension arm sensors. An interrupt-driven software algorithm com-
pares the rate of rotation of both reel motors with the otuput of
the real-time tachometer idler. By knowing this information, the
CPU calculates exactly how much tape is on each reel, and then
commands the reel servo to provide an appropriate torque with
each reel motor (via an 8-bit D-to-A converter). Additionally,
LED/LDR sensors on the top panel tell the CPU whether a small
or large reel is mounted on each turntable, so no manual switching
is required. This system enables one to load any combination of
different size reels, and "rock" tape with one hand without tape
slack or spillage.
The MTR-IO is carefully engineered and constructed to handle
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tape gently and keep it in perfect alignment. The capstan contacts
the back of the tape (for less tape wear), and the pinch roller
is relieved for extended roller life. The pinch roller is dual-
solenoid actuated; it provides plenty of clearance when initially
threading tape, but otherwise moves closer to the pinch roller for
faster, quieter tape starts.
A single-board approach has been used for the record/play
audio and bias circuits for each channel, simplifying setup and
service. Utilization of high slew rate IC op-amps and discrete
components at critical stages ensure the cleanest and quietest of
recordings. Electronic alignment has been greatly simplified by
providing separate controls for each speed (on those parameters
that are likely to change with tape speed). For example, each
channel has its own gain trimmers for repro (reproduce head play-
back) and sel-rep (record head playback), plus an input sensitivity
trimmer and a record level trimmer. Each channel also has separate
record and reproduce high frequency equalization trimmers for each
of the three speeds, as well as record phase compensation trimmers.
The phase compensation makes it possible to achieve nearly perfect
square wave reproduction, and increases the recording level
capability with complex waveforms for greater dynamic range. Low
frequency compensation 'may be switch selected and trimmed for each
channel. Repro level and record level can be manually adjusted on
the MTR-IO front panel, or standard reference level can be instantly
obtained by engaging an SRL switch adjacent to the controls; the
standard reference levels are adjustable for each channel with SRL
trimmers on the Audio boards.
Record bias level is adjusted with a trimmer on each Audio
card, primarily to obtain equal bias for each channel.
The Master Bias level is adjustable for all channels simultaneously
with trimmers on the Audio Control board; bias may be set for
each of the three operating speeds so that no re-adjustment is
needed when changing speeds. A second set of three Master Bias
trimmers may be switch-selected so that another tape formulation
can be accommodated. For studios that often change tape speeds and
formulations, this feature is a tremendous time saver. Another
switch on the Audio Control board enables equalization to be set
to NAB or IEC characteristics (for 7.5 or 15 ips); AES characteristic
is automatically provided at 30 ips, as shown on the MTR-10 front
panel indicators. In addition, the MTR-IO circuit calibration can
be "zeroed" to any of three standard reference flux levels (185,
250 or 320 nanoWebers per meter) by moving a switch on the Audio
Control board; the selected reference flux level is also indicated
on the MTR-IO front panel.
A built-in test oscillator provides 100 HZ, 1 kHz and 10 kHz
sine wave tone for alignment, plus 1 kHz and 10 kHz square wave
tone for record phase compensation adjustments. Oscillator output
levels are individually adjustable at the three sine wave frequen-
cies. A front panel test input jack applies your own test/align-
ment signal to all inputs.
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