Otari MX-5050
MARK III›Documents

Generation

First[Mini Pro]Mark IIBB-IIMARK III[BQ-II]B-IIIMARK IV

MARK III

OverviewIdentifySpecsHistoryDocumentsService

Machines

III/2III/4III/8BQ-II

MARK III/4 Instruction and Maintenance Manual — Digital Edition · Part 0 · scan pages 1-12

Front Matter

OS3-035

The OTARI wordmark logo in block capital letters, the lockup printed on the manual's cover.⤢ zoomThe OTARI wordmark logo in block capital letters, the lockup printed on the manual's cover.

OTARI

MX-5050 MK III-4
PROFESSIONAL RECORDER

INSTRUCTION AND MAINTENANCE MANUAL

Halftone cover photo of the MX-5050 MK III-4 recorder, shown at an angle with its reels and control panel.⤢ zoomHalftone cover photo of the MX-5050 MK III-4 recorder, shown at an angle with its reels and control panel.

CAUTION

To prevent fire or shock hazard:

Do not expose this appliance to rain or moisture.

Do not remove back.

No user-serviceable parts inside.

Refer servicing to qualified service personnel.

SAFETY INSTRUCTIONS↑ TOP

  1. Read Instructions -- All the safety and operating instructions 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 operating and use instructions should be followed.

  5. Water and Moisture -- The appliance should not be used near water - for example, near a bathtub, washbowl, 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 openings; 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 heat 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 -- The precautions that should be taken so that the grounding or polarization means of an appliance is not defeated.

  11. Power-Cord Protection -- Power-supply cords should be routed so that they are not likely to be walked on pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit from the appliance.

  12. Cleaning -- The appliance should be cleaned only as recommended 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 objects do not fall and liquids are spilled into the enclosure through openings.

  15. Damage Requiring Service -- The appliance should be serviced 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 exhibits marked change in performance; or

  16. Servicing -- The user should not attempt to service the appliance beyond that described In the operating instructions.

    All other servicing should be referred to qualified service personnel.

MX-5050 MK III-4
PROFESSIONAL TAPE RECORDER

INTRODUCTION↑ TOP

This manual provides descriptive information, installation, operation, maintenance and normal adjustment instructions for the Otari MX-5050 MK III-4 Professional Tape Recorder.

Photo of the MX-5050 MK III-4 recorder facing forward, captioned MX-5050 MK III-4 Recorder below it.⤢ zoomPhoto of the MX-5050 MK III-4 recorder facing forward, captioned MX-5050 MK III-4 Recorder below it.

MX-5050 MK III-4 Recorder

COMMUNICATION WITH OTARI↑ TOP

FOR SERVICE INFORMATION AND PARTS

OTARI PRODUCTS are manufactured under strict quality control and each unit is carefully tested and inspected prior to shipment from our factory.

If, however, adjustment or technical support becomes necessary, 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,
Suginamiku, Tokyo, 167, Japan
Phone: (03) 333-9631
Telex No.: OTRDENKI J26604

OTARI CORPORATION
2 Davis Drive, Belmont
California 94002, U.S.A.
Phone: (415) 592-8311
Telex No.: TWX 910-376-4890

OTARI ELECTRIC DEUTSCHLAND GmbH
Gielen Strasse
4040 Neuss 1
F.R. Germany
TEL :02101-274011 , 12
TLX :418517691

Another part of Otari's continuous technical support program for our products is the continuous revision of manuals as the equipment is improved or modified. In order to receive information and service applicable to your equipment, and for technical support to function properly, please include the following information, most of which can be obtained from the nameplate on the equipment when you communicate with Otari.

  1. Model Number
  2. Serial Number
  3. Date of purchase
  4. Name and address of dealer from whom unit was purchased
  5. Power requirements (voltage and frequency)
  6. Manual number to which you are referring

* Addenda * (MX-5050 BQ-2,MK-3-4,MK-3-8)↑ TOP

External Capstan Speed Control↑ TOP

For a special application such as interfacing with synchronizers or controllers,an external capstan speed control can be performed to connecting them to the "LOCATOR" connector located on the rear panel.

Capstan speed is controlled with the DC voltage (range:+-13V) which is fed to the "LOCATOR" connector PIN No.1 and No.2.

Capstan speed continuously varies in proportion to DC voltage;

At the -13V of DC voltage,capstan speed is minimum.

At the 0V of DC voltage,capstan speed is nominal. (15,7-1/2ips)

At the 13V (+8V on 15ips) of DC voltage,capstan speed is maximum.

To perform external capstan speed control,proceed as follows.

  1. Referring to SECTION 5-5 "FUSE REPLACEMENT of the manual,expose the Control P.C.B.
  2. Position two DIP switches on the Control P.C.B.,SW-2 and SW-3,to "NORMAL" and "EXT".
  3. Referring to the Table-2 "Pin Assignment",solder respective leads on connector,mated with the "LOCATOR" connector. Part No. of the mating connector : CN216203
  4. Connect the equipment to a synchronizer,or a controller.

Table-1 Control DC voltage and Capstan speed

Nominal speed (ips)Control DC voltage (V)Capstan speed (%)
15-13-60
1500
158 #+70
7-1/2-13-60
7-1/200
7-1/213+210

# On 15ips,Capstan speed is limited at the value of DC 8V.

(Ver.1.0)

Table-2 Pin assignment of the "LOCATOR" connector

PIN No.DescriptionNote
1 #GND,FGND of EXT. CONT
2 #EXT.CONTCapstan speed control DC voltage (range:+-13V)
3CLOCKTach pulses (TTL logic convention) Frequency:40Hz at 15ips
4DIR.(Rev/Fwd)Transport Direction (TTL logic convention)
5N.C.
615ipsTape speed command (24V/open)
77-1/2ips
8(3-3/4ips)
9N.C.
10RECORDTransport control (TTL logic convention :active "LOW")
11F.FWD
12RWD
13PLAY
14STOP
15N.C.
165VMaximum load:50mA

# On PIN No.1 and 2,a single-conductor shielded cable should be used.

(Ver.1.0)

TABLE OF CONTENTS↑ TOP

SectionTitlePage
1GENERAL INFORMATION
1-1System Description1-1
1-1-(1)Tape Transport1-2
1-1-(2)Record/Reproduce Electronics1-4
1-2Standard Accessories1-5
1-3Optional Accessories1-5
1-4Specifications1-6
2INSTALLATION
2-1Unpacking and Inspection2-1
2-2Location and Environment2-2
2-3Dimensions2-3
2-4Standard Switch Position on Shipment2-4
2-5Power and Signal Connection2-5
2-5-(1)AC Power Connection2-7
2-5-(2)Signal Connections2-8
3OPERATION
3-1Controls and Indicators3-1
3-2Operating Information3-11
3-2-(1)Using the Reel Hold Down Knobs3-11
3-2-(2)Pre-Operating Procedure3-12
3-2-(3)Reproduction3-14
3-2-(4)Normal Recording3-14
3-2-(5)Recording with Selective Reproduction3-16
3-2-(6)Fast Winding3-17
3-2-(7)Editing and Splicing Tape3-18
4GENERAL INFORMATION OF MAINTENANCE
4-1Test and Maintenance Equipment Requirements4-1
5ROUTINE MAINTENANCE AND CONVERSION INFORMATION
5-1Routine Maintenance5-1
5-1-(1)Cleaning5-1
5-1-(2)Demagnetizing5-3
5-1-(3)Lubrication5-4
5-2Tape Replacement5-6
5-3Equalizer Change5-6
5-4Line Voltage Conversion5-7
5-5Fuse Replacement5-8
6TAPE TRANSPORT MAINTENANCE
6-1Transport Access6-1
6-2Brake Adjustment6-2
6-3Capstan Pinch Roller Pressure Adjustment6-5
6-4Tape Speed Adjustment6-7
6-5Tape Transport Timing Chart6-8
6-6Recording Process Timing Chart6-9
7PERFORMANCE TESTING AND ELECTRONIC ALIGNMENT
7-1General Notice7-1
7-2Test Tapes7-1
7-3Test Conditions7-2
7-4Performance Tests7-3
7-4-(1)Overall Signal-to-Noise7-3
7-4-(2)Overall Distortion Test7-5
7-4-(3)Crosstalk Test7-6
7-4-(4)Erasure Test7-7
7-4-(5)Tape Speed Measurement7-8
7-4-(6)Flutter and Wow Test7-9
7-5Access to Electronics Assembly7-11
7-6Electronic Alignment7-12
7-6-(1)Reproduce System7-12
7-6-(2)Reproduce Head Azimuth Adjustment7-13
7-6-(3)Frequency Response7-15
7-6-(4)SRL (Repro Level) Adjustment7-17
7-6-(5)SEL/REP. Level Adjustment7-17
7-6-(6)Record System7-17
7-6-(7)Record Head Azimuth Adjustment7-17
7-6-(8)Record Bias Adjustment7-18
7-6-(9)Overall Frequency Response7-22
7-6-(10)Monitor Input Level and VU Meter Level Adjustment7-23
7-6-(11)Test OSC Level Adjustment7-24
7-6-(12)Record Level Adjustment7-25
7-6-(13)Peak Indicator Trigger Level Adjustment7-25
8MAJOR COMPONENT REPLACEMENT
8-1Reel Motor Assembly Replacement8-1
8-1-(1)Reel Table Replacement and Height Adjustment8-1
8-1-(2)Reel Motor Replacement8-2
8-1-(3)Brake Arm Assembly and Brake Solenoid Replacement8-3
8-2Power Transformer Replacement8-4
8-3Capstan Motor Replacement8-4
8-4Pinch Roller Replacement8-5
8-5Head Assembly Replacement8-6
8-5-(1)Description8-6
8-5-(2)Head Stack Replacement8-7
8-5-(3)Record and Reproduce Head Adjustment8-9
8-5-(4)Erase Head Alignment8-9
9TROUBLESHOOTING
9-1Preliminary Procedures9-1
9-2Troubleshooting Hints9-1
10PARTS LISTS AND SCHEMATICS
10-1Safety Components10-2
10-2Assembly Hardware Coding10-3
10-3Parts Lists and Exploded View10-4
10-4Pin Identification10-28

LIST OF ILLUSTRATIONS AND TABLES↑ TOP

FigureTitlePage
1-1MX-5050 MK Ⅲ -4 Major Components1-3
2-1Dimensions2-3
2-2MIC ATT2-4
2-3Adjusting Panel2-4
2-4Input/Output Assembly Connector Wiring2-9
3-1Reel Hold Down Knob3-12
3-2Tape Threading3-13
3-3Tape Splicing Block3-18
5-1Lifting the Head Cover5-2
5-2Demagnetizing5-4
5-3Lubrication5-5
5-4Voltage Selection Terminal5-7
5-5Access for Line Voltage Conversion5-8
5-6Main Power Fuse Location5-9
5-7Internal Fuse Location5-10
5-8Rotating Control P.C.B.5-11
6-1Tape Transport Access6-1
6-2Brake Measurement6-4
6-3Brake Assembly Location6-4
6-4Pinch Roller Pressure Measurement6-6
6-5Pinch Roller Pressure Adjustment6-6
6-6Capstan Servo Control P.C.B.6-7
6-7Control Timing Chart6-8
6-8Recording Process Timing Chart6-9
7-1Filter Schematics7-3
7-2Test Tape Loading7-9
7-3Electronics Access7-12
7-4Reproduce System Block and LevelDiagram7-13
7-5Head Assembly7-14
7-6Location of Record/Reproduce Electronics7-16
7-7Overall Frequency Response7-19
7-8Record System Block and Level Diagram7-20
7-9Bias Current v.s. Output and Distortion7-20
7-10Input v.s. Output and Distortion7-21
7-11Location of Record/Reproduce Electronics7-21
7-12Location of AMP. Control Electronics7-24
8-1Reel Motor Mounting8-1
8-2Brake Assembly8-2
8-3Location of DC Servo Capstan Motor8-5
8-4Pinch Roller Removal8-6
8-5Head Assembly8-8
8-6Head Alignment8-8
TableTitlePage
1-1Standard Accessories1-5
1-2Optional Accessories1-5
1-3Specifications1-6
2-1Standard Switch Position on Shipment2-4
2-2Rear Connector Panel2-5
3-1Tape Transport Controls and Indicators3-1
3-2Record/Reproduce Electronics Controls and Indicators3-7
4-1Test and Maintenance Equipment4-1
4-2Flutter Test Tapes4-2
4-3Reproduce Alignment Test Tape4-2
5-1Record Level5-6
5-2Fuse Information5-10
6-1Braking Force Specifications6-3
7-1Signal-to-Noise Specifications7-4
7-2Flutter and Wow Specification7-11
7-3Equalizer Time Constants & Fluxivity7-16
7-4Standard Level7-24
9-1Troubleshooting Hints for Amplifiers9-2
9-2Troubleshooting Hints for Transport9-2
10-1Safety Component10-2
General Information →