Ampex MM-1200 User manual

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AMPEX 4890400-02
TABLE OF CONTENTS
TITLE
SECTION 1 DESCRIPTION
General
Tape Transport Assembly
Supply and Takeup
Reel Assemblies
Capstan Drive Assembly
Pinch Roller Assembly
Tension Sensor Assembly
End-of-Tape Arm and Threading Switch Assembly.
Tape Lifter Assembly
Search-to-Cue/Tape Timer Accessory
Transport
Control Assembly
Motor-Drive Amplifier Assembly
Head Assembly
Electronics Assembly
Control Box Assembly
Meter Panel Assembly
Power Supply
Optional
Equipment
Specifications
SECTION 2 INSTALLATION
Equipment Siting
Unpacking . .
..
Power Requirements
Cable Connections .
Initial Adjustments .
Input Signal Setup
Balanced Line .
Unbalanced Line .
Output Signal Setup
Balanced Output
Unbalanced Output.
Sync Transfer Switch .
Speed Selection . . .
Fixed Speed Mode .
Variable Speed Mode
Search-to-Cue and Tape
Timer
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TABLE OF CONTENTS [Continued)
TITLE
SECTION 3 OPERATION
General
Controls
and Indicators
Speed Selection
Fixed Speed Mode
Variable Speed Mode
Line/Monitor
Output Signals
Operating Procedures
Making a Recording - Without Sel Sync
Making a Recording -With
Sel Sync
Reproducing a Previously Recorded Tape
Fast Winding
Fast Winding -Search-to-Cue
Tape
Lifter Defeat
SECTION 4 THEORY OF OPERATION
General
Audio Electronics
Record
Reproduce
Individual Channel Audio Switching
INPUT/REPRO/S/SYNC Switch Circuit.
Sync Transfer Switch
Audio Mute Function.
Record Function .
Master
and Standby Monitor Audio Switching
STANDBY MONITOR Switch Circuit
MASTER MONITOR Switch Circuit
LIFT DEFEAT Switch Circuit
READY/SAFE Switch Circuit
Status Display Circuits
TAPE SPEED Switch Circuit
MASTER MONITOR Switch Circuit
STANDBY MONITOR Switch Circuit
INPUT/REPRO/S/SYNC Switch Circuit.
READY/SAFE Switch Circuit
Bias Amp Module
Record Amplifier
Reproduce Amplifier f
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AMPEX 4890400-02

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AMPEX 4890400-02
TABLE OF CONTENTS (Continued)
,
TITLE
SECTION 4 THEORY OF OPERATION (Continued)
Transport Control . . .
Stop and Braking Logic
Initial Turn On
Brake Release . . .
End-of-Tape
(EaT) .
Record Stop
Dynamic Braking
Tape
Lifter Logic
Lift Defeat Logic
Play Logic ...
Record Logic . .
Fast Forward Logic
Rewind Logic . . .
Tape Tension Control and
Servo.
Tension Error Amplifier
Play/Record Mode
Rewind Mode
Fast Forward . .
Stop
.....
End-of-Tape
Search-to-Cue
and Tape Timer
Tape Timer
..... .
Search-to-Cue . . . . .
Reel Motor Drive Amplifiers
Capstan Servo . . . . . .
Block-Diagram Description
Circuit Description
Power Supply . . .
39-Vdc Regulator
Bias Oscillator
27-Vdc Regulator
15-Vdc Regulator
5-Vdc Regulator .
SECTION 5 MAINTENANCE
General . .
Test Equipment
Cleaning . . .
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TABLE OF CONTENTS (Continued)
TITLE
SECTION 5 MAINTENANCE (Continued)
Demagnetization ..... .
Lubrication. . . . . . . . .
Scrape-Flutter Idler Lubrication
Maintenance Adjustments . . .
Power Supply . . . . . . .
39-Volt Regulator Adjustment
15/27-Volt Regulator Adjustment -
27-Volt Section . . . . . . . .
15/27-Volt Regulator Adjustment -
15-Volt Section . . . . . . . .
Overcurrent Protection Adjustment
5-Volt Regulator Adjustment
Motor Drive Amplifier
Transport Control . . . . .
Preliminary Setup . . . .
Tension Sensor
Arm Calibration
Normalizing
Reel Servos
Tension Adjustments .
Capstan Servo
System. .
Search-to-Cue/Tape Timer
Checkout . .
.. .
Adjustment
... .
Alignment of Photo-Isolators
Mechanical Adjustments. . . .
Takeup
Reel Brake Adjustment
Brake Check and Adjustment
Brake Solenoid
Air Damping
Supply Reel Brake Adjustment
Capstan Servo
Motor . . . .
Tape
Lifter Assembly Adjustments
Tape
Lifter Solenoid Air Damping
Head Assembly
Pinch Roller
Check . . .
Adjustment
End-of-Tape
Arm
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AMPEX 4890400-02

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AMPEX 4890400-02
TABLE OF CONTENTS (Continued)
TITLE
SECTION 5 MAINTENANCE (Continued)
Audio Adjustments .,',.,
7-1/2-ln/S Reproduce Alignment
7-1/2 -15 In/S Record Alignment
15-30 In/S Reproduce Alignment
15-30 In/S Record Alignment,
Distortion Measurement , .
Noise and Erasure Depth .
Bias
Amp Module Alignment
Troubleshooting , , , . , .
Possible Corrective Actions
Causes of Tape Speed Error
Causes of Noise . . . . ,
Causes of Distortion
Causes of Flutter ..,..
Flutter Troubleshooting Hints
Transport
Control , .
Audio Switching
Audio Signal . , , ,
Reproduce
Amplifier
Record Amplifier
Bias Amp Module
Power Supply , , .
Removal and Replacement
Control Box Assembly
Disassembly
Toggle Switch Removal and Replacement
Pushbutton Switch Removal and Replacement
LED Removal and Replacement
Reassembly ,
Reel Motors
Capstan Motor
Head Assembly
Tension Sensor
Pinch Roller Assembly
End-of-Tape Arm and Tape Threading Switch,
Search-to-Cue and Tape Timer Assembly
Tape Lifter Assembly . , , . ,
Power Supply , , , , , , , ,
Motor Drive Amplifier Assembly
Meter Panel Assembly "',
",
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vi
TABLE OF CONTENTS (Continued)
TITLE
SECTION 6 PARTS LISTS AND SCHEMATICS
Indentured List of Assemblies
Numerical List
of Assemblies
Numerical List
of Schematics
APPENDIX A
Integrated Circuits .
APPENDIX B
Transport Control PWA 4050706 Alignment
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A-1
8-1
AMPEX 4890400-02

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A~PEX 4890400-02
LIST OF ILLUSTRATIONS
Location of Components (Front)
Location of Components (Rear)
Tape
Transport Assembly
Transport Control Assembly . .
Motor-Drive Amplifier Assembly
Head Assembly (Typical)
Electronics Assembly (Typical)
Control Box Assembly
Meter Panel Assembly
Power
Supply . . . .
TITLE
Input/Output Connector Panel
Input/Output Cable Wiring. .
Capstan Servo PWA ....
Search-to-Cue and Tape Timer PWA
Tape Threading Path . . . . . .
Head
Usage for Different Operating Modes
MM-1200 Block Diagram . . . . _ . .
Record Signal Path Partial Schematic . . .
S/Sync and Repro Signal Path Partial Schematic
Audio Control Partial Schematic _ . . . . . .
Divider Voltages with Neutral Control Signal (REPRO)
Divider Voltages with +27V Control Signal (S/SYNC)
Divider Voltages with Ground Control Signal (I NPUT)
Control Panel Simplified Schematic, Channel 1 Shown
Stop and Braking Logic Partial Schematic
Play and Record Logic Partial Schematic
Fast
Forward and Rewind Logic
Tension Servo
Circuits Partial Schematic
Tape
Timer Block Diagram . . . . . .
Search-to-Cue Block Diagram . . . . .
Reel Motor Drive Amplifier Simplified Schematic
Capstan Servo Block Diagram . . . . . . .
Capstan Phase Comparator, Typical Waveform
Power Supply Block Diagram . . . . . .
Power Supply Test Points and Adjustments
MDA PWA Test Point Location . . . . .
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LIST OF ILLUSTRATIONS Continued)
TITLE
Transport Control PWA, Control Locations
Tension Sensor
Arm Calibration
Tape Tension Adjustments . . . . . .
Positioning Tension Sensor
Arm . . . .
Servo PWA Test Points and Adjustments
Waveform at TP2 on Servo
PWA. . . .
Tachometer Preamplifier Adjustment
Tachometer Preamplifier Adjustment Waveforms With Tape
Moving in the Forward Direction
Transport Adjustment Points
Servo Motor Maintenance
Tape
Lifter Adjustment .
Pinch Roller
Adjustment.
End-of-Tape Arm
Tension Arm Dashpot Assembly.
End-of-Tape Arm and Threading Switch Adjustment
30-Hz to 18-kHz Band Limiting Filter
ASA 'A' Weighted Filter
Control Box Case Removal
Control Box Assembly
Switch PWA Disassembly
Switch Replacement
Transport Disassembly (Top)
Transport Disassembly
(Bottom)
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AMPEX 4890400-02

TABLE
1-1
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3-4
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Optional Equipment
Specifications . . .
Power Supply Strapping
Speed Strapping . . .
LIST OF TABLES
TITLE
Tape Speeds for Various Input Frequencies
Control Box Assembly -Controls and Indicators
Search-to-Cue and Tape Timer Controls and Indicators
Electronics Assemblies -Operator Controls
for a Typical Channel
Line Output/Monitor Signals
Audio Switching Bus Levels
High-Frequency Equalization Components.
Test Equipment and Maintenance Materials
Transport Brake Torques .. . . . . .
Electronics Assembly - Alignment Adjustments
Ampex Alignment Test Tapes .....
Rotational Rates (Revolutions/Second) . . . .
Troubleshooting Hints -Transport System
Troubleshooting Hints -
Audio Switching System
Troubleshooting Hints -Power Supply . . . .
AMPEX 4890400-02
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ix/x

13550-1
MM-1200 Multichannel Recorder/Reproducer
1-0
AMPEX 4890400-02

SECTION 1
DESCRIPTION
1-1. GENERAL
This manual, Catalog No. 4890400, provides
installation instructions, operation instructions,
maintenance and troubleshooting instructions, and
theory of operation for the Ampex MM-1200
Multichannel Recorder/Reproducer, Part No.
4010240, versions -13 through -24.
The Ampex MM-1200 Multichannel Recorder/
Reproducer provides up
to 24 channels of audio
recording/reproducing capability using one-inch
or
two-inch audio recording tape. The 8-channel
version uses one-inch tape and the 16- and 24-
channel versions use two-inch tape. The machine is
capable of operating in any of three speeds; i.e.,
7-1/2 in/s, 15 in/s and 30
in/so When the associated
PWA
is properly strapped, any two adjacent speeds
are front-panel selectable by means of a high/low
speed switch. NAB and I EC (CCI R) equalization
capabilities are also provided.
The MM-1200 provides the capabi
lity of recording
on one
or more channels simultaneously while
monitoring one or more previously recorded
channels. A Sel Sync* (Selective Synchronization)
feature permits
monitoring a previously recorded
channel while recording in synchronization on one
or more channels. This feature
is enabled by using
the record
head of that previously recorded channel
in a playback mode while one or more record
heads are in the record mode.
The MM-1200 Recorder/Reproducer, shown in the
frontispiece, consists
of a tape transport assembly,
a transport control assembly, a frame assembly,
a motor-drive amplifier assembly, a head assembly,
audio electronics assemblies, a control box assem-
bly, a power supply assembly, a meter panel
• Ampex Trademark
AMPEX 4890400-02
assembly, an accessory panel, and an input/output
panel assembly. Multi-pin connectors are used
extensively between units to facilitate removal
and replacement of various components and
assemblies. Location of the various components
and assemblies are shown in Figures 1-1 and 1-2.
1-2. TAPE TRANSPORT ASSEMBLY
The tape transport assembly (Figure 1-3) consists
of a supply reel assembly, a takeup reel assembly,
a capstan drive assembly, a pinch roller assembly,
a tension sensor assembly, an end-of-tape sensor
and tape threading switch assembly, a tape lifter
assembly, and a search-to-cue/tape timer assembly.
Also mounted on,
but not considered part of, the
tape transport assembly
is the head assembly
consisting of erase, record and reproduce heads,
and a scrape-flutter idler, mounted in a housing.
All of the above components of the tape transport
assembly are discussed in the following paragraphs.
1-3. Supply and Takeup
Reel Assemblies
The supply and takeup reel assemblies each consist
of a split-phase, four-pole ac torque motor and a
mechanical brake. These motors drive the tape reel
turntables. The brake assemblies are spring-loaded
and solenoid-actuated, and are adjustable for
correct braking tension. The reel assemblies are
removable through the top of the transport deck
plate for servicing.
1-4. Capstan Drive Assembly
The capstan drive assembly consists of a dc servo
controlled motor with an internal tachometer
assembly. The extended shaft of the motor is the
capstan
for the tape transport. The tachometer
assembly consists of a pickup coil and inner and
1-1

TAPE
TRANSPORT
ASSEMBLY
TRANSPORT
CONTROL
ASSEMBLY
FRAME
ASSEMBLY--'
CONTROL
BOX
ASSEMBLY
METER
PANEL
ASSEMBLY
ELECTRON ICS
ASSEMB LI ES
13550-5
Figure 1-1. Location of Components (Front)
outer tachometer wheels mounted on the motor
shaft and housing. The use of inner and outer
tachometer wheels minimizes
flutter in the tach-
ometer
output signal.
1-5. Pinch Roller Assembly
The pinch roller assembly consists of a solenoid-
operated, shaft-mounted arm on which is mounted
a rubber pinch roller. The pinch
roller is fitted with
ball bearings at each end of the roller shaft. An
adjustable pressure spring is used to maintain the
correct force
of the pinch roller against thecapstan.
1-2
1-6. Tension Sensor Assembly
The tension sensor assembly, adjacent to the
supply reel assembly, consists of two photovoltaic
cells and an incandescent lamp mounted on a fixed
bracket. The three active components
are wired
to a connector plug that interconnects with the
transport harness. A movable
window attached
to the sensor arm in the tape path passes an amount
of light, proportional to the amount of tape
tension,
from the lamp to the photovoltaic cells.
This signal is used by the motor-drive amplifiers
to maintain correct tape tension.
AMPEX 4890400-02

FRAME
ASSEMBLY
INPUT/OUTPUT
PANEL
ASSEMBLY
POWER
SUPPLY
ASSEMBLY
.11
/.
:fII
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e. •• _
llil!
,.
Hill
.<»"
Ql
, .
• • •
1&
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• • •
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------
til
TAPE
TRANSPORT
ASSEMBLY
ACCESSORY
PANEL
MDA PWA
MOTOR DRIVE
AMPLIFIER
ASSEMBLY
14245 - 8
Figure 1-2_ Location of Components (Rear)
1-7 End-of-Tape
Arm and
Threading
Switch Assembly
The end-of-tape arm and threading switch assembly,
adjacent to the takeup reel, is contained in a
housing and consists
of a spring-loaded tension
arm
fitted with a tape guide at the free end. The
AMPEX 4890400-02
post to which the tension arm is attached extends
through the transport chassis and is mechanically
coupled
to a dashpot assembly to damp the motion
of the spring-loaded arm. The end-of-tape arm is
equipped with an actuator that activates a switch
when there
is no tape pressure against the arm,
thereby signaling end-of-tape and applying the reel
motor brakes.
1-3

TENSION
SENSOR
ASSEMBLY
TRANSPORT CONTROL ASSEMBLY
CAPSTAN
END-OF-TAPE
ARM/THREADING
SWITCH
SEARCH-TO-CUE/
TAPE TIMER
ASSEMBLY
13703-54
Figure 1-3. Tape Transport Assembly
The end-of-tape arm may also be moved to the full
counterclockwise position, which activates another
switch
that performs the same function as the end-
of-tape switch, i.e., applies the reel
motor brakes.
The end-of-tape arm
is held in the threading
position
by a magnetic catch mechanism beneath
the transport chassis.
1-8. Tape
Lifter Assembly
The tape lifter assembly is a solenoid-operated,
spring-return, pivoted assembly. The tape
lifter
pins extend upward through the head assembly
and are moved outward of the head assembly
automatically during the fast wind modes of
transport operation, thereby lifting the tape away
from the heads. The lifter operation can be de-
feated
by the operator during the fast wind modes
of operation for cueing purposes. The lifters can
also be operator-activated while the transport is
in the standby mode and in the play and record
modes
of operation.
1-4
1-9. Search-to-Cue/Tape Timer Accessory
The tape
timer consists of a tape-driven idler
attached to a mounting" housing. The timer idler
roller drives a disc that has alternate opaque and
transparent segments. As this disc rotates,
caused
by tape motion, it interrupts light sources that
are focused on a pair of photosensitive diodes.
The diodes trigger
an electronic counter as the
light sources are interrupted by the moving disc,
and the counter and its associated decoder trans-
late the elapsed time into increments of + (plus)
or -(minus) hours, minutes, and seconds. The
counter
will count up or down according to the
tape
direction and will indicate the tape position
in terms
of elapsed time, regardless of speed. The
direction from zero is indicated by a + or -symbol
at the left of the hours display. The counter also
has an output that sends a motion-sense signal to
the transport control assembly when the tape is in
motion. The search-to-cue feature is controlled by
a part of the tape timer and will permit exact
return
to any predetermined point on the tape,
regardless of the direction of tape travel.
AMPEX 4890400-02

1-10. Transport Control Assembly
The transport control assembly (Figure 1-4) is in
an enclosed chassis having a lift-up cover and con-
taining three separate
printed wiring assemblies,
the main power switch, and the ac utility outlet
accessory. The three PWAs contain the transport
control electronics, the capstan servo electronics,
and the search-to-cue/tape ti mer electronics.
Each
of the PWAs plugs into a 56-pin connector
receptacle which is hardwired to the connector
cable that interconnects with the tape transport
assembly, the search-to-cue/tape timer assembly,
the remote control connector, the local control
box assembly, the capstan tachometer, and the
electronics assembly. The transport control chassis
is mounted at the rear of the meter panel adjacent
to the control box assembly.
1-11. Motor·Drive Amplifier Assembly
The motor-drive amplifier (MDA) assembly con-
sists
of a printed wiring assembly and two heat-
sinks, each
with three power transistors, all con-
tained in a
common housing. The printed wiring
assembly contains the preamplifiers for each of the
reel motors. Four of the transistors on two of the
heatsinks are the drive transistors for each of the
two reel motors. The remaining two transistors
are the drive transistors for the capstan motor.
The MDA is connected by means of a multi-pin
connector to the main transport control harness of
the MM-1200. There is sufficient slack in the
wiring harness such that the entire MDA assembly
may be removed for servicing. Figure 1-5 shows
the MDA assembly and the MDA printed wiring
assembly.
1-12. HEAD ASSEMBLY
Eight-track, 16-track, and 24-track head assemblies
are available for use with the MM-1200 in the
standard
configuration. The 8-track head assembly
utilizes one-inch-wide recording tape; and the 16-
track and the 24-track head assemblies utilize two-
inch tape. Each head assembly contains three
headstack assemblies; i.e., the record head, the
erase head, and the reproduce head. The head
assembly also contains one scrape-flutter idler with
a provision for another optiona I scrape-flutter
idler. The record and reproduce head stacks are
magnetically shielded with laminated mu-metal. A
hinged head shield assembly
is mounted in front
of the record and reproduce heads. In addition, a
precision tape guide
is mounted adjacent to the
erase head at one end of the assembly, and another
is mounted adjacent to the reproduce head at the
other end. The record heads are identical to the re-
produce heads and, at 15 and 30 in/s, provide Sel-
Sync response comparable to that of conventional
reproduce heads. Figure 1-6 shows a typical head
assembly.
SEARCH-TO-CUE/TAPE TIMER
ELECTRONICS
MAIN ~
POWER
SWITCH
Figure 1-4. Transport Control Assembly
AMPEX 4890400-02
CAPSTAN SERVO
ELECTRON ICS
TRANSPORT CONTROL
ELECTRONICS
14313-1
1-5

MOTOR DRIVE
AMPLI F IER PWA
MOTOR DRIVE
/ AMPLIFIER CHASSIS
13550-27
Figure 1-5. Motor-Drive Amplifier Assembly
1-13. ELECTRONICS ASSEMBLY
Each electronics assembly contains four separate
groups of electronic printed wiring assemblies.
Each group forms one record/reproduce channel
and consists of an audio switcher module, a bias
amp module, a record amplifier, and a reproduce
amplifier. Each of these units plugs into a mother-
board at the rear of the electronics assembly and
is removable from the front of the assembly.
Extender boards may be used to extend any of
the units for servicing. All electronics maintenance
controls (except the reproduce bias trap) and some
of the operatorcontrolsare contained on the remov-
able units. The bias trap components are mounted
on the motherboard adjacent to the reproduce
amplifier connector socket and are accessible with
the record amplifier removed.
1-6
Each group of units; i.e., audio switcher, repro-
duce amplifier, record amplifier, and bias amp
module, is associated with one audio channel.
Therefore, if the MM-1200 has an 8-track capa-
bility, two complete electronic assemblies are
required. Four electronic assemblies would be
required for a 16-track capability, and six elec-
tronic assemblies for a 24-track capability. Figure
1-7 shows a typical electronics assembly. Each
record and reproduce amplifier has a 10-pin
receptacle that accommodates a plug-in equaliza-
tion PWA. The plug-in equalization PWAs are at
right angles to the amplifier PWAs so that the
equalization adjustment controls are accessible
from the front of the electronics assembly. Each
electronics assembly includes a fuse at the rear
of the assembly which protects the 39-volt supply.
Each audio channel has a removable line-bridging
AM PEX 4890400-02

RECORD
HEAD STACK
PRECISION
TAPE GUIDE
HEAD
COVER
HEAD
SHIELD
SCRAPE
FLUTTER
REPRODUCE
HEAD STACK
HEAD
SHIELD
PRECISION
TAPE GUIDE
Figure 1-6. Head Assembly (Typical)
transformer in an accessory socket on the rear
panel of the electronics assembly. The line-bridging
transformer accessory may be removed and others
substituted, depending on the matching require-
ments
for the external interfacing equipment.
1-14.
CONTROL BOX ASSEMBLY
The control box assembly (Figure 1-8) is a remov-
able assembly that doubles as a remote control unit
when used with an optional extension cable (see
Table 1-1. A dummy control box is provided in
the miscellaneous parts
kit for use when the con-
trol box is removed for remote application).
The
control box assembly contains the controls
and indicators necessary for all operating functions
of the MM-1200 Recorder/Repro9ucer, with the
exception
of four audio controls located on the
electronics assembly. The transport control switches
are all of the illuminated pushbutton type, except
AMPEX 4890400-02
the TAPE SPEED switch, which is a two-position
toggle. Depressing any pushbutton switch, except
RECORD and LIFT DEFEAT, cancels any push-
button switch previously selected. The RE CO RD
pushbutton switch
has no effect unless it is pressed
concurrently with the PLAY pushbutton switch
to make a recording. The tape transport assembly
may be changed from any mode of operation to
any other mode of operation without depressing
the STOP
pushbutton switch first.
There
are two rows of toggle switches which are
used to control the record and reproduce functions
for each channel of audio. LEDs mounted beneath
the
control box assembly surface illuminate
through translucent windows to indicate the status
of each audio channel.
1-15. METER PANEL ASSEMBLY
The meter panel assembly contains an illuminated
meter for each channel of audio. The panel may be
1-7

1-8
LINE
BRIDGING _____
TRANSFORMER -----....
•
MOTHERBCJARD
AUDIO
SWITCHER
M()DULE
BIAS
AMP
MODULE
AMPLIFIER
REPRODUCE
AMPLIFIER
Figue 1-7. Electronics Assembly (Typical)
Figure 1-8. Control Box Assembly
13550-21
14245-3
AMPEX 4890400-02

tilted upward or centered vertically for the most
convenient viewing angle. A cable harness provides
interconnection
with the electronics assembly.
Figure 1-9 shows a
typical meter panel assembly.
1-16. POWER SUPPLY
The power supply
is contained in a single chassis
and
is mounted at the lower rear of the frame
assembly adjacent
to the MDA assembly. The
power supply contains a heavy
duty power trans-
former; two printed wiring assemblies; two heat-
sinks, one having
two power transistors mounted
on
it, the other having two power transistors
and a 5-volt
regu lator IC; and the necessary recti-
fiers and
filter capacitors. The PWAs and their
associated power transistors provide +39-volt,
+27-volt, and
+15-volt power for the transport
assembly, electronics assemblies, and the bias
oscillator. The 5-volt regulator mounted on the
heatsink provides power
to the search-to-cue/tape
timer assembly. The bias oscillator, which is a
part of the +39-volt regulator PWA, provides
bias current
to all the bias amp modules. The
39V and the 15/27V PWAs are removable for
service and can be used with extender cards for
maintennace purposes. Figure 1-10 shows the
power supply.
1-17.
OPTIONAL EQUIPMENT
Table 1-1 lists the optional equ ipment available
for use with the MM-1200 and the application
for each item.
1-18. SPECI
FICATIONS
Specifications for the MM-1200 Recorder/Repro-
ducer are presented in Table 1-2.
13550-8
Figure 1-9. Meter Panel Assembly
AMPEX 4890400-02
1-9

1-10
15/27-VOLT
REGULATOR
PWA
ITEM
2-lnch/1-lnch Conversion Kit
Fixed Guide, 1-lnch/2-lnch
8-Track Head Assembly
16-Track Head Assembly
8/16-Track Conversion Kit
16/24-Track Conversion Kit
Remote Cable Assembly
Brake Quiet Kit
Tape Lifter Solenoid Kit
Transport Control Box Assembly
39-VOLT
REGULATOR AND
BIAS OSCILLATOR PWA
POWER
TRANSFORMER
13550-26
Figure 1-10. Power Supply
Table 1-1. Optional Equipment
PART NO. USE
4850154
Converts from 2-inch to 1-inch capability.
4210353-01/02
Auxiliary 1- or 2-inch guide.
4020334
Converts from 16-track to 8-track capability.
4020372
Converts from 24-track to 16-track capability.
4010246
Converts to 16-track capability.
4010247 Converts
to 24-track capability.
4952348-02 Provides remote
capability for control box
assembly.
4010268
Provides air-damped brake solenoids.
4010280
Provides air-damped tape lifter solenoid.
4020411-01 Provides remote capability
for transport
control onIy.
AMPEX 4890400-02