General Information

1-1. SYSTEM DESCRIPTION↑ TOP

The MX-5050 Series Professional Recorder are professional quality two-speed audio tape recorder/reproducers designed for optimum performance and long life. They are available in three mounting configurations: standard portable case, rack, or floor console.

The MX-5050 Series uses ¼-inch or ½-inch tape and is available in eight diffetent[sic] model configurations as shown in Table 1-1. The configuration is determined by the tape width, the tape speed pair and the tape recording and reproducing format.

Table 1-1. MX-5050 Model Configurations

Model No.	Tape Width (inch)	Tape Speed (inch/sec)	Recording/Reproducing Method
MX-50502SHD₂ MX-50502SLD₂	¼	15 & 7½ 7½ & 3¾	4-track 2 channel recording with selective reproduce
MX-5050QXHD MX-5050QXLD	¼	15 & 7½ 7½ & 3¾	4-track 4 channel recording with selective reproduce
MX-5050 ½QXHD MX-5050 ½QXLD	½	15 & 7½ 7½ & 3¾	4-track 4 channel recording with selective reproduce
MX-5050 8SHD MX-5050 8SLD*	½	15 & 7½ 7½ & 3¾	8-track 8 channel recording with selective reproduce

Note: * Optional

Among the many professional features of the MX-5050 Series are: selective reproduce for overdubbing, motion sensing, dc capstan servo with variable control of capstan speed, edit control for spilling and rocking, adjustable cueing for audible monitoring in fast forward and rewind, built-in test and cue-tone oscillator, front adjustment bias and equalization control, XLR-type connectors for input and output lines, variable or fixed (standard reference level) output, separate line and microphone input level control for each channel, VU meter for each channel, optional external servo control to synchronize tape speed to other equipment, and external noise reduction control for a noise reduction system.

1-1-(1) TAPE TRANSPORT↑ TOP

All components of the tape transport are mounted on a rigid aluminume[sic] base for stability. The transport design incorporates two six-pole induction motors for the reels and a dc servo control motor for the capstan. Capstan speed can be controlled by pitch control knob on the face of the transport. Speed selection is made by operation of a front panel pushbutton switch which also switches equalization. The operating speed pairs of each model MX-5050 are summarized in Table 1-2.

Table 1-2. Available Standard Tape-Speed Combinations

Model Type	Model Numbers	Speed Combination — HIGH	Speed Combination — LOW
High Speed	MX-5050 2SHD₂, QXHD, ½QXHD, 8SHD	15 in/sec	7½ in/sec
Low Speed	MX-5050 2SLD₂, QXLD, ½QXLD, 8SLD	7½ in/sec	3¾ in/sec

The tape transport accomodates[sic] tape reels 10½ inches, eight inches, seven inches, and five inches in diameter in NAB or EIA hub configuration. A solenoid-actuated tape lifter lifts the tape away from the heads in fast forward and rewind modes in addition to stop mode to increase head and tape life. During fast modes, tape lifter action can be defeated by operating the front panel cue control to provide an audible signal for monitoring.

In addition to the editing controls, a tape-splicing block (Fig. 3-2) mounted on the head cover holds the tape for editing, cutting, and application of splicing tape. The head cover is hinged so it can be easily opened to facilitate maintenance and replacement. Momentary contact pushbutton controls on the transport are used to select operational modes, record, play, stop, rewind, and fast forward. These modes may be controlled from a remote location by means of an optional remote control unit (Table 1-5).

⤢ zoomMX-5050 8SD major components: the tape transport in its case beside the eight-channel record and reproduce electronics, with the control panel, tape transport, and record/reproduce electronics called out

Fig. 1-1 MX-5050 8SD Major Components Transport and Amplifier

1-1-(2) RECORD/REPRODUCE ELECTRONICS↑ TOP

The dual channel record/reproduce electronic unit is located directly beneath the transport control panel or in a separate mounting case. Each unit contains two separate record/reproduce channels including a bias buffer amplifier, selective reproduce controls, and facilities for setting standard reference level. MX-5050 electronics are all solid state and are incorporated on plug-in type printed circuit boards to facilitate maintenance. Equalizer charactristics[sic] can be changed to NAB or CCIR by resoldering and changing the appropriate terminals on the equalization printed circuit board inside the amplifier chassis assembly.

1-1-(3) HEAD ASSEMBLIES↑ TOP

The head assembly can be replaced as a plug-in assembly. As viewed from the front of the recorder, the configuration of the head assembly in each MX-5050 model is as shown in Table 1-3.

Table 1-3. Head Assembly Configuration

Model No.	Track Width	Head 1	Head 2	Head 3	Head 4
MX-5050 2SHD₂ MX-5050 2SLD₂	½ Track (0.075 in. or 1.9mm)	Two track in-line	Reproduce: ¼ Track head for tracks 1 and 3	Record: Two track in-line	Reproduce: Two track in-line
MX-5050 QXHD MX-5050 QXLD	¼ Track (0.04 in. or 1.0mm)	Erase: Two ¼ Track heads for tracks 1 and 3.	Erase: Two ¼ track heads for tracks 2 and 4.	Record: Four track in-line.	Reproduce: Four track in-line.
MX-5050 ½QXHD MX-5050 ½QXLD	½ Track (0.075 in. or 1.9mm)	Erase: Two ½ track heads for tracks 1 and 3	Erase: Two ½ track heads for tracks 2 and 4	Record: Four track in-line	Reproduce: Four track in-line
MX-5050 8SHD MX-5050 8SLD	¼ Track (0.04 or 1.0mm)	Erase: Eight track in-line	Record: Eight track in-line	Reproduce: Eight track in-line

1-2. STANDARD ACCESSORIES↑ TOP

The MX-5050 Serise[sic] is supplied with standard accessories listed in Table 1-4.

Table 1-4. Standard Accessories

Description	Quantity	Otari Part No.
Connecting Cable for 2SD₂	1	TZ127-028
Connecting Cable for ½QX D[sic] & QX D	1	TZ127-026
Connecting Cable for 8SD	1	TZ127-027
Noise Reduction Remote Connector for 2SD₂	1	CN09-MR8LWF
Noise Reduction Remote Connector for QX D & ½QX D	2	CN09-MR8LWF
Noise Reduction Remote Connector for 8SD	4	CN09-MR8LWF
Otari 10½ inch NAB Reel for 2SD₂ & QX D (¼ inch)	1	TY500
Otari 10½ inch NAB Reel for 8SD & ½QX D (½ inch)	1	TY561
NAB Hub Reel Hold Down Knob for 2SD₂ & QX D	2	TW670
NAB Hub Reel Hold Down Knob for 8SD & ½QX D	2	TW671
Reel Adjusting Disk (Shim) for 2SD₂ & QX D only[sic]	2	TY506
Instruction Manual	1	OIM-1004E

* The reel-adjusting disk (shim) is placed between the metal reel and the turn-table to compensate for the thickness between metal reels and plastic reels.

1-3. OPTIONAL ACCESSORIES↑ TOP

Available optional accessories are listed in Table 1-5.

Table 1-5. Optional Accessories

Description	Otari Part No.
Rack Mount Adaptor for 2SD₂	CS293
Rack Mount Adaptor for QX D & ½QX D	CS292
Rack Mount Adaptor for 8SD	CS291
Portable Case Cover for Tape Transport of QX D, ½QX D, & 8SD	TZ-307
Portable Case Cover for Amplifier of QX D & ½QX D	TZ306
Portable Case Cover for Amplifier of 8SD	TZ301
Remote Control Unit	CR705A
Balanced Input Line Transformer, 600 ohms	ET21-181
Balanced Output Line Transformer, 600 ohms	ET31-182
Cleaning Kit	TY502
Maintenance Manual	OMM-1002E

1-4. SERVICE AND REPLACEMENT PARTS↑ TOP

For service and replacement parts, or any necessary technical support, please contact your nearest service center, Otari dealer, or write to Otari. (See page ii for details.)

1-5. SPECIFICATIONS↑ TOP

The specifications of MX-5050 Series are as listed in Table 1-6.

Table 1-6. Specifications of MX-5050 Series

Description	8SD	QXD½[sic]	QXD	2SD₂
Tape Width:	½ inch (12.7mm)	½ inch (12.7mm)	¼ inch (6.3mm)	¼ inch (6.3mm)
Track Width:	¼ Track 0.04 in or 1.0mm	½ Track 0.075 in or 1.9mm	¼ Track 0.04 in or 1.0mm	½ Track 0.075 in or 1.9mm

Tape Speeds:	"H" type: 15 & 7½ ips (19 & 38cm/s) "L" type: 7½ & 33/4[sic] ips (19 & 9.5cm/s)

Description	8SD	½QXD	QXD	2SD₂
Reel Size:	½x10½ inch NAB	½x10½ inch NAB	¼x7 or 10½ inch NAB or EIA	¼x7 or 10½ inch NAB or EIA
Heads: Reproduce:	8-track	4-track	4-track	2-track and 4-track
Heads: Record:	8-track	4-track	4-track	2-track
Heads: Erase:	8-track	4-track 2 stack staggered	4-track 2 stack staggered	2-track

Motors: Capstan:	Dc servo controlled motor with variable (±7%) pitch control.
Motors: Reels:	Two induction torque motors.
Connectors:	Line input and line output: standard three-pin XLR. Microphone; standard ¼ inch phone lack.[sic]
Inputs: Line:	Minimum −15dBm, unbalanced 50k ohms. Minimum −15dBm, balanced 600 ohms with optional transformer.
Inputs: Microphone:	Minimum −70dBm, unbalanced, Input impedance 50k ohms, Applicable microphone impedance 150-10k ohms
Outputs: Line:	Level: +4dBm or −10dBm, rear panel switch selectable. Maximum Output Level: +19dBm Impedance: 600 ohms unbalanced (600 ohms balanced with optional transformer).
Outputs: Headphone:	−24dBm, Nominal 8 ohms unbalanced.
Equalization:	NAB standard for 3-¾, 7½, and 15 ips (IEC also available)

Description	8SD	½QXD	QXD	2SD₂
Frequency Response (Overall Record/Reproduce): 15ips		50 to 20,000 Hz ± 2dB (35 to 25,000 ± 3dB)	50 to 20,000 Hz ± 2dB (35 to 25,000 ± 3dB)	50 to 20,000 Hz ± 2dB (35 to 25,000 ± 3dB)
Frequency Response: 7½ips		50 to 18,000 Hz ± 2dB (30 to 20,000 ± 3dB)	50 to 18,000 Hz ± 2dB (30 to 20,000 ± 3dB)	50 to 18,000 Hz ± 2dB (30 to 20,000 ± 3dB)
Frequency Response: 3¾ips		50 to 12,000 Hz ± 2dB (30 to 15,000 ± 3dB)	50 to 12,000 Hz ± 2dB (30 to 15,000 ± 3dB)	50 to 12,000 Hz ± 2dB (30 to 15,000 ± 3dB)
Frequency Response (Selective Reproduce): 15ips		150 to 12,000 Hz ± 3dB	150 to 12,000 Hz ± 3dB	150 to 12,000 Hz ± 3dB
Signal to Noise Ratio: 15ips and 7½ips	60/63	63/65	57/60	63/65
Crosstalk (at 1kHz on adjacent tracks):	Greater than 50dB	Greater than 55dB	Greater than 45dB	Greater than 55dB

Flutter and Wow: 15ips	Less than 0.05%
Flutter and Wow: 7½ips	Less than 0.06%
Flutter and Wow: 3¾ips	Less than 0.12% (Measured per NAB weighted)
Distortion:	Less than 1% at 1kHz at 185nWb/m
Test Oscillator Frequency:	Nominal 1kHz
Operating Position:	Vertical or horizontal
Power Requirements:	117 volts, 60Hz, single phase AC or 220/240 volts, 50Hz, single phase ac, 2SD₂ 100W, QXD120W, ½QXD130W, 8SD200W.
Operating Environment:	40° to 104°F (5° to 40°C) 20 to 80% RH.
Storage Environment:	−5° to 113°F (−20° to 45°C)

Description	8SD	½QXD	QXD	2SD₂
Weight: Tape Transport:	51 lbs	51 lbs	51 lbs	64 lbs
Weight: Amplifier:	45 lbs	25 lbs	25 lbs

Mounting:	Standard wooden case, or optional rack mounting kit or optional floor console.
Standard Accessories:	Empty 10½ inch NAB reel, NAB reel precision hold down knob, fuse, and Instruction Manual.

Note 1. Signal to noise ratio is measured with respect to a record level of 520 nWb/m to biased tape noise when using Scotch 206 or equivalent high output low noise tape. Unweighted: Using a 30 to 18 kHz RC filter to attenuate noise outside the audio spectrum. Weighted: Using an NAB or ASA "A" weighting filter and 1,000 Hz reference.

2. Main schematic diagrams are attached to the last part of this manual.

3. Otari reserves the right to change specifications without notice and obligation.