MX-5050BII Instruction Manual — Digital Edition · Part 1 · scan pages 11-19
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 different models. The different models, and their application, are determined by the head format.
Table 1-1
| Model | Head Format | Speed | Tape |
|---|---|---|---|
| BII-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↑ TOP
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 monitoring in the fast-forward and rewind modes, a built-in two frequency low distortion test and cue-tone oscillator, a computerized 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, equalization, 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.
1.1.1 TAPE TRANSPORT↑ TOP
All components of the tape transport system are mounted on a rigid aluminum frame for stability. The transport design incorporates 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 location by means of an optional remote control unit (page 1-5).
⤢ zoomLine drawing of the MX-5050BII deck: the reel assembly, transport pushbuttons, and record/reproduce amplifier panel with its VU meters, each called out with a leader line.
Fig. 1-1 MX-5050BII Major Components
1.1.2 RECORD/REPRODUCE ELECTRONICS↑ TOP
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 controls 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↑ TOP
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 Head | |||
|---|---|---|---|---|---|
| H1 Erase | H2 Playback | H3 Record | H4 Playback | ||
| MX-5050BII-2 | 2T, 2CH | 4T, 2CH | 2T, 2CH | 2T, 2CH | 2T, 2CH Stereo |
| MX-5050BII-4 | 4T, 2CH | 2T, 2CH | 4T, 2CH | 4T, 2CH | 4T, 2CH Stereo |
| MX-5050BII-F | FT, MONO | 2T, 2CH | FT, MONO | FT, MONO | FT Monoaural |
| MX-5050BII-2E | 2T, 2CH DIN | 4T, 2CH | 2T, 2CH DIN | 2T, 2CH DIN | 2T, 2CH Stereo |
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.
⤢ zoomLine drawing of the head-assembly block, with the H1-H4 head stacks and the 2T/4T P.B. HEAD playback-head selector switch each labeled directly on the drawing.
Fig. 1-2 Head Arrangement
1.2 STANDARD ACCESSORIES↑ TOP
The MX-5050BII is supplied with the standard accessories listed below.
STANDARD ACCESSORIES (*ZA-12W)
- NAB Hub Reel Hold Down Knob KW0HO 2 pcs.
- NAB Empty Reel 10-1/2 inch ZA-51A 1 pc.
- Reel Adjusting Disc (Shim)** KW0C005 2 pcs.
- Instruction Manual OS3-038 1 pc.
- Power Cord PZ9D003 1 pc.
* This part number includes all parts described in numbers 1 through 5.
** 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↑ TOP
Optional accessories available are listed below.
OPTIONAL ACCESSORIES
- Remote Control Unit CB-102
- Cleaning Kit ZA-51B
- Balanced Input Transformer Ass'y ZA-53T
- Balanced Output Transformer Ass'y ZA-53S
1.4 SERVICE AND REPLACEMENT PARTS↑ TOP
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↑ TOP
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 | 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) |
| Tape Speeds | 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. |
| Reel Sizes | 7 inch or 10-1/2 inch plastic or metal, EIA or NAB. |
| Heads | Model MX-5050BII-2: Half-track configuration Model MX-5050BII-4: Quarter-track configuration Model MX-5050BII-F: Full-track configuration Model MX-5050BII-2E: Half-track configuration Four head stacks: MX-5050BII-2: 2T erase, 4T reproduce, 2T record, 2T reproduce. MX-5050BII-4: 4T erase, 2T reproduce, 4T record, 4T reproduce. MX-5050BII-F: FT erase, 2T reproduce, FT record, FT reproduce. MX-5050BII-2E: 2T DIN erase , 4T reproduce, 2T DIN record, 2T DIN reproduce. |
| Motors: Capstan | DC servo controlled motor. (Pitch control limits ± 7 %) |
| Reels | Two induction torque motors. |
| Operating Position | Vertical or horizontal. |
| Power Requirements | 50/60 Hz , 100/117/220/240 V ± 10 % Single phase AC , 100 W |
| Operating Environment | 40° to 104°F (5° to 40°C) 20 to 80 % RH |
| Storage Environment | -5° to 113°F (-20° to 45°C) |
| Dimensions and Weight | Height 527 mm (20.7 inch) Width 430 mm (16.9 inch) Depth 225 mm ( 8.8 inch) 24 kgs (53 lbs.) |
| Mounting | Dark grey leather-finished cabinet. |
| Standard Accessories | 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. |
| Remote Control Unit | An optional remote control unit is used to control the record, play, stop, rewind, and fast forward modes. |
| Connectors | Line input, line output, and microphone, standard three-pin XLR. |
| Inputs: Line | Minimum -15 dBm, active balanced 10 k ohms. (Floating type). Minimum -15 dBm, balanced 10 k ohms with optional transformer. |
| Microphone | Minimum -70 dBm, active balanced, adaptable 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 circumstances. |
| Outputs: Line | 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. |
| Headphone | Level: -24 dBm with an 8 ohm load. Load impedance: 8 ohms or greater. |
| Equalization | NAB or IEC for 3-3/4, 7-1/2, and 15 ips. Switchable on the rear panel, but calibration is necessary. |
| Frequency Response | 15 ips: 30 Hz to 20 kHz ± 2 dB 7-1/2 ips: 20 Hz to 18 kHz ± 2 dB 3-3/4 ips: 20 Hz to 10 kHz ± 2 dB Specifications refer to a 1 kHz reference when recorded on 3M 226. |
| Signal to Noise Ratio | Over-all measured at the level of 520 nWb/m. |
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 | With a 1 kHz signal on adjacent tracks: 2 tracks: greater than 55 dB 4 tracks: greater than 55 dB |
| Wow and Flutter | (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 % |
| Distortion | Less than 0.5% at 1 kHz at 250 nWb/m. |
| Erase Efficiency | Greater than 75 dB. |
| Test Oscillator Frequency | Nominal 1 kHz and 10 kHz |
| Bias and Erase Frequency | 133 kHz |
| Peak Indicator | Trigger level: 1040 nWb/m (15 dB above Ampex operating level) recorded flux level. |
| Record Level (SRL) | 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 Operating 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 Equalization |
* Short circuit flux ** Open circuit flux
NOTES:
-
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.
-
Otari reserves the right to change specifications without notice and/or obligation.
-
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