LUXMAN 5K50

Commentary

Stereo cassette deck with dual capstan system.

The mechanism section employs a closed-loop dual capstan system in which two sets of capstan and pinch rollers securely hold the tape. This keeps the tape tension in the loop constant and reduces level fluctuations and dropouts.
In addition, hard stainless steel is used for the capstan shaft. The hardness is increased by quenching treatment, and the shaft diameter is increased to approximately 1.5 times the normal diameter.
In addition, the roundness of the capstan has been reduced to less than 0.2 μ m and the accuracy of the pinch rollers and flywheels has been improved to achieve a wow flutter value of less than 0.03%, which is almost the limit value for a cassette deck.

A 3-motor configuration with independent dedicated motors for the capstan, feed reel, and take-up reel is adopted.
A crystal-controlled PLL direct drive type motor is used to drive the capstan. This motor is used for the take-up side capstan, while the send-out side capstan is driven by a belt with minimal thickness unevenness to obtain excellent tape running performance.
In addition, coreless motors are used for both the delivery side and the take-up side of the reel to achieve stable pulling torque and back tension.

The head section uses an independent 3-head configuration.
It uses a Sendust head for the playhead, a ferrite head for the recording and erasing heads, and an ideal gap setting for each head, with a playhead gap of 1 micron and a recorder gap of 4 microns.
Metal tape can be handled by replacing the head housing and bias block.

The recording amplifier uses BRBS (Bridge Recording by Bias current & Signal current) method, a new recording drive method unique to LUX, in order to make the recording amplifier DC.
In the conventional recording method, a signal current and a bias current are superposed by an adder circuit to drive a recording head, and a peaking coil and a trap circuit are indispensable for high-frequency correction in recording. However, when these circuits composed of coils and capacitors are inserted into the NFB loop of a recording amplifier, they cause transient distortion and phase shift, which adversely affects sound quality.
The BRBS system adopted in the 5K50 is a circuit that takes note of the fact that current flows into the load when the balance of the bridge circuit is lost. It drives the recording head by obtaining a superimposed current with the signal current by swinging the bias current with the signal voltage. This enables high-frequency correction in recording without using a peaking coil or trap circuit.

The playback amplifier section is also a DC amplifier configuration.

In addition to reducing the distortion of the bias oscillation circuit, the recording bias output line and the erase bias output line are separated to prevent interference, thereby reducing the distortion factor of the erase signal.
This eliminates most of the residual bias noise that is likely to remain during erasing.

Bias variable method is adopted, and the bias value according to the tape condition can be freely set.
In the recording mode, set the internal oscillator to 400 Hz, turn the bias adjustment knob slowly from the min position, and the indicator will light. This position will be the under-bias point of -0.25 dB, and turn it further to turn the indicator off. This position will be the over-bias point of -0.25 dB.
The peak bias value is 1/3 to the right of the position where the indicator first lights up.

Equipped with an azimuth adjustment mechanism.
If the two azimuth beacons turn on simultaneously when the built-in oscillator is set to 6 kHz after recording and re-recording, the proper azimuth state is obtained. If the azimuth is out of alignment, the proper azimuth state can be obtained by adjusting while watching the azimuth beacon.

A keyboard control circuit with highly reliable logic ICs enables feather-touch operation, and an automatic take-up mechanism is activated when a loose tape is attached, and instruction action begins after this is completed.
In addition, the tape is designed to be safe against accidental operation.

Equipped with a digital electronic display type tape counter using 4-digit 7-segment LED.
With this counter, you can display the accumulation time for normal cassette tapes and the time for LUX cassette tapes. The selection of tapes is automatically switched by an electronic circuit.
In the case of a general cassette tape, the rotation of the reel table on the tape winding side is optically detected and counted. The display is a general accumulation method, and the total count number is approximately 3100 for one side for C-60 and approximately 4650 for one side for C-90.
In the case of LUX cassette tapes, the time detection roller mounted on the cassette body is designed to be 4.75cm/sec. (standard speed) in two rotations. The rotation of this roller is optically detected and the running time of the tape is displayed in real time.

A 24 dot / ch. fluorescent indicator tube is used for the peak level meter.
It has a wide indication range of -40dB to + 6 dB, and can hold -5dB to + 6 dB (1 dB interval). The attack time is set to 10 ms, the recovery time is set to 700 ms, and 0 dB is set to 200nWb/m, which is the Dolby NR standard level.
For metal tapes, the maximum saturation level can be set higher, but a different scale is displayed so that the maximum is + 10 dB.

By integrating the mechanism of the cute review into one lever, the operability of the heading is improved.

Equipped with a recording mute function and an equalizer 3-stage switching function (CrO2, normal, EX).

Equipped with a Dolby noise reduction system with calibration.

Remote control unit AK-I (sold separately) allows remote operation.
The AK-I has the same layout of operation buttons as that of the main unit. In addition to normal operation, autoplay and autorewind are possible as operation functions. Although these functions are switchable, they can be combined for autorepeat operation.
The cord length of AK-I is 5m.

Model Rating

Type	Cassette deck
Truck type	4-track 2-channel stereo system
Head configuration	Independent 3-head system Recording : ferrite head Playing : Sendust head Erasing : ferrite heads
Motor configuration	Independent 3-motor system For Capstan : Crystal Controlled PLL / DD Motors For Reel (Delivery) : Coreless Motor For Reel (Winding) : Coreless Motor
Tape drive system	Dual capstan system
Tape used	Normal tape, chrome tape (Metal tape can be replaced with head housing, etc.)
Tape speed	4.75cm/sec.
Wow and flutter	0.03% or less (WRMS)
Operating system	Logic control system
Frequency characteristic	CrO2 : 20 Hz to 20 kHz (30 Hz to 18 kHz ± 3 dB) Normal : 20 Hz to 18 kHz (30 Hz to 16 kHz ± 3 dB)
Overall strain rate	1.2% or Less (LH Tape, 1 khz, 0 db) 0.3% or less (Real Analyzed Distortion)
Signal-to-noise ratio	CrO2: normal: 67 dB or More (Dolby on, CCIR corrected) 58 dB or More (Dolby off, JIS-A Correction) 65 dB or More (Dolby on, CCIR correction) 55 dB or More (Dolby off, JIS-A Correction)
Input sensitivity	Line:100mV Mic : 0.25 mV (Optimum Z ; 600 Ω ~ 10k Ω)
Output level	Line:580mV Headphone : 1 mW (8 ohm load)
Counter	Electronic Counter Method (General Tape) Running time counter system (LUX tape)
Peak meter	24-dot fluorescent display tube type (peak hold possible)
Attachment	Continuously variable bias control Azimuth Adjustment Mechanism (With Indicator) Search Mechanism (Queue & Reviewable) Recording mute mechanism Equalizer 3-stage switching (CrO2, normal, EX) Tape monitor circuit (tape, source, off) Timer rerecording function Remote control function (auto-rewind and auto-play are possible with the remote control unit) Dolby NR System (capable of oscillator calibration and recording calibration) Built-in oscillator (400 hz & 6 khz)
Pwer	100 VAC, 50Hz/60Hz
Power consumption	75W
External dimensions	Width 442x Height 146x Depth 389 mm
Weight	12.5kg
Sold Separately	Remote Control Unit AK-I (¥ 12,000)