KENWOOD KX-7050
¥ 55,000 (around 1993)
Commentary
A 3-head cassette deck with improved recording and rerecording characteristics in pursuit of basic performance such as tape running and head touch stability.
The mechanical part uses a 3-motor closed loop dual capstan drive.
By installing two capstan at the front and rear of the head and applying a constant tension, a reliable head touch is obtained. This improves wow flutter characteristics and prevents noise from being generated due to tape shaking.
In order to suppress bias noise, which adversely affects the Dolby circuit, it was common to install a bias trap coil in the reproduction equalizer, but this coil adversely affects sound quality.
Therefore, this trap coil has been removed and a newly developed equalizer circuit bias band noise suppressor for reproduction has been incorporated.
As a result, the S/N ratio when the filter is flat is improved by 3 db compared with the conventional reproduction equalizer.
The combination read / write head uses a hard permalloy head with excellent wear characteristics.
In addition, PC-OCC (single-crystalline high-purity oxygen-free copper), which is highly effective in reducing transmission loss, is used in the windings to prevent degradation of high-frequency characteristics and minimize transmission loss of the original signal to improve distortion characteristics.
The erasing head is equipped with a SENDUST alloy chip erasing head with ceramic guard.
In the case of a general ferrite erasing head, since the crystal density of the metal is low and the smoothness is bad, the abrasion by micro glove (small hole) adversely affects the high frequency component. However, due to the synergistic effect of ceramic guard and multilayer structure, high bias erasing becomes possible for the first time in SENDUST head, and contact demagnetization in the high frequency region is eliminated.
Die-cast head bases used in high-end machines are excellent in rigidity and earthquake resistance. However, die-cast head bases often suffer from azimuth displacement due to distortion generated during molding and shrinkage caused by aging.
The KX-7050 uses a rigid 1.2 mm stainless steel and brass boss on the head block base to prevent long-term changes in azimuth.
At a normal recording bias of 105 kHz, the beat with the high-frequency component of the music signal appears at a low frequency and is heard as noise.
In the KX-7050, the recording bias is set to 210 kHz, twice the frequency of the conventional one, eliminating beat distortion.
Equipped with A. T. C. S. which automatically adjusts fine adjustment of difficult bias level by microcomputer.
Using signals of 400 Hz and 12.5 kHz, the bias level is changed in 16 steps for recording, and at the same time, the proper bias value is detected according to each output level. Recording at the optimum bias value is possible.
In addition, the tape sensitivity is automatically adjusted at 400 Hz to compensate for different recording sensitivities for each tape.
The set value is stored as a preset memory for each type of tape, so that optimum recording can be performed when using the same tape or air check.
It is equipped with Kenwood's original tape bus stabilizer.
In addition to the plate spring method, compression coil springs and special elastic rubber are used to eliminate the effects of internal and external vibrations.
When the cassette holder is closed, it is firmly fixed so that the cassette half is wrapped from both left and right sides, so that vibration is absorbed and tape running is stabilized.
The reference point of the ground line for each circuit related to the audio signal is integrated, and the NEW pure signal ground line is adopted which is separated from power supply ripple and various noise components.
As a result, only pure signal flows through the main ground line, and pure recording and playback characteristics are obtained.
It is equipped with functions such as A-B repeat, index scan, CD peak search and timer Rec & Play.
Model Rating
| Type | Stereo cassette deck |
| Recording system | AC bias (high bias 210 kHz) |
| Heads | Recording : Hard Permalloy (Combination) Recycled : Hard Permalloy (combination) Erase : SENDUST Alloy Chip with Ceramic Guard |
| Motor | Capstan drive motor x1 One reel drive motor Mechanical Assist x1 |
| Wow flutter | ± 0.02% (W · Peak) 0.05%(WRMS) |
| Early winding time | Approximately 90 Seconds (C-60 Tape) |
| Frequency characteristic | Normal : 20 Hz to 18 kHz ± 3 dB Chrome : 20 Hz ~ 19 kHz ± 3 dB Metal : 20 Hz ~ 20 kHz ± 3 dB |
| Distortion factor | 2.0% (315 Hz, 3 rdHD, 250nWb/m, metal) |
| Signal-to-noise ratio | 56 dB (Dolby NR OFF, 250nWb/m, metal) 60dB(Dolby NR OFF) 68dB(Dolby NR B) 76dB(Dolby NR C) |
| Input Sensitivity / Impedance | Line : 100mV/47k Ω |
| Output Level / Impedance | Line : 775mV/1.0k Ω Headphone : 2.3mW/32 Ω |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 22W |
| External dimensions | Width 440x Height 127x Depth 326 mm |
| Weight | 5.4kg |