YAMAHA KX-640
¥ 54,800 (released in 1990)
Commentary
Stereo cassette deck equipped with Dolby HX Pro.
The mechanism uses a closed-loop dual capstan system with two capstan stations on the supply side and the take-up side. In addition, a silent type 3 motor with minimal vibration and noise is fully logic controlled to maintain a constant tension while the tape passes through the head, enabling accurate recording and playback.
The read / write head uses hard permalloy and the erase head uses double-gap ferrite head.
It is equipped with the Dolby HX Pro that automatically adjusts the bias amount according to the strength of the high-frequency level of the recorded signal in order to record with smooth frequency characteristics up to the high-frequency range.
In addition, it is equipped with Yamaha's original bias adjustment, and the bias level can be adjusted within ± 20% of the recording characteristic difference of each tape.
The bias frequency is 210 kHz high bias, which is twice the common 105 kHz, so that the audio signal and bias are sufficiently separated from each other to suppress beat distortion and intermodulation distortion caused by mutual signal interference.
In addition, the recording amplifier uses a constant current drive system, which does not depend on the impedance change of the head due to the signal frequency, and the dynamic margin and current distortion of the recording system are improved by more than 6 dB compared to the conventional system.
Equipped with Yamaha's original play trim function.
Play Trim is a high-frequency tone control that corrects the high-frequency characteristics that have been degraded due to azimuth deviation. By correcting the high-frequency characteristics before decoding Dolby NR, it is possible to reproduce the original sound more faithfully.
As a noise reduction system, Dolby B/C NR is installed.
The power supply section uses a ± power supply that supplies power independently to the mechanical / display system and audio system.
Equipped with a wide-range 19-segment multi-function display of -40dB to + 12 dB.
Equipped with a linear time counter.
Equipped with bidirectional introscan.
Equipped with a front-and-back one track cue function.
Equipped with high-speed quick winding function of 1.5 times speed.
Sound extraction search is available.
Equipped with auto rec mute, rec return, memory stop, and auto tape selector.
It is equipped with recording balance volume and headphone volume.
There are 2 color variations of titanium and black.
Wireless remote control is included.
.JPG)
.JPG)
Model Rating
| Type | Cassette deck |
| Basic form | Closed-loop dual capstan, one way |
| Heads | Recording : hard permalloy head Playing : hard permalloy heads Erasing : double-gap ferrite |
| Bias adjustment | Dolby HX Pro |
| Recording and erasing method | 210 kHz High Bias |
| Motor | For Capstan : DC Servo Motor For Reel : DC Flat Torque Motor For Mechanical Assist : DC Motor |
| Wow flutter | ± 0.08% (W. Peak, EIAJ) 0.05% (W. RMS, JIS) |
| Frequency Response (EIAJ) | 20 Hz to 18 kHz ± 3 dB (normal, -20dB) 20 Hz ~ 19 kHz ± 3 dB (Chrome, -20dB) 20 Hz ~ 21 kHz ± 3 dB (metal, -20dB) |
| Signal-to-noise ratio (EIAJ) | 57 dB or More (NR off) 65 dB or more (Dolby B on) 73 dB or more (Dolby C on) |
| Distortion factor | Not more than 0.8% |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 14W |
| External dimensions | Width 435x Height 122x Depth 273 mm |
| Weight | 4.6kg |
| Attachment | Wireless Remote Control |