Technics RS-690U
¥ 298,000 (around 1976)
Commentary
This is a stereo cassette deck in which the transport section and amplifier section are separated, and the performance of each section is pursued to the utmost.
The mechanism uses a closed loop double capstan system with a DD motor.
This system uses a 3-motor system that uses dedicated motors for FF and REW respectively, ensuring stable tape running, reliability and durability.
A 3-head system using an HPF head is adopted for the head part.
Equipped with a peak meter conforming to DIN standard.
The response speed of this meter is close to 10 msec / -1dB and 3 msec / -4dB, and the recovery time is set slowly (650 msec) so that level setting can be done easily.
It is equipped with a full-scale bias and equalization adjustment function similar to the open-reel professional tape deck, and an oscillator which oscillates the reference signal for adjustment.
It is equipped with a remaining meter that shows the remaining time of the tape.
This meter detects voltage changes due to rotational speed from the reel motor on the supply reel side, and can accurately check the remaining amount of tape.
For operation switching of the mechanism, pure electronic control using IC and switching transistor is adopted.
The keyboard switches used in computers and other devices are used for operation buttons.
Equipped with a Dolby NR system as a noise reduction system.
In addition, a calibration system is installed to fully compensate for the sensitivity of the tape.
The recording amplifier section pursues a dynamic range, ensuring 55 dB linearity with a sensitivity of -72dB.
The playback amplifier achieves an SN ratio of -132dB (input conversion).
Equipped with a 2 dB-step detent volume.
Standard rack size dimensions are adopted.
Model Rating
Type | Stereo cassette deck |
Head configuration | For Recording : HPF For playback : HPF For Erase : Double Gap Ferrite |
Motor used | 1 DD Motor Two coreless motors |
Frequency characteristic | Normal : 20 Hz to 18 kHz CrO2 : 20 Hz to 20 kHz |
Signal-to-noise ratio | Dolby out:55dB Dolby in : 5 kHz or more, 10 dB improvement |
Wow flutter | 0.04%(WRMS) |
Input Sensitivity / Impedance | Mic : 0.25 mV (-72dB) / 400 Ω ~ 20k Ω Line in:60mV(-24dB) |
Output Level / Impedance | Line out : 420 mv (-7.5 db) / 47k Ω or more Headphone : 0 ~ 900mV/8 ohm |
Semiconductor used | Transistor : 141 units FET : 6 IC : 6 Diode : 94 units Other semiconductors : 16 pcs |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption | Approx. 40W |
External dimensions | Amplifier Part : Width 480x Height 173x Depth 375 mm Transport Part : Width 480x Height 193x Depth 375 mm |
Weight | Amplifier Section : Approx. 8.5 kg Transport Part : About 13.5 kg |
Sold Separately | Wireless Remote Control Unit RP 070 (¥ 30,000) |