The Technics RS-686D top-of-the-line professional portable 3-head cassette deck was introduced in 1977. The RS-686D is light and small but it contains such high-performance parameters as the following: 0.07% (WRMS), 0.18% (DIN) wow & flutter | 3-head configuration | brilliant anti-rolling mechanism | FG Servo DC motor | advanced electronic amplifier circuitry and many other features absent from many non-portable decks. Full tape transport stability is maintained even under the most severe operating conditions. This is achieved by the use of a FG servo-controlled DC motor and the anti-rolling mechanism. This device depends upon the action of a large counter-flywheel which is linked to the main capstan flywheel by the drive belt. This counter-wheel moves in the opposite direction from the capstan flywheel and acts to maintain constant tape speed by cancelling out any outside forces which otherwise would cause a slowdown or increase in tape speed. In addition to the standard erase and record/playback heads the RS-686D is equipped with a third head for monitoring monaurally what is being recorded on the tape. With this feature the user can monitor what is going on the tape to make sure the result is what he desires. This (mono) monitor head is a super permalloy head while the all-important record/playback head is Technics' famed HPF (high pressure ferrite) head. For greater reliability and resistance to wear the frame that holds the components are made of stainless steel while this whole assembly is mounted inside a diecast cabinet. The RS-686D is compatible with normal and chrome tapes and it features Dolby noise reduction and manual record level adjustment (L+R and Master Level) with two needle type VU meters with peak indicators.
Other features include a Mic attenuator switch for avoiding distortion when recording high volume sounds such as rock music, Limiter switch to prevent distortion due to sudden loud sound during live recordings, Low cut filter to cut off frequencies below 200 Hz. Ideal for eliminating wind noise when recording outdoors or for reducing human breathing noise when speaking on microphone. The recorder also features Tape-End Alert-Eye and Silent Auto-Stop. Three minutes before the end of tape, the end-eye will begin blinking. When the tape comes to its end, this light will shine steadily. Also, when the tape ends the motor shuts off automatically but the transport mechanism does not snap back to neutral postion until the user releases it by hand. This system is used so that no sudden noise is produced which could disturb the program or any person making other recordings nearby. The RS-686D is also fully equipped with a 3-way power supply feature. Batteries are used in normal outdoor situations, but when at home, or when using the car, AC mains, and car battery (RP-997 AC adaptor supplied and RP-917 car adaptor optional) should be used. A carrying strap is standard accessory while the RP-9686 leather carrying case can be purchased separately. Technical specifications: Frequency response: 40-14000 Hz normal tape, 40-16000 Hz chrome tape | Signal-to-Noise ration 56 dB Dolby off | Recording time approx. 4 hours with six R-14 dry cell batteries | Dimensions: 243x77x200 mm | Weight: 2.8 kg (without batteries) | Original sale price 1800 DM in Germany.
