DENON DR-F8

Commentary

This is a stereo cassette deck with a direct-drive mechanism that enhances the completion of the entire tape drive system.

We have adopted a flat twin DD motor for the capstan drive motor.
This motor is a flat-faced DD motor. The flywheel itself serves as a rotor, and DENON's unique symmetrical arrangement of stator coils is adopted. This system consists of a pair of stator coils facing each other, another pair of stator coils electrically offset by 90 degrees, and a Hall element that controls the current of the coils. This system solves the torque characteristics required to obtain good head touch in a 3-head machine and the problem of capstan vibration (center shake). In addition, there are no brushes, slots, or cores that affect rotational accuracy or noise problems, and only the motor bearing is mechanically worn. This improves the durability of the motor itself.

The DR-F8 uses a PLL (Phase Locked Loop) in the motor servo circuit to further improve rotation accuracy and control the change of rotation (temperature drift) in response to temperature change in a severe manner to enhance the completeness.

A unique non-slip reel drive system is adopted.
By utilizing the characteristics of the relationship between the rotational speed and torque of the reel motor, this method keeps the winding torque constant at all times, eliminating the problem of tape winding. This eliminates the mechanical slip mechanism (using friction between felt and metals) between the motor and the take-up reel stand, eliminating the fluctuation of the winding force due to changes in environmental conditions such as temperature and moisture, eliminating the drop-out caused by uneven winding, and the deterioration of wow flutter and phase characteristics.

Equipped with the Tension Servo Sensor II, which is an improved version of the Tension Servo Sensor, a unique servo mechanism. By expanding the servo area, the Tension Servo Sensor II achieves sufficient follow-up performance against large and sudden fluctuations in tape tension.
This servomechanism has an extremely short servo loop and directly applies servo to the tape itself, so it has a high response and does not put too much stress on the tape. This eliminates the influence of the structure of the cassette half, stabilizes the back tension that changes depending on the remaining amount of tape, and achieves good head touch.

An M & X combination head is used for the recording / reproducing head.
The recording head is designed to maximize the MOL of each tape. The reproducing head is designed to have a narrow gap of approximately 1/5 of the recording gap in order to obtain a flat frequency characteristic up to the high-frequency range. In addition to minimizing the azimuth deviation of the A/B plane of the tape by precise assembly technology, the magnetic field (cross feed) from the recording head to the reproducing head is also completely suppressed.

The erasing head uses a double-gap ferrite head with an E-shaped core that is compatible with the high retention force and high residual magnetic flux density of metal tapes.

In the amplifier section, the condenser between the head and the first stage amplifier is eliminated, and all DC amplifiers are used up to the last stage.
With particular emphasis on clipping distortion in transmission systems, the equalizer amplifier uses a low-noise differential input push-pull circuit and a ± 2 high-voltage power supply system to expand the dynamic range. The DR-F8 uses an independent power supply system to further stabilize the circuit.
The bias circuit has a push-pull configuration to improve the bias waveform distortion and at the same time obtain sufficient erase current.

Equipped with FTS (FTS (Flat Tuning System), the bias amount is automatically set according to the characteristics of each tape.
FTS first adjusts the sensitivity so that the recording input and playback output are equal, then automatically adjusts the bias so that the mid-range and high-range characteristics become flat, and then stores the data after correcting the sensitivity. After this automatic adjustment is completed, the tape is wound back to just before the leader tape and stopped. This takes about five seconds. If a dropout occurs during the automatic adjustment, the operation is repeated.

Equipped with Dolby B Type and Dolby C Type as noise reduction system.
In addition, by adopting the double Dolby system, it is possible to confirm the Dolby effect when monitoring simultaneous playback.

Equipped with MPX filter switch to prevent malfunction of Dolby system.

Feather touch control by IC circuit is adopted for the operation system of the tape running.
Timing control is also considered in this circuit to prevent overstretching of the tape.

It is equipped with the output level control which can adjust the volume of the headphone.

Equipped with a one touch rec pause function, recording standby can be set just by pressing the REC button.

The Rec Mute and Pause buttons are combined into one to improve operability.

Equipped with one touch eject function, the mechanism is released and ejected just by pressing the eject button even if the mechanism is in operation state.

Equipped with a timer recording / playback mechanism capable of intermittent recording.

Gold-plated terminals are used for input / output terminals.

Wired Remote Controller RC-57 sold separately can be used.

Model Rating

Type	Cassette deck
Track system	4-track 2-channel stereo
Tape selector	Normal, CrO2, Metal
Heads	Recording : M & X Combination Head Erasing : double-gap ferrite heads
Motor	For Capstan : Quartz PLL Flat Twin DD Servo Motor For Reel : DC Motor
Wow and flutter	0.025%W.rms(JIS)
Early winding time	Approximately 90 seconds (C-60)
Overall frequency characteristic	Metal tape : 20 Hz to 22 kHz (25 Hz to 21 kHz ± 3 dB)
Overall signal-to-noise ratio	Dolby CNRon : 73 dB or more (CCIR/ARM measurement method for 3% THD level)
Input terminal	Mic : 0.35mV/10k Ω Unbalanced (suitable for microphones of 10k Ω or less) Line : 77.5mV/50k Ω Unbalanced
Output Terminal (Vol. max)	Line : 775mV/10k Ω Unbalanced Headphone : 1.2 mW (8 Ω load, suitable for 8 Ω ~ 2k Ω headphones)
Pwer	100 VAC, 50Hz/60Hz
Power consumption	34W
External dimensions	Width 434x Height 115x Depth 320 mm
Weight	7.5kg
Sold separately : Remote Control Unit RC-57 (¥ 6,000)
Cord length	5m
External dimensions	38 mm wide x 17 mm high x 120 mm deep
Weight	Approx. 160g (including cord)