Audio Database

DR-F3
Commentary

This cassette deck was developed as the top model of the F series.

The mechanism uses a new 3-head mechanism with improved tape running accuracy and head touch.
This mechanism is equipped with a newly developed tension servo sensor to obtain good running performance. In this tension servo sensor, a sensor set between the recording / playback combination head and the erasing head constantly detects the back tension of the tape between the two heads. Minute fluctuations are amplified through the sensor arm and servo bracket, and the pressure force between the erasing head and the erasing head and the pressure post on the opposite side is controlled by the sensor arm and servo bracket. This servo system has an extremely short servo loop and applies direct servo to the tape itself. Therefore, it has an extremely high response and forms a stable tape running system that does not put excessive force on the tape. This eliminates the influence of the tape supply reel in the cassette half, the left side guide roller, and the left side first tape guide, and constantly adjusts the remaining amount of the tape and the tape tension converted by the cassette half.

The basic mechanism of tape travel employs a two motor drive mechanism that completely separates the capstan drive and reel drive mechanisms. The mechanism is driven by an IC logic circuit and two plungers.
In addition, by using two plungers, the movement mechanisms of the pinch roller and the head are made independent. When the recording pause state is set, only the head part touches the tape, and when the recording state is set by pressing the PLAY button, only the pinch roller moves. This head plate mechanism prevents erasure during recording, does not give magnetic flux change to the tape while the head is moving, and also prevents unpleasant noise.

The DR-F3 uses a quartz-locked PLL servo motor for the capstan drive motor in order to obtain more severe constant speed rotation, and a coreless motor for the reel to ensure stable tape travel.

A non-slip reel drive mechanism drive mechanism that takes advantage of the relationship between the rotational speed and torque of the reel motor, eliminating the general mechanical slip mechanism (using friction between felt and metal, etc.) that is installed between the motor and the take-up reel stand in a general cassette deck.
In this mechanism, the voltage of the reel motor is reduced to about 1/5 of the speed when it is fast-forwarded or rewound, and the rotation speed is reduced to about 1/20 to transmit the rotation of the motor to the reel table. Originally, DC motors have characteristics that when the load increases, the rotational speed decreases and the torque increases, and when the load decreases, the opposite phenomenon occurs. This characteristic is used to equalize the winding tape tension and eliminate the slip reduction mechanism.
This eliminates the instability of take-up due to changes in environmental conditions such as temperature and humidity, and improves the durability of the mechanism.

The head section uses a 3-head system consisting of a read / write combination head and an erase head.

An F-ALLOY combination head is used for the recording / reproducing head.
The recording head has a wide gap to maximize the MOL of each tape. The reproducing head has a narrow gap width of approximately 1/5 of the recording gap to obtain a flat frequency characteristic up to high frequencies. In addition, F-ALLOY, which has excellent characteristics of high magnetic flux density, high magnetic permeability, and high wear resistance, achieves high sensitivity and low distortion.
In order to eliminate the coil winding method and core shape are carefully examined in order to eliminate the influence between both recording and playback heads. A shield mask is inserted between both heads to strictly suppress the magnetic field (cross feed) from the recording head to the reproducing head to -78dB.
In addition, by adopting a special core shape, good head touch is obtained, drop-out is reduced and contour effect is suppressed.

A double-gap erase head with an E-shaped core is used for the erase head.
The core of this erasing head is made of a special ferrite material with high saturation magnetic flux density to enhance the erasing effect.

The amplifier section uses an all-DC configuration amplifier with independent recording and playback.
In this amplifier, the condenser between the head and the first stage amplifier is removed to eliminate the deterioration of sound quality in the signal transmission system. In addition, all of the microphone amplifier, recording amplifier, equalizer amplifier, playback amplifier, headphone amplifier, and meter amplifier are composed of DC amplifier units, and ± 2 power supply system is used to drive them. Together with the low-noise differential input push-pull circuit, this amplifier increases the dynamic range and prevents clipping distortion in the signal transmission system.

The bias oscillation circuit adopts a push-pull configuration to improve bias waveform distortion.

The noise reduction system uses a double Dolby system for recording and playback. You can play back Dolby recordings on an after-monitor.

Equipped with a 20 to + 6 dB wide scale VU meter.
It also features three LeD peak level indicators : red (+ 8 dB), yellow (+ 5 dB), and green (0 dB).

Equipped with a 4-stage tape selector with a bias and equalizer linked together.
In addition, the DR-F3 is equipped with a bias fine adjustment mechanism, and the bias can be adjusted by ± 30% for each position by the fine adjustment volume.

It is equipped with an output level control function that can also adjust the volume of headphones.

Equipped with an auto-cue review mechanism that finds out between songs of more than 4 seconds and automatically enters the play state from that position.

Equipped with one touch rec-pause function.

The Rec Mute and Pause buttons are grouped together.
During recording, if you keep pressing the button, it becomes REC MUTE ; if you release it, it becomes PAUSE ; and if you press the PLAY button again, it becomes recording.
When there is no signal, the PAUSE/MUTE LED lights up at approximately one second intervals.

It uses a one touch eject mechanism, and regardless of the operation state of the mechanism, the mechanism automatically stops, releases each operation and ejects.

Equipped with timer recording and playback mechanism.

Remote control terminal is mounted on the front, and operation from a remote place is possible by using an optional remote control unit.

Model Rating
Type Cassette deck
Format 4-track, 2-channel stereo
Heads Recording / Playback : F-ALLOY Combination Head
Erasing : double-gap ferrite head
Motor For Capstan : Quartz Lock PLL DC servo motor x1
For Reel : 1 high-precision coreless motor
Wow and flutter 0.04% wrms or Less (JIS)
Early winding time Approximately 85 seconds (C-60)
Overall signal-to-noise ratio Dolby NR on : 67 dB or more
Dolby Improvement effect against NR off : 5 dB at 1 kHz, 10 dB at 5 kHz or more
Total third harmonic distortion factor normal:0.7%
metal:1.0%
Overall frequency characteristic
(at -20VU recording)
Normal : 25 Hz to 20 kHz (30 Hz to 19 kHz ± 3 dB)
CrO2 : 25 Hz to 21.5 kHz (30 Hz to 20 kHz ± 3 dB)
Metal : 20 Hz to 22 kHz (25 Hz to 21 kHz ± 3 dB)
Crosstalk 65 dB or More (1 kHz)
Input Microphone : 0.35mV/10k Ω unbalanced (suitable for microphones of 10k Ω or less)
Line : 70mV/50k Ω unbalanced
Output Line : 775 mv (at 10k Ω load, input level 200pwb/mm, VR maximum)
Headphones : 1.2 mW (8 Ω - 2k Ω compatible at 8 Ω load)
Pwer 100 VAC, 50Hz/60Hz
Power consumption 25W
External dimensions Width 434x Height 117x Depth 300 mm
Weight 7.0kg
Sold separately : Remote Control Unit RC-55 (¥ 6,000)
Code 3m
External dimensions 38 mm wide x 17 mm high x 120 mm deep
Weight Approx. 160g (including cord)