¥ 225,000 (released in 1978)
This is a stereo tape deck that inherits the technology of the DH-710F/DH-610S and newly adopts a direct tension servo.
A direct drive capstan system is adopted for the mechanism.
The capstan motor uses an outer rotor type AC servo motor with low vibration and smooth rotation. In addition, the capstan motor uses a speed servo system with a high-precision recording detection method to ensure high performance.
The capstan diameter and accuracy (roundness) meet broadcasting station standards, and durability and reliability are ensured by applying a hard chromium treatment.
Equipped with a newly developed direct tension servo.
In this mechanism, the servo arm constantly detects gradual changes in back tension caused by changes in the feed radius on the feed reel side, uneven winding of the tape, and sudden changes in tape tension caused by eccentricity of the reel. The movement of the arm is transmitted directly to the brake band wound around the brake drum for approximately 1 1/4 (approximately 450 degrees) to keep the tape tension constant.
For example, when the tape tension is increased, the servo arm moves, the brake band is loosened, the brake pressure is reduced, and feedback acts to keep the tape tension constant. The backspring compensates for changes in the weight of the reel and tape, and changes in the friction coefficient between the brake drum and the brake band due to environmental conditions.
This mechanism has the same performance as an electronic tension servo, and we have developed and adopted new materials for brake shoes that are not affected by environmental conditions and aging.
The direct tension servo does not damage the tape because it is extremely fast from tension detection to response, the vibration generated by the motor is eliminated because voltage is not applied to the supply side reel motor, and the start-up characteristic of the tape is improved because impedance rollers are not required.
Equipped with brake servo.
This mechanism not only facilitates tape setting because the servo is activated when the tape is hooked on the roller of the servo arm, but also operates the back-tension servo during running or until the tape stops completely.
The servo effect can also be achieved while the power is turned off.
By installing a guide roller and scrape filter, minute vibration of the tape is efficiently suppressed, and sound quality with less modulation noise is obtained.
The drive mechanism, head, and amplifier are all mounted on a frame made of all-aluminum casting, improving machining accuracy and preventing the entire mechanism from getting out of order, greatly contributing to the improvement of overall characteristics.
By adopting a high hardness Permalloy type narrow gap head, the frequency characteristics are improved.
In addition, a special shape is adopted in order to reduce the shape effect that causes the expansion of the low frequency range.
The power supply for the amplifier section is a high voltage (35 v). In particular, in order to eliminate sound distortion and clip in the recording amplifier, the dynamic margin is provided with a sufficient margin like a professional model, and the margin is provided with more than 10 dB above the saturation level of the tape, which is more than 30 dB above the standard recording level.
In addition, the playback amplifier is a 3-stage direct connection type to improve the quality of the playback sound.
The microphone input consists of a microphone amplifier with a high dynamic margin of 55 dB relative to the reference recording input level and a microphone attenuator with a 12 dB attenuation.
The mixing circuit of the line and microphone contains the same mixing amplifier as the DH-710F/610S.
Using a continuously variable bias / equalizer, you can set the bias amount and recording equalizer characteristics to the optimum values according to the tape you are using.
The operation control part is a direct function using IC logic.
This allows you to move from any operation mode to the next mode without going through a stop. Inside the deck, it automatically checks that the tape has stopped completely before moving to the next operation, so tape safety is not affected.
Equipped with Rec mute/Pause mechanism.
If you want to create a white space between songs during recording, you can press and hold the Pause button to activate the Rec mute mechanism and create an unrecorded portion for any length of time, which is effective for editing the recording. After that, simply release the Pause button to return to the normal pause (recording standby).
An optical sensor type non-contact safety switch has been adopted for the winding side tension arm to improve reliability.
Timer recording and playback mechanism is installed.
Remote control is possible.
You can use headphones from low impedance type to high impedance type.
It can be used either horizontally or vertically.
|Track format||2-track 2-channel recording and playback|
|Heads||Recording and playing : hard permalloy heads
Erasing : ferrite heads
|Tape Speed||38cm/s, 19cm/s|
|Speed deviation||Within ± 0.5%|
|Motor used||For Capstan : 6 Pole Outer Rotor Type AC Servo Motor
For Reel : 2 x 6 Pole Eddy Current Motors
|Capstan drive system||Direct drive by AC servo motor|
|Tension servo system||Direct back tension servo|
|Wow flutter||38cm/s : 0.025% Wrms or less
19cm/s : 0.03% wrms or less
|Reel Diameter Used||Maximum No. 10 (Type 26)|
|Quick winding time (with No. 10 reel, 740m tape)||Approximately 2 minutes and 30 seconds|
|Recording bias||Frequency : about 180 kHz
Bias Amount : ± 40% Adjustable
|Recording and playback compensation characteristic||NAB standard (recording guarantee can be adjusted depending on the tape used)|
|Overall SN ratio (hearing correction JISA)||66 dB or more for maximum recording level (514pWb/mm)
58 dB or more (for reference recording level (200pWb/mm))
|Total Distortion Rate Characteristics (1 khz Reference Level)||Total harmonic distortion rate : 0.5% or less
Third harmonic distortion factor (using Scotch #250) : 0.1% or less
|Overall frequency characteristic||38cm/s : 30 Hz to 30 kHz ± 2 dB
19cm/s : 20 Hz to 25 kHz ± 2 dB
|Channel Separation (1 kHz)||50 dB or more|
|Input (0 dB : 0.775 V)||Mic : 0.2 mV (-72dB, Att 0 dB) / 50k Ω unbalanced
Line : 62 mV (-22dB) / 100k Ω unbalanced
|Power (reference power level (0 VU))||Line : 0.775 V (0 dBm) / 100 Ω or less, Applicable load : 600 Ω or more
Mic : 8 Ω or more compatible
|Remote control terminal||Yes|
|Pwer||100 VAC, 50Hz/60Hz|
|External dimensions||Width 455x Height 475x Depth 210 mm|
|Attachment||Reel 10 x1
No. 10 Reel Clamper x2
No. 7 Reel Clamper x2
Reel Height Adjustment Sheet x2
Two parallel pin cords
Socket Wrench x1 for M3