Audio Database


AIWA AD-7400
59,800 yen(around the 1977 time)


The stereo cassette deck of the MFR (More Flat Response) series which valued affinity with a tape.

Three steps of bias, three steps of recording equalizers, and two steps of playback equalizers have adopted the independent and switched tape selector, and are pulling out the capability of various tapes. Furthermore, there are most kinds and it is possible to choose a proper bias value with a bias fine-tuning knob to the tape of LH type with which each characteristics differ. The variable range can be adjusted in }10% of range.

Also as opposed to a momentary sound in which 2 step peak indicator which carries out a shop front by +3dB and +7dB other than VU meter is carried and which cannot be followed in VU meter,+ At 3dB, a yellow peak indicator shows a warning level and a red peak indicator shows a distorted level by +7dB.

The 38 pulse FG servomotor is adopted as a motor, and motor speed is controlled so that the power generation frequency from a motor always becomes fixed. Moreover, compared with the conventional motor, speed of response is very quick, and exact and positive speed control can be performed.
Furthermore, the wow and flutter is improved by the use of a capstan and the adoption of a large-sized flywheel or a special-shaped reel axis which pursued straightness and roundness.

The erecting type loading mechanism is adopted as the wearing system of a tape.
Moreover, ejection operation also adopted the oil dumping system original with an Aiwa, and has protected the precise mechanism of the operation feeling of a soft touch, or a tape drive system.

Absence recording and alarm clock playback are possible by carrying the timer standby mechanism and connecting an option timer.
Moreover, in a standby state, since a pinch roller and a capstan are left and set, a burden is not placed on a mechanism as for them.

The input selector which improves sharply the signal to noise ratio at the time of the recording from line-in is carried.
It is possible to send into recording amplifier direct unlike the conventional system which drops the signal from line-in on resistance, and is again amplified with microphone amplifier by this.

The Dolby system which reduces hysteresis noise peculiar to a tape stereo is carried.

The non-contact system by the combination of a Hall device and IC is adopted as an auto stop.

The ferrite guard head of the super-hard ferrite use which was excellent in antiwear quality on the both sides of the core part guard part is adopted as a head.

Quick review cue is adopted as a search mechanism, and if the button of fast forward and rewinding is pushed with recording / playback state, the head of a monkey talk can be pulled out to reliance.

The volume only for playback other than recording volume is carried.

If the player sink terminal is carried and it connects with the record player with the Lec sink terminal of an Aiwa, the pause button of a deck will be canceled simultaneously with the start of a player at the time of record recording.

The tape lighting lamp is carried.


Rating of a mode
Form Stereo cassette deck
Truck form Four trucks [ two ]
Motor D38 pulse FG servomotor
Head Ferrite guard head
Frequency response LH tape: 20Hz - 15kHz (30Hz-13kHz}3dB)
FeCr tape: 20Hz - 17kHz (30Hz-15kHz}3dB)
CrO2 tape: 20Hz - 17kHz (30Hz-15kHz}3dB)
Signal to noise ratio 65dB (Dolby NR on, FeCr, peak level)
Wow and flutter 0.05%(WRMS)
Magnetic tape velocity 4.8cm/s
Fast forward, rewinding time 90 seconds (C-60)
Recording system AC bias
Elimination system AC elimination
Input sensitivity/impedance Line: More than 50mV / 50kohm
Din: 0.1mV/3kohm
Mic: 0.3mV/200 - 10kohm conformity
An Output voltage/impedance Line: Below 0.775V/10kohm
Din: Below 0.775V/10kohm
Headphone: 3.4mW/eight ohms
The semiconductor used Transistor: 34 pieces
ID: Three pieces
Diode: 22 pieces
LED: Two pieces
Power source AC100V, 50Hz/60Hz
Power consumption 10W
Dimensions Width 420x height 150x depth of 300mm
Weight 7.5kg
Attachment Head cleaning stick
Connecting cord