What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

Akai AS-1080 DB

 4-Channel Stereo Receiver
4-channel Dolby recording and payback  with an ordinary tape deck for first time in audio history. This is only one of the many outstanding features of the new AS-1080 DB. This new 4/2 channel compatible receiver incorporates all the latest engineering techniques and offers performance quality to match anything on the market todey. Yet the cost of this deluxe model is far below what you would expect to pay for such quality. Robust 3mm thick aluminium front panel. Easy-to-operate precise controls. Designed for efficient operation of present and future audio capability.
 All-Stage Direct Coupled OCL Pure Complementary Power Amplifier
40 watts per channel continous power output (80 watts per channel at 2-Ch power Doubler), minimum RMS at 8 ohms load impedance with no more than 0,2% distortion. These outstanding specifications are the result of employing an all-stage direct-coupled OCL pure complementary 4 Power IC circuit in the all important power section.

Power Transistor Protection Circuit
A protection circuit is activated in case of a short caused by a wrong speaker connection or when input is excessive to protect the power transistors. Further, this circuit cancels the irritating speaker shock noise when the power switch is turned On or Off

Varied 4-channel operation includes Dolby 4-channel performance (a first in the field of audio)
This 4-channel / 2-channel compatible unit, in addition to regular and discrete stereo, SQ Full Logic and Matrix 4-channel stereo, and CD-4 capability, also features 4-channel Dolby recording and playback with an ordinary 4-CH tape deck.

SQ Full Logic Decoder Circuit
The SQ Full Logic decoder of this model is a superior Front/Back Logic wave matching circuit employing a 6-pole phase shifter for excellent front and rear channel separation.  3 advanced large scale Sony ICs.  SQ Indicator lamp.

Matrix Decoder Circuit
Facilitates playback of matrix encoded phonograph records.
 CD-4 Demodulator Circuit and Separation Adjust
A built-in CD-4 demodulator circuit and CD-4 Separation Adjusters facilitate easy playback of CD-4 records. Front panel CD-4 indicator Lamp. CD-4 test record included in standard accessories.

Four separate Dolby Circuits
A separate Dolby Circuit for each channel enables 4-channel Dolby Recording and Playback with an ordinary 4-channel tape recorder or tape deck for the first time in audio history.

Dolby Operation
The Dolby System of this model facilitates recording and playback with an ordinary 4-channel tape recorder or tape deck. Precise Dolby Controls, a Dolby Level Meter Switch, and Dolby Level Adjustment Tape (included in the standard accessories) enable easy and precise Dolby System level adjustment, 40channel or 2-channel Dolby recording and playback, 4-channel or 2-channel Dolby Dubbing (Dolby recording from ordinary tape playback)from Tape 1 to Tape 2 System, and Dolby FM broadcast reception are among the outstanding Dolby capabilities of this model.

Two compelete 4-channel Tape Deck Connections for varied recording and Dubbing techniques.
Multiple Source Selector, Tape Monitor, and Mode Switch positions and two complete tape systems for a plethora of 2-channel or 4-channel recording and dubbing techniques. Use Tape 1 and tape 2 systems separately or simultaneously. Easy dubbing to and from Tape1 and tape 2 Systems. Also equipped with two complete 4-channel speaker connections.

Two Channel Power Doubler
Setting the Speaker Switch to 2-Ch Power Doubler switches the amplifiers to BTL for all available power in 2-channel mode. Further, transition is smoothe with no irritating speaker noise.

Up-to-Date High Efficiency IC Circuitry in FM IF Section
This totally new up-to-date element is comprised of a 6-stage limiter circuit, a detection circuit, and several auxiliary circuits and does the work of 213 separate parts using parts available to date. Namely, it would require 100 transistors, 84 resistors, 25 dides and 4 condensers to accomplish the same thing. Further, because the detection circuit employs "Quadrature" detection, excellent linearity and low distortion is attained over an exceptionally wide frequency range.

PLL  MPX Section for Good Separation and Low Distortion
This model features the new PLL (Phase Lock Loop) circuit which locks the 19 kHz FM pilot signal phase to the phase of the 38 kHz switching signal for complete stability. Separation better than 40 dB. Less than 0,4% THD.

Automatic FM Center Tuning and FM Mute Switch
Perfect center tuning is always attained. With AFC (Automatic Frequency Control), it is not necessary to tune to exact FM center frequency. Simply bring the needle within the FM center scale of the meter and perfect center tuning is automatically of fluctuation in power supply voltage or temperature. An FM Mute Switch enables the operator to effectively cut noise originating prior to antenna input.

Large Balanced Flywheel Tuning
Large balanced flywheel tuning and superior FM and Am circuitry provides smooth and easy "power steering" tuning and top FM and Am reception.

Loudness Circuit for Balanced Sound at Low Volume
Boosts bass and treble response for balanced sound at low volume

High and Low Filter Switches
Eliminates high and low frequency disturbances for clearer playback

4-Channel Remote Control Balance
A rear panel Remote Control Jack accomodates AKAI optional accessory Remote Control Unit RC-4CH for remote control of front/rear and left/right speaker balance and volume

FM 4-CH Output Terminal
Equipped with rear panel FM 4-channel output terminal for connection of an adapter for future FM 4-CH broadcast reception.

 Other Features
Two full speaker systems feature easy push button connectionn.
300 Ω and 75 Ω antenna terminals with distance/local switch plus AM bar antenna.
Separate front and rear channel Bass and Treble controls for perfect tone control.
Front and rear channel headphone jacks.

Amplifier Section
Continuous Power Output 4-channels driven:
40 watts per channel, min. RMS, at 8 Ω from 20 to 20,000 Hz, with no more than 0,2% THD
4 x 50 watts into 8 Ω at 1 kHz with no more than 0,2% THD
Continuous Power Output 2-channel driven (Power Doubler ON):
80 watts per channel,min.RMS at 8 Ω from 20 to 20,000 Hz, with no more than 0,2% THD
2 x 100 watts into 8 Ω at 1 kHz with no more than 0,2% THD
Power Bandwidth (IHF):  10 Hz to 60,000 Hz / 8 Ω (distortion within 0,2%)
Input Sensitivity:
Phono : 3 mV/ 47 k Ω (CD-4 1,5 mV/ 47 k Ω)
AUX : 160 mV/47 k Ω
Tape 1 & 2 : 160 mV/47 k Ω
Signal-to-Noise Ratio (IHF): 
Phono : Better than 80 dB
AUX : Better than 90 dB
Channel Separation (IHF):
Phono :  Better than 50 dB (at 1kHz)
Equalizer: RIAA Standard ± 1 dB (Phono)
Tone Control
Bass : ±10 dB at 100 Hz
Treble : ±10 dB at 10 kHz
Loudness Control:  +9 dB at 100 Hz,  +4 dB at 10 kHz (Volume Control at -30 dB position)
High : -6 dB at 10 kHz
Low : -10 dB at 50 Hz
Dolby System:  Dolby "B" processor
Dolby Tone:  400 Hz / Rec. Out, PIN 150 mV
FM Tuner Section
Frequency Range:  88 MHz to 108 MHz
Sensitivity (IHF):  1,9 µV
Capture Ratio (IHF):  1.0 dB
Selectivity (IHF):  Better than 70 dB at 98 MHz
Signal-to-Noise Ratio:  Better than 70 dB
Image Rejection:  better than 75 dB at 98 MHz
IF Rejection:  Better than 90 dB at 98 MHz
Spurious Rejection:  better tham 80 dB at 98 MHz
Harmonic Distortion
Monaural : less than 0,2%
Stereo : less than 0,4%
FM Stereo Separation:  Better than 40 dB (1kHz)
FM Muting:  Variable (3 to 300 µV) ON - OFF
Antenna Input Impedance: 
Balanced : 300 Ω
Unbalanced : 75 Ω
AM Tuner Section
Frequency Range:  535 kHz to 1,605 kHz
Sensitivity (IHF): 
200 µV/m (Bar antenna)
5 µV (External antenna)
Image Rejection:  Better than 55 dB at 1,000 kHz
IF Rejection:  Better than 45 dB at 1,000 kHz
Selectivity (IHF):  better than 30 dB at 1,000 kHz
AM Distortion:  Less than 0,6%
Signal-to-Noise ratio:  Better than 50 dB
General Section
Semiconductors:  1 FET, 90 Transistors, 68 Diodes, 18 ICs
Power Requirement:  110 - 120 V, 220 - 240 V (Switchable) 50/60 Hz
Dimensions (W x H x D):  520 x 182 x 409 mm  (20,5" x 7,2" x 16,1")
Weight:  19,3 kg (42,5 lbs)

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