Sansui 1000A

 The latest power tubes and push-pull output amplifier combine to give the 1000A a distortionless output up to 80 watts and maximum music power of 100 watts. The head amplifier utilizes a transistor circuit for a gain three times larger and a S/N ratio far superior to conventional tube-type amplifiers. Power bandwidth range is from 20 to 20,000 Hz and the distortion factor a low 1% at 1khz. A two-stage noise limiter, muting circuit, advanced switching matrix and  stereo indicator help to put the 1000A into the studio class of stereo equipment.

Features:

The 7591 power tubes operate in class AB, Push-pull )fixed bias) for high fidelity reproduction. Their combined maximum out put is limited to 100 Watts. Total harmonic distortion at 1 kHz is 0,8%,and even at very low frequency where it is extremely difficult to minimize harmonic distortion, the distortion is limited to not more than 1%. This is quite a feat for a 100 watts amplifier.

Another remarkable feature is the damping factor of 9,5, a figure which is lower than that of triode power tubes coupled in P.P.. This is way bass sounds come out with such clarity.

New 7591 P.P. produces 80 W without distortion

NFB used in all amplifier circuits, from pre-amplifier to power amplifier. The low distortion of the power amplifier is meaninglass if the pre-amplifier generates distortion. This 1000A uses a three-stage  amplifier circuit in its intermediate or control amplifier - unlike conventional one-stage control amplifiers - and has all its circuits in a single negative-feedback loop. These make 1000A free from noise and distortion.

Super precision transistor pre-amplifier eliminates hum and noise.

The exclusive Sansui four-transistor pre-amplifier, which features a transistor circuit factor of 4-as compared with conventional 5 dB, eliminates hum and noise, the enemy of high-fidelity reproduction. The amplifier has a much netter S/N ratio and a gain three times larger than vacuum tube amplifer.

 Highly sensitive two-stage RF amplifier using two Nuvistors a three gang variable condenser.

The 1000A has an extremely compact high gain RF amplifier for FM, which uses two cascode-coupled, low noise Nuvistor tubes with a three-gang variable condenser.

Therefore the tuner outperforms conventional single-stage grounded grid RF amplifiers by 10 dB in amplification and assures stable, high-selectivity, high-fidelity reception.

Double-limiter shuts out noise.

The 1000A is equipped with a two-stage noise limiter, which works effectively even where the field intensity is weak. It reliably eliminates a wide variety of noise such as annoying ignition sounds and other interferences.

Muting switch supresses noise during channel selection.

Unlike conventional EM receivers, which produce loud noise in the absence of input because their limiters require a certain level of input voltage to perform their noise-limiting function, the 1000A produces no noise even when not tuned to any station. This is because it has a built-in "Muting switch" (squelch circuit) which disconnects the audio amplifier stage automatically when tuner input drops below a certain level.

Three-dimension performance possible with center-channel output terminal.

The 1000A has an output terminal for the center-channel amplifier. Connect it to a monaural amplifier, and enjoy a three-dimansion effect.

Each channel can be operated independ ently (equipped with double-knob conrol)

Each channel has an independent tone control for bass and treble. This makes fine adjustment possible.

 Equipped with advanced high-performance accessory circuits.

This amplifier is equipped with various advanced accessory circuits such as loudness control, low and high filters, tape monitor, presence, and headphone jack.

Amazing channel separation of 35 dB and more ensured by advanced FM multiplex circuit. The adoption of the most advanced switching matrix method for the multiplex circuit has amazingly improved the performance of the 1000A. The amplifier has a full-fledged AFC, which can be switched off if you like.

The  AFC enables you to enjoy a stabilized reception of FM broadcast for many hours once you have  tuned in.

Easy-to-see FM multiplex stereo indicator

The FM multiplex stereo indicator actuated helps you tune in FM stereo stations easily and reliably.

Single-stsge RF amplifier with three-gang vaiable condenser for AM

The addition of a single-stage RF amplifier to the AM tuner has improved its sensitivity remarkably. This makes it particulary useful for DX reception.

Moreover, it has such an excellent image ratio that no beat is produced between your ststion and another neighboring station.

Built-in, high-sensitivity ferrite antenna

The built-in, high-sensitivity ferrite antenna adds to your listening pleasure by reducing noise to less than that of conventional tuners.

Specifications:

Audio Section

Music Power Output:  100 watts total

RMS Music Power:  40 + 40 watts

Harmonic Distortion:  1% at 1 kHz at RMS rated power

Frequency Response:  20 - 20,000 Hz ±1 dB (Over-all)

Frequency Power Amp Section:  10 - 80,000 Hz ±1 dB

Hum and Noise (IHFM):

High Level Input :  90 dB below rated output

Low Level Input :  70 dB below rated output

Channel Separation:  55 dB at 1 kHz (phono)

Input Sensitivity (rated output):

Phono 1 :  0,5 mV (by using extra matching transformers)

Phono 2 :  1,5 mV

Tape Head (NAB) :  1,5 mV

Mic :  1,8 mV

Aux 1 :  65 mV

Aux 2 :  110 mV

Damping Factor:  9,5 at 16 Ω, 1 kHz

Output Impedance:  8 - 16 Ω

Controls and Switches:

Bass Control :  26 dB total variation at 50 Hz

Treble Control :  21 dB total variation at 10 kHz

Loudness Control:  50 Hz + 7,5 dB; 10 kHz + 7,5 dB

Volume Control at -30 dB

Low Filter:  -10 dB at 50 Hz

High Filter:  -11 dB at 10 kHz

Presence Switch:  6 dB 50 Hz

Mode Selector Switch:

Stereo Rev;  Stereo Nor;  Mono L;  Mono R;  mono L + R

Other Special Features:

Direct Tape Monitor, Headphone Jack, Center-channel output for connection to a third amplifier, DIN Connector

FM Section

Frequency Range:  88 - 108 MHz

Sensitivity:  1,0 µV for 20 dB quieting at 100% mod.;  1,8 µV (IHFM Standard)

FM Stereo Separation:  35 dB at 1 kHz

FM Distortion:  less than 1%

FM Stereo Frequency Response:  50 - 15,000 Hz ±1 dB

Other Special Features:

Muting; Two Nuvistor cascode front-end; Meter tuning; Double limiter; FM stereo indicator; Heavy flywheel tuning; Solid state AFC

AM Section

Frequency Range:  535 - 1605 kHz

IF Selectivity:  6 kHz, 12 kHz  -3 dB

Sensitivity:  5 µV (IHFM standard)

iF Frequency:  455 kHz

Semiconductors:

Tubes: 2 x 6CW4 (Nuvistor); 3 x 6BA6 9EF-93); 1 x 68E6(EK-90); 2 x 6AU6(EF-94); 3 x 6AQ8(ECC-85); 2 x 12AX7(ECC-83); 1 X 12AU7(ECC-82); 1 x 6BL8; 2 x 6AN8; 4 x 7591

Transitors: 4 x 25B-381

Diodes: 12 x OA-91; 1 x MA-301; 2 x SD-1B; 1 x TC-02P

Power Requirements:  100,117, 240 volts 50/60 Hz

Power Consumption:  180 VA

Dimensions (W x H x D):  17-7/8" x 5-1/2" x 14-3/16"

Weight:  44,7 lbs