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





Marantz SR-320L

 SR-320 AM/FM Stereo Receiver (1982).
Flywheel tuning system with LED tuning indicators. Bass and treble tone controls. Low filter (50 Hz  - 6 dB/oct). Tape copy 2 to 1 with ape monitor 1. speaker switching between system 1 and 2. low Transient Intermodulation Distortion (TIM) design to eliminate  intermodulation distortion.  Pilot canceller for clean FM reception.
The SR-320 is also available with long waves as SR-320L
Specifications
Amplifier Section
Power Rated Output  per Channel:
RMS 1 kHz at 8 Ω :  30 W
RMS 1 kHz at 4 Ω :  33 W
Dynamic Power (IHF)
At 8 Ω :  35 W
At 4 Ω :  55 W
Total Harmonic Distortion (RMS at 8 Ω):  0,05%
Damping Factor (1 kHz, 8 Ω):  50
Frequency Response:
Phono :  RIAA standard ±2 dB
Aux :  16 - 30,000 Hz ±1 dB
Signal-to-Noise Ratio:
Phono  :  85 dB
Input Sensitivity/Impedance:
Phono :  2,8 mV/47 k Ω
Aux :  160 mV/25 k Ω
FM Tuner Section
Frequency Range:  87,5 - 108 MHz
Sensitivity:
DIN Mono (S/N 26 dB - 300 Ω) :  2,2 µV
DIN Stereo (S/N 46 dB - 300 Ω) :  80 µV
Selectivity Adjacent Channel 98 MHz DIN:  60 dB
Signal-to-Noise Ratio 98 MHz : 
Unweighted [Mono/Stereo] :  70 dB / 60 dB
Weighted [Mono / Stereo] :  75 dB / 62 dB
MW Tuner Section
Frequency Range :  525 - 1605 kHz
Sensitivity (20 dB S/N 30% mod. 1 MHz):  30 µV
Selectivity:  30 dB
LW Tuner Section
Frequency Range :  150 - 350 kHz
Sensitivity (20 dB S/N 30%, 250 kHz):  200 µV
Power Requirements:  110/120/220/240 V, 50/60 Hz
Dimensions (W x Hx D):  416 x 100 x 190 mm

Weight:  5,2 kg

Marantz TT-221

 Marantz TT-221 (1982)
Direct drive semi-automatic turntable. Dual suspension. Front panel controls including cueing. Low mass straight tonearm fitted with matching high performance cartridge. Speed control with stroboscope. Reject knob. Heavy aluminium diecast platter.

Specifications
Drive:  Direct-drive
Motor Type:  FG Servo
Speeds:  33 and 45 rpm
Wow and Flutter: 
WRMS :  0,03%
DIN :  0,055%
Rumble DIN:  70 dB
Power Requirement:  110-220 / 220-240 V, 50/60 Hz
Dimensions (W x H x D):  416 x 115 x 385 mm
Weight:  5,3 kg

Marantz ST-320

 Marantz ST-320  (1982)
AM/FM analogue tuner. Illuminated dial window. 3 LED's for optimal tuning and 5 LED's for signal strength indication. Pilot frequency rejection filter. AM detachasble loop antenna. 
 This model is also available with long waves as ST 320L.
Specifications
FM Section
Frequency Range:  87,5 - 108 MHz
Sensitivity:
DIN Mono (S/N 26 dB) :  1,8 µV (300 Ω)
DIN Stereo (S/N 46 dB) :  60 µV (300 Ω)
Selectivity Adjacent Channel 98 MHz:  65 dB
Image Frequency Rejection:  55 dB
Intermediate Frequency Rejection:  80 dB
Spurious Response:  85 dB
AM Suppression:  47 dB
Signal-to-Noise Ratio (DIN)
Unweighted [Mono/Stereo] :  70 / 60 dB
Weighted [Mono/Stereo] :  70 / 65 dB
Pilot Frequency relection 19 kHz :  62 dB
Carrier Frequency Rejection 38 kHz :  65 dB
Total Harmonic Distortion:
Mono :  0,25%
Stereo :  0,4%
Frequency Response :  30 Hz - 15 kHz (+0 -1 dB)
Stereo Separation:  40 dB
Channel Balance:  0,2 dB
MW Section
Frequency Range:  522 - 1611 kHz
Sensitivity (S/N 20 dB 30% mod. 1 MHz):  10 µV
Selectivity (1 MHz ±9 kHz):  30 dB
Image Rejection at 1 MHz:  45 dB
Intermodulation Frequency Rejection at 1 MHz:  40 dB
Signal-to-Noise Ratio at 1 MHz:  50 dB
Total Harmonic Distortion at 1 MHz:  0,3%
LW Section
Frequency Range:  153 - 360 kHz
Sensitivity (S/N 20 dB 30% mod. 250 kHz):  90 µV
Image Rejection at 250 kHz:  30 dB
Intermodulation Frequency Rejection at 250 kHz:  60 dB
Signal-to-Noise Ratio at 250 kHz:  48 dB
Power Requirement:  110-220 / 220-240 V, 50/60 Hz
Dimensions (W x H x D):  416 x 55 x 190 mm
Weight:  2,4 kg

Marantz SD-330

 Soft touch tape transport mechanism. Dolby "C" and Dolby "B" noise reduction systems. LED meters for level setting. Timer standby. Line and Mic selector switch. Record mute. Convenient sliding level controls. Normal, CrO₂ and Metal tape selector.
Specifications
Style:  Front load
Tape Drive System:  Single Capstan Drive
Cartridge:  Philips type compact cassette
Track System:  Compatible Stereo 4-track 2-channel
Tape Speed:  4,75 cm/sec.
Heads:  2 head system
Rec/Playback :  Super Hard Metal Alloy
Erase :  Dual gap Ferrite
Motor:  1 Motor System Dc Servo Motor
Overall Frequency Response (at -20 dB):
Normal Tape :  30 Hz - 16 kHz
CrO₂ Tape :  30 Hz - 17 kHz
Metal Tape :  30 Hz - 18 kHz
Signal-to-Noise Ratio:
Dolby C9On):  70 dB
Dolby (Off):   56 dB
Wow and Flutter (DIN WTD):  0,15%
Outputs:
Line Level/Impedance :  600 mV/50 k Ω
Headphone Level/Impedance :  50 mV/ 50 Ω
Input ( Level at 0 VU):
Line Sensitivity/Impedance :  70 mV/50 k Ω
Mic Sensitivity/Impedance :  0,3 mV/10 k Ω
Fast Rewind/Forward Time:  90 sec (C-60)
Power Requirement:  110 - 120 /220 - 240 V AC, 50/60 Hz
Power Consumption:  17 W
Dimensions (W x H x D):  416 x 100 x 194 mm
Weight:  3,2 kg

Onkyo TA-2028

 A wide range of Onkyo's advanced technology has gone into the creation of the TA-2028 Stereo Cassette Tape Deck. Its superbly quiet transport system is teamed with up-to-date noise reduction systems to ensure noise-free sound reproduction. You'll also find a deck adjustable to any cassette tape type, including the newest high-position and metal tapes, thanks to Onkyo's exclusive Accubias system. This and many more valuable features make this tape deck a great value and a fine addition to any high quality home entertainment system.

Computer Controlled Tape Transport with Two DC Servo Motors.
The 2 DC-motor transport system is designed for quiet operation without annoying mechanical noises when stopping and starting. The use of a special "silent solenoid" means that the unit doesn't need a large current when transports starts, which helps avoid hum and induction noise. A customized microcomputer controls transport mode switching, assuring quick response to commands from the transport keys. Computer control also allows you to switch directly between any two transport modes without pressing the stop key in between.
Accubias for the Best Sound Possible from Any Tape.
The normal and high tape bias selector settings found on most decks are not always matched to the unique characteristics of many of today's recording tapes. Onkyo's exclusive Accubias allows  the user to fine tune the bias current for optimum recording results. With a simple Accubias adjustment you will obtain the flattest and widest possible frequency response from each different kind of tape.

Dolby B and C Noise Reduction.
Besides the conventional Dolby B noise reduction, the TA-2028 featuresDolby C NR as well, to battle both high frequency and mid range noise. It also helpsprecvent distortion due to tape saturation.

Two Repeat Play Modes
Single and Full repeat modes allow you to repeat a single song or to listen a second time to a whole cassette side. The clearly marked repeat mode buttons assure that repeat operations are smooth and error-free.

Automatic Music Control System (AMCS)
If you want to slip forward to anorher track, locate a specific song or scan the contest of a cassette tape al. Press the AMCS button. The deck will automatically detect the silent spaces between songs and stop brieffly at the beginning of a song to play about 10 seconds of music and skip ahead. When the desired spot onthe cassette si reached, press the play button and normal playback resumes.
TA-2028 Features at a Glance
Microcomputer-controlled operation with two DC motors.
Accubias for fine tuning of recording bias.
Automatic Music Control System (AMCS) in the Forward mode that plays the first ten seconds of each song on a cassette.
Dolby B and C noise reduction.
Automatic Tape Selector and Indicator.
5 second Auto Space key
Two repeat Modes
Slider type input level control.
Balance knob for left and right Recording level adjustment.
Two 7-segment LED peak level indicators.
Special Hard permalloy record and playback head.
Timer recording and playback possible.
Full auto-stop.
Separate left and right microphone jacks.
Compatible with RC-5T remote control unit (US and Canada Models).
DIN output terminals (European and other models).
Solid aluminum front panel.

Specifications
Track Format:  4-tracks, 2-channels
Erase System:  AC erase
FF and Rewind Time:  90 sec. (C-60)
Wow and Flutter:  0,06% (WRMS)
Frequency Response:
Metal Tape :  20 - 17,000 Hz (30 - 16,000 Hz ±3 dB)
High Position Tape :   20 - 16,000 Hz (30 - 15,000 Hz ±3 dB)
Normal Tape :  20 - 15,000 Hz (30 - 14,000 Hz ±3 dB)
Signal-to-Noise Ratio:  58 dB (Metal, Dolby Nr Out)
Inputs [Sensitivity/Impedance]:
Line In Jacks :  2 [60 mV/50 k Ω]
Microphone Jacks : 2 [0,6 mV/600 Ω /2,7 k Ω]
DIN in Jack :  1 (EU models) [0,1 mV/1 k Ω /2,7 k Ω]
Outputs [Level/Impedance]:
Line Out Jacks :  2 [500 mV (0 dB)/more than 50 k Ω]
Headphone Jack :  1 [-/8 - 200 Ω]
DIN Out Jack :  1 (EU models) [500 mV (0 dB)/more than 50 k Ω]
Motors:  2 motor system, DC servo Motor x 1 , DC motor x 1
Heads:  Rec/Pb Special hard permaloy  x 1; Erase, Ferrite x 1
Power Supply Rating (4 types):  AC 120/220 V Switchable 50/60 Hz
Dimensions (W x H x D):  435 x 112 x 257 mm (17-1/8" x 4-3/4" x 10-1/8")
Weight:  3,8 kg (8,4 lbs)

Onkyo TA-RW 66

 The TA-RW 66 is a highly versatile double cassette deck with auto reverse, automatic tape selection and Onkyo's superbly engineered soft touch mechanism. Along with these single deck features the system offers a choice of dubbing at regular or high speed. So whether you're recorcing from a broadcast, compact disc or other source, this double cassette  system makes your recording foolproof and easy.

Features :
Two Cassette Transport and Auto Reverse.
High and Normal Speed Dubbing
Unitized Die-Cast head Mount.
Automatic Tape Selection.
Dolby B and C Noise Reduction.
Two DC servo-controlled motors.
Two 2-color, 6-segment LED peak level meters.
Timer standby mode (play and record).
Solid aluminum front panel.
Specifications
Track Format:  4-tracks, 2-channels
Erase System:  AC erase
FF and Rewind Time:  90 sec. (C-60)
Wow and Flutter:  0,07% (WRMS)
Frequency Response:
Metal Tape :  20 - 17,000 Hz (30 - 16,000 Hz ±3 dB)
High Position Tape :   20 - 16,000 Hz (30 - 15,000 Hz ±3 dB)
Normal Tape :  20 - 15,000 Hz (30 - 14,000 Hz ±3 dB)
Signal-to-Noise Ratio:  58 dB (Metal, Dolby Nr Out)
Inputs [Sensitivity/Impedance]:
Line In Jacks :  2 [60 mV/50 k Ω]
Outputs [Level/Impedance]:
Line Out Jacks :  2 [500 mV (0 dB)/more than 50 k Ω]
Headphone Jack :  1 [- /8 - 200 Ω]
Motors:  2 motor system, DC servo Motor x 2 
Heads:  Rec/Pb Special hard permaloy  x 2; Erase, Ferrite x 1
Power Supply Rating (4 types):  AC 120/220 V Switchable 50/60 Hz
Dimensions (W x H x D):  435 x 112 x 258 mm (17-1/8" x 4-3/4" x 10-1/8")
Weight:  5,3 kg (11,7 lbs)

Fostex GZ 1001

 The Printed Ribbon Planer Loudspeaker - Patented Technology.
The GZ Series employs the Fostex RP (Regular Phase) principle embodied in the acclaimed Printed Ribbon Microphone Series, a technology protected by 19 patents pending. An extremely thin and lightweight diaphragm is used whose entire effective plane is driven at the same phase. The mass is small and uniformly driven, which results in high efficiency and durability not found in similar units. This is a unique loudspeaker with all the classic characteristics:  flat frequency response, high definition, superior transient response, low distortion and unusually good front-to-back depth perception.
 Edgeless Woofers SLE34W SLE24W (GZ1001) - Articulate Reproduction of the Fundamentals.
The cone surround, weak point of most cone woofers, is completely eliminated in the SLE34W and SLE24W. An acoustic low pass filter in the form of a sloted ring replaces the conventional cone surround. The voice coil/cone assembly is supported by push-pull, distortion-cancelling double spiders. Employing also a super heat-resistant voice coil, this special synthetic material (SM) cone reproduces powerful and articulate low frequency sound-the fundamentals of music. Of particular note are the excellent transient response and low distortion - the perfect complement to the Printed Ribbon Planer Loudspeaker.

Midrange FS21RP (GZ1001) - True Dipole Radiator for the Heart of the Music.
Although its size is about half that of the mid-bass, the midrange construction is identical. The system consist of a flat coil diaphragm with a polyamide film as the base material, and a powerful magnetic circuit of high flux density through the use of a high coercivity ferrite magnet. This driver possesses superior acoustic response in the mid and mid-high regions (1 kHz to 7 kHz). The construction is such that sound is symmetrically projected from both the front and the rear. This true dipole radiator design reproduces the heart of the music with astonishing depth and clarity.
 Super Tweeter FT7RP - High Fidelity Reproduction Clear Up TO 45 kHz.
The super tweeter FT7RP boasts a flat, non-distorted response clear up to 45 kHz, far beyond the audible range of human hearing. The 12,5 mm effective width diaphragm is made from an extremely lightweight polyamide film of 12,5 µ thickness, and it is formed in a special rib patern. Disperision is further enhanced by making the front and rear dimensins of the magnet assembly non-symmetrical. This super tweeter employs a Samarium Cobalt magnet 3 times more powerful than conventional units. Due to this design, super high frequencies and important musical harmonics are faithfully reproduced in a wide dispersion pettern.
Specifications GZ1001
Impedance:  6 Ω
Frequency Range:  40 - 45,000 Hz
Output Sound Pressure Level:  90 dB [W/1m]
Input:  100 W Music
Driver Complement:
Tweeter :  FT7RP
Mid-Range:  FS21RP
Woofer :  SLE34W
Dimensions (H x W x D):  1115 x 400 x 250 mm
Weight:  25 kg
Enclosure Type:  Bass reflex

Fostex GZ 2001

The Printed Ribbon Planer Loudspeaker with Super Long Excursion (SLE) Edgeless Woofer  an Artistic Blendig of High Technology.


The GZ Series of high performance speaker systems has been developed in pursuit of true fidelity reproduction throughout the audible spectrum. These absolutely natural and live sounding systems make you forget about the speaker source, so clearly is the acoustic image positioned within the rich sound field. A true dipole radiator design provides startling front-to-back depth perception. The GZ Series directly represents the achievement of true fidelity - not only for traditional music, but also foe new sonic dimensions - with accurate reproduction of all information from any type of program source.

 The Printed Ribbon Planer Loudspeaker - Patented Technology.
The GZ Series employs the Fostex RP (Regular Phase) principle embodied in the acclaimed Printed Ribbon Microphone Series, a technology protected by 19 patents pending. An extremely thin and lightweight diaphragm is used whose entire effective plane is driven at the same phase. The mass is small and uniformly driven, which results in high efficiency and durability not found in similar units. This is a unique loudspeaker with all the classic characteristics:  flat frequency response, high definition, superior transient response, low distortion and unusually good front-to-back depth perception.
 Edgeless Woofers  SLE34W (GZ2001) - Articulate Reproduction of the Fundamentals.
The cone surround, weak point of most cone woofers, is completely eliminated in the SLE34W and SLE24W. An acoustic low pass filter in the form of a sloted ring replaces the conventional cone surround. The voice coil/cone assembly is supported by push-pull, distortion-cancelling double spiders. Employing also a super heat-resistant voice coil, this special synthetic material (SM) cone reproduces powerful and articulate low frequency sound-the fundamentals of music. Of particular note are the excellent transient response and low distortion - the perfect complement to the Printed Ribbon Planer Loudspeaker.
Mid-Bass FS41RP (GZ2001) - Accurate Reproduction of Important Bass Harmonics.

With the tremendous progress in music program sources, the role of the mid-bass is becoming increasingly important. In the nerly perfect GZ2001 4-way speaker system, the mid-bass FS42RP handles the important 200 Hz - 1 kHz range, a key to excellent sound reproduction. A powerful magnetic circuit uses a 1,8 kg high coercivity ferrite magnet. The planer diaphragm is made of polyamide film, onto which the high density voice coil is precision etched. The result: brisk and lively mid and mid-bass reproduction.

 Midrange FS21RP (GZ2001) - True Dipole Radiator for the Heart of the Music.
Although its size is about half that of the mid-bass, the midrange construction is identical. The system consist of a flat coil diaphragm with a polyamide film as the base material, and a powerful magnetic circuit of high flux density through the use of a high coercivity ferrite magnet. This driver possesses superior acoustic response in the mid and mid-high regions (1 kHz to 7 kHz). The construction is such that sound is symmetrically projected from both the front and the rear. This true dipole radiator design reproduces the heart of the music with astonishing depth and clarity.

 Super Tweeter FT7RP - High Fidelity Reproduction Clear Up TO 45 kHz.
The super tweeter FT7RP boasts a flat, non-distorted response clear up to 45 kHz, far beyond the audible range of human hearing. The 12,5 mm effective width diaphragm is made from an extremely lightweight polyamide film of 12,5 µ thickness, and it is formed in a special rib patern. Disperision is further enhanced by making the front and rear dimensins of the magnet assembly non-symmetrical. This super tweeter employs a Samarium Cobalt magnet 3 times more powerful than conventional units. Due to this design, super high frequencies and important musical harmonics are faithfully reproduced in a wide dispersion pettern.

Specifications GZ2001
Impedance:  6 Ω
Frequency Range:  30 - 45,000 Hz
Output Sound Pressure Level:  92 dB [W/1m]
Input:  150 W Music
Driver Complement:
Tweeter :  FT7RP
Mid-Range:  FS41RP and FS21RP
Woofer :  SLE34W
Dimensions (H x W x D):  1300 x 540 x 280 mm
Weight:  45 kg
Enclosure Type:  Sealed

Kenwood KW-5066

 4 head Sosslid State Streo Tape Deck
Kenwood's KW-5066 is equipped with epoch-making Recording Bias Adjustment, high Speed full Track Erase System, Sound-on-Sound and Echo Recordings with Level Control etc., which will no doubt recall the real pleasures of Recording most tape decks have been long passed by.  Its recording and reproduction quality is needless to say refined by low noise pre-amplifiers. Add on your line-up and fully make use of  this Super Recording machine, KW-5066.

Special Features
Recording Bias Adjustment System permits the most desiderable bias for high fidelity recording on the recorder for a specific tape by the incorporated test signal oscillator.
 The exclusive Full Track Erase head with triple safety mechanism for rewinding provides instant full track erase of a pre-recorded tape.
 Easy-to read large size dual illuminated VU meters on the front panel ensures accurate recording and playback levels.
 Separate Input and Output level Control for easy monitoring.
 The exclusive DIN connector permits easy dubbing.
 Easy loading by one hand.
Sophisticated special recording can be done by setting only Sound-on -Sound and Echo recording level control and switch on front panel.
 Auto-Stop mechanism built into the head housing and 4-digit tape counter.
 Low-noise Silicon Transistors are used in special record and playback pre-amplifiers for high signal-to-noise ratio and low distortion.
 A Tape  Monitor Switch enables a fast, easy means to check sound immediately before and after it is recorded during the recording process.
 Three tape speeds to suit your recording requirements - 71/2 ips and 33-/4 ips speeds for high fidelity recordings and 1-7/8 ips for speech recordings
Noise Filter enables one to eliminate undesirable hiss noise on pre-recorded tape.
Specifications
Recording System:  4-Track Stereo/Mono recording and playback
Tape speeds:  7-1/2 ips, 3-3/4 ips 1-7/8 ips
Reels: Standard NAB 7" or smaller
Frequency Response:
25 - 20,000 Hz at 7-1/2 ips
25 - 12,000 Hz at 3-3/4 ips
25 - 6,000 Hz at 1-7/8 ips
Signal-to-Noise Ratio:  better than 50 dB
Harmonic Distortion (Preamp):  less than 0,6% at 0 dBs (0,775 V)
Wow and Flutter (Playback): 
At 7-1/2 ips :  less than 0,15% (RMS); 0,08% (WRMS)
At 3-3/4 ips : less than 0,25% (RMS); 0,10% (WRMS)
At 1-7/8 ips :  less than 0,35% (RMS); 0,15% (WRMS)
Recording Time (4-Track Stereo)
1 hrs at 7-1/2 ips
2 hrs at 3-3/4 ips
4 hrs at 1-7/8 ips
Fast Wind/Rwind Time:  within 150 sec. With 1200 ft tape
Level Indicator:  Two VU Meters
Inputs Sensitivity/Impedance: 
Mic :  63 dBs (0,55 mV)/ 50 k Ω
Line :  18 dBs (100 mV)/ 100 k Ω
Output Level/Impedance:
Line :  0 dBs (0,775 V)/ 100 k Ω
Headphone :  28 dBs (30 mV)/ 8 Ω or more
DIN Connector: 
Input Sensitivity/Impednce:  38 dBs (9.8 mV) / 100 k Ω
Output level/Impedance:  0 dB (0,775 V)/ 3 k Ω
Equalizer:  NAB (record and Playback)
Heads:  4 Heads - Playback ; Recording, Erase and Full-track Erase
Bias Frequency:  approx 85 kHz
Transistors:  19 low-noise silicon transistor
Diodes:  2
Operating Position: Horizontal or Verical
Power Requirement:  110 - 120 V;  220 - 240V, AC 50/60 Hz
Dimensions (W x H x D):  16-1/2" x 7" x 15-1/2"
Weight:  24 lbs

Kenwood KW-4066

 Kenwood's KW-4066 is a durable 3-head, easy tape loading tape deck that performs according to the highest audio principles. With all-silicon transistor recording and playback pre-amplifiers, this unit can be easily panel-mounted to become the center of your hi-fi system. The KW-4066 offers a choice of three tape speeds, slide-type recording level control, tape monitor switch for recording quality cheks and independent left, right recording buttons.

Special Features
Specially designed pre-amplifier minimizes distortion during recording and playback to eliminate the "hiss" inherent in tapes at high frequencies, as well as hum modulation at lower frequencies.
 The KW-4066 incorporates a new, exclusive Kenwood tape transport system which features an auto-stop mechanism built into the head housing.  It simplifies tape handling considerably, and the tape can be loaded easily by one hand.
 Three tape speeds are available; 7-1/2 ips and 3-3/4 ips for high fidelity recordings and playback, 1-7/8 ips for speech.
 A slide-type level control similar to those used for mixing in broadcasting studio equipments can vary and increase recording qualities.
 Completely separated Left, Right, recording capabilities enable mixed "Sound with Sound" recordings. One channel can be used for recording while the other is being used simultaneously for playback.
 A Tape Monitoring Switch permits fast, easy means to check sound immediately before and after it is recorded during the recording process.
 The natural monaural sounds can be produced from 2-Track tapes by Mode Switch.
Specifications
Recording System:  4-Track Stereo/Mono recording and playback
Tape speeds:  7-1/2 ips, 3-3/4 ips 1-7/8 ips
Reels: 7" or smaller
Frequency Response:
25 - 20,000 Hz at 7-1/2 ips
25 - 12,000 Hz at 3-3/4 ips
25 - 6,000 Hz at 1-7/8 ips
Signal-to-Noise Ratio:  better than 50 dB
Harmonic Distortion (Preamp):  less than 0,6% at 0 dB. Recording Amp or Playback Amp
Wow and Flutter (Playback): 
At 7-1/2 ips :  less than 0,15% (RMS); 0,08% (WRMS)
At 3-3/4 ips : less than 0,25% (RMS); 0,10% (WRMS)
At 1-7/8 ips :  less than 0,35% (RMS); 0,15% (WRMS)
Recording Time (4-Track Stereo)
1,5 hrs at 7-1/2 ips
3 hrs at 3-3/4 ips
6 hrs at 1-7/8 ips
Fast Wind/Rwind Time:  within 150 sec. With 1200 ft tape
Level Indicator:  Two VU Meters
Inputs Sensitivity/Impedance: 
Mic :  63 dBs (0,6 mV)/ 50 k Ω
Line :  18 dBs (100 mV)/ 100 k Ω
Output Level/Impedance:
Line :  0 dBs (0,775 V)/ 100 k Ω
Headphone :  27,5 dBs (33 mV)/ 8 Ω or more
Equalizer:  NAB (Record and Playback)
Heads: 3 Heads - Playback (1,7 µ gap); Recording and Erase
Bias Frequency:  approx 85 kHz
Transistors:  16 low-noise silicon transistor
Diodes:  6
Operating Position: Horizontal or Vertical
Power Requirement:  110 - 120 V;  220 - 240V, AC 50/60 Hz
Dimensions (W x H x D):  16" x 7-1/16" x 12-11/16"
Weight:  22 lbs

Sansui Model 350

 AM/FM Multiplex Stereo Tuner Amplifier Solid State
With most of the same design and performance features of the larger Sansui 800, this model is the most complete receiver available anywhere under 50 watts. For better FM performance, it too, features an FET and 3-gang capacitor frontend. In addition to improved FM sensitivity and selectivity (S/N ratio of better than 50 dB), the Model 350's FM section provides channel separation of better than 30 dB.
At home within a wide 30 to 20,000 Hz power bandwidth, the 350 keeps distortion below a negligible 1% and features a damping factor of 34 at 8 ohms.
Other large receiver features include an ability to power up to two speaker systems, to operate off both 75 and 300 Ω antennas, and automatic FM mono stereo switching.
Specifications
Amplifier Section
Music Power (IHF):  46 watts at 8 Ω ±1 dB
Continuous Power:  18 / 18 watts at 8 Ω  ±1 dB
Harmonic Distortion:  less than 1,0% at rated output
Power Bandwidth (IHF):  30 - 20,000 Hz (at 8 Ω)
Input Sensitivity (for rated output): 
Phono :  2,2 mV (±3 dB)
Aux :  150 mV (±3 dB)
Tape Monitor [PIN, DIN] :  150 mV (±3 dB)
Hum and Noise (IHF):
Phono :  60 dB
Aux :  65 dB
Damping Facator:  34 at 8 Ω
Output Impedance:  8 Ω and 16 Ω
FM Tuner Section
Frequency Range:  88 - 108 MHz
Sensitivity:  2,5 µV  ±3 dB (S/N 20 dB quieting)
Sensitivity:  3,0 µV  ±3 dB (IHF)
Selectivity:  better than 45 dB
FM Stereo Separation:  better than 30 db
AM Tuner Section
Frequency Range:  535 - 1605 kHz
Sensitivity (IHF):  25 µV  at 1 MHz (±3 dB)
Selectivity:  better than 20 dB at 1 MHz
Seminonductors:  31 Transistors ; 21  Diodes ; 4 Varistors
 Power Voltage:  100, 117, 220 and 240 V;  50/60 Hz
Power Consumption:  90 VA max
Dimensions (W x H x D):  15-13/16 x 4-1/2 x 13-1/8 inch
Weight:  19,5 lbs

Sansui Model 250

 AM/FM Multiplex Stereo Tuner Amplifier Tube-Type
Even at a modest 22 watts, Sansui engineering has made the Model 250 a completely self-contained unit with Multiplex tuner and amplifier all in one.  Like Sansui's larger tube model, the 1000A , Model 250 incorporates the latest push-pull connection of super wide-band transformers with high-performing multi-unit tubes 6BM8, an advanced silicon transistor head amplifier, plus a newly designed NF circuit for a power bandwidth from 35 to 15,000 Hz, a 22 watt power output and a distortion factor of only 1,5%. The 250 has also been provided with the latest multiplex circuit for a stereo separation figure of 35 dB.
A tape recording terminal, tape monitoring circuit, center channel output terminal, headphone jack, loudness compensation control, noise filter and automatic tuning eye put the 250 far out in front of similar sized and priced receivers.
Specifications
Amplifier Section
Music Power (IHF):  22 watts ±1 dB
Continuous Power:  10 / 10 watts ±1 dB
Harmonic Distortion:  less than 1,5% at rated output
Power Bandwidth (IHF):  35 - 15,000 Hz
Input Sensitivity: 
Phono :  3 mV
Aux :  150 mV
Tape Monitor :  660 mV
Hum and Noise (IHF):
Phono :  65 dB
Aux :  70 dB
Output Impedance:  8 Ω and 16 Ω
FM Tuner Section
Frequency Range:  88 - 108 MHz
Sensitivity:  2,5 µV  ±3 dB (S/N 20 dB quieting)
Sensitivity:  4,0 µV  ±3 dB (IHF)
AM Tuner Section
Frequency Range:  535 - 1605 kHz
Sensitivity (IHF):  30 µV  ±3db
Seminonductors:  2 Transistors ; 10  Diodes
Tubes :  16
Power Voltage:  100, 117, 220 and 240 V;  50/60 Hz
Power Consumption:  115 VA max
Dimensions (W x H x D):  17-3/8 x 5-5/32 x 12-19/32 inch
Weight:  28,2 lbs

Sansui Model 220

 Similar to the Sansui Model 250 in size, looks and performance characteristics, this model features an additional radio band in place of a multiplex circuit.
It is ideal for places where stereo broadcasting facilities are not available. In addition to regular AM and FM bands, the Model 220 offers worldwide radio pick-up capabilities with a shortwave band frequency range from 3,5 to 10 MHz.
Compact with 12 tubes, two transistors and six diodes. Special FM AFC control for stable FM reception, tape monitor, mode, loudness and noise filter controls.
This model has also been provided with a multiplex terminal for fast and convenient connection with a multiplex adaptor if desired.
Specifications
Amplifier Section
Music Power (IHF):  22 watts ±1 dB
Continuous Power:  10 / 10 watts ±1 dB
Harmonic Distortion:  less than 1% at rated output
Power Bandwidth (IHF):  35 - 15,000 Hz
Input Sensitivity: 
Phono :  3 mV
Aux :  150 mV
Tape Monitor :  660 mV
Hum and Noise (IHF):
Phono :  65 dB
Aux :  70 dB
Output Impedance:  8 Ω and 16 Ω
FM Tuner Section
Frequency Range:  88 - 108 MHz
Sensitivity:  2,5 µV (S/N 20 dB quieting)
Sensitivity:  4,0 µV (IHF)
MW Tuner Section
Frequency Range:  535 - 1605 kHz
Sensitivity (IHF):  30 µV  ±3db
SW Tuner Section
Frequency Range:  3,5 - 10 MHz
Sensitivity (IHF):  40 µV ±3 dB
Seminonductors:  2 Transistors ; 6  Diodes
Tubes :  12
Power Voltage:  100, 117, 220 and 240 V;  50/60 Hz
Power Consumption:  106 VA max
Dimensions (W x H x D):  17-3/8 x 5-5/32 x 12-19/32 inch
Weight:  27,1 lbs

Technics RS-1700

 The "Isolated Loop" Reveals its Full Potential in  "Two-Way-Forward" Auto-Reverse.
The ingeniously conceived "Isolated Loop" structure (previously introduced in the RS-1500US) was primarily designed to eliminate hitherto "unsolvable" problems such as speed deviation and fluctuation, wow and flutter, and modulation noise. But that was by no means the end of the story. The perfect symmetrical structure of the "Isolated Loop", formed by a single super-large capstan (34 mm diametere), reversing roller, and pair of pinch rollers exerting equal pressure on the capstan, means that tape may be transported in either direction under exactly identical conditions, thereby maintaining the same high standard of performance. The RS-1700, which is basically the same precision "wonder" machine as the epochmaking RS-1500US, reveals the full potential of the "Isolated Loop" tape path by completely eliminating any loss of performance in the reverse direction. It really should be called the "two-way-forward" tape deck rather than just another auto-reverse deck. The incredible wow and flutter of 0,018% (15 ips) remains unchanged in both forward and reverse directions.
 Multiple Auto-Reverse Functions
Three Basic Transport Modes
The RS-1700 features 3 separate auto-reverse transport modes: "cont"; "rev"; "non rev". In "cont" mode, tapes will play endlessly until commanded otherwise, in "rev" mode, a single cycle will be completed in either record or playback modes, while in "non rev" mode, tape transport will be the same as any other tape deck.
Auto-Stop in Fast Forward and Rewind Modes
In "cont" and "rev" modes, this highly efficient photoelectric tape-end detector is also utilized to bring tape transport to an automatic stop in fast forward and rewind modes. This features can be used  to even greater effect by inserting transparent leadeer tape in between desired selections.
Pre-Timed Auto-Reverse Recording and Playback
By connecting up the RS-1700 to an audio timer, the pre-timed automatic recording or playback will also continue in the reverse direction. If the timer is so designed, a second recording or playback session will continue in the same direction.
Direction Indicator Lamps
The reverse and forward control keys are equipped with built-in blinker lamps for immediate indication of transport direction during all modes, and even when pause or stop keys are pressed.
 Photoelectric "No Touch" reverse Point Detection.
Precision, fail-proof reversing action is assured by the unique infrared LED - infrared filter - infrared sensitive transistor tape-end detector system. No machanical contacts, no wear on tapes. When the transparnt leader tape reaches the detector mechanism a 512 Hz quartz- controlled flicker beam generated by the infrared LED passes through the tape and infrared filter to activate the infrared sensitive transistor (designed to respond only to this intermittent infrared readiation). The emission spectrum and infrared sensitive transistor thus make mis-operations due to external light practically impossible.
 Unique 6-Head Configuration
Super Alloy laminated heads are used for both playback and recording , while a double-gap ferrite head is used for erasing. Completely separate sets of heads are employed for forward and rewerse directions.
Imperceptible Modulation Noise in Either Direction
As the following diagrams illustrate, the "Isolated Loop" all but eliminates modulation noise in either direction.
Highly Reliable Forward/Reverse Head Switching Relay
The gold-clad twin-contact relay employed in switching forward and reverse heads responds immediately and efficiently to all switching commands. Switching time is of the order of 0,1 sec.
Interchangeable Plug-In Type Head Assembly
The 24-pin plug-in type head assembly may be removed quite easily for simple replacement with other Technics head assemblies which will become available in the future.
Higly Stable Bias Oscillation
In view of the repleceable head assemblies, an independent constant voltage circuit and power amplifiers have also been included in the bias oscillator stage, thereby further improving the stability of the bias oscillation frequency and output level.
 Direct-Drive 3-Motor Tape Transport
Quartz-Locked Direct-Drive Capstan Motor
By bringing the high-torque DC direct-drive capstan motor under the control of a quartz oscillator phase control system, the RS-1500US achieved unprecedented performance in motor speed control and the elimination of wow and flutter. Improving upon such a near-perfect system was hard to imagine, but the RS-1700 has done just that, by adopting newly developed IC's for even stricter  contorl of phase, speed, torque, etc despite changes in load, temperature, power and time.
Integrated Direct-Drive Reel Motors
Employing the same integrated rotor-platter structural design as Technics direct-drive turntables, the RS-1700 reel motors consist of integrated reel-base and rotor coupled to the fixed stator. Tape speed from start to finish during fast forward and rewind modes remains unchanged.
Tape Tension Control
In addition to the "Isolated Loop" designed for intimate and stable tape-to-head contact by eliminating the effects of changes in tape tension, the RS-1700 even employs an electronic tension control system to prevent any changes in tape tension occurring in the first place, thereby making doubly sure modulation noise remains at an indiscernible level.
Aluminum Diecast Chassis
The housing blocks for all three direct-drive motors are firmly set into the precision-designed aluminum diecast chassis to ensure greater stability for longer operational life.

IC Logic Control
Newly Developed  I²L  IC for Surer Tape Transport Control
The newly developed Integrated Injection Logic (I²L) IC employed in the RS-1700 is really fail-proof, ensuring immediate, accurate rate switching with a light touch of the finger.
Electro-Brake and Quick-Play
Changing directly from any transport mode to any other is both possible and efficient in the RS-1700, thanks to the logic controlled Electro-Brake which slows the tape down to almost a stop by applying a reverse torque to the supply reel, before applying the mechanical brake. This means greater safety and longer life for both mechanism and tape Furthermore, with this sophisticated logic control system, the RS-1700 goes from any mode to a momentary stop and then in a mere 0,7 second to play mode by only touching the forward or reverse button.
 Amplifier Stage of Unrivaled Dynamic Margin
77 dB Dynamic Margin Microphone Amplifier
The 3-stage direct-coupled microphone amplifier, employing strictly selected low-noise circuit components, achieves an almost incredible dynamic margin of 75 dB when the attenuator is switched to the -20 dB position. Live recordings under a very wide range of conditions will be conspicuous for the lack of distortion.
Recording Amplifier with +28,5 dB Linearity
With an SEPP circuit in the recording amplifier output stage, the RS-1700 attains a linearity right up to +28,5 dB (1 khz0 over the "0" VU reference level. Distortion level also exceeds the performance of many professional use models.
Minimal Mutual Interference in Mic/Line Mixing Circuit
The RS-1700 mixing amplifier stage features very little mixing loss, and imperceptible mutual interference between mic an line-in.
3-Position Bias and Equalization Selectors
Complete coverage of all major types of tapes on the market is provided by the independent 3-position bias and equalization selectors.

Operational precision and Efficiency
The RS-1700 retains the many outstanding operational control functions of the RS-1500US. The major features include the :
Double-Scaled VU Meters;  reads up to =6 dB when priority given to S/N ratio, or switchable to +3 dB scale when priority given to linearity.
Real Time Tape Counter;  indicates minutes and seconds to an accuracy of ±1% at 15 ips (38 cm/sec.)
Cue Lever:  tape remains in contact with playback head during fast forward and rewind modes for easier location of start and end of recorded selections.
Edit Dial;  for precision editing/splicing of tapes, employing the edit points on the reversing roller, and the tape marker.
Pitch Control (±6%);  tape speed may be increased or decreased by up to 6% (approx. one-half tone)
Battery Operation;  with the optional battery adaptor (RP-086) , the RS-1700 may be freely used in any location.
Remote Control:  another useful addition is the optional remote control (RP-9170).
Specifications
Track System:  Auto-Reverse 4-track, 2-channel recording/playback, 6-heads system
Motor Capstan:  Quartz control phase-locked DC brushless direct-drive motor
Reel Table:  2-tape tension controlled DC brushless direct-drive motor
Reel Size:  10", 7" and 5" (outside diameter)
Tape tension Control:  Automatic control for above size of reel
Tape Speed:  38 cm/s, 19 cm/s, and 9,5 cm/sec. (15 ips, 7 ½ ips, and 3 ¾ ips)
Speed Deviation:  ±0,1%with 1,0 or 1,5 mil thickness tape at 15 ips
Speed Fluctuation:  0,05% with 1,0 or 1,5 mil thickness tape at 15 ips
Pitch Control:  ±6% recording and playback
Wow and Flutter (Rec/PB):
0,18% WRMS at 15 ips (38 cm/s)
0,03% WRMS at 7 ½ ips (19 cm/s)
0,06% WRMS at 3 ¾ ips (9,5 cm/s)
Time Counter Accuracy:  ±1% at 15 ips (38 cm/s)
Fast Forward and rewind Time:  150 sec with 2500 feet (762 m) 1,5 mil tape
Reverse Point Detection:  photoelectric (Infrared LED/ filter/ photo-transistor)
Frequency Response:
15 ips (38 cm/s) :  30 -30,000 Hz ±3 dB (-10 dB rec. Level)
7 ½ ips (19.5 cm/s) :  20 - 25,000 Hz ±3 dB (-20 dB rec. Level)
3 ¾ ips (9,5 cm/s) :  20 -15,000 Hz ±3 dB ( -20 dB rec. Level)
Signal-to-Noise Ratio (NAB weighted 185 nWb/m  =6 dB):
15 ips (38 cm/s) :  60 dB
7 ½ ips (19 cm/s) :  60 dB
3 ¾ ips (9,5 cm/s) :  58 dB
Total Harmonic Distortion (measured via tape at 400 Hz Operating level "0" VU):
15 ips (38 cm/s) :  0,8%
7 ½ ips (19 cm/s) :  0,8%
3 ¾ ips (9,5 cm/s) :  0,8%
Channel Separation:  greater than 50 dB
Erasing Ratio:  greater than 65 dB (rec. at 1 kHz +10 dB)
Recording Bias:  120 kHz
Bias Level at Tape Selector:
"1" for 90%
"2" for 100%
"3" for 110%
Equalization (NAB standard):  Position "2" of "EQ" and "Bias" selectors set for Scotch No.207 tape
Recording Level Calibration:  referenced to 185 nWb/m
Inputs :
MIC :  Unbalanced phone type jack
Sensitivity : 
0,25 mV (-72 dB) / 4,7 kohm (0 VU at Vol. Max)
2,5 mV (-52 dB) / 4,7 k Ω with 20 dB attenuation
Overload Margin :  55 dB (75 dB with 20 dB att.) applicable microphone impedance 200 Ω to 100 k Ω
LINE:  Phono type jack
Sensitivity :  60 mV (-24 dB) / 150 k Ω
Overload margin = infinity (line input connected to line In Vol. Before amplifier)
Through Out:  same as Line In (parallel connected to Line In)
Outputs
LINE:  2 pairs of phono type jack
Output level 420 mV at "0" VU (output level control at "8"), 600 mV at output level control max.
Output impedance less than 3 k Ω load impedance 22 k Ω over
HEADPHONE: Stereo phone type jack
Output level 60 mV at 420 mV line output,
Load impedance 8 Ω
Dimensions (W x Hx D):  492 x 446 x 257 mm (19-3/8" x17-1/2" x 10-1/8")
Weight:  25,2 kg (55,6 lbs

Finish with rosewood veneer side panels