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





ADC XLM phono cartridge

The ADC XLM cartridge - this is the only cartridge we have seen that is really capable of tracking almost all stereo discs at 0,4 grams.

The Sound Authorities go on to say: "the XLM went through the usual torture test at 0,4 grams (some models require more than a gram)….the XLM is capable of reproducing anything found on a phonograph record." "the CBS STR-100 test record showed less than ±1,5 dB variation up to 20,000 Hz … response is within ±2 dB over the entire range, and Frequency Response is exceptionally flat."

"Distortion readings, are almost without exception better than those for any other model we've tested, … the XLM has remarkably low distortion in comparison with others, …at 0,6 grams the distortion was low  - under 1,5 percent."

"The XLM could be instrumental in lowering the input noise from the first stage of a modern transistor amplifier, … the cartridge had very good shielding against induced hum."

"This would be a very hard cartridge to surpass at any price, … we found it impossible to attribute superior sound to costlier competing models,  priced as it is, it is a rel bargain in cartridges."

Specifications

Company (Year):  ADC (1971)

Body/Molding/Stylus:  Gold / Black /Black

Stylus:  RXL

Stylus Tip:  .3 x .7 mil

Stylus Mount:  Nude

Compliance:  50 cu

Tracking Force:  .4 - 1 g

Frequency Response:  10 - 25,000 Hz

Channel Balance:  2 dB at 1 kHz

Output:  0,85 mV

Channel Separation:  25 dB at 1 kHz

Inductance:  300 mH

Resistance:  625

Capacitance:  235 pF

Weight:  5,5 grams

Nakamichi TA-1/1A/1E receiver

 

Nakamichi High Definition Tuner Amplifier


Features:

Discrete Power Stage with High Curent Capability

Multiple Isolated-Ground Power Supplies

Quartz PLL Tuner with 10 Presets and Auto-Seek Tuning

Nakamichi-Concept Tone and Loudness Controls

High Accuracy Phone Equalizer with Built-in Subsonic Filter

Speaker Selector for A / B or A + B System

Protection Circuitry

 


Discrete-Configuration / High-Current Power Amplifier

If you were to look into the average basic receiver, chances are you'd find IC power amplifiers. That's not surprising because IC power amps are convenient, inexpensive and produce adequate sound for the not-too-discriminating listener. For better or for worse, Nakamichi engineers are a pretty discriminating lot and, after auditioning the various IC power amps on the markeet, decided to design their own "discrete" power amplifier. By "discrete" we mean a custom-designed circuit using carefully selected individual components that can be fine tuned for optimum performance. It's a more expensive way to go, but it permits us to create a uniquely musical design that guarantees "Nakamichi Sound" at an entry-level price.

The discrete output transistors used in the TA-1 have a higher current capability than those in the average 35-watt power IC. With an ability to deliver peak currents of 10 amperas, the TA-1 output devices drive difficult loudspeakers easily and that means purer, more natural sound. Then, too, by designing our own circuit, we ensure adequate output-stage and loudspeaker protection without audible side effects. That means the TA-1 will play safely and more loudly than a comparably rated receiver that uses power ICs. Finally, by custom designing the output stage, we are able to increase the gain over that of an IC, incorporate the tone controls as part of the power amp and thus eliminate need for a line amplifier - another step in simplifying the signal path.

 


Nakamichi Concept preamp and Tone Controls

You'll find the Nakamichi TA-1 substantially different from the ordinary in its phono preamp and tone controls too. For example, the preamp has a subsonic filter built into the phono equalizer - not as an appendage to the line amplifier. This means that, not only can you play warped records without overloading your speakers, you can make clean copies of them without overloading your tape recorder - an advantage many designs do not provide. And, thanks to Nakamichi precision components, equalization accuracy is within ±1 dB from 30 Hz to 20 kHz including the effects of the filter.

TA-1 tone controls were designed to be useful, not flashy. Compared with those in other receivers TA-1 controls have a carefully limited range and are most effective at frequency extremes, not in the midband. This means you can create a subtle boost or cut in the extreme bass or treble without altering the character of the music. Similary, the TA-1 loudness contour comes into increasing prominence as volume is reduced and therefore tracks the characteristics of human hearing at low listening levels in a more natural way.

 


Multiple Power Supplies with Isolated-Ground Topology

Even though the TA-1 is Nakamichi's "entry-levl" receiver, it has been designed with separate transformer windings and power supplies for the audio and control circuits to prevent control-circuit noise from contaminating musical purity. In addition, the tuner's power source is regulated independently of the power-amp and preamp sources and that for the preamp features Nakamichi's unique "Isolated-Ground" topology to ensure a noise-free ground reference for the critical low-level stages. Circuit grounds are kept separate for each channel both in the power amp and in the preamp for best channel separation and absolute musical purity.

 

Quartz PLL Synthesized Tuner

The TA-1's  tuner complements the excellent sound of its preamp and power amp. A quartz PLL synthesized "front-end", with twin varicap diode, provides accurate drift-free reception, 10 station presets and a choice of manual or auto-seek tuning modes. As with every Nakamichi tuner, the TA-1 uses an unusually high reference frequancy to provide better Signal-to-Noise ratio and lower distortion.

 



Specifications

Power Amp Section

Continuous Average Output Power:  35 watts per channel into 8 Ω (both channels driven, 20-20,000 Hz at no greater than 0,1% T.H.D.)

Dynamic Output Power:

52 watts / channel at 8 Ω

65 watts / channel at 4 Ω

Power Bandwidth:  10 - 40,000 Hz

Frequency Response:  20 - 20,000 Hz ±1 dB; 10 - 50,000 Hz +1 -3 dB

Signal-to-Noise Ratio (A-weighted, Input Shorted):  better than 98 dB re Rated Power

Total Harmonic Distortion:  less than 0,1%

Peak Output Current Capability:  10 A per channel

Preamplifier Section

Sensitivity (for rated output)

Phono MM :  2,5 mV

CD/Tape :  150 mV

Input Impedance

Phono MM :  47 k Ω

CD/Tape :  20 k Ω

Phono Max. Input level (1 kHz):  150 mV

Phono T.H.D. (1 kHz, 1 V at Rec Out):  less than 0,01%

Phono Signal-to-Noise Ratio (IHF-A-202):  better than 76 dB

RIAA Deviation:  30 - 20,000 Hz ±1 dB

Record Output Level/Impedance:  150 mV/2,2 k Ω

Bass Control :  ±10 dB at 20 Hz

Treble Control :  ±10 dB at 20 kHz

Loudness (Volume at -30 dB):  +10 dB at 20 Hz ; +6 dB at 20 kHz

FM Tuner Section

Frequency Range:  87,5 - 108,0 MHz (in 100 kHz steps)

IHF Usable Sensitivity [Mono]:  12,0 dBf/2,2 µV

-50 dB Quieting Sensitivity:

Mono :  15,7 dBf/3,3 µV

Stereo :  38,5 dBf/46,1 µV

Signal-to-Noise Ratio at 65 dBf

Mono :  better than 79 dB

Stereo ;  better than74 dB

Muting Threshold:  30 dBf/17,3 µV

Frequency Response:  30 - 15,000 Hz ±1,5 dB

Total Harmonic Distortion at 1 kHz

Mono :  less than 0,15%

Stereo :  less than 0,20%

Capture Ratio:  2,0 dB

Alternate Channel Selectivity:  55 dB (±400 kHz)

Stereo Separation at 1 kHz:  better than 45 dB

Spurious Response Rejection:  better than 80 dB

Image Rejection:  better than 47 dB

IF rejection:  better than 80 dB

AM Suppression:  better than 60 dB

AM Tuner Section

Frequency Range:  520 - 1710 kHz (in 10 kHz steps)

Sensitivity:  53 dB µ/m

Signal-to-Noise Ratio:  better than 52 dB at 90 dB µ/m

Total Harmonic Distortion:  less than 0,5% at 90 dB µ/m

Selectivity:  better than 20 dB (±10 kHz)

General Section

Power Requirements:  120, 220, 240 V (or 110/120/220/240 V) AC 50/60 Hz

Power Consumption:  220 W max

Dimensions (W x H x D):  430 x 100 x 265 mm (16-15/16" x 3-15/16" x 10-7/16")

Weight:  6 kg (13 lb 4 oz)

Yamaha CR-620 receiver

Natural Sound FM/AM Stereo Receiver

Pure, low distortion power and wide NDCR

FM section with NFB-PLL-MPX

Completely independent tape recording and audition

Continuous Loudness Control

 

The Power Section

Distortion Cut in half - to an incredible 0,05%

Our first complete receiver line, with 0,1% distortion, astounded the audio world. Others rushed to improve their performance specs, but no other manufacturer has equalled that figure for its whole line. Now, in the new Yamaha receiver line, Intermodulation DIstortion and Total Harmonic Distortion are reduced even further to 0,05%. Makers who had not succeeded in matching the 0,1% figure are going to find it even harder to attain the new Yamaha level of 0,05%.

What SVR means in Reducing Dynamic Crosstalk

With many conventional power supply circuits, a loud signal in one channel will draw heavy current which produces a spurious signal - distortion - in the other channel. Supply Voltage Rejection (SVR) must be high if this form of distortion is to be kept well below the level of audibility. The special power supply circuit of the CR620 is even more effective, and gives a higher SVR, than expensive dual power supplies, providing a marked improvement in detailed accuracy in the loudest and most complex passages.

 


The Pre Section

Supern Signal-to-Noise Ratio

Precision circuit design gives the CR620 outstanding Signal-to-Noise characteristics. This results in an extra measure of clean quiet music performance

Accurate RIAA Equalization

The CR620 boasts an equalizer section with only ±0,5 dB deviation from RIAA characteristics, for faithful reproduction of everything recorded on the disc. And at 120 mV (1 kHz), the phono dynamic range is amply wide enough for top quality enjoyment of high cutting level discs with high output cartridges.

Continuously Variable Loudness Control

The CR620 features the same continuous type loudness compensation control as on the Prestigious C-1 control amp, letting you retain an unvarying, natural tonal balance at any and all listening levels, compensating perfectly for the ear's constantly changing loss of sensitivity to bass and treble frequencies at lower levels.

Record One Program while listening to another

This Yamaha original feature lets you choose a source for recording by the Rec Out selector while listening to that source, or any other, selected by the Input switch. You can record an FM program while listening to a favorite record on your turntable, and you can let a friend tape a record or copy tapes without having to give up listening to the tuner.

Full Tone and Filter Controls

Tone Controls

The bass and treble controls on the CR620 have turnover frequencies carefully chosen for the best control of tonal quality to suit your mood, the music, and the acoustic of your room. In the flat position the response is completely unaffected by the tone control circuits.

Filters

Both high and low filters are provided, with 12 dB/ocatave cutoffs, to reduce record scratch or tape hiss noise above 10 kHz, and to cut turntable rumble or subsonic noise from warped records or line noise below 25 Hz

 


The Tuner Section

Direct Assessment of Differential Gain

The world famous CT-7000 tuner offered switched narrow/wide selection modes for ideal reception under all conditions. Now, however, direct visual cheks of the critical differential gain linearity enabled Yamaha engineers to give you the best of both mode settings in the CR620; the high selectivity of the narrow mode (70 dB) and the low distortion of the wide mode (0,25% for stereo at 1 kHz) - without the need to choose between them.

FM/Original: Direct Comparison

The CR620 was developed by comparing reproduction of a sound source heard first through the amplifier section alone, and then as received by the tuner section after FM modulation. That way our music specialists could switch back and forth to compare, immediately detecting any sound coloration introduced by the tuner, and correcting for the last measure of fidelity.

Unique Negative Feedback Multiplex Section

Full negative feedback applied overall to the whole FM multiplex demodulator section reduces distortion in this unique Yamaha circuit to the level where it cannot be measured even on the most sensitive test equipment. Phase-locked loop circuitry adds the ultimate in stability for FM reception quality found in no other receiver of its class.

Special Sharp Cut-off MPX Filter

This high performance filter performs the difficult job of suppressing the 19 kHz pilot sinal (which can interfere with other audio equipment) while retaining full treble response to a5 kHz. Sharp cut-off and low distortion combine to give the best possible audio quality.

Signal Strength and Quality Meter

In addition to a center-zero FM tuning meter for precise FM tuning, the CR620 features a signal strength meter which doubles to show signal quality for FM reception. The presence of multipath signals often appears as needle flutter during FM signal strength readings.

Superb AM Tool

AM quality on the CR620 is also excellent. For top sound quality the AM signal is passed through the FM multiplex section to take advantage of its low distortion characteristics. Special equalization then compensates for the built-in FM frequency deemphasis curve.

 


Specifications

Audio Section

Minimum RMS Output Power per Channel (from 20-20,000 Hz at no more than 0,05% T.H.D.)

40 Watts at 4

35 Watts at 8  

Continuous RMS Power (both channel driven, 1 kHz)

50 Watts at 4

40 Watts at 8

Total Harmonic Distortion (20 - 20,000 Hz)

Phono to Rec Out :  0,12% , 2 V output

Aux, Tape to Sp Out (8 ) :  0,02% at 20 W

Intermodulation Distortion (Aux, Tape) :  0,05% at 35 W

Input Sensitivity/Impedance

Phono :  2 mV/ 50 k

Aux, Tape 1, 2 :  120 mV/45 k

Maximum Input Level

Phono :  120 mV at 1 kHz

Output Level/Impedance

Rec Out terminals (Phono):  120 mV/ 200  (rated); 7,2 V (max. 1 kHz)

Frequency Response

Phono RIAA Deviation :  ±0,5 dB

Aux, Tape 1, 2 to Sp Out :  20 Hz to 20 kHz ±0,5 dB

Tone Control Characteristics

Bass Turnover Frequency :  350 Hz

Bass Boost/Cut :  ±13 dB at 50 Hz

Treble Turnover Frequency :  3,5 kHz

Treble Boost/Cut :  ±10 dB at 20 kHz

Filters and Loudness Control Characteristics

Low :  25 Hz (12 dB/oct.)

High :  10 kHz (12 octave)

Loudness Control :  level-related equalization

Signal-to-Noise Ratio (IHF-A network)

Phono :  92 dB (for 10 mV, shorted)

Aux, Tape :  97 dB

Residual Noise :  0,11 mV

Noise Distortion Clearance Range (NDCR) for 0,1% into 8  , 20-20,000 Hz, from 100 mW to 35 watts with Vol -20 dB (Phono Input to Sp Out)

Power bandwidth (IHF) :  10 Hz to 50 kHz (at 0,05% T.H.D.)

Damping Factor (at 1 kHz):  40 into 8

FM Section

Tuning Range:  88 - 108 MHz

Usable Sensitivity:

300  :  10,3 dBf / 1,8 µV

75  :  10,3 dBf /0,9 µV

50 dB Quieting Sensitivity:

Mono :  15,3 dBf (3,2 µV)

Stereo :  38 dBf (43,5 µV)

Image Response Ratio (98 MHz):  50 dB

IF Response ratio (98 MHz):  75 dB

Spurious Response ratio (98 MHz):  75 dB

AM Suppression Ratio (98 MHz):  56 dB

Capture Ratio:  1,0 dB

Alt. Channel Selectivity (IHF):  70 dB

Signal-to-Noise Ratio (at 65 dBf, IHF)

Mono :  77 dB

Stereo :  73 dB

Mono Distortion (at 65 dBf)

At 100 Hz :  0,15%

At 1 kHz :  0,15%

At 6 kHz :  0,3%

Stereo Distortion (at 65 dBf)

At 100 Hz :  0,25%

At 1 kHz ;  0,25%

At 6 kHz :  0,4%

Intermodulation DIstortion (IHF)

Mono :  0,1%

Stereo :  0,2%

Sub-Carrier Product Ratio:  50 dB

Stereo Separation

At 50 Hz :  30 dB

At 1 kHz :  40 dB

At 10 kHz :  30 dB

Frequency Response

50 Hz to 10 kHz :  ±0,5 dB

30 Hz to 15 kHz :  +1,0 -3,0 dB

Muting Threshold:  19,2 dBf (5 µV)

AM Section

Tuning Range:  525 to 1605 kHz

Sensitivity (IHF, Bar Antenna):  316 µV/m (50 dB/m)

Selectivity (1,000 kHz):  25 dB

Signal-to-Noise Ratio:  50 dB (at 80 dB/m)

Image Response Ratio (1,000 kHz):  50 dB

IF Response Ratio (1,000 kHz):  40 dB

Spurious Response Ratio (1,000 kHz):  55 dB

Total Harmonic Distortion :  0,6% (at 80 dB/m)

Tuner Section Output Level /Impedance

FM (100% mod at Rec Out) :  450 mV/6,5  k

AM (30% mod at Rec Out) :  120 mV/6,5 k

General Section

Semiconductors:  68 Transitors; 3 ICs; 1 FET; 29 Diodes; 5 Zener Diodes, 4 LEDs; 4 Ceramic Filters

Power Requirements:  AC 110/ 120/ 130/ 220/ 230/ 240 V switchable, 50/60 Hz

Power Consumption:  190 W

Dimensions (W x H x D):  508 x 167 x 395 mm (20" x 6-3/8" x 15-1/2")

Weight:  12,5 kg (27 lbs 8 oz) U.S.A. and Canada 11,5 kg (25 lbs 5 oz)

SAE 2900 pre-amplifier

 

The SAE2900 Preamplifier-Equalizer presents a unique combination of sonic excellence and sophisticated system control. Carefully designed to compliment any system, the 2900 contains many attributes and features that confirm its truly exceptional value. These include the Parametric Equalizer, which ensures precise program tone control, and a multiple tape monitor/ copy/EQ system, which offers maximum useability of all tape facilities. Even though the 2900 has this comprehensive system of input, tape, tone, and output control, sonic excellence is still the primary concern at SAE. Our new ultra low distortion phono and line circuits have been carefully developed to provide the clarity and definition that establish the 2900 as still another of SAE's Components for the Connoisseur.

 

Features:

Phono Circuit

The most critical single component of any preamplifier is the phono section. Our multi-stage design ensures that all active devices will operate well within their design parameters. This careful attention to linear area operation minimizes any distortion or slewing problems. Further, active devices for this stage are hand selected for optimum performance. The result of these efforts? A circuit that delivers optimum performance from any of the fine phono cartridges available.

Parametric Equalizer

This unique tone control system is the result of years of extensive research into the purpose and uses of tone networks. With the parametric you now have the flexibility to precisely contour the tone network to create any desired effect. Every effect, from conventional wide-band bass and treble, to continuously variable notch filters, or virtually anything in between, is at your fingertips. This system, considered the standard of the recording industry , is now available to you in the 2900

Taping Facilities

Tape circuits and their uses have received careful scrutiny during the 2900's development. The end product of this scrutiny includes provisions for 3 tape machines or other devices and the ability to monitor any of these circuits. Now you can copy from any tape circuit to another tape circuit, and while copying you can monitor either machine or another source. Besides these capabilities, the following features are provided to further extend the 2900's tape capabilities.

Tape EQ.

Now you can create your own special effects, or overcome program problems. With the Tape EQ feature, our unique Parametric tone circuit can be switched between the source you wish to record, and your tape machine. Creation of background music or car stereo tapes is a simple matter with the 2900.

Filters

The 2900 provides two low frequency filters for optimum bass control. The first is at 30 Hz, designed to remove rumble and other subsonic phenomena that may compromise musical quality. The second filter operates at 100 Hz, to correct low bass accentuated by room characteristics, speaker placement and program material. To increase their effectiveness these filters are combined in the EQ group. This allows them to be switched to before or after the tape circuits along  with the Parametric. Being able to switch the filters ahead of the tape circuits ensures that rumble and other subsonic problems that may distort the recordings you wish to make will now  be removed.

 


Specifications

Total Harmonic Distortion (at any level to rated output from 20 Hz to 20 kHz):  less than 0,01%

Intermodulation Distortion (at any level to rated output with any two mixed frequencies between 20 Hz and 20 kHz at a 4/1 voltage ratio):  less than 0,01%

Rated Output:  2,5 Volts RMS

Phono

Frequency Response (RIAA Equalized):  20 Hz to 20 kHz ±0,25 dB

Signal-to-Noise Ratio (20 Hz to 20 kHz. Ref. 10 mV input at 1 kHz):  greater than 75 dB

Input Overload (at 1 kHz):  greater than 150 mV

Gain:  35 dB (to tape out); 60 dB (to pre out)

Line

Frequency Response:  20 Hz to 20 kHz ±0,25 dB

Sn (20 Hz to 20 kHz. Ref. 2,5 V RMS out)"  greater than 95 dB

Maximum Output (10 k   load):  9 Volts RMS

Minimum Load:  600  

Gain:  25 dB

Power Requirements:  110 - 125 V AC, 50 -60 Hz

Power Consumption:  25 watts

Dimensions (W x H x D): 

Front Panel (W x H): 483 x 133 mm (19" x 5,25")

Chassis (D):  89,9 mm (3,5 ") excluding knobs and connectors

Weight:  4,08 kg (9 lbs)

 

Dokorder 8090A cassette deck

Complete your stereo system with a superb 4-trackk cassette tape deck to match the Dokorder Dub-A-Tape system or other fine stereo systems.

This highly functional solid state model perform in a manner that completely belies the price - considerably below that of other high quality units.

Redesigned to add even greater utilization to its known high performance, this model meets you face to face for vertical stacking in the Dokorder Dub-A-tape stereo system, or it may be wall-mounted. All controls are on the face, including the cassette compartment. A touch of the Stop/Eject button halts the tape, while full depression snaps open the cassette compartment for partial ejection - to protect it from dropping - yet handy for removal.

All controls are before you for instant use. In logical sequence you have the five push-buttons - Stop, Play, fast-Forward, Rewind and Record. To prevent accidental erasures both Play and Record must be pushed simultaneously. At hand are twin volume controls (left one pushes in for on-off) which control both recording and playback levels.

Separate VU meters (one for each channel) operate in both record and playback modes and are lighted when power is on. The face panel provides two convenient jacks, a Mic  jack with an impedance of 10 k   and a headset jack with a 10 - 20 k   impedance.

Quality engineering includes 22 carefully selected transistors and diodes for a wide 40 to 7,5000 Hz in frequency response. A built-in pre-amplifier enables you to monitor any program being recorded.



Dokorder 8080A 8-track player

An exciting 8-track stereo cartridge player for powerful reproduction of all popular 8-track cartridge tapes

This attractive Dokorder component has been designed and built to deliver rich stereo performance from popular 8-track stereo cartridges thoughout a wide 40 to 8,5000 Hz frequency response range.

Because its usage has been limited to playing tapes by design, the 8080A is a very specialized component. All of its ten transistors and diodes, as well as every other internal engineering feature, have been concentrated to ensure an accurate, unwavering speed of 3-3/4 ips, greater channel separation and a better Signal-to-Noise Ratio. The result is richer, more professional stereo reproduction. The attractive 8080A is also easy and convenient to operate.

A single push button selector allows the operator to choose any one of four programs in a cartridge, while four easy-to-see indicator lamps allow him to see the program being played. An Auto/Repeat switch enables the 8080A play all four programs consecutively, or to continue repeating any single program until stopped by the operator.

A spring door over the entrance of the cartridge compartment moves up when a cartridge is inserted, but flips down when a cartridge is removed to keep the playing heads free of dust and other foreign elements.

Designed and color coordinated to form an intrinsic part of the Dekoder Dub-A-Tape stereo system, the 8080A offers top stereo cartridge performance in any quality stereo system.

Dokorder 8060A amplifier

A completely new 100 watt stereo control amplifier - the heart of a new approach to stereo system

There are two ways to look at the sensational Dokorder 8060A solid state control amplifier as a powerful foundation for any existing stereo system or as the heart of Dokorder's new and completely integrated Dub-A-Tape series of stereo components.

Any way you look at the Dokorder 8060A has the credentials and ability to do the job better than any comparably sized and priced amplifier you can buy. Its all solid state circuitry, complete with a pair of sophisticated integrated Circuits IC, offers a full 100 watts in power output a wide power bandwidth from 15 to 50,000 Hz and an extremely low distortion figure of only 0,5% at rated output.

This performance is complemented by no fewer than 6 outputs and 4 inputs, a two-speaker system selector, special circuitry for power transistor protection and easy-to-use controls, including the latest sliding graphic type for volume.

Every bit indicative of the 8060's careful internal engineering is its handsome and functional styling. Any control that isn't absolutely essential has a clean, refined appearance which makes it a standout in any multi-component system, as well as an intricate part of Dokorder's handsome black paneled and rationally designed Dub-A--Tape series of stereo components.

Sony ST-3950 tuner

Sony FM Stereo / FM-AM Tuner

The ST-3950 is Sony's answer to the audiophile's need for ultra-high tuner performance, without a correspondingly high price tag. The new tuner, which includes a Dolby noise reduction system, is built to satisfy demanding listening standards, while also providing the convenience of top-notch tuning and control facilities.

 

Features:

MOS FET RF amplifier

RF front-end electronics untilized into 4-gang tuning capacitor assembly

Buffered local oscillator for high spurious and AM suppression

Two 4-element uni-phase IF filters, plus 5 stages of limiting IF differential amplifier and quadrature detector

Phase-Locked-Loop IC stereo MPX stage

Direct coupled audio output amplifier with separate power supply

Dolby noise reduction system for decoding Dolbyized FM broadcasts, and Dolby indicator light.

Center station and signal strength/multipath meters

Dial pointer with LED station indicator, plus smooth flywheel tuning action

Frequency linear calibration for both FM and AM dial scales

FM interstation muting with FET circuit

FM discriminator output for future 4-channel FM

High Blend Switch

Variable output level control to match tuner with other program sources, and 2 pairs of audio output terminals

Automatic mono/stereo switching, and stereo indicator light

Wooden side panels included

 

FM Section

FM circuitry incorporates the same type of advanced electronics which are used in Sony's most expensive tuner. To start, the front-end is unitized into the 4-gang tuning capacitor assembly - a Sony construction that assures ultra-high stability, almost permanent alignment and an extra-high degree of accuracy in dial calibration. Nextt, the MOS FET RF amplifier assures high sensitivity and interference rejection. The local oscillator is equipped with a buffer amp, for good spurious response rejection and AM noise suppression, plus high stability with strong input signals. IF design features two 4-element uni-phase IF filters. These new devices provide for good selectivity while at the same time maintain a wide band-pass characteristic, with high phase linearity. This means there's no trade-off between excellent selectivity and low audio distortion.

Additionally, the IF section includes a stage of differential amplification, 5 stages of limiting and a quadrature detector - for excellent caapture and Signal-to-Noise ratios and high AM suppression.

For FM stereo decoding, there's a Phase -Locked-Loop IC, a circuit element which accounts for the unit's superior stereo performance - wide separation across a wide range, and low distortion. A direct coupled audio amplifier stage, with an independent, stabilized power supply circuit, completes the final stage design, assuring low distortion and wide dynamic range.

For listening to the growing number of fine music programs broadcast with Dolby encoding, the ST-3950 features a built-in system that simplifies the decoding process to one step, one touch. This eliminates the need for an outboard noise reduction unit, along with the complication of altered FM de-emphasis.

 

AM Section

Because Sony designed the AM section with only-top-quality elements - like a balanced AM mixer circuit - the ST-3950's AM performance is exceptionally good. Listening to AM only broadcasts over the ST-3950 will not offend sound connoisseurs, since the AM ssound approaches hi-fi level.

 

Tuning

Precision and luxury combine to make tuning the ST-3950 a smooth, comfortable process. The unit's highly readable tuning meters provide for pinpoint accuracy - even in crowded urban dial areas where the multipath reading can provide additional aid.

The wide, frequency linear dial scale and LED equipped dial pointer also provide for high readability. And the large flywheel-coupled knob provides an added touch ofluxury with ultra-smooth action

 

Specifications

FM Tuner Section

Antenna Terminals:  300 Ω (balanced), 75 Ω (unbalanced) F-coaxial connector

Usable Sensitivity (IHF '58):  1,7 µV

50 dB Quieting Sensitivity: 

Mono :  3,0 µV

Stereo :  40 µV

Signal-to-Noise Ratio: 

Mono :  75 dB

Stereo :  70 dB

Capture Ratio:  1,0 dB

Selectivity:  50 dB

Image Rejection:  80 dB

IF Rejection:  100 dB

Spurious rejection:  90 dB

AM Suppression:  56 dB

Total Harmonic Distortion:

At 100 Hz

Mono :  0,15%

Stereo :  0,25%

At 1 kHz

Mono :  0,15%

Stereo :  0,25%

At 10 kHz

Mono :  0,2%

Stereo:  0,6%

IMDistortion: 

Mono :  0,15%

Stereo : 0,3%

Frequency Response:  30 Hz - 15,000 Hz  +0,3 -1,5 dB

Stereo Separation

At 100 Hz -  35 dB

At 1 kHz - 40 dB

At 10 kHz - 35 dB

RF Intermodulation:  65 dB

Subcarrier product Ratio:   60 dB

SCA Suppression:  60 dB

AM Tuner Section

Antenna:  Built-in ferrite bar antenna w/terminal for ext.wire

Sensitivity: 

250 µV/m (w/built-in antenna)

100 µV (w/ext. Antenna)

Selectity:  35 dB at 50 mV/m

Signal-to-Noise Ratio:  50 dB at 50 mV/m

Image Rejection:  40 dB at 1,000 Hz

Total Harmonic Distortion: 0,5% at 50 mV/m, 400 Hz

General Section

Output Level/Impedance 9at 100% modulation)

Fixed : 750 mV / 10 k Ω

Variable : 1,5 V / 1,5 k Ω at max

Discriminator :  150 mV/2,5 k Ω

Semiconductors:  4 ICs , 5 FET, 34 Transistors, 15 Diodes, 1 LED

Power Requirements:  AC 120 V, 220 -240 V, 50/60 Hz

Dimensions (W x H x D):  460 x 170 x 335 mm

Weight:  8 kg (17 lb 10 oz)

Altec Lansing Model Three II loudspeakers

Altec Lansing Model Three series II

Efficiency. What does it mean? It means a lot of sound out from a little power in - yes, always. It means large components and cabinets - well, most of the time. It means expensive systems - practically all of the time. But not with the Model Three. The Three is a system of moderate size and price with an efficiency level rivaling much more expensive systems. Efficiency, or sensitivity, is one of the most important yet most overlooked performance parameters. It indicates how much acoustic output a speaker can deliver for a given amount of electrical input. The larger the number, the more sensitive the speaker.

As an example, if a speaker has a sensitivity rating of 90,5 dB SPL, as does the Three, it will have more than 10 times the acoustic output as another speaker with a rating of 80 dB SPL, with the same input power. This is like multiplying the amplifier's power by 10. your 20-watt receiver just becomes a 200-watt super-amp.

The Three gets its efficiency from its 10-inch bass driver (which features a quality die cast frame) and optimally tuned, vented enclosure. The unique low-loss magnet structure creates a high level of flux in the gap, allowing the lighter-than-normal cone/voice coil assembly to be excited with small amounts of power.

A 12 dB per octave dividing network provides signal transition at 1500 Hz to a 4-inch  frame cone-type driver for high-frequency reproduction.

The hand-rubbed oak veneer cabinet and stretched knit grille form gracefully styled piece of furniture constructed of quality, natural materials that have virtually disappeared from other speaker systems in the price range of the Model Three.

 


Specifications

Speaker Components:

Low Frequency :  10" bass driver

High Frequency :  4" frame cone driver

Nominal Impedance:  8

Crossover Frequency:  1500 Hz

Enclosure Type:  Vented

Sensitivity:  90,5 dB SPL (Measured at 4 feet, 1 watt input referenced to 8 , using pink noise which has been limited to a bandwidth of 500 Hz to 3 kHz)

Frequency Response:  50 Hz to 20 kHz

Dispersion (Measured with pink noise limited to a bandwidth of 800 Hz to 8 kHz at a distance of 4 feet):

Vertical :  120° at -6 dB

Horizontal :  140° at -6 dB   

Long Term Broad Band Maximum Power:  35 watts (measured with a source of pink noise limited to the frequency response bandwidth of the system, over an extended time period)

Operational Power Range:  10 watts to 100 watts (Recommended for use with amplifiers between these levels)

Long Term Maximum Acoustic Output:  106 dB SPL at 35 watts  (measured with a source of pink noise limited to the frequency response bandwidth of the system, at a distance of 4 feet)

Finished:  Hand-rubbed oiled oak

Grille:  Acoustically transparent black knit fabric mounted on removable frame)

Dimensions (W x H x D):  318 x 609 x 292 mm (12-1/2" x 24" x 11-1/2")

Weight:  12 kg (26,25 lbs)

Royd Eden loudspeakers

The Eden loudspeaker

The Eden is the latest and most exciting development if our range of compact loudspeakers. It is the logical step forward from our established A7 and Coniston R models and as such represents the result of 7 years of continuous research and development. We believe The Eden offers the most satisfying musical performance for a loudspeaker of its size in today's market. Like all our compact loudspeakers it is designed to be used close to a wall.

 the Eden features Royd's unique modified reflex bass loading to give you accurate bass reproduction and underpin the outstanding musical performance. Cabinet panel resonances have been eliminated by very heavy and rigid laminated construction.

The drive units developed for this loudspeaker are ideally matched to each other and to the cabinet. The tweeter is a 19 mm polyamide dome with vented centre magnet system and dual cavity, critically damped, rear loading to give you exceptional transparency and clarity. The coil is wound on an aluminium former and is cooled and damped by ferrofluid. The bass unit chassis is an aluminium die casting to provide the strength and rigidity essential for fast and accurate sound reproduction and is retained in the cabinet by eight screws reinforced by silicone rubber sealing. The chassis also provides the large free area behind the cone essential to minimise reflection of sound waves and give you uncluttered, detailed reproduction. Because the drive units are so well matched, the crossover circuit is uncomplicated thus allowing the signal from your amplifier to be revealed unhindered.

The loudspeakers are available in either passive form with internal crossovers, at extra cost, are available for use with the active version.

The speaker are designed for use on good quality stands or wall brackets, with their backs close to a wall.

 


Specifications:

Recommended Amplifier Power:  20 - 40 watts

Sensitivity:  90 dB

Peak Power Handling:  60 watts

Nominal Impedance:  8

Crossover Frequency:  4 kHz

Bass Resonance Frequency:  57 Hz

Dimensions (W x H x D):  203 x 305 x 190 mm

Weight:  14 lbs

Finish:  Walnut or Black Ash Veneer

Akai AA-5500 amplifier

Solid State Stereo Pre-Main Amplifier

This dynamic 120 W music power stereo pre-main amplifier is ahead of its time with highly advanced circuitry, multiple amplifier convertibility, versatility, and design. SEPP-ITL-OTL circuit and power bandwidth of 20to 45 Hz for full dynamic range and the realization of less than 0,1% distortion. The direct-coupled preamplifier and phono amplifier circuits utilize spece-age integrated circuits for superb tone quality. The playback and recording jacks can be used separately or simultaneously for varied recording and playback techniques. Multiple input, output and speaker connections. The pre and the main amplifiers can b separated for future multiple amplifier operation. Attractive design to blend in with any audio components.

 


Specifications:

Music Power Output:  60 W/ 60 W at 4  or 40 W / 40 W at 8

Rated Power Output:  45 W/ 45 W at 4   or 30 W/ 30 W at 8  (0,8% I.H.F.)

Rec Output: 

PIN :  150 mV

DIN :  25 mV

Input Sensitivity:

Aux :  150 mV

Tuner :  150 mV

Phono 1, 2 :  3 mV

Tape 1, 2 :  150 mV

Mic :  1 mV

Total Harmonic Distortion.  Less than 0,1% at 10 W, 8

Frequency Response:  20 to 50,000 Hz _3 dB (20 to 50,000 Hz-5 dB at 0 dBm, 8 )

Hum and Noise:  less than -44 dBm , Volume Minimum

Signal-to-Noise Ratio

Aux :  more than 70 dB

Tuner :  more than 70 dB

Phono 1, 2 :  more than 65 dB

Tape 1, 2 :  more than 70 dB

Mic :  51 dB

Tone Controls

Bass :  ±10 dB at 100 Hz

Treble :  ±10 dB at 10,000 Hz

Loudness Control:  7 dB (+_1,5) at 100 Hz and 4 dB (±1,5) at 50 Hz (-10 dBm output)

Filters: 

Low Cut Filter :  -12,5 dB (±1,5) at 50 Hz

High Cut Filter :  -6 dB (±1,5) at 10 kHz

Mute Level:  -20 dB ±1

Power Bandwidth:  20 to 45,000 Hz (20 to 30,000 Hz at 15 W, 8 , 0,8 I.H.F.)

Semiconductors:  17 Transistors; 5 ICs; 10 Diodes; 2 Varistor: 1 SCR

Power Requirements:  100 - 240 V AC 50/60 Hz

Power Consumption:  300 W

Dimensions (W x H x D):  432 x 143 x 330 mm (17,2" x 5,7" x 13,2")

Weight:  9,9 kg (21,8 lbs)