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 GX-255 (1978)

Akai Stereo Tape Deck

Auto-reverse Playback in Stereo

Compact, attractively designed 4-track, 2-channel stereo tape deck for those who are satisfied with nothing less than fully professional sounding stereo recordings. Features auto-revers playback, Akai's exclusive GX Head for peak sound fidelity and light pressure IC logic control buttons.

Specifications

Track System: 4 track 2 channel stereo/monaural system

Reel Capacity: Up to 7 inch reel

Tape Speed:

19 cm/s ±0,8% (7½ ips.)

9.5 cm/s ±1% (3¾ ips.)

Wow & Flutter:

Less than 0,04% W RMS; 0,10% DIN 45500 at 19 cm/s

Less than 0,06% WRMS; 0,12% DIN 45500 at 9.5 cm/s

Frequency Response:

30 - 24,000 Hz ±3 dB at 19 cm/s (WR tape)

30 - 19,000 Hz ±3 dB at 9.5 cm/s (WR tape)

Distortion: Less than 0,5% (at 1,000 Hz 0 VU)

Signal to Noise Ratio: Better than 61 dB DIN 45500 at 19 cm/s

Erase Ratio: Better than 70 dB (at 1,000 Hz)

Cross Talk: Better than 40 dB (at 1,000 Hz)

Channel Separation: Better than 55 dB (at 1,000 Hz)

Bias Frequency: 100 kHz

Heads: 4 (GX recording head; GX forward playback head; GX reverse playback head and erase head)

Motors: 3 (One A.C. servo motor for capstan drive; Two Eddy Current motors for reel drive)

FF. & RWD. Time: 75 sec. using 360m (1,200 ft.) Tape

Output Jacks:

Two Line; 0.775V (0 VU) Required load impedance: more than 20 kΩ

One Phone; 100 mV/8Ω

Input Jacks:

Two Microphone; 0.25 mV Required microphone impedance: 600 Ω

Two Line; 70 mV Input impedance 100 kΩ

DIN Jack:

Input; 2.0 mV Input impedance 10 kΩ Output; 0.3 V

Power Requirement:

120V 60 Hz for U.S.A. & Canada

220/240V, 50/60 Hz switchable for Europe, UK & Australia

110/120/220/240V,50/60 Hz switchable for the other countries

Dimensions (W x H x D): 440 x 419 x 242 mm (17,3" x 16,5" x 9,5")

Weight: 16 kg (35,3 lbs.)







































Accuphase M-60

The Accuphase Monophonic Power Amplifier Model M-60 was completed after extensive engineering efforts in which perfection was sought without compromises. Monophonic design was chosen to completely eliminate any possibility of inter-channel interferences from power supply circuit and wirings, and also to feature a handy weight so that it can be handled even by one person. The M-60 provides 19" rack mounting facilities and a cannon type input terminal for studio monitor or PA system applications.

Specifications

Power Output (from 20Hz to 20 kHz, 0,1% THD):

450 watts, min. RMS at 4 ohms,

300 watts,min. RMS at 8 ohms,

150 watts, min.RMS at 16 ohms

THD (from 20 Hz to 20 kHz at any power output from 1/4 watt to rated power):

4 ohms; 0,1% max.

8 ohms; 0,1% max.

16 ohms; 0,1% max.

Intermodulation Distortion: 0,1% at rated power output (for any combination of frequencies between 20 Hz and 20 kHz)

Frequency Response:

20 Hz - 20,000 Hz; +0, -0,2 dB at rated power output

2 Hz - 90,000 Hz; +0, -3 dB at rated power output

Damping Factor: 45 (at 8 ohms load, 20 - 20,000 Hz)

Rise Time: 3 μSec.

Slewing rate: 25 V/μSec.

Input Sensitivity and Impedance: (2,0 Volts, 100 kohms, for rated output at the max. level control)

Hum and Noise: 100 dB below rated output

Output Load Impedance: 4,8 and 16 ohms

Subsonic Filter: cutoff frequency 17 Hz, 18 dB/oct.

Power Level Meter: switchable for Volume Level and Peak level, calibrated to read 0 dB - 300 watts into 8 ohms load and capable of directly reading down to -50 dB (3 mW)

Attenuator: precision, 1 dB stepping type

Power Requirement: 100, 117, 220, 240 V, 50/60 Hz

Power Consumption: 65 watts at zero signal output;

540 watts at rated otput (8 ohms load)

800 watts at rated output (4 ohms load)

Semiconductor Complement: 47 transistors, 51 diodes, 3 IC's

Dimensions (W x H x D): 482 x 170 x 345 mm (19" x 16-11/16" x 13-9/16")

Weight net: 27 kg (59,4 lbs)

Merry Christmas! Buon Natale!

Thorens TD-524 (1982)

With this project, Thorens intended to offer disc-jokeeys, dance teachers and professional users, a transcription turntable meeteing thier specific requirements both from the basic performances and from the convenience of use points of view.

Considering the exacting operation conditions, new solution had to be found in order to guarantee uncoloured reproduction in this particular field. The lay-out of all function controls as well as the specific requirements for this turntable have been developped in cooperation with several renowed disc-jokeys. The acoustic characteristics of the TD-524 have also been tested and refined in some of the most reputed discotheques.

The heavy casting chassis is resiliently suspended in a massive wooden base. The spring suspension elements have been meticulously calculated in order to suppress any vibrations or acoustic feedback.

The rotational vibrations occasioned by the fast start of the unit are eliminated by means of a special compensation device. The turntable platter has a diameter of 330 mm and it incorporates a cueing ring. The momentum of inertia of the platter amounts to 200,000 gr/cm². The high damping rubber mat prevents any vibration of both the platter and the record.

Equipped with the isotrack TP16L tonearm, the turntable TD-524 can be used either manually or with semiautomatic operation. Luminescent diodes indicate the selected mode.

Specifications

Drive system: Direct Drive Thorens

Motor: Low polarity DC motor with 256 pole tachogenerator-incorporated long life lubrification system

Motor speed contol: Quartz

Pitch control: ±6% resp. ±25% commutable

Speeds: 33, 45, and 78 rpm

Speed accuracy: ±0

Turntable Platter: Aluminium alloy with high damping rubber mat

Platter diameter: 330 mm with cueing rubber mat

Rumble unweighted: -52 dB according to DIN 45539

Wow and flutter:

measured with test record: <0,035% according to DIN 45507

Calculated value resulting from the desing: <0,01%

Tonearm Isotrack TP16 (Long)

Effective lenght: 245 mm

Offset angle: 22°

Scating compensation: magnetic force without friction

Stylus pressure appliance: by calibrated spring

Bearing friction: ±0,15 mN (15 mg) in both planes

Cartridge fitting: standard 12" centres

Remote controlfor: Tonearm lift, start-stop, pitch control, start from the mixing console, commutation between quartz lock

Dimensions: 500 x 445 x 180 mm

Ruark Classic Sceptre

Ruark's new Classic Serie loudspeaker, the Sceptre, replaces the popular Swordsman model. It is a compact two-way reflex-loaded design using a 170 mm bass/midrange driver and a 28 mm silk fabric type tweeter.
A simple eight-element crossover is employed, centred on 2000 Hz. The bass driver has been custom built for the Sceptre. Finished in a choice of real wood veneers.


Specifications
"Ruark Serie Classic"
Monitor Loudspeakers.
System type: Bass Reflex with 2 Ways.
Drive units:
Bass/Mid: 170 mm treated paper cone, pure rubber surround,precision cast chassis,high flux low leakage double magnet system
Tweeter: 28 mm silk fabric dome, ferrofluid cooled and damped, balanced magnet construction.
Frequency: 50 Hz - 20 kHz ±3 dB
Sensibility: 88 dB/1 Watt
Crossover frequency: 2 kHz (Precision audio grade components, 8 element)
Nominal Impedance: 8 ohms
Amplifier Requirements: 20 - 100 watts
Cabinet: Stand or shell mount ACZD. Damped particle board with MDF front and Rear baffle
Finish: Veener in Natural Cherry, oak, walnut, rosewood and black oak
Dimensions (HxWxD): 380 x 210 x 300 mm
Weight: 10 Kgs each.

Ruark Classic Icon

Ruark's new entry level loudspeaker, the Icon, replaces the popular Swordsman model. It is a compact two-way reflex-loaded design using a 140mm bass/midrange driver and a 25mm doped fabric type tweeter.
A simple eight-element crossover is employed, centred on 2200Hz. The bass driver has been custom built for the Icon. Finished in a choice of real wood veneers.

Specifications "Ruark Serie Classic"
Monitor Loudspeakers.
System type: Bass Reflex with 2 Ways.
Drive units:
Bass/Mid: 140mm treated NRSC paper cone, High loss rubber surround, injection moulded chassis, low leakage double magnet system
Tweeter: 25mm fabric soft dome, ferrofluid cooled and damped with low leakage balanced magnet assembly.
Frequency: 58 Hz - 20 kHz ±3 dB
Sensibility: 88 dB/1 Watt
Crossover frequency: 2,2 kHz (Precision audio grade components, 8 element)
Nominal Impedance: 8 ohms
Amplifier Requirements: 20 - 100 watts
Cabinet: Stand or shell mount ACZD. Damped particle board with MDF front and Rear baffle
Finish: Veener in Natural Cherry, oak, walnut, rosewood and black oak
Dimensions (HxWxD): 350 x 190 x 260 mm
Weight: 6 Kgs each.

Janszen Model Z-210

Over the years the electrostatic loudspeaker has been recognized by audiophiles as the most accurate acoustic transducer. Its widespread use has been limited in the past by its high cost, rumors about problems with humidity and limited power capacity, and a general fear by the less sophisticated audiophile of such an unusual looking device, plus its esoteric operating principles.

Since Arthur A. Janszen developed what is known as the push-pull electrostatic element in 1949, JANSZEN has been manufacturing these speakers. Combining years of manufacturing experience with research, we have developed a new improved electrostatic radiator that truly represents fourth generation technology. This new driver is manufactured to tolerances so precise that typical units are within 0,5 dB of our specifications. Furthermore the new electrostatic have proven so totally reliable and rugged under all weather and power conditions that we have elected to offer an unprecedented "Five Year Conditional Warranty". The overall system is warranted for parts and labor for five years commencing on the date of original purchase from a franchised JANSZYN dealer. To deny the musical integrity of Janszen Electrostatic speakers would be to deny the laws of physics.

Special Features:

Super clean and smooth "mids" and "highs"

Solis bass

Efficient

Ultra-low distortion

Small size

Electrostatic sound at a modest price

Overall Acoustic Specifications

Frequency Response: 40 - 20,000 Hz ±3 dB; 35 - 30,000 Hz ±6 dB

Minimum RMS Power Required: 15 watts

Maximum RMS Power Handling: 74 watts

Low Frequency Transducer

Type: Dynamic, Acoustic Suspension

Cone Diameter: 254 mm (10 inch)

Voice Coil Diameter: 38,1 mm (1,5 inch)

Total System Resonance: 48 Hz

Q Factor (Damping Characteristic): 1,1

Crossover Configuration: Mass Loaded

Crossover Point: 800 Hz

Nominal Impedance: 4Ω

High Frequency Transducer

Type: Electrostatic

Radiating Area: 206 cm² (32 sq. inch)

Polarization Voltage: 1200 Vdc

Distortion THD 9Over operating range): 0,5%

Crossover Point: 1800 Hz 12 dB/octave

Dispersion: 50° Horizontal, 30° Vertical

Power Supply Type: Full Wave Voltage Multiplier

Power Requirements: Local AC Line Voltage, 50/60 Hz , 2 Watts

Dimensions (H x W x D): 470 x 318 x 280 mm (18½" x 12½x 11")

Cabinet Finish: Walnut Vinil (W) Black Cloth-Grill

Shipping weight: 12,5 kg (28 lbs) Pair

Axiom 80 for Goodmans

The Goodmans Axiom 80 is a 10-inch, twin-cone, full range loudspeaker, whose performance, in a prpoer enclosure is as astounding as its unique design.

The most revolutionary advance embodied in the Axiom 80 is its achievement of free cone suspension - the theroretical ideal that permits the cone to move as a true piston at low frequencies, without restriction and without distortion.

Another direct result is that the fundamental resonance of the Axiom 80 is only 20 cycles - lower than that of any other commercially available loudspeaker.

The new ARU Friction Loaded Enclosure represents the perfect solution to the enclosure requirements of this superb reproducer. The axiom 80, mounted in a Model C-1800 ARU Enclosure, will reproduce true bass fundamentals down to 20 cycles - with no "hang-over" and without peaks above that frequency. Mid-range reproduction is clean and articulate and the :highs" smooth to 20,000 cycles. All of this is accomplished without the use of special "tweeters" and elaborate crossover networks.

Power handling capacity of the single Axiom 80/ARU system is entirely siutable for use in most home systems (8 -12 watts, continuous program material: 4 -6 watts , RMS sine wave). Where greater power handling is desired, two Axiom 80 loudspeakers may be used together in the Model B-2800 ARU Enclosure or four may be used in the Model A-4800.

No multi channel system, however elaborate or costly, cansurpass in performance these dual and quadruple Axiom 80/ARU systems.

ARU Enclosures are now available in easy-to-assemble kits, supplied complete with the necessary precut lumber, grille cloth, padding, glue, hardware and the all-important ARU Acoustical Resistance Unit.

Astounding performance from 2o to 20,000 cycles with a single channel speaker system.

Goodmans "free suspension" Axiom 80 Loudspeaker in "friction loaded" Aru enclosure


Dimensions (H x W x D):

Model C-1800 (for 1 Axiom 80): 24" x 18" x 16"

Model B-2800 (for 2 Axiom 80): 26" x 20" x 20"

Model A-4800 (for 4 Axiom 80): 30" x 24" x 20"

Tannoy Westminster TW (1990)

The Westminster TW is a classic horn-loaded design driven by the best in modern Dual Concentric technology. This newly revised loudspeaker is capable of truly outstanding high fidelity reproduction while remaining an imposing and traditional piece of furniture. It is based around the famous 15-inch Tannoy twin-magnet Dual Concentric driver, now with the computer designed Tulip Waveguide for truly extended high frequency performance.

Fine walnut veneers and solid walnut edgings conceal a complex horn-loaded 25 mm particle board cabinet. The horn loading system gives greatly improved efficiency and a large wavefront area approaching that from real instruments. The Westminster TW offers high frequency energy tailoring through high current gold-plated switch blocks with controls for both treble energy and roll-off. Van den Hul wiring is used throughout. Signal handling is via gold-plated terminals with captive link bi-wire/normal wiring and a hard-wired time compensated crossover network. The combination of this closely integrated mid band and single point source guarantees exceptionally realistic stereo imaging.

The Tannoy Westminster TW is effortessly capable of the realistic stereophonic reproduction of truly low frequencies and of the widest dynamic ranges.

Specifications

Power Rating: 125 watt RMS (520 watt peak)

Recommended Amplifier Power: 50 - 200 watt/channel

Sensitivity ( 2,83 V at 1 m): 99 dB

Maximum SPL: 120 dB at 1m for 125 watt RMS (126 dB at 1m for 520 watt peak)

Nominal Impedance: 8 ohm

Minimum Impedance: 5,5 ohm

Frequency Response: 18 Hz - 25 kHz , ±3 dB

Crossover Frequencies:

300 Hz acoustical;

1000 Hz electrical

Crossover Control:

±3 dB over 1 kHz to 25 kHz shelving;

+2 dB to -6 dB per octave over 5 kHz to 25 kHz slope

Crossover Type: 1st order LF; 1st order HF,

Bi-wired, hard-wired, passive, low-loss,time compensated Type 1109

Driver Type: 15-inch Dual Concentric High Compliance Type 3858

Enclosure Type: Compound horn

Enclosure Volume: 521 litre

Dimensions (H x W x D): 1290 x 1030 x 636 mm (1490 x 1080 x 680 mm packed)

Weight: 116 kg complete (132 kg packed)

Enclosure Material: Solid walnut with 25 mm particle board, crossbracing and heavy internal damping

Pioneer QX-949 (1974)

Pioneer's QX-949 stereo receiver is the most complete 4-channel unit now on the market. Boasting a built-in CD-4 demodulator as well as regular matrix and SQ matrix decoding circuitry - plus a prodigious power output - the QX-949 is prepared to deliver superlative sound from all 4-channel discs, tapes and FM broadcast now available today. It is truly a one-of-a-kind receiver, Pioneer's most distinguished contribution to the art of 4-channel sound. Inclusion of the CD-4 demodulator means that, for the first time, one professional 4-channel receiver is capable of decoding and reproducing all 4-channel sources. No longer must the hi-fi enthusiast add multiple additional components, like a demodulator, to his system to achieve perfect 4-channel sound. The QX-949 does it all, and does it better than any other receiver. Power of this unit is vast - 40W x 4 of continuous RMS power with all 4 channels driven at 8 ohms. And this figure is measured at the most critical listening range, within the audible human range of 20 - 20,000 Hz. Better yet, when you choose to use the QX-949 for conventional two-channel sound, it will give you 60W x 2 of continuous RMS power, by the use of a new "Power Boosting Circuit". And that's a lot of power by anyone's standards. The AM/FK tuner section of the QX-949 is a classic of sensitivity and selectivity, thanks to its four-gang variable capacitor and phase-linear ceramic filters.

Other features include a 4-channel level indicator that illuminates any adjustments you might make'when listening to 4-channel sound. The unit also handles four pairs of speaker systems (two in the front, two in the rear, each operated independently or simultaneously) and three tape decks for tape-to-tape duplication. The QX-949 also hooks up two turntables and an additional auxiliary source. For any kind of 4-channel sound-regular matrix, CD-4, SQ or discrete, along with regular two-channel sound - the QX-949 is a milestone event in music reproduction.

The Latest CD-4 Demodulator

Playing CD-4 records with full fidelity and space expanding four channel realism is easy withthe Pioneer QX-949. They have a built-in CD-4 demodulator of the latest design, clear sound localisation in the four channels is achieved by simple manipulation of CD-4 separation controls.

SQ Full Logic Matrix Decoder

Newly developed integrated circuits for the matrix logic and gain control section of this advanced full logic SQ decoder help to obtain the very best separation between the front and rear, as well as the left and right channels, essential for the true to life reproduction of sound field when you play an SQ encoded four channel record throught either the Pioneer QX-949.

Regular Matrix (RM) Decoder

The RM position on the four channel mode selector of both Pioneer QX-949 is to be used when you play any matrix four channel record other than SQ or wish to synthesise four channel stereo from a normal stereo disc.

Other Four Channel Features:

A 4 CH-MPX out terminal is located on the back panel enabling you to hook up an FM four channel adaptor to receive FM discrete four channel broadcast when they become available in the future.

A four channel level indicator.

In addition to this advance quadraphonic performance the QX-949 A offers excellent FM - AM tuner performance with very wide stereo separation thanks to:

FM front end with MOS FET

Local oscillator with buffer circuit (QX-949 A)

Excellent phase linearity and high selectivity.

High performance multiplex integrated circuit.

Effective FM muting switch.

Linear FM dial scale and tuning meter.

Outstanding AM section

All The Power You Need For A BIg Four Channel Sound; QX-949 produce 40 watts per channel at 8 ohms (4-channel driven) 20 Hz to 20 kHz with no more than 0,3% THD

Specifications QX-949

Audio Section

Continuous power:

4 x 58 W; 2 x 85 W (1 kHz, 4Ω)

4 x 44 W; 2 x 65 W (1 kHz, 8Ω)

4 x 40 W; 2 x 60 W (20 - 20,000 Hz, 8Ω)

75 W/ 4-ch.; 100 W/2-ch. (each channel driven DIN 1kHz, 4Ω)

THD at rated output power 1 kHz, 8Ω (IHF): <0,3%

THD at 4 x 50 mW, 8Ω, 1 kHz (DIN): <0,2%

Power bandwidth 4 channels driven: 7 Hz - 40 kHz

Frequency response at AUX input DIN: 7 Hz - 25 kHz (+0,5 dB, -1 dB)

Input sensitivity impedance:

Phono: 2,5 mV/50 kΩ

Tape monitor, Tuner, Aux: 150 mV/100 kΩ

Bass control (100 Hz): ±10 dB

Treble control (10 kHz): ±10 dB

CD-4 Demodulator Section

Input sensitivity: 2,5 mV

Input impedance: 100 kΩ

Distortion: 0,07%

Signal-to-noise ratio: >70 dB

Separation 1 kHz: 50 dB (left to right); 30 dB (front to rear)

Frequency response: 20 Hz - 15 kHz

FM Section (87,5 to 108 Hz)

Sensitivity:

IHF: 10,3 dBf

DIN (26 dB S/N ratio, 40 kHz dev.): 1,2 μV

Capture ratio: 1 dB

Selectivity (±400 kHz): 80 dB

S/N ratio (mono): 70 dB

Image rejection: >85 dB

THD (stereo) 1kHz: <0,4%

Stereo separation 1 kHz (DIN): >40 dB

Subcarrier suppression: 65 dB

MW Section (525 - 1605 kHz)

Sensitivity (IHF): 15 μV/m

Image rejection: >65 dB

IF rejection: >85 dB

S/N ratio: 50 dB

Power consumption: 530 W

Dimensions (W x H x D): 550 x 160 x 440 mm

Weight: 22,4 kg

Pioneer QX-747 (1974)

Pioneer has studied the problem of quadraphonic receivers with the aim of enabling you to play every four channel program source a available today - and tomorrow, and they have succeeded, it's all four channel in four different ways.

The Latest CD-4 Demodulator

Playing CD-4 records with full fidelity and space expanding four channel realism is easy with the Pioneer QX-747. They have a built-in CD-4 demodulator of the latest design, clear sound localisation in the four channels is achieved by simple manipulation of CD-4 separation controls.

SQ Full Logic Matrix Decoder

Newly developed integrated circuits for the matrix logic and gain control section of this advanced full logic SQ decoder help to obtain the very best separation between the front and rear, as well as the left and right channels, essential for the true to life reproduction of sound field when you play an SQ encoded four channel record throught either the Pioneer QX-747 .

Regular Matrix (RM) Decoder

The RM position on the four channel mode selector of both Pioneer QX-747 is to be used when you play any matrix four channel record other than SQ or wish to synthesise four channel stereo from a normal stereo disc.

Other Four Channel Features:

A 4 CH-MPX out terminal is located on the back panel enabling you to hook up an FM four channel adaptor to receive FM discrete four channel broadcast when they become available in the future.

A four channel level indicator

All The Power You Need For A BIg Four Channel Sound

QX-747 A produces 20 watts per channel at 8 ohms (four channels driven) 20 Hz to 20 kHz with a total harmonic distortion of 0,5%

Specifications QX-747 A

Audio Section

Continuous power:

4 x 30 W; 2 x 55 W (1 kHz, 4Ω)

4 x 25 W; 2 x 45 W (1 kHz, 8Ω)

4 x 20 W; 2 x 40 W (20 - 20,000 Hz, 8Ω)

45 W/ 4-ch.; 65 W/2-ch. (each channel driven DIN 1kHz, 4Ω)

THD at rated output power 1 kHz, 8Ω (IHF): <0,5%;

THD at 4 x 50 mW, 8Ω, 1 kHz (DIN): <0,2%

Power bandwidth 4 channels driven: 7 Hz - 40 kHz

Frequency response at AUX input DIN: 10 Hz - 25 kHz (+0,5 dB, -1 dB)

Input sensitivity impedance:

Phono: 2,2 mV/50 kΩ

Tape monitor, Tuner, Aux: 140 mV/100 kΩ

Bass control (100 Hz): ±10 dB

Treble control (10 kHz): ±10 dB

CD-4 Demodulator Section

Input sensitivity: 2,5 mV

Input impedance: 100 kΩ

Distortion: 0,07%

Signal-to-noise ratio: >70 dB

Separation 1 kHz: 50 dB (left to right); 30 dB (front to rear)

Frequency response: 20 Hz - 15 kHz

FM Section (87,5 to 108 Hz)

Sensitivity:

IHF: 10,8 dBf

DIN (26 dB S/N ratio, 40 kHz dev.): 1,3 μV

Capture ratio: 1 dB

Selectivity (±400 kHz): 60 dB

S/N ratio (mono): 70 dB

Image rejection: >80 dB

THD (stereo) 1kHz: <0,4%

Stereo separation 1 kHz (DIN): >40 dB

Subcarrier suppression: 65 dB

MW Section (525 - 1605 kHz)

Sensitivity (IHF): 15 μV/m

Image rejection: >45 dB

IF rejection: >55 dB

S/N ratio: 50 dB

Power consumption: 340 W

Dimensions (W x H x D): 550 x 160 x 420 mm

Weight: 19,1 kg

Lowther TP1 A (1954)

"Built as a music instrument, sounds like a musical instrument.

This amazing development is yet another Lowther contribution to the art of electro-acoustic reproduction.

The most efficient reproducer of audio frequencies in the world with single driver unit/compound horn housing.

Now in use by Television, Broadcasting and Recording studios throughout the world as a standard monitor."


The PM3 Drive Unit used in the TP1 has been designed specifically for this cabinet and is not not available as a separate reproducer. The cabinet is a "compound horn" design utilizing two horns to cover the entire audible range. The smaller of the two, which has its mouth at the grille at the upper part of the enclosure, is for the middle register and treble range-roughly the frequencies from 150 to 22,000 Hz. These frequencies are distributed through the listening space by a reflector type horn of unique design. The source is near ear level (when seated) as it should be. The range below 150 Hz is derived from the back of the driver unit, through a folded horn whose mouth is located on the uderside of the enclosure. This unusual configuration not only utilizes the space below the cabinet itself as an effective working part of the speaker system, but the remainder of the room as well, since the floor and walls (forming the corner) act as extensions of the horn. Thus, the entire range of frequencies is reproduced by true horns, providing performance of unrivalled purity and smoothness, reproduced free of bass resonant devices, cross-over networks, or units added to compensate for others found wanting. Efficiency of the TP1 is of a very high order, the average input for listening use being about 100-200 milli-watts.

Attractively styled the TP1 is available in a modern distinctive design. Construction is of the finest workmanship, using natural woods throughout. Selected veneers hand rubbed to a lustrus finish assure a beautiful apperance. natural walnut and mahogany are standard finishes available from stock.


Dimensions of Lowther TP1

Total Height in corner: 47"

Height to front edge: 42"

Width of front: 32"

From front into corner: 24"

Net weight: 90 lbs

Lowther PM3


An 8 inch twin cone loudspeaker of radically new design the PM3 was especially developed for use in the Lowther TP1 corner enclosure. Possessing one of the largest magnetic structures in use on loudspeakers today, it uses a powerful field to provide phenomenal efficiency over the full audible range.

The two cones-constructed of special material - operate from a single voice coil and divide the audible spectrum. True mechanical crossover permits smooth transition of lows and highd in proper phase and balance without any dips at the crossover frequency.

An outstanding contribution to the performance of the PM3 is the Stabilizer, a (non magnetic) shaped continuation of the center pole partially filling the space inside the tweeter cone. Providing air loading to the cone, it uniformly disperses the frequencies in the high and mid-ranges.

The contour between the Stabilizer and inner cone also forms a short horn for emission direct from the voice coil of very high harmonics and overtones.

The main cone surround is plastic foam. Energy not radiated or absorbed by the cone will reach the periphery and be absorbed in the foam, damping cone resonance in the middle and high frequency ranges. In the bass, because it can stretch, it permits large movements without sudden restrait, minimizing distortion in this range. The rear suspension is also foam, thus preventing reflection at both cone anchorage points.

The voice coil is of aluminum wire, for lightness, and is would half inside and half outside the voice coil former. This form of construction - much stronger than the normal form - makes it impossible for voice coil and former ever to separate under extremes of mechanical stress or temperature.

Forming the heart of the TP1, the PM3 makes an outstanding contribution to the uniformly high efficiency and superior performance of the reproducer.

Specifications

Frequency range: 20 - 22,000 Hz

Gap Flux: 22,000 Gauss

Power Rating: 25 Watts

Impedance: 16 Ohms

Weight: 10 kg

Pioneer PA-5000 (1978)

Static-balanced S-shaped universal tonearm with extra light aluminum alloy pipe and magnesium alloy headshell. Special alloy avoids partial resonance caused by bends in the arm pipe which often cause distortion in less well designed S-shaped arms. Gimbaled support system provides high sensitivity and arm height adjustment lever calls upon special Helicoid system for fine height change of +/- 3mm. Newly developed antiskating system applies lateral pressure directly without affecting sensitivity.

The PA-5000 features a unique counterweight incorporating several precision engineered parts, which damps both stylus and tone arm resonance. When moved by stylus vibrations, due to warped or uncentered records a 50 g "dynamic absorber" weight inside the counterweight applies a "brake". The weight is supported inside by means of a spring and several concentric rubber washers, called a Bellows damper. It is coupled to the tone arm vis stainless steel stranded wires.

Specifications

Effective arm lenght: 250 mm

Overhang: 14 mm

Offset angle: 20°30'

Revox B 790

Will Studer developed the revolutionary Revox b790 true tangential tracking turntable. It replaces the conventional tonearm and all its problems with a unique, patented opto-electronic playback servo-system. The cartridge moves up, down and laterally guided by a beam of light. It's easy on your record grooves and easy on your nerves. It's so simple and goof-proof even a child can safely play your most treasured records.

The new revox B790 looks and performs better than any turntable you've ever seen or heard. ...

The Revox B790 record player with quartz-controlled direct drive and tangential pick-up arm was not just exciting because of its advanced design but because of a complete range of functional innovations. The B790 united security and simplicity of operation and essentially offered new solutions to old problems.

The B790 features adjustable speed over a '7% range and a four-digit LED indicator which displays the measured rate of rotation, but otherwise the two models are the same. The tonearm design provides straight line (tangential) tracking which maintains a constant lateral tracking angle and thereby reduces certain forms of playback distortion, since record masters are always cut with tangential heads. Distortion due to skating is said to be eliminated by this design as well. Another goal of the Revox design was for the moving system to have very low effective mass. This was achieved by hanging the cartridge from a horizontal rail system. The "arm" on which the cartridge is mounted is just four centimeters long and its dynamic mass is claimed to be only 3.75 grams.

The Revox system is sold at present with either an Ortofon or an AKG cartridge. Users can buy a kit which facilitates the installation of other cartridges. Tests by Revox have shown that the fundamental resonance of this arm with most cartridges lies between 10 and 11 hertz where it would not readily be stimulated either by record warps or recorded audio signals.

The arm and cartridge are guided along the rail system by a small motorized carriage. A block assembly which contains these rails and the carriage, arm, and cartridge is then pivoted in much the same way as a conventional tonearm. To put on or to remove a record, one sets the block assembly into its "at rest" position out of the way of the platter. And to play a record, one sets the assembly over the record's surface into a detent with a claimed repeatability of ± 0. 01 mm! This starts the turntable motor, but the stylus stays lifted above the record's edge until the user presses a button to lower it. While it is lifted, cuing can be accomplished with two other push buttons.

As a record is played, the carriage is propelled forward in response to signals from an ingenious optical and electronic system. Time constants of the system are chosen so that the arm moves smoothly, and so that an eccentric groove is tracked about in the center of its range of excursion. (The back-motion is absorbed by the free-swinging arm, not the servo. )

The little tonearm has only one point of contact with the motorized carriage, a jeweled bearing which forms the lower pivot point. The vertical shaft of the tonearm is held captive by the field of a small, oblong, concave, permanent magnet. This magnet keeps the arm from rocking laterally, yet adds no friction to the system.

The mechanical suspension for the overall turntable system has its basic resonance at or below 3 Hz, rendering it quite insensitive to feedback even if it is set directly atop a subwoofer cabinet. This was demonstrated.

The dustcover, which is transparent and removable, is contoured such that it can be opened or closed even when the turntable is placed flush against a wall, and is sprung to "stay put" in any position. All operating controls are outside the locus of the dustcover.

Specifications

Turntable drive: Quartz-controlled direct drive

Speeds: 33,33 and 45 rpm, crystal accurate

Speed accuracy: ±0,01 %

Speed indication: 4-digit LED readout, quartz precise

Manual fine adjustment: ±7%

Platter diameter: 313 mm (12,32 inch)

Platter weight: 1,1 kg (2 lbs 7 ozs)

Run-up time: better than 2 sec. at 45 rpm

Braking time: better than 1,5 sec. from 45 to 33,33 rpm

Wow and Flutter: better than 0.05 % (weighted); 0,1% (unweighted)

Signal-to-noise ratio: better than 65 dB

Rumble to signal ratio:

A weighting: better than 48 dB

A weighting +20 Hz high-pass: better than 51 dB

Bweighting: better than 68 dB

Transmission characteristic for rumble measurement: Replay response -3 dB at 20 Hz

Tonearm: Linear tracking tonearm with servo electronic follow-up control

Tangential tracking angle error: less than 0.5 degrees

Tracking force: adjustable of 5... 20 mN (0.5... 2 p)

Tonearm lowering: electronically controlled, pneumatically damped

Muting: electronically muted, until the stylus contacts the record

Tonearm follow-up: Opto-electronic sensing with LED as light source, servo-electronics and DC motor

Run-out switch: automatically activated via servo-electronics

Operating controls:

Turntable drive:

3 tactile feedback keys for 33,33 and 45 rpm as well as for variable speed operation

Tonearm:

3 tactile feedback keys for fast inward or outward movement plus lowering and lifting of the pick-up cartridge; cartridge illumination built-in

Automatic functions:

Swinging the tonearm support in: Platter stsrts to rotate at the selected speed

Swinging the tonearm support out:

Immediate lifting of the cartridge

Tonearm returns to start pposition (run-in groove of a 12 inch disk)

Electronic braking of the platter

Components: 29 ICs, 30 transistors, 24 diodes, 1 LED, 4 seven segment displays and 3 bridge rectifier

Power supply: 100/110/120/200/220/240 V, 50/60 Hz

Dimensions (W x H x D): 452 x 142 x 382 mm (17,8 x 5,6 x 15,03 inches)

Weight: 11 kg 924 lbs 4 ozs)

Revox B 760

With the B760 Revox brought the FM fM-Tuner to the third generation on the market. It united the successful construction principles of the predecessor models A76 and A720 with large convenient operation and far improved receivings caracteristics. Augenfuelliges characteristic of the Revox B760 - Frontplatte was the field with 15 programmable transmitter keys. The display indicated the station frequency and the storage location.

The dissolution of the crystal accurate tuning was doubled, the raster amounted to now 25 kHz or 840 steps in the UKW volume again. Thus the Revox B760 was from the outset suitable also for "bent" transmitter frequencies and the arising cable systems with converters.

Who wanted to test its receipt situation accurately exactly, an oscilloscope exit was available at the B760. On the screen were analyzable thereby signal strength and stroke. In Europe for the start time of the Revox B760 of attempts with dolbysiertem UKW broadcast made with the goal of improving the dynamics further. The B760 was prepared for it. The optional modules are today useless witnesses of an attempt.

With the designation Studer A176 was adapted the FM fM-Tuner B760 also for professional employments. For the purists with rotor antennas the Revox B760 brought likewise a principal innovation: the programmable direction control. The code for antenna position was along-stored thereby in the MEMORY so that when touching the station key lightly the rotor turned equal on the programmed position.

Specifications

Tuning Range: 87.00 to 107.975 MHz

Station Preselection: 15 station keys, raster 25 kHz

Accuracy: 0,005 %

Tuning Signal Strenght: log. 100 mV/75 ohms

Center Tuning Meters: linear 20 kHz/mm

Usable sensitivity: 2 μV (mono) and 20 μV (stereo)

Absolute Sensitivity: 0,7 μV

Image Rejection: 106 dB

IF Rejection: 110 dB

Spurious Response: 106 dB

Capture Ratio: 0,8 dB

Stataic Selectivity: 80 dB

AM Suppression: 70 dB

Frequency Response: 30 Hz to 15 kHz ±1 dB

De-Emphasis: 25, 50 75 μs selectable

Total Harmonic Distortion: 0,1%

Stereo Crosstalk: from 10 dB to 42 dB

Signal-to-Noise Ratio: 75 dB

Pilot Signal And Subcarrier Suppression: 70 dB (including all harmonics)

Trigger Threshold InterStation: 1.5 - 10 μV at 75 ohms

Trigger Threshold InterStereo: 4 - 60 μV at 75 ohms

Antenna Inputs:

Coaxial: 60- 75 ohms

Balanced: 240 - 300 ohms

Components: 65 ICs, 63 transistors, 2 diode matrices (91 diodes), 42 diodes, 19 co-ordination double diodes, 3 bridge rectifier, 7 seven segment displays

Dimensions: 452 x 151 x 348 mm (17.8 x 6 x 13.7 inches)

Weight: 12 kg (26 lbs 7 oz)