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 1070

 The Marantz Model 1070 stereo console amplifier was designed by American engineers, but is manufactured under their control in Japan. With a total power output approaching 100 watts RMS, it is compact in comparison with many competitive amplifiers, yet has a wide range of facilities.
 The amplifier is fully screened, with a metal housing finished in imitation wood veneer, and the brushed aluminium front panel is protected by a removable clear plastic cover. The main controls are mounted on a recessed black anodized panel with a clear perspex protective cover over the lettering and control calibrations. This panel is not back illuminated and therefore it is essential that the panel is placed in a good light. The controls on the front panel are a large selector knob for phono, tuner, auxiliary, tape 1 and tape 2. Next comes the tape monitor switch which can select either of two tape machines. In the centre are three slider-type tone controls for bass, mid-range and treble. To the right of these controls is the mode selector switch for left, right, Stereo, stereo reverse, and mono L R, and finally the rotary volume control. Below the main controls are the following: sockets for stereo microphone and headphones, push-buttons for low filter, high filter, loudness, main speakers, remote or ambience speakers, and power on-off. In the centre is the balance control.
 There are four fuses to protect the amplifier and loudspeakers but to gain access to these it is neces.snry to remove the outer top cover. The well-designed rigid chassis carries a heavy Marantz Model 1070 stereo amplifier power transformer, fully screened. Separate printed circuit boards are used for the stabilized power supply, the input pre-amplifiers and tone control circuits. The fully complementary output stages are mounted on heavy heat sinks together with the penultimate driver stages. Whilst conventional soldering is used on switches, plugs etc, inter-panel wiring makes use of wrapped joints, a technique claimed to have a lower contact resistance than soldered joints.
 On the rear panel are eight spring-loaded terminals for the main and remote pairs of loudspeakers, and below these are a 200W unswitched AC mains flat-contact American socket and a similar switched 100W one. Normally the pre-amplifier is directly connected to the power amplifier but, with the gradual use of graphic equalizers, for example, it is desirable to separate the pre-amplifier from the power amplifier. In the case of the Marantz 1070 this is achieved by having left and right 'pre-out' and `main-in' phono sockets on the rear panel. These automatically bridge together but, when a phono plug is inserted, the internal connection is interrupted and any external unit can be connected between the two parts of the amplifier. There are input and output phono sockets for two separate tape recorders, duplicated with DIN sockets. Finally there are three pairs of phono sockets for phono, tuner and auxiliary. A 168cm (66-inch) three-core mains cable is permanently fixed to the amplifier.

Gain-Phono (low level) to pre-amp:  55 dB
Phono to recording output:  40 dB
High level to pre-amp output:  15 dB
Input Impedance
Low level input Phono, Microphone:  47 kΩ
High level input:  >50 kΩ
Input sensitivity
Phono (low):  1,8 mV to equal 1 volt output at pre-amp out
Frequency Response:  20 - 20,000 Hz;  ±1 dB at rated power output
Intermodulation Distortion:  Less than 0,3% at rated power output (SMPTE)
Damping Factor (20-20,000 Hz):  Greater than 20 into 8Ω load
Total Noise
From magnetic phono input to power amp output:  Less than 1,5 μV equivalent input at rated output into 8Ω
Volume Tracking:  Within 3 dB
Rated Power Output (continuous average per channel, all channels driven)
Power output:  38 watts into 4Ω
Power band:  20 - 20,000 Hz
Total Harmonic Distortion:  0,3%
Power requirement:  120, 220, 240 V AC 50/60 Hz
At rated output both channels operating:  190 Watts
Idling Power (volume channels at zero):  48 Watts
Dimensions (W x H x D):  14-11/64 x 4-23/32 x 11-1/32 inches
Weight net:  18 lbs

McIntosh MAC 4100

Power to the entire stereo system can be controlled from either the front panel power switch or the turntable's power switch. A current sensing relay connected to the turntable AC power outlets is controlled by the turntable power switch. The relay, in turn controls the AC power to the remainder of the system. Sensitivity of the circuit is adjustable to match the current consumption of your turntable.
Loudspeakers are protected from burnout by the Power Guard circuit and also by other circuits that instantaneously disconnect the speakers in the event of the presence of DC on the output.
Two power guard indicators indicate when the power amplifier has reached full output. At this point the power guard circuit begins to control amplification dynamically so that you will not hear the harsh distorted sound of square wave clipping. In addition your speakers are protected from burnout.
The volume control, is a step attenuator which has tracking accuracy within 1 dB throughout its entire range. Such extremely accurate matching is achieved through electronically controlled trimming of the resistance material deposited on pairs of printed circuits. Tracking accuracy and quiet performance are permanently maintained. Use does not affect performance as in ordinary volume controls.
Speaker outputs are connected only after power supplies and circuits have stabilized eliminating turn on thumps or clicks.
Five separate controls permit individual musical spectra shaping to satisfy personal preference or program limitations. There is 12 dB plus or minus control at center frequencies of 30, 150, 1.500 and 10,000 Hz. In the center (detent) position the tone shaping circuits are not active.
Loudness controls typically are simple, passive circuits connected to a portion of the rotation range of the volume control. As a consequence,  loudness compensation accuracy is dependent on many variables such as speaker efficiency, amplifier gain and differences in input level. The loudness control is continuously variable, operates independently of the volume control, and its contour is accurately modeled after the Fletcher Munson family of "Equal Loudness" curves.
Three sets of loudspeakers may be used one at a time, two together, or all three simultaneously.
Two tape recorders can record simultaneously from the program being listened to or you may record from one to the other without interfering with the "Listen" program.

100 watts minimum sine wave continuous average power output, per channel, both channels operating into 4 ohms 20 Hz to 20 kHz, with no more than 0.05% THD
75 watts minimum sine wave continuous average power output, per channel, both channels operating into 8 ohms 20 Hz to 20 kHz, with no more than 0.05% THD.
OUTPUT LOAD IMPEDANCE:  4 ohms, 8 ohms
RATED POWER BAND:  20 Hz to 20 kHz
TOTAL HARMONIC DISTORTION:  0.05% maximum at any power level from 250 milliwatts to rated power per channel, 20 Hz to 20,000 Hz, both channels operating
FREQUENCY RESPONSE:  20 Hz to 20 kHz  + 0, -0.5 dB at rated power
INTERMODULATION DISTORTION:  0.05% maximum at any power level from 250 milliwatts to rated power per channel both channels operating for any combination of frequencies 20 Hz to20,000 Hz
Power Amplifier :  100 dB IHFA, 95 dB unweighted, below rated output.
Tape and Aux Input :  95 dB IHFA, 90 dB unweighted below rated output.
Phono Input :  90 dB IHFA, 80 dB unweighted, below 10 mV input
DAMPING FACTOR:  Greater than 30
Power Amplifier :   2.5 volts,  22,000 ohms;
Tape, Auxiliary :  250 millivolts,  100,000 ohms;
Phono: 2 millivolts,  47,000 ohms, 87 pF
Tuner : 1.0 volts at 100% modulation [FM];
Tape :  250 millivolts with rated input;
Phono : 250 millivolts with rated input
PROGRAM EQUALIZER:  ±12 dB at 30, 150, 500, 1500, and 10,000 Hz
SENSITIVITY:  2mV [11.2dBF] IHF minimum
HARMONIC DISTORTION:  Mono: 0.18% IHF (maximum);  Stereo: 0.38% IHF (maximum)
FREQUENCY RESPONSE:  20 Hz to 15 kHz,   +0, -1 dB
SELECTIVITY:  75 dB IHF minimum
STEREO SEPARATION:  45 dB minimum at 1 kHz
SCA REJECTION:  60 dB minimum
SENSITIVITY:  75 mV IHF [External antenna]
SIGNAL TO NOISE RATIO:  45 dB minimum IHF, 55 dB at 100% modulation
HARMONIC DISTORTION:  0.8% maximum at 30% modulation
FREQUENCY RESPONSE:  6 dB down at 3500 Hz
IMAGE REJECTION:  65 dB minimum, 540 kHz to 1600 kHz
45 Transistors,  31 Integrated Circuits,  62 Diodes,  1 Silicon Controlled Rectifier
POWER REQUIREMENTS:  120 Volts, 50/60 Hz, 0.6 to 4 amperes (72 to 480 watts)
IN CABINET: 473 x 165 x 394 mm  (18-5/8 x 6-1/2 x 15-1/2 inches)
Front panel measures  446 x 133 mm (17-9/16 x 5-1/4 inches)
Chassis measures  435 x 125 x 343 mm (17-1/8 x 4-15/16 x 13-1/2 inches)
Knob and handle clearance required is 32 mm  (1-1/4 inches) in front of the mounting surface.
Front panel is clear anodized to produce a brushed satin/silver finish with black trim.
Cabinet is walnut grained vinyl
WEIGHT:  19 kg (42 pounds) net, 25,4 kg (56 pounds) in shipping carton

Luxman 5T10 (1978)

Our original C.L.L. system which has realized quite accurate and stable tuning condition.
We employed our original Closed Loop Locked (C.L.L.) circuit in the 5T10 to realize extremely accurate and stable tuning conditions at all receiving FM frequencies. With the C.L.L. circuitry, total control is effected throughout all the stages, from the front end to the IF and detector circuits in accordance with the crystal controlled transmission frequency of a broadcasting station. Therefore, this may be called the ideal tuning system offering accurate and stable tuning conditions even if ambient conditions such as temperature fluctuate. Generally, in the case of quartz lock and synthesizer systems, only the local ascillator or front end is partially controlled by the P.L.L. circuitry. Therefore it is necessary to design the IF stage and the detector stage with additional stability. In addition, C.L.L. circuitry, like the P.L.L. ciruit, has the capture range near the center frequency of the broadcasting station and the required lock range to achieve a stable receiving condition. Thus, C.L.L. circuitry always provide the perfect receiving condition thanks to powerful feedback once the signal wave of an FM station is within the capture range and firmly locked at the lock range. Even if the receiving frequency drifts, feedback is applied to bring it back to follow the crystal controlled transmission frequency, and stable reception is always obtained.  In addition, the C.L.L. circuitry incorporates a lock-retaining circuit, and no new locking is needed when power is turned off and on once the station has been tuned in.

The "Accutouch" System which makes the most of the C.L.L. Tuning System
The 5T10 employs the "Accutouch" system. This system makes it possible to tune in all the tuning circuits easily to the accurate center frequencies of broadcasting stations. To obtain more precise tuning, an extremely narrow capture range is set  for the C.L.L. circuit of the 5T10. It would be hard for a conventional tuning method to obtain such a precise tuning point, since such tuning method requires observation of a center tuning meter, which is seldom accurate enough.
The "Accutouch" system detects the exact center tuning point utilizing a control voltage at the C.L.L. circuit, which triggers a mechanical lock on the tuning knob. This is a very unique system in mhich the tuning knob is temporarily locked with a positive response at the exzct tune-in point as the knob is gradually turned to locate an FM station. Precise tuning to a station is possible with an incomparable accuracy compared with that of current visual tuning systems.

 IF bandwidth Selector
In the IF stage, a 2-step bandwidth selector is provided to provide both excellent distortion and selectivity. In the "wide"  position, 2 pairs of wide-bandwidth block filters of good group-deley characteristics are employed to realize lower distortion, while in the "narrow" position an additional 2 pairs of narrow-bandwidth ceramic filters are added to offer high selectivity.

DC amp configuration is employed at the Audio Output Stage. The basic design theme is Sonic Excellence.
A 5-gang variable capacitor exclusively designed for FM reception is adopted at the front end to make the most of the excellent characteristics realized after the IF stage.  Also superb interference rejection characteristic is obtained by improving the selectivity at each RF amplifing circuit. The IF stage is so designed as to be inherently low in distortion, but to make it perfect, a quadrature wide-bandwidth detector circuit is combined with it, which not only realizes low distortion but high S/N ratio as well.
Of course, a pilot canceller circuit is provided in the multiplex circuit, but further the phase characteristic of the low-pass filter is improved. A DC amp configuration is employed at the audio output stage. All of these circuit features are specially considered in terms of good sonic quality.

Receiving Frequency:  87,5 MHz - 108 MHz
50 dB Quieting Sensitivity:  16,0 dB (3,3 μV)
IHF Usable Sensitivity:  10,3 dB (1,8 μV)
Signal-to-Noise Ratio:  80 dB
Frequency response:  20 - 17,000 Hz (-0,5 dB, mono and stereo)
Total Harmonic Distortion Mono
0,5% (wide) at 100 Hz - 1 kHz
0,7% (wide) at 6 kHz
0,2% (narrow) at 1 kHz
Total Harmonic Distortion Stereo
0,07% (wide)  at 100 Hz
0,06% (wide)  at 1 kHz
0,1% (wide)  at 6 kHz
0,5% (narrow)  at 1 kHz
Capture Ratio:  ),8 dB (wide); 2 dB (narrow)
Adjacent Channel Selectivity:  12 dB (narrow, ±200 kHz)
Alternate Channel Selectivity:  90 dB (narrow, ±400 kHz); 30 dB (wide, ±400 kHz)
Spurious Response Ratio:  100 dB
IF Response Ratio:  100 dB
Image Response Ratio:  100 dB
AM Suppression Ratio:  62 dB
Stereo Separation: 
45 dB (wide, 100 Hz); 50 dB (wide, 1 kHz)
45 dB (wide, 10 kHz); 30 dB (narrow, 1 kHz)
Muting Threshold:  30 μV - 500 μV (variable)
Output Impedance:  100 Ω (fixed);  100 Ω to 1,25 kΩ (variable)
Output Voltage:  1V (fixed): 0 - 1 V (variable)
Additional Features:
Tuning Lock System, IF Bandwidth Selector, Center Indicator, Signal Strength Indicator, Multipath Check Circuit, recording Test Tone Circuit, FM Muting Circuit, Muting level Adjuster, Time-delay Muting, output level Control, 75-ohm Coaxial Connector
Power Consumption:  20 W
Dimensions (W x H x D):  442 x 101 x 400 mm ( 17-13/22 x 4 x 15-3/4 inch)
Weight Net:  7,0 kg ( 15,4 lb)

Pioneer QC-800 (1972)

A single unit, four-channel preamplifier with unique Quadralizer for the creation of a living presence sound field in the home.

Quadraphonic stereo is the ultimate in sound realism, and with Pioneer's Model QC-800,a quadraphonic power amp (or two stereo amplifiers) and four speakers you can enjoy this sound brilliance today in your own home. This well-made, highly-advanced unit is unusually versatile. It provides a choice from any existing two-channel stereo source (tape,disc of FM), as well as discrete four-channel stereo, the most genuine and thrilling four-channel sound. And it can also be used as a conventional two-channel stereo pre-amplifier if you intend to wait until adding another pair of speakers to your existing stereo set. The QC-800 is a perfect match to Pioneer's Quadraphonic Power Amplifier (Model QM-800). And it's your most versatile introduction to the grandeur of four-channel stereo, a solid investment it the sound of the future that Pioneer has perfected today.

Your Own Acoustical Field

The exclusive Pioneer Quadralizer contained within the QC-800 creates an all-encompassing four-channel sound field in your home, giving you the same, full, life-like sansation of being in an acoustically perfect concert hall.

Choose Your Four-Channel System

The Quadralizer creates four-channel sound from any existing two-channel stereo source - either tape, disc or FM. And the QC-800 gives you a choice of three totally different four-channel effects.

Discrete Four-Channel Stereo

This is both the most authentic in terms of sound quality, and the most expensive since it requires a four-channel tape deck and special four-channel tapes. The sound is reproduced at a very high degree of fidelity, since the tape deck reproduces sound recorded on each of four separate tracks.

Matrix-Type Four-Channel Stereo

The "matrix" system of four-channel sound is one of the quadralizing effect systems in the QC-800. This systems creates a room-enveloping sound field, when signals from a two-channel program source are fed through a unique matrix circuitry contained within the preamplifier. These signals are analyzed and divided into four different signals which are then fed to four loudspeakers systems for sound reproduction. the matrix system is highly suitable for the reproduction of popular music or small combo group performances.

Phase Shift Four-Channel Stereo

The "phase shift" system of four-channel sound is another of the quadralizing effect systems in the QC-800. With this system, the conventional left and right stereophonic channels are reproduced from the two loudspeakers systems situated in front of the listener. But added to this sound is a phase-shifted 'wall of soud", or concert hall effect which emanates from the pair of loudspeakers placed behind the listener. The result is the rich depth of a live performance a slight enveloping echo effect through the two rear speakers, a thrilling musical experience. The Pioneer phase shift system is especially effective in the reproduction of classical or operatic music.

High Stability Head Amplifier

The head amplifier section of the QC-800 incorporates a 3-stage direct-coupling negative feedback circuitutilizing low-noise silicon transistors and emitter-to-emitter feedback. These features result in accurate equalizing characteristics with a wide dynamic range and stable performance.

Switch-Type Tone Controls

The tone control amplifier is a directly coupled three-stage design with a low-noise FET in its first stage. Its high, stable input impedance assures precise tone control at any setting without affecting the head amplifier. The tone controls are true switch types which regulate negative feedback. Each switching step has an effect of +/- 3 dB. Additionally, separate controls are provided for front and rear channels, permitting total control over the total tonal quality.

Versatile Inputs And Auxiliary Controls

Inputs of the QC-800 accept two turntables, two tape decks, a tuner and a choice of two other sound sources. There are separate headphone jacks for monitoring both front and rear channels. Controls include an output on/off switch, a -20 dB muting switch, high and low filters and a tape monitor switch. Versatility of the unit is practically unlimited.

Channel Level Controls

Each of the four channels is equipped with a level control, which permits total control over the sound field intensity even when different speaker types are used for front and rear listening.

Tape-To-Tape Duplicating

Because the QC-800 has a pair of tape deck inputs, tape-to-tape duplicating may be accomplished with ease. Normal two-channel tape-to-tape duplicating is also possible as if four-channel tape-to-tape duplicating.


Pre-amplifiers Section

Output Voltage/Impedance: Output 1,2; 4V/less than 5 Ω (2 ch)

Harmonic Distortion: less than 0,05% (2V output)

Frequency Response: 10 to 70,000 Hz ±1 dB

Input Sensitivity/Impedance:

Phono 1, 2: 4 mV/50 kΩ (2 ch)

Tuner: 250 mV/180 kΩ (4 ch)

Aux 1,2: 250 mV/180 kΩ (4 ch)

Tape Monitor 1, 2: 250 mV/200 kΩ 94 ch)

Recording Output: Tape Rec 1, 2 (pin jack); 250mV (4 ch)

Bass Control: -9 dB, +12 dB at 100 Hz (3 dB step)

Treble Control: -12 dB, +9 dB at 10 kHz (3 dB step)

Low Filter: -8 dB/50 Hz

High Filter: -8 dB/10 kHz

Equalization Curve: Phono RIAA STD

Muting: -20 dB

Hum amd Noise (IHF):

Phono : More than 89 dB

Tuner, Aux : More than 100 dB

Channel Separation (1 kHz):

Phono : More than 50 dB

Tuner, Aux : More than 50 dB

Phones: For (ch 1, ch 3) and (ch 2, ch 4)


Transistors : 32

FET (s) : 4

Diodes : 3


Power Requirements: 110, 120, 130, 220, 240 V (switchable) 50/60 Hz

Power Consumption: 5 watts (max.)

Dimensions (W x H x D): 430 x 145 x 337 mm (16-15/16 x 5-11/16 x 13-1/4 inches)

Weight: 7,6 kg (16 lb 12 oz)

Pioneer QM-800 (1972)

The Pioneer Quadraphonic Power Amplifier, model QM-800 is designed to serve in a 4-channel stereo installation, together with a 4-channel preamplifier, 4 speaker systems and one or several program sources. Engineered for highest sound fidelity, it will open up a whole new world of "environmental sound."


Direct coupling of all amplifier stages greatly improves phase characteristics and permits an extremely wide frequency response down to near-DC. A load-regulated power supply unit is employed, and output power is higher than will ever be required.


To obtain optimum sound balance in a 4-channel system, four separate level meters are provided. Moreover, the meters sensitivity can be adjusted in three stages (0, -10 and -20 dB) to permit accurate readings at all volume levels.


As the power amplifier's input sensitivity can be adjusted in 6dB steps (at 0.5, 1 and 2 volts), it is easy to match with any preamplifier.


ln addition to the four normal, full-range speaker terminals, a set of high-range speaker outputs are provided. The QM-800 can be used as an exclusive high-range amplifier in a multi-amplifier installation.


The output transistors are protected from damage (in the case of overload or short-circuits in the speaker leads) by a dual system of relay and DC drift voltage detector circuits. The latter also guard against possible speaker damage by DC current.


The front panel is attractive as well as logically laid out. With its natural wooden cabinet, the QM-800 matches other Pioneer hi-f i components perfectly.


Even if the power switch of the QM-800 is turned on, the speaker system will not operate for the first 5 to 8 seconds. This is because the QM-800 is provided with a circuit which protects transistor, speakers, etc. from possible damage due mainly to unexpected trouble.

If any of the speaker systems stops operating during a performance, or if mechanical noise (click, click, . . .) of the relays is heard continuously, a short-circuit in the speaker leads may be responsible. Turn off the power and check all speaker connections. Since the protector circuit is very sensitive, it may be activated if the power switch of the preamplifier combined with the QM-800 is turned on and off separately. It is therefore advisable to obtain AC power for the QM-800 from a switchable AC outlet of the preamplifier, as this guarantees simultaneous on-off switching of both units.



Music Power Output (lHF):

280 Watts per channel at 4 Ω;

200 Watts per channel at 8 Ω

Continuous Power Output (2 channels driven):

42W + 42W / 42W + 42W at 4 Ω;

35W + 35W /3 5W + 35W at 8 Ω

Continuous Power Output (4 channels driven):

32 W x 4 at 4 Ω;

25 W x 4 at 8 Ω

Power Output in the range of 2OHz to 20kHz (2 channels driven):

32W + 32W / 32W + 32W (8 Ω, THD Less than 0.5%)

Harmonic Distortion: Less than 0.5% (Continuous power output)

lntermodulation Distortion: Less than 0.5% (Continuous power output)

Power Bandwidth (lHF):

5 Hz to 50 kHz (8Ω, 2 channels driven, THD Less than 0.5%)

10 Hz to 50 kHz (8Ω, 4 channels driven, THD Less than 0.5%)

Frequency Response: 5 Hz to 80 kHz, ±1dB

lnput Sensitivity/lmpedance (1kHz, Continuous Power output)

0,5 V/70 kΩ

1,0 V/110 kΩ

2,0 V/170 kΩ

Speakers: 4 to 16 Ω (FRONT, REAR, HIGH RANGE)

Damping Factor: 70 (8 Ω, 1kHz)

Hum and Noise (IHF): More than 90 dB

Level Meters: 0 dB = 35 W/8 Ω, (Sensirivity selector 0dB, -10d8 and -20d8)


Transistors : 39

Diodes : 37


Power Requirements:

110V, 120V, 130V, 220V and 240V (Switchable) 50/60Hz

Power Consumption: 400 W (Max)

Dimensions (W x H x D): 430 X 145 X 337 mm (16-15/16 x 5-11/16 x 13-1/4 inch)


Without package: 11,5 kg (26 lb)

With package: 13,5 kg (30 lb)

Sony STR-313L

Stereo Receiver Features

Programme sensor so that 5 stations on both FM and LW can be preprogrammed. Using the pre-set markers, and the programme buttons, any of your favourite stations can be pre-set. When the programme sensor position is selected any pre-set station on FM or LW can be picked up as you move the tuning indicator

25 watts per channel at 8 ohms into 20 Hz - 20 kHz

4 wavebands; Fm, MW, SW,LW

Loudness switch for improved sound at low listening levels

Separate controls for bass and treble

Automatic muting in stereo mode

FM and LW programme sensor indicators

Programme sensor indicator

Stereo indicator light

Function indicators for tape,phono and tuner

Separate signal strength and centre tuning meters

Headphones socket

Audio Amplifier Section

Power Output Continuous RMS

Less than 0,5% THD, both channel driven simultaneously:

25 W + 25 W (8 Ω) at 20 - 20,000 Hz

27 W + 27 W (8 Ω) at 1 kHz

According to DIN 45500

25 W + 25 W (8 Ω)

25 W + 25 W (4 Ω, less than 0,7% THD)

Dynamic Power Output: IHF constant power supply method 90 W (8 Ω)

Power Bandwidth: 10 - 40,000 Hz, IHF

Damping Factor: 20 at 1kHz (8 Ω)

Total Harmonic Distortion:

Less than 0,5% at rated output (8 Ω)

Less than 0,7% at rated output (4 Ω)

Less than 0,2% at 1W output (8 Ω)

Less than 0,3% at 1W output (4 Ω)

IM Distortion (60 Hz : 7 kHz = 4 :1):

Less than 0,5% at rated output

Less than 0,2% at 1W output

Residual Noise: Less than 0,08 μW (8 Ω)

Frequency Response

Phono: RIAA equalization curve ±1 dB

Tape: 10 -50,000 Hz +1 dB, -3 dB

Inputs Sensitivity/impedance (¹):

Phono: 2,5 mV(-50 dB)/50 kΩ, 70 dB S/N

Tape: 150 mV (-15,5 dB)/100 kΩ, 90 dB S/N

Outputs (with rated input):

Rec Out: 150 mV (-15,5 dB)/ 10 kΩ

Headphones: Accepts all low or high impedance headphones

Speaker: From 4Ω to 16Ω speakers are suitable

Tone Controls:

Bass: ±8 dB at 100 Hz

Treble: ±8 dB at 10 kHz

Loudnes Control: +8 dB at 100 Hz; +3 dB at 10 kHz (att. 30 dB)

FM Section

Frequency Range: 87,5 - 108 MHz

Antenna: 300 Ω Balanced; 75 Ω unbalanced

Intermediate Frequency: 10,7 MHz

Sensitivity at 50 dB Quieting:

Mono: 3,5μV (10,7 dB)

Stereo: 45μV (33 dB)

Sensitivity at 46 dB Quieting (at 40 kHz deviation):

Mono: 4μV (12 dB)

Stereo: 50 μV (34 dB)

Usable Sensitivity (at 40 Hz deviation):

1,8 μV (5 dB), IHF

1,6 μV (4 dB), S/N = 26 dB

S/N Ratio: 75 dB (mono); 70 dB (stereo)

Harmonic Distortion:

At 100 Hz : 0,2% (mono); 0,3% (stereo)

At 1 kHz : 0,2% (mono); 0,3% (stereo)

At 10 kHz : 0,3% (mono); 0,5% (stereo)

IM Distortion: 0,2% (mono); 0,3% (stereo)


30 dB at 100 Hz

45 dB at 1 kHz

35 dB at 10 kHz

Frequency Response:

40 - 12,500 Hz +0 -5/-1 -0 dB

30 - 15,000 Hz +0 -5/-2 -0 dB


60 dB (400 kHz)

40 dB (300 kHz, S/N=26 dB, 40 kHz deviation)

Capture Ratio: 1,0 dB

AM Suppression Ratio: 54 dB

Image Response Ratio: 45 dB

IF Response Ratio: 90 dB

Spurious Response Ratio: 75 dB

RF Intermodulation: 60 dB

Muting Threshold: Approx. 5μV

SW/MW/LW Section

Frequency Range

SW : 5,8 - 15,8 MHz

MW : 530 - 1,605 kHz

LW : 150 - 350 kHz


SW/MW External antenna terminal (Attached antenna wire)

LW: Built-in Ferrite-rod antenna (External antenna terminal)

Intermediate Frequency: 468 kHz

Usable Sensitivity:

SW: 30 μV (29,5 dB) external antenna 910 MHz)

MW: 100 μV (40 dB) external antenna (1,000 kHz)

LW: 500 μV/m (53,8 dB0 built-in antenna; 100 μV (40 dB) external antenna (230 kHz)

S/N Ratio:

SW/MW: 52 dB 95 mV)

LW: 52 dB (50 mV/m)

Harmonic Distortion:

SW/MW: o,3% (5mV, 400 Hz)

LW: 0,3% (50 mV, 400 Hz)


28 db (9 kHz)

30 dB (10 kHz)


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

Power Consumption: 180 W, 210 W (UK model)

Dimensions( W x H x D): 410 x 145 x 310 mm (16" x 5¾" x 12½")

Weight Net.: 7,6 kg (16 lb 13 oz)

(¹) Measured with rated output power into 8Ω loads (both channels driven simultaneously) at 1 kHz

Shure M75ED Type2 (1972)

The M75ED type2 is High Trackability Cartridge with ¾ to 1½ gramme tracking.

This new improved cartrdige offers sound re-creation performance never before available in its price class. Optimized design, parameters give superior high frequency trackability and overall performance second only to the peerless V-15 Type II Improved. Gem-quality "naked" diamond tip is mounted directly to the stylus bar to reduce effective stylus tip mass - and improve trackability. Bi-radial Elliptical Dynetic Stylus. De Luxe moulede housing assembly. An excellent cartridge choice for use in finest quality playback equipment.


Typical Trackability

400 Hz: 22 cm/sec

1,000 Hz: 33cm/sec

5,000 Hz: 28 cm/sec

10,000 Hz: 19 cm/sec

Frequency Response: 20 to 20,000 Hz

Output Voltage: 5,0 mV/channel at 1,000 Hz, 6 cm/sec

Channel Balance: within 2 dB

Channel Separation: over 25 dB at 1,000 Hz

Stylus: N75ED Type @ alliptical diamond tip

0,0007 in (0,018 mm) frontal radius

0,0002 in (0,005 mm) side contact radii

0,0010 in (0,025 mm) wids between records contact points

Tracking Force: ¾ to 1½ grammes

Recommended Load Impedance: Nominally 47,000 ohms per channel. Up to 70,000 ohms causes little audible change in frequency response.

Optimum Input Capacitance: 400 - 500 pF per channel including arm cable

Inductance: 720 mH

DC resistance: 630 ohms

Connections: 4-terminal

Mouting Centres: Standard ¾ inch

Weight Net: 6 grammes

JBL L 150 (1979)

The JBL L150. Capable of live-performance volume levels with true deep bass reproduction and high efficiency, the JBL L150 is a worthy addition to JBL's line of outstanding loudspeaker systems. JBL designed each component of this three-way floor-standing model for maximum power-flat frequency rsponse, controlled dispersion, and extended bandwidth. The newly developed low frequency driver is the product of over two years of intensive research by JBL engineers. The result of this careful engineering is clearly audible: smooth,transparent sound at any volume level, over a frequency range extending from the lowest organ tones to the limit of audibility and beyond. JBL takes as much care with the appearance as with the sound, and the elegant columnar design occupies little floor space and fits comfortably into any room.

Advantages of the Floor-Standing Design.

While bookshelf loudspeakers systems such as the JBL L150 have reached a high degree of refinement, there are a number of significant advantages to the floor-standing design of the JBL L150. Most immediately apparent to the listener is the increased bass performance. The JBL L150 will comfortably reproduce the power of an organ or bass guitar; if the bass information is in the music, the listener will hear it. To accomplish this, JBL engineers utilized both the larger enclosure volume of the floor-standing design and a passive rediator. The bass performance of the L150 is true deep bass, without the artificial boost in the mid-bass region that often substitutes for actual low frequency reproduction. The response of the L150 extends to the lowest octaves and is completely natural in sound with no hollow quality.

Another very audible advantage of the JBL L150 is the placement of the mid range and high frequency drivers at approx. ear level of the listener. Such placement aids in the perception of the sound as being "live", and also reduces the proportion of high and mid-frequency energy that is absorbed by furniture in the room. Although placing a bookshelf system on a tall stand will produce the same effect, the L150 provides much better bass performance and is also more easily integrated visually into a room.

A loudspeaker system should do more than merely reproduce the notes. It should bring the essence of the live performance into the living room. Listen to the L150 and hear what we mean.


Each component od the JBL L150 loudspeaker system is designed and produced to meet the most rigorous standards in the audio industry. The loudspeaker frames are massive cast structures, machined to exacting tolerances. The magnetic assemblies are precisely manufactured oflow-reluctance iron, energized by powerful, high-grade magnets. Voice coils are hand wound and held within one turn of design specifications. Cones are designed from the best possible combination of stiffness, density, and weight.

Low Frequency

The Newly developed 300 mm (12") low frequency loudspeaker produces the powerful bass of the L150. The driver utilizes a stiff, heavy cone, coated with an exclusive damping formulation (the white material on the cone) to give it optimum mass and density. The 75 mm (3") voice coil, formed of cooper ribbon and hand wound on edge, is powered by a 4,7 kg (10,25 lb) magnetic assembly. Beacuse the voice coil is unusually large for a 300 mm driver, the L150 offers exceptional transient response and high efficiency.

The magnetic assembly is the first JBL low frequency design to incorporate a ferrite magnet. Ferrite magnets have many desirable characteristics, but these have been overshadowed in conventional designs by unacceptably high (by JBL standards) levels of second-and third-harmonic distortion. However, after two years of concentrated research, JBL engineers have developed an assembly that solves the distortion problem.

One key to the new JBL design is the Symmetrical Field Geometry (SFG). Accurate reproduction of the audio signal requires that the cone and voice coil move in or out with equal facility. This does not happen in conventional designs because the magnetic field around the voice coil gap is not symetrical; such designs generate large amounts of third-harmonic distortion. JBL's new SFG design greatly reduces this distortion by creating a symmetrical magnetic field on both sides of the gap.

JBL has also devised an innovative solution to the problem of second-harmonic distortion. As the voice coil moves in the gap in a conventional ferrite design, the electrical field produced by the coil (from the audio signal) modulates the flux in the magnetic structure. This in turn affects cone movement and generates from 3% to 5% second-harmonic distortion. JBL engineers found an ingenious solution - the Flux Stabilizer, an aluminum ring surrounding the pole piece. The Flux Stabilizer minimizes this flux modulation and thereby reduces second-harmonic distortion to 0,01% or less.

The low frequency reproduction of this driver is not only powerful, but clean, exhibiting a depth and transparency seldom encountered outside a live performance.

A 300 mm (12") passive radiator extends bass response to the lowest octaves. The passive radiator, essentially a loudspeaker cone with no magnet or voice coil but of a precise mass, takes the place of a large volume of air and allows the L150 to achieve its deep bass in an enclosure of modest size. Similar performance from a conventionally ported system would require a much larger enclosure; a completely sealed (acoustic suspension) design would be much less efficient.


The 130 mm (5") midrange driver, housed in an isolated sub-chamber to prevent interaction with the low frequency loudspeaker, delivers clear, undistorted reproduction, even at extremely high volume levels. The combination of a stiff cone and large voice coil (22 mm, 7/8") give this driver exceptionally good transient response, crucial to accurate reproduction. The midrange driver is designed to be more efficient than the low frequency loudspeaker in order to maintain the substantial reserve dynamic range necessary to reproduce high-intensity program peaks without strain or distortion. (This reserve dynamic range is important because most music has far more energy in the midrange than in the bass or treble regions.)

High Frequency

The 25 mm (1") dome radiator produces high acoustic output with exceptional clarity and dispersion. The dome is constructed from phenolic-impregnated linen and combines stiffness with light weight; it is small enough to provide the dispersion necessary for excellent stereo imaging, yet strong enough to produce live-performance volume levels without distorting. Special clamping rings assure linear movement to further aid in distortion-free performance.

Frequenvy Dividing Network

The dividing network receives the signal from the amplifier and allocates each portion to the appropriate driver. The sophisticated network of the L150 utilizes phase-correcting and impedance-leveling circuitry so that the drivers operate through the transition frequencies in a manner approaching the theoretical ideal. All of the network components are mounted on a single large printed circuit board, which improves the already excellent reliability. The driving network of the JBL L150 does its job so well that the listener will never be aware of separate drivers - just the smooth, transparent sound.

Controls for midrange and high frequency output accomodate variations in room acoustic and personal preferences.


A tightly constructed, non-resonant enclosure is important to any loudspeaker system and especially importand to a robust system such as the L150. Therefore, the enclosure panels are made of dense compressed wood, superior to solid wood in its acoustic properties. For maximum strength and resistance to vibration, all panels are cut from 19 mm (3/4") stock. In addition all joints are hand fitted and heat cured. To absorb unwanted resonances, the enclosure is lined with fiberglass. The finish veneer is American black walnut, hand-rubbed to alustrous finish.

Power Capacity

The JBL L150 will produce sound at comfortable listening levels when driven by an amplifier having an output of as little as 10 watts continuous sine wave per channel. However, the L150 combines high efficiency with high power capacity; for the best possible performance, an amplifier capable of delivering up to 300 watts continuous sine wave per channel is recommended. Such an amplifier has the reserve power necessary for accurate reproduction of transients, which can reach momentary peaks equivalent to ten times the average power level.


JBL has traditionally refrained from listing data for which no widely accepted test procedures have been establoshed. In the absence of such standards, any laboratory can legitimately produce a variety of values, depending on the conditions selected.


Max. Recommended Amplifier Power: 300 watts per channel

Nominal Impedance: 8 ohms

Crossover Frequencies: 1,000 Hz; 4,000 Hz

System Sensitivity: 88 dB SPL, (1W/1m)

Low Fequency Loudspeakers

Nominal Diameter: 300 mm (12 inch)

Voice Coil: 76 mm (3 inch) copper

Magnetic Assembly Weight: 4,7 kg (10¼ lbs)

Flux Density: 1.05 tesla (10,500 gauss)

Sensitivity (Averaged from 100 Hz to 500 Hz, within 1 dB): 89 dB SPL (1W/1m)

Midrange Loudspeaker

Nominal Diameter: 130 mm (5 inch)

Voice Coil: 22 mm ( inch) copper

Magnetic Assembly Weight: 0,74 kg (1 lbs)

Flux Density: 1,4 tesla (14,000 gauss)

Sensitivity (Averaged from 1 kHz to 3 kHz, within 1 dB): 91 dB SPL (1W/1m)

High Frequency Dome Radiator

Nominal Diameter: 25 mm ( 1 inch)

Voice Coil: 25 mm (1 inch) aluminum

Magnetic Assembly Weight: 0,68 kg (1½ lbs)

Flux Density: 1,4 tesla (14,000 gauss)

Sensitivity (Averaged above 5 kHz, within 1 dB): 90 dB SPL (1W/1m)


Finish: Oiled walnut

Grille Colors: Brown, rust, camel

Dimensions (W x H x D): 1054 x 432 x 330 mm (41½ x 17 x 13 inch)

Weight (net): 36,4 kg (80 lbs)