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

EMT 938 Broadcast Disk Reproducer

 EMT 938 Features
Robust Tone Arm
Simple and Rational Operation
High Immunity to Vibrations with Effective Shock Absorber System
Direct Drive with Quick Start
Three Speedes: 33, 45, 78 rpm
High-Quality Amplifiers

The mains power switch, speed selector switch, Start/Stop button, and button for the tone arm lift comprise the operating elements of the EMT 938 BDR (Broadcast Disk Reproducer). Both Start and  i.e., run-up of the turntable platter and platter braking, are accomplished in less than 500 milliseconds. The unit cantherefore be started precisely at any syllable in the groove.
To facilitate locating a desired point on the record (such as the beginning of the modulation, or a specific cueing point), theplatter rim extends 2,4 cm beyond the edge of an LP, enabling the record platter to be turned back and forth by hand. A phone jack is provided for connecting stereo headphones.

 The EMT 938 BDR is now equiped with a synchronization indicator, which illuminates as soon as the started turntable platter has reached the selected speed.

 The front view shows the level controls of the audio amplifiers. The insertion of a pre-preamplifier for moving coil pickup cartridges is indicated by a coloured dot.

Jacks for external connections are located on the rear side of the EMT 938 BDR. Printed legends identify the functions of the jacks.

Turntable Diameter:  330 mm
Turntable Speeds:  78 rpm, 45 rpm, 33 1/3 rpm
Accuracy of turntable speed:  Quartz controlled, max. ±0,1%
Speed Variation with VCD Operation:  ±25 %
Run-up Time at Tamb = 20°C
Quick Start:  max. 200 msec
Wow and Flutter:  max. ±0,075% (at 33 1/3 rpm measured with EMT 424, weighted in accordance with DIN 45507/IEC)
Rumble (measured in accordance with DIN 45 539 with test record DIN 45 544):
Unweighted : min. 50 dB
Weighted : min. 70 dB
Amplifier Section
Equalization (DIN,NAB, IEC):  75/318/3180 µsec 
Frequency Response:  40 Hz to 15 kHz ±0,5 dB;  30 Hz approx. -3 dB below 30 Hz approx. 20 dB/octave rolloff above 25 kHz approx. 12 dB/octave rolloff
Input Voltage
For magnetic Hi-fi  cartridges:  2  to 10 mV (version with Ri =47 kohms)
For dynamic cartridge:  0,3 to 1,4 mV (with active impedance transformer, gain = 17 dB)
Overload margin of the Input:  20 dB above nominal level
Output Voltage:  +6 dB (1,55 V) max. 10 V on 200 ohms
Harmonic Distortion:  max. 0,2%,  30 Hz to 12 kHz, at =15 dB (4,4 V) 0n 200 ohms
Crosstalk Supression:  min. 50 dB ,  30 Hz to 15 kHz
S/N Ratio RMS
Unweighted Peak : min. 70 dB
Weighted  : min. 64 dB (in accordance with CCIR 468-2)
Mono Switching:  Remote controllable
Headphone Outputs Mono and Stereo (200 Ohms):  0,5 to 2 V, unbalanced

Switchable for mains voltage of 100 to 120 V, 200 to 240 V, 50 Hz or 60 Hz
Power Consumption:  max. Approx. 85 VA (normally approx. 40 VA)
Dimensions (W x D x H):  500 x 440 x 195 mm (19,7" x 17,3" x 7,7")
Weight:  approx. 25 kg (55,12 lbs)

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