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





JVC KD-21D cassette tape deck

This easy-to-afford KD-21D shares many of the features of other, more expensive JVC decks. Among its noteworthy features are the 5-LED Peak Indicator, Timer Standby Facility, Dual-Ball Cassette Hold System.

Every circuit and every control is designed for the cleanest, most musical recording and playback.

The KD-21D thus offers high-quality specifications such as 56 dB Signal-to-Noise Ratio to guarantee long years of musical enjoyment. Add this high-performance deck to your present audio system to make it complete.

 

Dolby Noise Reduction

If you're familiar with tape recording, so must you be with this useful feature. With it switched in, you hardly notice hiss - the objectionable intruder inherent to tape recording. Unless effectively reduced, tape hiss is particularly more annoying during soft musical passages. And it's a problem no matter what type of tape you use. With the Dolby in the KD-21D, hiss noise is reduced by as much as 5 dB at 1 kHz and 10 dB above 5 kHz. Pulsive peaks are tamed to render high-frequency signals sound free from distortion and all forms of high-frequency noise.

JVC use the Dolby in a compact IC with components inside directly coupled. Its improved transient response means crisp reproduction, while dependability and stability are impeccable.

 


Considerations for Wider Dynamic Range

If a signal is clipped and distorted anywhere along the way from a deck's input to output, there's no way to restore it entirely to its original quality. Therefore, JVC have taken every consideration in the KD-21D to widen dynamic range and prevent distortion and clipping. There are, for example, a separate low-distortion amp for mics in an advanced 2-stage, direct-coupled NPN transistor ; a Mic/Line input selector that permits line inputs to go straight to the recording amp without adding distortion of its own; two 2-position Bias and Equalizer switches to make most of every tape on the market; and more.

 

Useful Recording Aids

These large VU meters enhance visibility to  help you make correct level adjustments. Together with the JVC's 5-LED Peak Indicator, they help you make clean tape recordings every time. As on the more expensive JVC models, our KD-21D is equipped with the Full Automatic Stop Mechanism to eliminate worry about stretched tapes or an overheated motor. A light in the tape well permits you to keep a close watch on the cassette at all times.

 


Specifications

Type:  stereo cassette deck

Track System:  4-track, 2-channel

Motors:  Electronic Governor DC motor

Tape Speed:  4,8 cm/sec

Fast Forward/Rewind Time:  100 sec with C-60 cassette

Heads: 

Recording/Playback :  Cronios head

Eraser: 2-gap , Ferrite head

Bias:  AC bias (95 kHz)

Erasure:  AC erasure (95 kHz)

Frequency Response: 

CrO₂ :  30 - 15,000 Hz (Typical)

Norm :  30 - 14,000 Hz (Typical)

Signal-to-Noise Ratio :  56 dB from peak level, weighted

The Signal-to-Noise Ratio is improved by 5 dB at 1 kHz and by 10 dB above 5 kHz with Dolby NR on.

Wow and Flutter:  0,10% (WRMS) 2,20 % (DIN 45 511)

Crosstalk:  65 dB at 1 kHz

Total Harmonic Distortion :  1,3% ( 1khz, 0 VU, Normal tape)

Input Sensitivity/Impedance:

MIC :  0,2 mV/600   - 10 k

Line :  80 mV/100 k

DIN :  0,07 mV/ k  

Output Level/Impedance

Line :  420 mV/3,5 k

DIN :  420 mV/3,5 k  

Headphone :  0,3 mW/8    - 1 k

Power Requirements: AC 120 V, 60 Hz (KD-10 C/J); AC 240/220/120 V 50/60 Hz (KD-10 A/B/E)

Power Consumption:  15 W

Dimensions (W x H x D):  390 x 157 x 259 mm (15-3/8" x 6-1/4" x 10-1/4")

Weight:  4,5 kg (9,9 lbs)


 

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