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-85 cassette deck

 

Switchable 25-LED Spectro Peak Indicator

Superb Transient TTL IC Amp Design

Memory Stop

Gear/Oil-Damped Cassette Lid

 

The JVC KD-85 stereo cassette deck always lets you make a perfect recording.. Damage to tapes and mechanism is also avoided. A beautiful machine to behold, this deck is a JVC design coup. Among the extras is the Spectro Peak Indicator. Superb specifications include a 30 to 17,000 Hz Frequency Response with CrO₂ tape, a better than 57 dB Signal-to-Noise Ratio and -0,04% wow/flutter .

 


Tape-transport has never been more accurate than Full Logic control and Two-Motor drive.

The KD-85 uses the best mechanism ever conceived for a cassette deck - the two motor ID mechanism. In this configuration, two motors ensure stable tape transport. One is a frequency generator (FG) servomotor for capstan drive. The other is DC for reel drive. Because each drive mechanism operates independently of the other, and because operation is thus simplified, the very, very low/flutter of the KD-85 is assured at all times. Full logic control of the deck is the job of three dependable TLL ICs - one custom-made MSI (Medium-Scale IC) and two TTL (Transistor-Transistor Logic) Ics. They permit direct change of modes at a light touch of the fingertip - the buttons require only a 6 mm push.

 

Watch the frequency spectra on this Spectro Peak Indicator

This handy rec/playback convenience allows you to visually and constantly check the level of recording in five low-to-high frequency ranges. You can thus avoid saturation (less distortion) and keep noise out (better Signal-to-Noise Ratio).

 

JVC has perfected several systems for Better Tape Handling

JVC's exclusive Dual-Ball Cassette Hold System clamps cassettes in tight for better, smoother performance. Compartment is topped with Gear/Oil-Damped Cassette Lid - press Eject button and balls release tape. Designed for advanced audiophiles, the JVC KD-85 packs in all these features at a practical and accessible price to please all.

 


Specifications

Type:  Stereo cassette deck

Track system:  4-track, 2-channel

Frequency Response Nominal

Chrome Tape:  20 - 18,000 Hz

SF Tape :  20 - 17,000 Hz

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 ANRS on.

Effect of Super ANRS (Normal Tape)

Improvement of S/N  :  the same as with ANRS

Improvement of Frequency Response  :  0 VU recording (6 dB at 10 kHz), +5 VU recording (12 dB at 10 kHz)

Improvement of Distortion :  0 VU recording (3% lass at 10 kHz)

Wow and Flutter:  0,05% (WRMS); 0,18% (DIN 45 500)

Crosstalk:  65 dB

Total Harmonic Distortion:  1,2%

Bias:  AC bias (95 kHz)

Erasure:  AC Erasure (95 kHz)

Heads:

Recording/Playback :  Sen-Alloy head

Erasure :  Double gap, Ferrite head

Motors:  FG servo DC motor

Tape Speed:  4,8 cm/sec

Rec Time:  2 x 30 minutes with C-60 cassette

Fast Forward Time:  85 sec. With C-60 cassette

Rewind Time:  85 sec. With C-60 cassette.

Playback equalizer time constant

Normal/SF :  3180 µs/120 µs

SA/CrO₂ and Fe-Capture Ratio :  3180 µs/70 µs

Semiconductors:  18 Ics;  65 Transistors, 94 Diodes (including 30 LEDs), 5 Zener diodes and 1 hall element

Input Terminals Sensitivity/Impedance

MIC Jack (X 2) :  0,2 mV/600  - 10 k

Jack (x 2) : 80 mv/10 k

Output Terminals Level/Impedance

Jack (x 2) :  0 - 0,5 V / 3,3 k  (Matching load Impedance 50 k  or more)

Headphone :  0 - 05 mW / 8  - 1 k

DIN Socket: 

Min. Input Level:  0,1 mV/ k

Input Impedance :  10 k

Output Level : 0 - 0,5 V

Output Impedance :  3,3 k

Matching lad Impedance :  50 k  or more

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

Power Consumption:  30 W

Dimensions (W x H x D):  450 x 158 x 327 mm ( 17-3/4" x 7-1/8" x 12-7/8")

Weight:  21,8 kg (9,9 lbs)

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