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





Sony TC-K71 cassette tape deck

The Sony TC-K71 is outstanding examples of advanced technology in the service of music. This machine provide the exceptional sound quality of Sony's Independent-Suspension three-head design and the absolute precision of Closed-Loop Dual Capstan drive. The K71 offers variable bias for TypeI tapes, and including two-motor tape drive with BSL capstan motor and FG servo system, Sony's Dolby IC for greater dynamic range and lower distortion, microprocessor logic control with remote and timer capabilities, LED Peak-Program Meters with double indication peak-hold, and selected electronic parts for superior performance.

 


Three-Head Design

Many audiophiles prefer three-head decks - with separate erase, ecord, and playback heads - because this format permits them to monitor the tape an instant after it has been recorded. In this way, the user can compare the quality of the recorded music with the original source. Tape monitoring is convenient and in demanding applications, the monitored sound can be an invaluable recording tool. But three heads yield significant performance advantages, too.

A conventional cassette deck, with a combined record/play head different physical requirements from playback. Recording is a high-energy process, involving signal levels some 40 dB higher than playback. For good recording dynamic range, the head gap should be wide - three to five microns. Yet for playback high-frequency response, the gap should be narrow - no more than one micron. Any combined record/play head must necessarily represent a compromise between these two requirements.

The Sony TC-K71 circumvent this compromise. This deck have separate record and playback heads, each optimized to its particular function. The playback head has a narrow 0,9  micron gap for response out to 18,000 Hz. And the record head has a wide 4,5 micron gap for superb dynamic range. In fact, the high-energy capabilities of the record head easily meet the requirements of the most demanding tape formulations, including metal particle tape.

 

Variable Bias for Type

Slight variations in bias requirements from one brand to another can result in overly "bright" or "dull" high frequency response, and excess distortion. The problem is most serious for Type I tapes, which have the widest range of bias need. For this reason, the TCK71 variable bias for Type I cassettes. To use the bias control, you record sample material and switch back and forth between Tape and Source, correcting the bias for proper tonal balance.

 

 

 Specifications

Fast-Forward/Rewind Time (C-60):  80 sec.

Wow and Flutter:  0,04% (WRMS), 0,12% (DIN 45507)

Frequency Response (±3 dB, Re: -20 dB)

Metallic Tape : 30 - 18,000 Hz

FeCr Tape : 30 - 18,000 Hz

EHF Tape : 30 - 17,000 Hz

SHF Tape : 30 - 15,000 Hz

Re: 0 dB Metalic Tape : 30 -13,000 Hz

Signal-to-Noise Ratio ( Dolby NR Off, Re: 3% THD, Peak, IHF-A Wtd.)

Metallic Tape : 60 dB

FeCr Tape : 60 dB

EHF Tape : 58 dB

SHF Tape : 54 dB

Improvement with Dolby NR On :  Up to 5 Db at 1 kHz, 10  Db at 5 kHz or above

Total Harmonic Distortion (1 kHz, Re: 0 db Record level)

Metallic Tape : 0,8%

FeCr Tape : 0,8%

Crosstalk (1 kHz, tracks):  60 dB

Separation (1 kHz, channels):  35 dB

Erasure (400 Hz, incl. Metallic Tape):  60 dB

Bias Frequency:  105 kHz

Meter Range:  -40 dB, +8 dB

Line Input Sensitivity/Impedance:  77,5 mV/50 k ohms

Mic Input Sensitivity/Impedance:  0,25 mV/Low

Line Output Level: 

Fixed :  435 mV

Variable :  27,5 - 435 mV

Line Output Load Impedance Nominal/Minimum:  50/10 k ohms

Headphone Output Level:  4,9-77,5 mV

Nominal Headphone Impedance:  8 ohms

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

Power Consumption:  26 W

Dimensions (W x H x D):  430 x 130 x 290 mm (17" x 5-1/8" x 11-3/8")

Weight:  5,6 kg (12 lbs 5 oz)


 

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