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-K555ES cassette deck


Quite simply, Sony wanted to build a deck goodenough to be a part of the ES system. Se we addressed each of the three essential issues concerning cassette deck design - the heads, the transport, and the noise reduction system. Each was designed and constructed incorporting the most advanced technology available today.
A Third Head for Better Performance
Let's begin with the heads - the TC-K555ES employs a unique Independent Suspension three-head design. The record head has been designed with the wide head gap that is essential for wide dynamic range recordings, while the playback head retains the narrow gap required for accurate high frequency response. This is in sharp contrast to the glaring compromises of a two-head deck, in which a single head gap must adequately accommodate both requirements - an impossible task.

Superior Sound without the Struggle
Three-head design has been the cornerstone of superior cassette performance.  Unfortunately, in the past, three-haed decks have required critical and nearly constant azimuth adjustment to be effective. But Sony's inventive three-head design places the record and playback heads in close proximity to one another, eliminating the need for cumbersome azimuth adjustments. Yet the heads still remain physically distinct 9for optimized performance) and magnetically shielded from one another 9for minimal crossfeed). And Sony's exclusive independent Suspension design improves tape contact and azimuth accuracy, while reducing flux leakage. Result? Outstanding (and adjustment-free) performance.
The heads also combine an amorphous core material (whose irregular molecular structure provides superior magnetic performance) with modern laser construction technology to assemble the heads with exceptional precision. These laser Amorphous (LA) heads assure you superior sound and long life.

More Innovative Transport Technology
Another problem often associated with cassette decks is the distortion caused by inaccurate tape transport. A common manifestation of transport imperfection is called modulation noise. Sony's closed-loop dual capstan transport combats this problem. We've placed a capstan on either side of the tape path to isolate the tape passing across the heads form external influences 9such as the spooling motor). And, as a bonus, head-to-tape contact is also improved and performance remains consistent from one end of the tape to the other.

The Beautiful Sound of Silence
Perhaps the most heralded recent achievement in cassette deck technology is in the field of noise reduction - specifically, the development of Dolby C. and it's an impressive accomplishment, to be sure. With no more effort than simply flipping a switch, you can reduce the tape hiss in its most annoying frequencies by nearly 20 dB. The TC-K555ES lets you experience the wonder of Dolby C, while still providing compatibility with your tapes recorded with Dolby B - the older noise reduction system is included as well. And an anti-saturation circuit improves treble headroom by up to 4 dB, which makes proper recording utterly simple.
The TC-K555ES also includes a variety of convenience features, such as auto play; memory play; feaather-touch full-logic controls; a fluorescent Concentrated Display; variable bias for tape types I, II and II; and a Linear Counter that accurately reveals elapsed tape time in all transport modes (including rewind and fast forward). But it is most impressive for its unsurpassed basic performance and remarkable sonic capabilities.

Specifications
Fastforward/Rewind Time:  80 sec C-60
Wow and Flutter (WRMS):  0,04%
Frequency Response (±3 dB, re-20 dB)
Metal Type IV  :  25 Hz - 18,000 Hz
FeCr  Type III :  25 Hz - 18,000 Hz
UCX Type II :  25 Hz - 17,000 Hz
AHF Type I :  25 Hz - 17,000 Hz
Signal-to-Noise Ratio (re 3% T.H.D., peak Wtd):
Dolby Nr Off
Metal Type IV  :  60 dB
FeCr  Type III :  62 dB
UCX Type II :  59 dB
AHF Type I :   56 dB
Dolby B NR On
Metal Type IV  :  67 dB
FeCr  Type III :  69 dB
UCX Type II :  66 dB
AHF Type I :   63 dB
Dolby C NR On
Metal Type IV  :  73 dB
FeCr  Type III :  75 dB
UCX Type II :  72 dB
AHF Type I :   69 dB
Total Harmonic Distortion (at 1 kHz, re 0 dB record level):  0,8% (Type IV, Type II)
Crosstalk (1 kHz):  60 dB between tracks
Separation (1 kHz):  35 dB between channels
Input Sensitivity
Line :  77,5 mV (50 k Ω) - 20 dB
Output Level
Line :  435 mV (10 k Ω) -5 dB
Headphone level (8 Ω):  -20 dB to - 50 dB
Power requirement:  AC 120 V, 60 Hz
Power Consumption:  26 watts
Dimensions (W x H x D):  430 x 105 x 285 mm (17' x 4-1/4" x 11-1/4")
Weight:  6,1 kg (13 lb 8 oz)

1 commento:

  1. There is one first series of the TC-K555ES ("MK 1") - which offers Dolby B/C - which, very interestingly, uses a set of 8 (!) CX174 chips in a tandem configuration - instead of the later newer chip set CX20087and CX20088 in the "MK II" series of this deck. There is also a service manual around for the TC-K555 (Dolby B and C) still using 4 x CX174 chips plus still discretely added-on amp circuitry sitting around these ICs to enable Dolby C functionality.

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