Frequency (Hz) - Yamaha K-1020 Owner's Manual

То improve the distortion characteristics during recording, it is im-
portant that, along with the recording tape head, a bias current
precisely adjusted to the type of tape being used be supplied to
the recording tape head. However, an excessively high bias current
will cause the high frequency signal components to deteriorate, with
a resuitant rolling off of the high frequencies.
' The HX-Professional system incorporates a DC-controlled bias servo
amplifier between the recording tape head and the bias oscillator,
which automatically controls the bias amount independently for the
left and right channels, according to the level and the frequency
components of the signal input. Thus, this system assures optimum
recording of the entire audio frequency spectrum under all record-
ing conditions. The deterioration of the high freguency signal com-
ponents has been drastically improved, resulting in dynamic and
clear recording with sufficient headroom, even at О dB. Unlike other
noise reduction systems, the HX Professional system operates
automatically, but only during recording. Thus, a tape recorded on
a deck equipped with the HX Professional system can be played
back on any conventional tape deck, and still retain the dynamic .
and clear sound that results from. using the HX Professional system.
e Dolby noise reduction and headroom extension manufactured
under license from Dolby Laboratories Licensing Corporation.
HX professional originated by Bang and Olufsen.
REC Amp
— O Input Signal
DC Control Bias Servo Amp
4 Біаз О5С
Controller
Integration
Circuit
REC Head
әс?
Tape Selector
BIAS ADJ
With cassette tapes, the most noticeable form of noise is high-
frequency hiss. To reduce this hiss noise, the K-1020 has been
equipped with a newly developed Dolby C noise reduction system
in addition to its conventional Dolby В NR. Either type of noise
reduction may be selected with the switch provided.
Dolby В NR has а noise-reduction effect of about 10 dB in the'
high-frequency range. The corresponding figure with Dolby C NR
is about 20 ОВ, but this is over the entire range where the human
ear is most sensitive to noise (2 kHz to 8 kHz). Dolby C NR also
improves the tape's MOL (maximum output level. — _
Dolby C NR has two new circuits: a spectral skewing circuit and an
anti-saturation network. By improving the saturation level of the tape
it is possible to prevent high-frequency loss and encode/decode er-
ror, etc., improve dynamic range and signal-to-noise ratio, and make
it easier to set the recording level. With Dolby C NR, it is possible
to achieve the same noise reduction effect at both high and low
+10 _
—20
Level (dB)
1
| Ф
о
—80
20 100 500
signal levels and to set the recording level at a point where side-
effects such as "breathing" are eliminated. Also, by expanding the
operating frequency range to two octaves more than that of Dolby
same position on record and play. |
2K 5K 10K 20K
Frequency (Hz)