Yamaha K-1020 Owner's Manual page 9

The К-1020 incorporates a dbx system which greatly expands the
dynamic range of cassette tapes. If the softest sound that the
human ear can near is "1", then the loudest is "1 million", or
120 dB, This is the dynamic range of the human ear. The dynamic
range of cassette tape, however, is only about 55 dB. Even metal
tapes only offer an improvement of 3 dB in the midrange and 8 dB
in the high frequencies.
*The priciple of dbx system ENCODE
+20
=0
Input dynamic E
range 100dB
~ 40
-60.
–80 У
*Characteristics of dbx Encode/Decode - +20
5 + 0
— :
> =20
ш
—!
@ ENCODE T
(2) GENERAL Б 80
Ф DECODE ©
The dbx system works by compressing the dynamic range of the
record signal by half and then doubling the dynamic range of the
playback signal. (see diagram). With the dbx system functioning, a
program source compressed to 50—60 dB at recording will be
expanded to а dynamic range of 100—120 dB. At the same time,
noise levels will be reduced throughout the entire frequency range,
and the effective saturation level of the tape will be increased.
е Tapes not recorded with the dbx system should be played back
with the dbx system off.
DECODE
3 +20
Qs |
Output dynamic
range 100dB
-40
—80 -60 -40 -20 +0 +20
INPUT LEVEL (dB)
input
This tape recorder uses a full-scale three-head configuration, with
independent recording, playback and erase tape heads, as well
as independent recording and playback amplifiers. Since a major
characteristic of a three-head tape deck system is simultaneous tape
recording and tape playback, tapes can be monitored directly as
they are made.
The AUTO MONITOR function automatically switches to SOURCE
MONITOR during the REC/STANDBY and RECORD modes, and to
TAPE MONITOR during the PLAY mode. The AUTO MONITOR
function can also be manually switched by using the MONITOR
button if required.
Recording head Playback head
Erase head
REC. AMP P
O Output
AUTO MONITOR SWITCH