Daewoo DV-K580DZ-T, Service Manual

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16
CIRCUIT OPERATION
2. AUDIO PART
2-1) EE MODE
External AUDIO signal which is input to pin 16 of IC201 is output from pin 22 of IC201 after being ampli-
fied through ALC and Line Amp.
2-2) REC MODE
It will be the REC mode when REC 5V is input to pin 24 of IC201. Input signal will be replaced on the
tape through R/P HEAD after being amplified and modulated with Bias Frequency. Input signal is ampli-
fied and frequency compensated by REC AMP, ie. it means high band compensation in order to match
AUDIO HEAD characteristic. Each mode’s peaking frequency will be determined by BIAS element (R, L,
C) of REC AMP. OSC oscillation frequency is 70KHz sinewave, it will be used for tape’s full erasing and
AUDIO TRACK erasing.
2-3) PB MODE
It will be the PB mode when PB 5V is input to pin 11 of IC201. The signal which is picked up from AUDIO
HEAD is input to EQ AMP, then constant Audio Level will be output by PB LEVEL fixed resistor after
each mode is amplified and frequency is compensated.12/24H AUDIO output level will be compensated
with receiving Audio 12H/Audio 24H control of u-COM. Finally this output signal is output through 20KHz
LPF.