Casio CTK-631 Service Manual

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680‰
50V22
C341
Q309
R340
1.5K
AVDD
AG
AGAG
50V22
Q308
C340
C123H
C346
R342 R343 R344
3.3K 4.7K 1K
6.3V220
2SC1740STPR
2SC1740STPR
R341
C345
C821BA
C339
1.5K
R335
C123H
C343
Q310
Q311
3.3K 4.7K 1K
R337 R338
C349
50V22
C350
50V22
R336
AG
AG AG
AVDD
2SC1740STPR
2SC1740STPR
1K
22K
22K
10K
3.9K
1K
R339
R346
R348R349
C348
10V100
R347
R345
C342
C821BA
R334
680‰
From DAC
To main volume
Synch signal
Data
Word clock
Bit clock
Data
Word clock
Bit clock
DSP
LSI2
HG51B277FB
DAC
IC1
UPD6379GR
CPU
LSI1
GT913F(T)
L OUT
R OUT
SI
LRCK
CLK
SO
WCKO
SCK1
SO
LRCK
BCK
SINC
SI
WCKI
BCKI
FILTER BLOCK
Since the sound signals from the DAC are stepped waveforms, the filter block is added to smooth the
waveforms.
DAC (IC1: UPD6379GR)
The DAC receives 16-bit serial data output from the DSP. The data contains digital sound data of the
melody, chord, bass, and percussion for the right and left channels. The DAC converts the data into
analog waveforms and output them to each channel separately.

Casio CTK-631 Specifications

General

Brand	Casio
Model	CTK-631
Category	Electronic Keyboard
Language	English