Toshiba GD-1221 Manuale Utente
GD-1220/1221
© 2006 - 2008 TOSHIBA TEC CORPORATION All rights reserved
ELECTRICAL CIRCUITS
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The monitoring signal selected by IC9 is input to the analog switch (IC10) to select the output sound
volume. The sound volume is selected by switching IC10 according to the SPVOL0-2 signals output
from the ASIC and selecting an input resistance for the monitoring signal.
volume. The sound volume is selected by switching IC10 according to the SPVOL0-2 signals output
from the ASIC and selecting an input resistance for the monitoring signal.
The relation between the signals and sound volume is as follows.
The monitoring signal whose volume is controlled by IC10 is amplified by the OP amplifier (IC17), then
output to the speaker.
output to the speaker.
* Values in [ ] are GD-1221 in case that the descriptions vary between GD-1220 and GD-1221.
Sound volume
SPVOL2
SPVOL1
SPVOL0
Max. (7)
LOW
LOW
LOW
(6)
LOW
LOW
HIGH
(5)
LOW
HIGH
LOW
(4)
LOW
HIGH
HIGH
(3)
HIGH
LOW
LOW
(2)
HIGH
LOW
HIGH
Min. (1)
HIGH
HIGH
LOW
Silent (0)
HIGH
HIGH
HIGH
Signal Name
Type
Active
Description
Destination
TONESEL
O
H
Line/Tone Selection Signal
IC9
RING/TONE
O
H
Ring/Tone Selection Signal
IC9
SPVOL0-2
O
H
Speaker Volume Control Signals 0-2
IC10
08/08