Kenwood TS-990S Service Manual

TS-990S
34
CIRCUIT DESCRIPTION
8-5. Signal Path to External I/O
The signal (ANI) output from the ACC2 and the signal
(USB-ANI) output from the USB are applied to CN671 and
CN672 respectively, and either one of which is selected by
the analog switcher (IC684). This signal is applied to the R
channel of the ADC (IC392) through the active fi lters (IC672
and IC682).
The ANI signal or USB-ANI signal sampled by the ADC
at an fs of 96kHz is sent to the SRX-DSP.
The signals (MANO and SANO) output to the ACC2 are
sent from the SRX-DSP to the DAC (IC391) and converted
to an AF signal at an fs of 48kHz. The MANO signal output
from the L channel of the DAC and the SANO signal output
from the R channel of the DAC are output to the ACC2 from
CN671 after passing through the active filter (IC651 and
IC659) and the active fi lter (IC651 and IC657), respectively.
The signals (USB-MANO and USB-SANO) output to
the USB are sent from the SRX-DSP to the DAC (IC391)
and converted to an AF signal at an fs of 48kHz. The USB-
MANO signal output from the L channel of the DAC and the
SANO signal output from the R channel of the DAC are sent
to the digital unit (X46-339 CN11) from CN672 after passing
through the active fi lter (IC653) and the active fi lter (IC654)
and input into the USB codec IC (X46-339 IC703).
8-6. Signal Paths of Recording Sound and Play-
back Sound
The recording signals (MRECI and SRECI) are output
from the SRX-DSP to the DAC (IC387) and converted to an
AF signal at an fs of 48kHz. The MRECI signal output from
the L channel of the DAC and the SRECI signal output from
the R channel of the DAC are sent to the digital unit (X46-339
CN11) from CN672 after passing through the active filter
(IC653) and the active fi lter (IC654) and input into the digital
unit (X46-339 CN11).
The playback sound signals (MRECO and SRECO) are
input into CN672 from the digital unit (X46-339 CN11). The
MRECO signal is applied to the L channel of the ADC (IC389)
and the SRECO signal is applied to the R channel of the
ADC (IC389). The signal sampled at an fs of 48kHz by the
ADC is sent to the SRX-DSP.
Fig. 39 External I/O and signal paths of recording and playback sounds
IC392
ADC
R+/-
IC300
SRX-DSP
IC391
DAC
L+/-
R+/-
IC386
DAC
L/R
CN671
CN672
ANI
USB-ANI
(UANI)
ANISEL
IC685(1/2)
Active LPF
IC684(1/2)
Analog SW
IC684(2/2)
Analog SW
Q652
Q653
IC682(B/2)
Active LPF
IC682(A/2)
Inverter
IC672(B/2)
Active LPF
IC672(A/2)
Active LPF
IC653(A/2)IC653(B/2)
Active LPF
IC654(B/2) IC654(A/2)
MANO
SANO
Active LPF
IC651(A/2)IC659(A/2)IC659(B/2)
IC651(B/2)IC657(A/2)IC657(B/2)
USB-MANO
USB-SANO
(SUANO)
(MUANO)
IC387
DAC
L/R
IC663(A/2)IC663(B/2)
Active LPF
IC655(B/2) IC655(A/2)
MRECI
SRECI
IC389
ADC
L/R
SRECO
MRECO

Kenwood TS-990S Specifications

General

Receiver Type	Triple Conversion Superheterodyne
Antenna Tuner	Built-in automatic antenna tuner
DSP	Yes
IF DSP	Yes
Modes	SSB, CW, AM, FM
Display	7-inch TFT color LCD
Weight	25 kg (55.1 lbs)
Antenna Connectors	SO-239
Power Supply	13.8V DC