Accuphase T-1100 - Advanced Digital Signal Processing; DS-DC (Direct Synthesis - Double Cancellation); Pilot Tone Direct Synthesis; Crosstalk Double Cancellation

ResponseindB
FrequencyinHz
Stereo Separation
#HANNEL
3EPARATOR
#ROSSTALK
$OUBLE#ANCELLATION
Pilot Tone
Stereo-Modulated
Signal
#ROSSTALK
#ANCELLATION
（STSTAGE）
,
2
#ROSSTALK
#ANCELLATION
（NDSTAGE）
0ILOT4ONE
$IRECT
3YNTHESIS
20 30 50 100 200 500 1k 2k3k 5k 10k
0
− 10
− 20
− 30
− 40
− 50
− 60
− 70
− 80
− 5
− 15
− 25
− 35
− 45
− 55
− 65
− 75
Lch→Rch
Rch→Lch
Stereo Separation Characteristics
■ DS-DC Type Stereo Demodulator Circuit
■Intermediate frequency (IF) signal from
front end is digitized by high-precision
A/D converter
■Functions after intermediate frequency (IF) stage (variable
bandwidth IF filter, multipath reduction, digital FM
detector, DS-DC stereo demodulator) are performed
through fully digital signal processing b y a h i g h - s p e e d ,
h i g h - a c c u r a c y D S P c h i p , p r o v i d i n g d r a s t i c a l l y i m p r o v e d
performance. The end result is an FM tuner of the highest
order.
■ Supplied Remote Commander RC-410
 Provides access to all functions of the tuner
(except power switching), as well as
(Accuphase) amplifier volume control.
●
DS-DC (Direct Synthesis − Double Cancellation)
/Pilot Tone Direct Synthesis
A conventional FM tuner uses a PLL circuit to extract the pilot tone and obtain the
frequency and phase components from the input signal (stereo-modulated signal). If the
level
of the pilot tone decreases, noise will be heard and stereo separation becomes
extremely poor.
With DS-DC, the waveform of the pilot tone in the input signal is identified as is* and
generated directly by the DSP arithmetic. Therefore the pilot tone can be extracted
reliably even when a high level of noise is present. Impressive stereo separation can be
achieved even when the pilot tone level is low.
※Simply analyzing the signal and determining similarities.
4Crosstalk Double Cancellation
After the input signal has been separated into the left and right components, the circuit
eliminates crosstalk using a dual approach that also takes phase components into
consideration. The result is extremely thorough left/right separation.
DS-DC principle with DSP ensures ideal stereo
demodulation for amazing channel separation
The stereo demodulator in the T-1100 features
another Accuphase innovation called DS-DC (Direct
Synthesis
− Double Cancellation). The demodulator
comprises the two technologies described below.
Since all operations are carried out through software-
based algorithms in Digital Signal Processor, ideal
demodulation performance can be achieved, result-
ing in previously unheard-of channel separation.