m Revolutionary DDS principle for local oscillator m Dual-stage tuning front
end easily handles high signal levels m High-performance “Advanced DGL”
FM detector m DS-DC achieves ideal stereo demodulation with DSP
technology m FREQ.TRIM function reduces adjacent station interference
m 32 station memories also store reception settings m Pulse tuning principlem Digital output connector m Balanced outputs m Supplied remote control

Witness the DDS revolution – Advanced RF technology and latest digital knowhow join forces in this ultimate FM stereo tuner. The front end easily handles evenvery high signal levels. An “Advanced DGL” Detector delivers high performanceand is fully adjustment-free. DS-DC based on digital signal processing assures ideal
stereo demodulation performance. Choose between manually operated pulse tuning
and 32-station memory. Explore the many other impressive features.
The range of available program sources is getting
ever more varied: SA-CD, CD, DVD, net-based
music distribution, to name but a few. But FM
broadcasts still have a special role to play, since
they cover the entire spectrum from live
performances of time-honored classical works tothe latest hits. The FM band provides a rich choiceof music all day long. In recent years, many local
stations have come onto the scene, coveringcommunity events and using the live broadcast
medium to its best advantage.
Many audiophiles and music lovers were wishingfor the re-appearance of a truly high-class tuner
to complement a modern-day audio system andprovide the means to enjoy FM broadcasts with
optimum sound quality. By developing new circuitcomponents and applying its innovative thinking
to circuit topology, Accuphase has created aproduct that meets and exceeds these
expectations. The T-1000 is an FM stereo tunerof the highest order. It represents a bold fusionof advanced RF technology with latest digitalfinesse.
The newly developed front end employs therevolutionary DDS (Direct Digital Synthesis)
principle in the local oscillator. In addition, theDS-DC type stereo demodulator performs allnecessary operations through software-basedarithmetic processing in a DSP microprocessor.
This radically new approach to circuit design
results in amazing S/N ratio and channel
separation, elevating FM tuner performance to a
new level. Convenient features such as a 32station memory, digital output, and balanced
output circuitry are further advantages that ensure
pure signal transmission without any soundquality degradation. The T-1000 is the ultimate
luxury-class FM tuner representing a successful
blend of sound quality, perfor mance, andergonomics.
Dual-stage tuning front end easily deals withvery high signal levelsn Double-tuned antenna circuit prevents crossmodulation interference at high input levels.
n FET-based RF amplifier is configured as acascode circuit with low feedback.
n Input gate features an attenuator that prevents
overload even in close proximity of strongtransmitters.

Revolutionary DDS principle in local oscillator
achieves exceptional S/N ratio
An FM tuner amplifies the signal from the antenna
input in an RF amplifier and then mixes it withthe signal from a local oscillator for conversion
into the intermediate frequency (IF). In the T-1000,
the local oscillator is a highly advanced DDS(Direct Digital Synthesis) circuit. Unlike
conventional PLL circuits, DDS does not use
feedback, allowing it to produce an output signal
whose frequency accuracy is exactly the sameas that of the quartz oscillator itself. Because nounwanted frequency modulation components arepresent in the IF stage, the Super Heterodyne
front end achieves drastically improved S/N ratio.

Sine wave
data

D/A
converter

Quartzoscillator

Frequency
divider

OutputThe output of the quartz oscillator is supplied
to the frequency divider to create the timing (inother words the sampling frequency) with which
the sine wave data are read out.
Using this sampling frequency, the sine wave
data are read in the D/A converter to create theanalog waveform output.
Because there is no feedback loop, thefrequency purity of the D/A converter output canbe kept identical to that of the quartz oscillator.

Attenuator

DoubleBalanced
Mixer

From
Microprocessor

DDS
Local
Oscillator

IF AmplifierFig. 1 Front end circuit diagram

High-performance Advanced DGL Detector

RF removal

INPUT

The FM (frequency modulation)
detector is a so-called Advanced
DGL (Differential Gain Linear)detector developed by Accuphase.
This circuit delivers superb
performance (minimal distortion,high S/N ratio) while requiringabsolutely no adjustment, assuring
optimum reliability.
As shown in the diagram at right,
the input stage employs a highspeed comparator in the 2.5 MHz
wide-band amplifier, to eliminate
beat interference. The delay circuitachieves outstanding stability
through the use of 24 high-speed
C-MOS ICs.

LPFComparator

OUTPUT

EX-OR
Delay circuit with 24 high-speed C-MOS
ICs features wide linearity range Highspeed

Point a inFig. 2(Input signal)

Point b in
Fig. 2(Delay signal)

Point c inFig. 2(EX-OR output)

When input signal a is non-modulated, theEX-OR output c is at parity and theaveraged output of the low-pass filter is 0(zero).

EX-OR output isopen if 10 or 01,
closed if 00 or 11

High-speed "Exclusive OR"
C-MOS ICWhen input signal a is modulated, the EX-OR output
c is at non-parity. The integral value after the lowpass filter represents the potential change indicatedby the slanted line (audio signal).

DS-DC (Direct Synthesis - Double Cancellation)
DS-DC principle with DSP ensures ideal stereo
demodulation for amazing channel separation
The stereo demodulator in the T-1000 features
another Accuphase innovation called DS-DC (DirectSynthesis - Double Cancellation). The demodulator
comprises the two technologies described at right.
Since all operations are carried out through softwarebased arithmetic in a DSP (Digital Signal Processor),
ideal demodulation performance can be achieved,
resulting in previously unheard-of channel
separation.

A Pilot Tone Direct Synthesis
Commonly, an FM tuner employs a PLL circuit to extract the pilot tone and obtain thefrequency and phase components from the input signal (stereo-modulated signal). If thelevel 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 (✽) andgenerated directly by the DSP arithmetic. Consequently, the pilot tone can be extracted
reliably even when a high level of noise is present. Good stereo separation can be achieved
even when the pilot tone level is low.
✽ Identification here means to analyze the signal and determine similarities.

B Crosstalk Double Cancellation
After the input signal has been separated into the left and right components, the circuiteliminates crosstalk using a dual approach that also takes phase components intoconsideration. The result is extremely thorough left/right separation.

L

Stereo modulated signal

ChannelSeparator

CrosstalkCancellation

CrosstalkCancellation(1st stage)(2nd stage)

R

Pilot Tone
DirectSynthesis

CrosstalkDouble Cancellation

Pilot tone

Stereo separation characteristics

n DS-DC type stereo demodulatorn Supplied Remote Commander RC-33
Allows tuning, storing and recalling
stations, and controlling all other functionsof the tuner.

n Front panel

FREQ.TRIM function is great for avoiding interference
When the FREQ.TRIM function
is set to ON, the filter center
frequency (f 0 ) bandwidth ismaintained, but the reception
frequency (f 1 ) can now bechanged in fine steps (10 kHzintervals).
In situations where there are two
closely adjacent stations that areinterfering with each other, thismakes it possible to move awayfrom the area of interference
while still staying tuned to thedesired station.

2 stations can be
programmed in eachbutton

Shift reception center frequency
while maintaining bandwidth

Noise10-kHzstep★

n Rear panel★

The reception frequency
indication also switches to 10kHz steps when the FREQ.TRIMbutton is ON.

n Display example with
“FREQ.TRIM” ON (10 kHz step)n All function settings are also stored
in memory with a station (for up to32 stations).

★

n Accuphase original pulse tuning
system provides that traditional
manual tuning feel.

A Power switch
B Muting on/off button
C Forced monophonic operation button
D Stereo noise filter button
E Memory button
F FREQ.TRIM button
G Station buttons (32 stations)
H Tuning knobI Signal strength metern Two sets of analog outputs(balanced and unbalanced)
n High-quality digital output connector(coaxial)

Pulse tuning systemn Versatile array of other functions:

J Station number indicator
K Indicators (MONO/MUTE OFF/FILTER)
L Reception frequency indicator★
M Indicators (STEREO/FREQ.TRIM)
N Antenna input connector (IEC or F type)★
O Analog output connectors(BALANCED/UNBALANCED)
P Digital output (COAXIAL)Q AC power connector (for supplied power cord)★

m FILTER button reduces noise on weak stereoRemarksstations
m Muting circuit can be defeated (MUTE OFF)★ This product is available in versions for 120/230 V AC. Make sure that thevoltage shown on the rear panel matches the AC line voltage in your area.
★ The shape of the AC inlet and plug of the supplied power cord depends on thevoltage rating and destination country.
★ The reception frequency range, number of display digits, and tuning frequency
steps differ in models for different countries. The antenna connector may also
be an IEC type or F type connector. Please verify that you have the correctmodel for your area.

m Stereo reception can be forced to monophonic(MONO)
m Confirmation beep when operating tuning knob andDigital output connector

function buttons

GUARANTEED SPECIFICATIONS [Guaranteed specifications are measured according to EIA standard RS-490.]
Frequency range and tuning step width
Model for Europe

87.50 MHz - 108.00 MHz(in 50-kHz channel steps)

Model for USA

87.5 MHz - 108.0 MHz(in 100-kHz channel steps)

Model for Japan

76.0 MHz - 90.0 MHz(in 100-kHz channel steps)

m Capture ratiom RF intermodulationm Spurious response rejection
m Image rejection
m AM suppression (65 dBf input)
m Subcarrier suppression
m Output voltage (±75 kHz deviation)

1.5 dB
80 dB
120 dB
100 dB
80 dB
70 dB
1.0 V

m Standing wave ratio

1.5

m Tuning principle

DDS synthesizer tuning
32-station random memory tuning

29 dBf (IHF)
37 dBf (IHF)

m Output impedance
BALANCED (XLR type connector)
200 ohms (100 ohms/100 ohms)
UNBALANCED
200 ohms

StereoMonophonicm Sensitivity

m Sensitivity
Usable sensitivity
50 dB quieting sensitivitym S/N ratio (80 dB input, A-weighted)

11 dBf (IHF)
17 dBf (IHF)

90 dB

m Total harmonic distortion (80 dBf input, ±75 kHz deviation)
20 Hz
0.02%
1 kHz
0.02%
10 kHz0.02%

40 dB quieting sensitivity
50 dB quieting sensitivitym S/N ratio (80 dBf input, A-weighted)

m Intermodulation distortion (80 dBf input, ±75 kHz deviation)
0.03%

m Intermodulation distortion (80 dBf input, ±75 kHz deviation)
0.01%

m Frequency response 10 - 15,000 Hz +0m Frequency response 10 - 15,000 Hz +0 –2.0 dB

m Stereo separationm Alternate channel selectivity (IHF)
Interference signal
400 kHz300 kHz200 kHz

Selectivity
70 dB
30 dB
10 dB

100 Hz
1 kHz
10 kHzm Stereo trigger voltage

50 dB
50 dB
40 dB

m Antenna input

Advanced DGLm Stereo demodulation principle

DS-DC

m Digital output (EIAJ CP-1201)
Coaxial0.5 Vp-p, 75 ohms
Sampling frequency
48 kHzm Meter

Signal strengthm Power requirements

AC 120 V/230 V, 50/60 Hz(Voltage as indicated on rear panel)m Power consumption

17 watts

m Maximun Dimensions

Width 465 mm (18-5/16”)
Height 140 mm (5-1/2”)
Depth 402 mm (15-13/16”)

m Mass11.8 kg (26.0 lbs) net
17.0 kg (37,5 lbs) in shipping carton–2.0 dB

28 dBfGeneralNotes

75 ohms, unbalanced(IEC or F type connector)

m An FM antenna is required to use the T-1000. Please consult your dealer regarding antenna installation.
m In dwellings with shared antenna systems, confirm that the antenna outlet carries FM signals.
m Use a 75-ohm coaxial cable with IEC type or F type plug for the antenna connection.

n Supplied accessories:

85 dB

m Total harmonic distortion (80 dBf input, ±75 kHz deviation)
20 Hz
0.04%
1 kHz
0.04%
10 kHz0.04%

m FM detection principle

m Supplied Remote Commander RC-33
Remote control principle: Infrared pulse
Power supply:
3 V DC (IEC R6 batteries × 2)
Dimensions:
55 × 194 × 18 mm
Weight:
100 g (including batteries)• AC power cord
• Audio cable with plugs• Remote Commander RC-33• Specifications and design subject to change without notice for improvements.

http://www.accuphase.com/G0505Y

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