Audio Database

The

Accuphase T-1000
280,000 yen(August, 2005 release)

Description
 
The highest peak FM stereo tuner developed by uniting advanced high frequency technology and the newest digital technology.

The antenna double tuning circuit which prevents the intermodulation in the time of the Dainyuu power is adopted as a front end part. Moreover, FET of cascode composition with little feedback is adopted as high frequency magnification. Furthermore, an Attenuator circuit is established in the gate of an input and the excess Dainyuu power in the area where a transmitting tower is near is also coped with.

DDS (Direct Digital Synthesis) is carried in the local oscillator.
This DDS carries out the divide of the output of a crystal oscillator by a frequency divider first, and makes the sampling frequency which is the timing which reads sine wave data. And it has structure which reads the data of a sine wave by the sampling frequency, and makes the analog-spectrum form of a sine wave by a D/A converter.
The front end of the outstanding signal to noise ratio is realized without being able to generate the output signal of the completely same frequency purity as a crystal oscillator, and injecting an unnecessary frequency modulation ingredient into IF stage, since the feedback system is not used like a PLL circuit.

The original Advanced DGL (DIfferential Gain Linear) detection circuit of an Accuphase is carried in the detection part.
The input unit used the high-speed comparator for a 2.5MHz broadband amplifier, and has lost beat disturbance. Moreover, stability is raised to the delay circuit using 24 high speed C-MOS IC.
Paying attention to the delay time of the output of a high-speed logic IC, a delay circuit carries out operation of this circuit to the composition which delayed the degree of phase angle 114 degrees so that the distorted minimum and the signal to noise ratio might become the maximum by 24 ICs. This delay signal and incoming signal are applied to an exclusive OR circuit, the electric potential between two signals is chosen, and a circuit is opened and closed. The compression waves produced by abnormal conditions at this time are detected in digital one, and a music signal is taken out.
This system has a linear region of a delay circuit as large as ±2.5MHz, and since it moreover is not adjusting, the differentiation profit straight line characteristic of it having been stable and having excelled can be acquired.

The stereo recovery circuit of the original DS direct current (Direct Synthesis-Double Cancellation) system of an Accuphase is adopted as a stereo recovery part.
DS-direct current consists of two technology, the direct compositing process of a pilot signal, and double denial processing of a cross talk.
By a general tuner, if a pilot signal becomes small at the time of extraction in order to use a PLL circuit for extracting a pilot signal and to extract frequency and a phase ingredient from an incoming signal, a separation will worsen in response to the influence of noise. In DS-direct current, since the ripple of the pilot signal included in an incoming signal is identified as it is and it makes directly by operation of DSP, even if it is strong in a noise and the level of a pilot signal is small, a separation is securable.
Moreover, since it takes into consideration to a phase ingredient and the denial of a cross talk is performed twice after dividing an incoming signal into a right-and-left signal, it is possible to raise a separation on either side more.
The stereo recovery which was excellent by performing software operation on DSP (Digital Signal Processor) in these all is enabled.

The FREQ.TRIM function to demonstrate power at the time of interference is carried.
The step of received frequency is finely changeable, securing a zone to the center frequency of a filter by changing this function to ON (at intervals of 10Hz). For this reason, when interference with an adjoining broadcasting station is intense, the reception which avoided jamming and reduced interference is possible.
If a FREQ.TRIM button is turned ON, received frequency spectrum designation will change to 4 figures from triple figures.

16 station memories which also bundle up each function setup and can perform memory/call are adopted.
Moreover, manual tuning is also possible by the original pulse tuning system of an Accuphase.

The analog output carries two lines of balance / imbalanced output.
Moreover, the digital coaxial output terminal is also carried.

The function of the Filter switch which reduces the noise of the weak stereo office of an electric wave, the Mute off switch which turns OFF a muting circuit, the Mono switch which uses the output of a stereophonic broadcast as a monophonic recording compulsorily, etc., etc. is carried.

When operating the time of rotation of a tuning knob, and all the functional buttons, an electronic sound called "pi" is attached.

Rear Attached
Internal
Front DDS

Rating of a mode
Form FM stereo tuner
<Monophonic characteristic>
Practical speed 11dBf(IHF)
S/N 50dB sensitivity 17dBf(IHF)
S/N (80dBf input, A compensation) 90dB
THD
(80dBf input, ±75kHz deflection)
20Hz:0.02%
1kHz:0.02%
10kHz:0.02%
IM distortion (80dBf input, ±75kHz deflection) 0.01%
Frequency response 10Hz-15000Hz+0 -2.0 dB
The degree (IHF) of 2 signal selection 400kHz:70dB
300kHz:30dB
200kHz:10dB
Capture ratio 1.5dB
RF inter-modulation 80dB
Spurious disturbance ratio 120dB
Image ratio 100dB
AM oppression ratio (65dBf input) 80dB
Subcarrier oppression ratio 70dB
Output voltage (±75kHz deflection) 1.0V
<Stereo characteristic>
Sensitivity S/N 40dB sensitivity: 29dBf (IHF)
S/N 50dB sensitivity: 37dBf (IHF)
S/N (80dBf input, A compensation) 85dB
THD
(80dBf input, ±75kHz deflection)
20Hz:0.04%
1kHz:0.04%
10kHz:0.04%
IM distortion (80dBf input, ±75kHz deflection) 0.03%
Frequency response 10Hz-15000Hz+0 -2.0 dB
Stereo separation 100Hz:50dB
1kHz:50dB
10kHz:40dB
Stereo change Input sensitivity 28dBf
<Synthesis>
Antenna 75-ohm disequilibrium (F type connector)
Standing-wave ratio 1.5
Alignment system DDS synthesizer system
16-game random memory tuning
Detection system Advanced DGL system
Stereo recovery system DS-direct current system
Digital output (EIAJ CP-1201) Coaxial: 0.5 Vp-p/75ohms
Sampling frequency: 48kHz
Output load impedance Balanced: 200ohms (100ohm/100ohm, balanced XLR type)
Unbalanced: 200ohms (disequilibrium)
Meter Signal strength
Power supply voltage AC100V, 50Hz/60Hz
Power consumption 17W
The maximum Dimensions Width 465x height 140x depth of 402mm
Weight 11.8kg
Attachment Remote commander RC-33
AC power cord
An audio cable with a plug