Accuphase T-1000 (2005)

Name: Accuphase T-1000
Brand: Accuphase

FM stereo tuner released in August 2005 with advanced digital synthesis and DSP-based demodulation.

Overview

The Accuphase T-1000 is an FM stereo tuner from Accuphase Laboratory, Inc. It combines high-frequency engineering with digital technology. It came out in August 2005. Tuning runs on a DDS (Direct Digital Synthesis) synthesizer, and 32 station memories store and recall all function settings. It was built to handle high signal levels, with a double-tuned antenna circuit and an attenuator at the input gate for strong RF inputs. Analog outputs are balanced (XLR) and unbalanced (RCA), there is a coaxial digital output, and the RC-33 remote commander ships with it.

Specifications

Product Type	FM stereo tuner
Release Date	August 2005
Original Price	¥280,000
Weight	11.8kg
Dimensions (W×H×D)	465 × 140 × 402 mm
Power Consumption	17W
Power Supply	100 VAC, 50/60Hz
Tuning Range	87.5–108 MHz
Preset Memory	32 stations
Antenna Input	75 Ω unbalanced (F-type)
Output Impedance (Balanced)	200 Ω (XLR)
Output Impedance (Unbalanced)	200 Ω (RCA)
Digital Output	Coaxial, 0.5Vp-p/75Ω, 48kHz sampling
Output Voltage	1.0V (±75 kHz deviation)
Standing-Wave Ratio	1.5
Capture Ratio	1.5dB
Image Ratio	100dB
Spurious Interference Ratio	120dB
RF Intermodulation	80dB
AM Suppression Ratio (65 dBf)	80dB
Subcarrier Suppression Ratio	70dB
Practical Sensitivity	11dBf (IHF)
S/N 50 dB Sensitivity	17dBf (IHF)
S/N (80 dBf, A-corrected)	90dB
THD (20Hz–10kHz)	0.02%
IM Distortion	0.01%
Frequency Response	10 Hz – 15,000 Hz (+0, -2.0 dB)
Stereo S/N (80 dBf, A-corrected)	85dB
Stereo THD (20Hz–10kHz)	0.04%
Stereo IM Distortion	0.03%
Stereo Separation	100Hz: 50dB, 1kHz: 50dB, 10kHz: 40dB
Stereo S/N 50 dB Sensitivity	37dBf (IHF)
Two-Signal Selectivity (IHF)	400kHz: 70dB, 300kHz: 30dB, 200kHz: 10dB

Design

The front end has two tuning stages: a double-tuned antenna circuit and cascode FET amplification. That combination handles high signal levels without cross-modulation. The local oscillator is based on DDS instead of a phase-lock loop. This gives precise frequency control and the FREQ. TRIM function, adjustable in 10 Hz steps. Detection uses Accuphase's Advanced DGL (Differential Gain Linear) circuit. Stereo demodulation is done by the DS-DC (Direct Synthesis-Double Cancellation) system, and both are implemented in DSP. Manual tuning uses a pulse tuning method. The front panel has switches for Filter, Mute, and Mono, and an electronic beep confirms knob and button operation.

Context

The T-1000 was described as a top-of-the-line FM stereo tuner. At its release it represented the culmination of Accuphase's digital tuner development, and its performance reputation followed on from earlier models like the T-107.