Accuphase T-107 (1985–1991)

Name: Accuphase T-107
Brand: Accuphase

FM stereo tuner with quartz-synthesized tuning and DGL detection, produced by Accuphase Laboratory, Inc.

Overview

The Accuphase T-107 is an FM stereo tuner manufactured from 1985 to 1991 by Accuphase Laboratory, Inc., originally known as Kensonic Laboratory, Inc. It was available in black as the T-107B. The tuner features a varactor-based digital synthesizer tuning system and employs the DGL (Digital Gain Linear) detection method using 19 high-speed logic ICs to delay phase angle by 114 degrees. It shares front-end design elements with the T-105 and T-106, including double tuning between input and amplifier stages across two gangs. The T-107 was part of a series of high-performance digital tuners from Accuphase and is noted for significantly lower noise compared to the T-106.

Specifications

Receiving frequency	76.0 MHz to 90.0 MHz
Practical sensitivity	11 dBf (IHF)
S/N 50 dB sensitivity	17 dBf (IHF)
Stereo Sensitivity (IHF) S/N 50dB	37 dBf
Output voltage (± 75 kHz deviation)	1.0 V
Frequency characteristic	10 Hz ~ 16000 Hz +0, -1.0 dB
Stereo separation factor	100Hz: 50 dB, 1kHz: 50 dB, 10kHz: 40 dB
Total harmonic distortion factor (80 dBf input)	20Hz:0.04%, 1kHz:0.04%, 10kHz:0.04%
Stereo THD (80 dBf input ±75 kHz shift)	20Hz:0.04%, 1kHz:0.04%, 10kHz:0.08%
IM distortion factor	0.01% (80 dBf input, ±75 kHz shift)
Stereo IM distortion factor	0.03% (80 dBf input, ±75 kHz shift)
Two signal selectivity (Normal)	400kHz: 70dB, 300kHz: 30dB, 200kHz: 8dB
Two signal selectivity (Narrow)	400kHz: 100dB, 300kHz: 80dB, 200kHz: 30dB
Capture ratio	1.5 dB
RF intermodulation	80 dB
Spurious interference ratio	120 dB
AM suppression ratio (65 dBf input)	80 dB
Subcarrier suppression ratio	70 dB
SCA interference ratio	80 dB
S/N (80 dBf input, A-correction)	90 dB
Stereo S/N (80 dBf input, A-correction)	85 dB
Stereo switching input voltage	20 dBf
Antenna	75 Ω unbalanced (with 300 Ω balanced converter)
Tuning system	Quartz synthesizer method
Detection system	DGL method
Output impedance	Fixed Output: 200 Ω, Variable Output: 1.25k Ω (maximum)
Power	100 VAC, 50Hz/60Hz
Power consumption	12 W
External dimensions (Body)	Width 445 x Height 107 x Depth 330 mm
External dimensions (A-11 wood cabinet)	Width 463 x Height 131 x Depth 338 mm
Weight	5.8 kg
Semiconductor used	Transistor: 16, FET: 2, IC: 22, Diode: 59, LED: 18 pcs

Design

The T-107 uses a quartz synthesizer tuning system with a varactor-based digital synthesizer. Its front end implements double tuning between the input and amplifier stages across two gangs. The internal oscillation circuit combines a PLL, ceramic resonator, and voltage-controlled variable positive/negative reactance circuit. Two IF filters (Normal and Narrow) are installed. The DGL detection method relies on 19 high-speed logic ICs to achieve a 114-degree phase delay. The IF section uses Sanyo LA1222, Toshiba TA7302P, and Hitachi HA12412 chips, with the latter implementing a quadrature detector. The MPX stage uses the Hitachi HA11223W chip, and audio output is handled by two NJM4560d dual op-amps. The digital frequency display operates via a static, noise-free method.

Context

The T-107 was part of a series of high-performance digital tuners from Accuphase and is considered by some, along with the Tandberg 3001A, as "the high-water mark for varactor-based tuners." It can perform sonically on par with the Kenwood KT-917, though it may not match its RF performance. The tuner followed earlier models like the T-100 and was listed alongside the T-101 and T-106 in Accuphase’s product family.

Market

The optional A-11 wood cabinet was sold separately for ¥16,000. The T-107 is described as "very rare," with current market prices (2023–2026) typically ranging from €350 to €480. Some listings note defective units ("Defekt").