Audio Database

The

Accuphase T-105
120,000 yen(October, 1980 release)

Description
 
The Quartz lock synthesizer FM tuner which made full use of microprocessor technology.

Bureau synthesizer-election in crystal oscillator circuit is standard frequency to create the necessary program divider receive a preset frequency PLL circuit and the combination of a front-end electronically tuned to the desired signal.
It is possible for received frequency not to change continuously like the conventional variable condenser system, to lock received frequency correctly at intervals of 100kHz, and to always receive in the distorted minimum point.

In order to also enable manual type tuning of the same feeling as a variable condenser system, the pulse tuning system developed by T-104 is carried. This system has the structure of generating a pulse signal, controlling a synthesizer now and changing received frequency with the optical pulse generator attached to the core of a rotating knob.
Moreover, it is possible to make it memorize beforehand in the office of choice, to carry the memory tuning system called by one-touch, and to carry out the memory of the six games.
Furthermore, the scanning system to which the sweep of the received frequency is carried out quickly is also carried.

The pure electronic control system which used for the front end part the Barak Tarr element combined with the PLL circuit is adopted, and RF inter-modulation is sharply improved by composition of a two-step double alignment system and an alignment buffer.

In order to reconcile the high selection degree characteristic and a low distortion in an intermediate frequency circuit, the bulk wave filter which was excellent in the degree of selection and delay characteristics is adopted.
Moreover, the selectivity changeover switch from which interference of an adjoining office is removed is carried, and the degree of high selection and coexistence of the low distortion are aimed at with the exclusive bulk wave filter also at the time of Narrow (the degree of high selection).

The "phase conversion type wave detector" which multiplies by the signal and input wave using the phase converter (circuit which carries out deflection of the phase) which changes linearly according to frequency focusing on 90 degrees, and acquires an audio signal is used for a wave detector. The outstanding detection characteristic has been acquired by this broadband linear phase phase converter.

The PLL Demodulator which contained the circuit which removes a pilot career is carried in the stereo recovery circuit.

The check of meter of an incoming signal level, a peak directions degree of modulation, and a multipass increases d systems with a changeover switch.
If an incoming signal level goes into a dBf Direct-reading scale, a degree of modulation enters to full-scale 200% and, as for a multipass, a meter guide goes into the range of a clear mark, a good electric wave is receivable by the multipass minimum.

The noise filter which reduces the noise of the weak stereo office of an electric wave, the mode switch which changes a stereophonic broadcast to a monophonic recording, the muting switch which removes the noise between offices, the output level control, etc. are carried.

There was a natural rosewood cabinet as an option.

Rear Pulse
A

Rating of a mode
Form Synthesizer FM tuner
<Monophonic characteristic>
Practical speed 11.2dBf (2.0 microvolts)
S/N 50dB sensitivity 17.3dBf (4.0 microvolts)
Standing-wave ratio 1.5
S/N ratio 80dB (65dBf (1mV) input)
THD
(at the time of 65dBf (1mV) input, ±75kHz deflection, and Normal)
100Hz:0.04%
1kHz:0.04%
6kHz:0.08%
10kHz:0.04%
IM distortion (14kHz:15kHz=1:1) 0.01% (65dBf (1mV) input, ±75kHz deflection)
Frequency response 10Hz-16kHz+0 -0.5 dB
The degree of 2 signal selection (45dBf (100-microvolt input))
Disturbance wave Normal Narrow
400kHz 60dB 100dB
200kHz 8dB 22dB
Capture ratio 1.5dB
RF inter-modulation 80dB
Spurious disturbance ratio 120dB
Image ratio 120dB
AM oppression ratio (65dBf (1mV) input) 80dB
Subcarrier oppression ratio 70dB
SCA disturbance ratio 80dB
Output voltage (±75kHz deflection) 1.0V
<Stereo characteristic>
Sensitivity S/N 40dB: 28.8dBf (15 microvolts)
S/N 50dB: 37.3dBf (40 microvolts)
S/N (65dBf (1mV) input) 75dB
THD
(at the time of 65dBf (1mV) input, ±75kHz deflection, and Normal)
100Hz:0.04%
1kHz:0.04%
6kHz:0.08%
10kHz:0.08%
IM distortion (9kHz:10kHz=1:1) 0.03% (65dBf (1mV) input, ±75kHz deflection)
Frequency response 10Hz-16kHz+0 -0.5 dB
Stereo separation 100Hz:50dB
1kHz:50dB
10kHz:45dB
Stereo change inlet pressure 19.2dBf (5.0 microvolts)
<Synthesis>
Received frequency 76.1MHz - 89.9MHz
Antenna 75-ohm disequilibrium
Alignment system Quartz lock frequency synthesizer system
Manual: Pulse tuning
Memory: Six games
Frequency accuracy ±0.002%
Output load impedance Fixed output: 200ohms
Variable output: 1.25kohm (maximum)
Meter Signal strength / multipass / modulation change type
The semiconductor used Transistor: 26 pieces
FET: Three pieces
IC: 24 pieces
Diode: 73 pieces
Optocoupler: Two pieces
Power source AC100V, 50Hz/60Hz
Power consumption 25W
Dimensions the width 445x height 128(piece -- it includeds) x depth of 370mm
Weight 8.4kg
Option Wood cabinet A-9 (16,000yen)