SONY TA-F60
¥ 69,800 (around 1978)
Commentary
A pre-main amplifier developed under the theme of reducing total dynamic distortion.
It employs a straight transmission system in which parts are arranged at the shortest distance along the signal flow.
The inputs are routed from the rear jacks to the equalizer amplifier on the front panel. To the equalizer amplifier, a printed circuit pattern is used to prevent signal degradation, avoiding the use of large shield wires.
In the preamplifier section, the front panel itself is made into a chassis, and switches are arranged along the signal flow.
Using a pre-power separation structure, the pre-part and power part are clearly separated by a shield plate to prevent mutual interference.
A heat pipe structure is used for the cooling system.
The heat pipe instantaneously transfers heat from one end of the pipe to another by enclosing a special liquid in a copper pipe under reduced pressure and continuously performing vaporization and liquefaction. As a result, the thermal conductivity is several hundred times higher than that of copper or silver metal rods of the same diameter.
This heat pipe structure increases the freedom of placement of the power transistor and avoids wiring by wires.
The power transistor has Hi-f with reduced transient intermodulation distortion (TIM distortion).TTransistor is used.
This transistor was developed by taking advantage of Sony's semiconductor engineering. It is like an integration of an infinite number of low-power transistors with good high-frequency characteristics. It realizes safe operation even at high power.
In terms of characteristics, the cut-off frequency is significantly improved from 4 MHz to 20 MHz to 60 MHz or more, and the high-frequency response is extremely fast.
Pulse power supply is used for the power supply part.
The pulse power source rectification system consists of direct rectification of 100 VAC, conversion to 20 kHz pulse with a power oscillator, high voltage with a high-frequency transformer, and re-rectification. High voltage with a high-frequency transformer makes it highly efficient and easy to obtain excellent regulation characteristics. Unlike sine wave rectification, almost DC state can be obtained only by rectification, so smoothing is easy and the pulse current component is almost 0.
In addition, the direct rectification of 100 VAC virtually eliminates the AC hum source, which is also a significant effect.
The power amplifier section is configured as a DC power amplifier to suppress low-frequency phase rotation and prevent distortion of the original sound waveform.
Equipped with MC cartridge direct input, MC cartridge can be directly input by changing equalizer amplifier gain.
A newly developed LEC transistor improves the signal-to-noise ratio, and the phono terminal is gold-plated.
Equipped with a 20-step peak power indicator that can read directly from 0.005W to 100W.
Equipped with a bidirectional tape copy switch, Tape1-Tape2 and Tape2-Tape1 can be copied regardless of the signal of the amplifier.
Equipped with a Low filter.
Model Rating
| Type | Stereo pre-main amplifier |
| Circuit system | Preamp section : Low-noise NF type equalizer amplifier for MC cartridge Power Amplifier : All Stages Directly Connected Pure complimentary service SEPP, DC Power Amplifier Power Supply Part : Pulse Power Supply (PPS) |
| Power Amplifier Unit | |
| Effective output (both channel drive) | 75W + 75W (8 Ω, 0.01% distortion rate, 20 hz to 20 khz) |
| Output bandwidth | 5 Hz to 30 kHz (IHF, 0.01% distortion, 8 Ω, 37.5W) |
| Harmonic distortion factor (20 Hz to 20 kHz) | 0.01% (Effective Output) 0.008% at 10W output |
| Cross modulation distortion factor (60Hz:7kHz=4:1) |
0.01% (Effective Output) 0.008% at 10W output |
| Residual noise (A-network) | 150 μ V (8 Ω) |
| Damping factor | 40 (8 Ω, 1 kHz) |
| Suitable speaker impedance | 8 Ω ~ 16 Ω |
| Preamplifier Section | |
| Input Sensitivity / Impedance | Phono : 2.5mV/50k Ω Phono MC : 0.25mV/100 Ω Tuner, Aux, Tape1, 2 : 150mV/50k Ω |
| Signal-to-noise ratio (A network) | Phono:88dB Phono MC:75dB Tuner, Aux, Tape1, 2 : 100 dB |
| Output Level / Impedance | Rec out1, 2 : 150 mV (maximum output 20.0 V) / 4.7k Ω |
| Phono maximum allowable input | Phono MM:250mV Phono MC:25mV |
| Frequency characteristic | Phono : RIAA deviation ± 0.2 dB Tuner, Aux, Tape1, 2 : 3 Hz to 70 kHz + 0 -1dB |
| Tone control | Bass : 60 Hz ± 10 dB (turnover frequency : 300 Hz) Treble : 25 kHz ± 10 dB (Turnover Frequency : 5 kHz) |
| Low Filter | 15 Hz, 6dB/oct (Phono input only) |
| <General> | |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 110W |
| Power outlet | Power switch interlock : 1 system, 100W Power switch not linked : 2 systems, 100W |
| External dimensions | Width 430x Height 160x Depth 340 mm |
| Weight | 6.7kg |