SONY TA-F80

Commentary

Based on the theme of reducing total dynamic distortion, this high-grade pre-main amplifier incorporates the concept of simplicity and straightness into the transmission characteristics of individual components.

In order to realize the concept of simplicity and straightness, straight transmission and pre-power separation structure are adopted, and the shortest wiring of input / output terminals, natural arrangement of parts along the signal flow, avoidance of signal intersection, etc. are strictly enforced.
In the TA-F80, the preamp section is arranged in the front panel section and the volume switches are directly attached to eliminate unnecessary wires and transmit them to the power amplifier which is shielded by a shield plate. In the power amplifier section, the installation location of the power transistor can be arbitrarily determined by the heat pipe, which has been a difficult problem, so that the power transistor is arranged in an ideal position in the signal flow.

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.

The power supply section uses a pulse power supply equipped with a pulse-width controlled constant voltage circuit.
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.
In addition to the pulse power supply system, the TA-F80 uses a pulse-width-controlled constant-voltage circuit. This circuit converts voltage fluctuations into changes in pulse width, and in the form opposite to the pulse waveform, demodulates the DC obtained by the primary rectifier circuit from ON to OFF to obtain a voltage with the fluctuations canceled.
As a result, the voltage fluctuation rate is less than 1%, taking advantage of the purity of the signal system.

By adopting a high-gain DC amplifier for the power amplifier, the flat amplifier can be omitted.
This allows DC transmission between the Tuner, Aux, and Tape inputs and the speaker out in the "Direct" state. In addition, when the MC cartridge is being played back, only the minimum necessary circuits (head amp → equalizer, power amp) pass through, minimizing the loss of sound quality.

We have developed and adopted volumes with improved precision and various characteristics such as crosstalk and square-wave response distortion factor.

Metal glaze type variable resistor is used for balance and cartridge control variable resistor.
This variable resistor is made by mixing and sintering fine particles of metal and glass instead of carbon as a resistor. It is called thick metal coating resistance = metal glaze type. Temperature characteristics and strain rate are good, and the error is within 0.1%.

In order to minimize the length of the lead wire, a molded RIAA unit with three dimensional wiring without a printed circuit board is used to suppress the mechanical resonance of the capacitor caused by changes in the signal input.
A non-inductive Styrofoam type capacitor and a highly stable single metal coated resistor are used for the resistor.

We have adopted a 4-terminal electrolytic capacitor that uses two relatively small capacitors connected in parallel.
The pulse response is faster and sound quality is improved.

The MC head amplifier realizes low-noise noise through a super-LEC with parallel low-noise transistors and high-performance ICs, and is equipped with a 3 Ω -40 Ω impedance selector.

Equipped with cartridge load control function, input impedance matching of of the cartridge can be set arbitrarily between 100 pF ~ 400pF/100 Ω ~ 100k Ω.

Equipped with a 20-step peak power indicator that can read directly from 0.008W to 130W.

Equipped with a Low filter.

Model Rating

Type	Stereo pre-main amplifier
Circuit system	Preamplifier section : Head amplifier for low-noise MC, NF-type equalizer amplifier Power Amplifier : All Stages Directly Connected Pure complimentary service SEPP, DC Power Amplifier Power supply unit : pulse power supply, pulse width controlled constant voltage circuit (PLPS)
Power Amplifier Unit
Effective output (both channel drive)	120W + 120W (8 Ω, 0.007% distortion, 20 Hz to 20 kHz)
Output bandwidth	5 hz to 30 khz (IHF, 0.007% distortion rate, 8 Ω, 60W)
Harmonic distortion factor (20 Hz to 20 kHz)	0.007% (at effective output) 0.0025% (at 10W output, spectrum analyzer measurement) 0.0033% (at 1W output, spectrum analyzer measurement)
Cross modulation distortion factor (60Hz:7kHz=4:1)	0.007% (at effective output) 0.0025% at 10W output
Residual noise (A-network)	100 μ V (8 Ω)
Damping factor	100 (8 Ω, 1 kHz)
Suitable speaker impedance	8 Ω ~ 16 Ω
Preamplifier Section
Input Sensitivity / Impedance	Phono1, 2 mm : 2.5mV/100 Ω ~ 100k Ω / 100 pF ~ 400 pF Phono1, 2 mc : 0.125mV/33 Ω, 100 Ω Tuner, Aux, Tape1, 2 : 150mV/50k Ω
Signal-to-noise ratio (A network)	Phono1, 2 mm : 88 dB Phono1, 2 mc : 80 dB Tuner, Aux, Tape1, 2 : 105 dB
Output Level / Impedance	Rec out1, 2 : 150 mV (maximum output 20.0 V) / 4.7k Ω
Phono maximum allowable input	Phono1, 2 mm : 300 mV Phono1, 2 mc : 15 mV
Frequency characteristic	Phono1 and 2 : RIAA deviation ± 0.2 dB Tuner, Aux, Tape1, 2 : DC ~ 100 kHz + 0 -1dB
Tone control	Bass : 25 Hz ± 10 dB (turnover frequency : 250 Hz) Treble : 50 kHz ± 10 dB (Turnover Frequency : 5 kHz)
Low Filter	15 Hz, 12dB/oct. (Phono input only)
<General>
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	145W
Power outlet	Power switch interlock : 1 system, 100W Power switch not linked : 2 systems, 100W
External dimensions	Width 430x Height 160x Depth 410 mm
Weight	9.9kg
Attachment	Code clamper