SONY TAN-5550
¥ 87,800 (around 1975)
Commentary
This is a V-FET stereo power amplifier developed by inheriting the technology of TAN 8550, the highest grade amplifier of ES-II series.
The complimentary service stage employs a parallel push pure output configuration using newly developed N-channel and P-channel V-FETs, with four power V-FETs per channel.
The V-FET is a power FET with a vertical structure. While the conventional FET has a horizontal structure, the vertical structure is realized by a unique manufacturing method and selective oxidation method.
V-FET features extremely fast switching operation, low distortion, excellent frequency and phase characteristics up to high frequencies because NFB can be applied stably up to high frequencies, pure complimentary service stage can be constructed because N-channel and P-channel complimentary service elements can be obtained, and because no phase inversion circuit is required, the signal of A-class stage is applied to B-class stage as it is, and beautiful sound with little distortion up to high frequencies can be obtained. In addition, since the pinch-off characteristics are smooth, connection in push-pull operation is good, and high frequency characteristics with little crossover distortion and notching distortion can be obtained with B-class amplifier.
In addition, because of its high input impedance and low output impedance characteristics, the V-FET can display its power without affecting the circuits before and after it.
In addition, since it is a voltage response element, there is no local current concentration in each V-FET, so it is reliable and can be operated effectively in parallel. In addition, since the heat source is dispersed, the element is highly safe and the amplifier itself can be made lightweight and compact.
The V-FET protection circuit employs a load impedance detection type protection circuit with a PC limiter using an electronic circuit with an extremely fast response.
After detecting the DC of the speaker terminal and heat sink temperature, the relay used for the output stage operates to prevent damage to the speaker and power transistor.
The A-class stage is a 3-stage differential amplifier configuration. The first stage is a dual-FET differential amplifier configuration. By integrating two FETs with the same characteristics into one package, there is no temperature drift, so no DC component is generated in the speaker, and high input impedance characteristics are obtained.
The second and third stages are composed of PNP and NPN differential amplifiers with good bare characteristics.
In the A-class stage, all power supply circuits are set to constant voltage to maintain stability against fluctuation of power supply voltage and to reduce noise from power supply.
A newly developed chimney type heat sink has been adopted.
By using air convection and installing a duct like a chimney, the heated air goes up the duct, and the air is sucked from the lower part of the heat sink. This gives a large cooling effect despite being small and lightweight.
It is equipped with a subsonic filter to cut out ultra-low frequency noise, which is a problem in records with large sleds.
If the normal / test switch is set to the normal position, low-frequency noise is cut off.
Equipped with a speaker switch that allows you to train two speakers separately or simultaneously.
Equipped with a function switch that can switch between two inputs with one touch.
It is equipped with a level control to adjust the dispersion of the left and right input levels.
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Model Rating
| Type | Stereo power amplifier | ||||
| Circuit system | By a V-FET pure complimentary service symmetry circuit Fez Linear, DC Amplifier Configuration |
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| Output (both channel operation) |
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| Dynamic Power | 140W (4 Ω) 160W (8 Ω) |
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| Harmonic distortion factor | 0.1% or Less (at Rated Output) | ||||
| Cross modulation distortion factor | 0.1% or Less (at Rated Output) | ||||
| Frequency characteristic (8 Ω load, 1W output) |
Test : DC ~ 100 kHz + 0 -2dB Normal : 10 Hz to 100 kHz + 0 -2dB |
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| Damping factor (1 kHz) | 100 (8 Ω) | ||||
| Input Sensitivity / Impedance | 1V/50k Ω (at Rated Output) | ||||
| Semiconductor used | Transistor : 43 Dual FET : 2 units V-FET : 8 Diode : 29 units |
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| Pwer | 100 VAC, 50Hz/60Hz | ||||
| Power outlet | Power switch not linked : 1 system, 400W | ||||
| Power consumption | 165W | ||||
| External dimensions | Width 430x Height 168x Depth 323 mm | ||||
| Weight | 11.0kg | ||||
| Sold Separately | Sidewood TAC-15 (1 Set, ¥ 2,800) |