SONY TA-N9000ES

Commentary

A 5-channel power amplifier developed for use with the TA-E9000ES.

A dynamic 5-amp system is used, and all channels are in the same stage, including the rear channel, which has been assigned a smaller output than other channels. This allows for more powerful surround playback.
The TA-N9000ES can be used as an independent 5-channel amplifier, as a 2/3/4-channel amplifier, or as a BTL connection for connecting two blocks of amplifier circuits to form a single high-output amplifier.

It has an extra input terminal in addition to the normal 5-channel input terminal, so you can connect a preamp for pure audio.

Uses a direct ground drive system that reexamines the relationship between the power amplifier circuit and the power supply.
Conventional amplifiers have a structure in which the output of the transformer is sent to a rectifying circuit and supplied to each power transistor from the rectifying circuit. However, in the direct ground drive system, the power transformer is directly connected to the speaker load, and the load current is supplied directly from the power transformer. This enables high-speed and high-power power supply and improves the sense of volume and rhythm of low sound.
A crab-shaped ground unit is used for the ground circuit that is important for this system. This component uses a copper plate 1 mm thick, equivalent to 30 times the thickness of a normal printed pattern, with 10 branch points and an appropriate connection sequence to realize a ground circuit with extremely low impedance.

The power amplifier block is designed as a discrete configuration with all channels separated.
A surface mount circuit board is used for the circuit board so that five amplifier circuits can be constructed without difficulty. This structure is resistant to vibration. Lead-type electrolytic capacitors for high sound quality that are not suitable for surface mounting are used. The MELF resistor developed in Sony's high-grade component R series is used in place of the rectangular chip resistor. For example, the MELF resistor is used in place of the rectangular chip resistor.

A mill wrapper rate dual-chip power transistor is used for the output stage.
This transistor consists of two power transistor chips with the same characteristics arranged close to each other on a single copper plate. This ensures the same heat balance, and the current path also passes close to each other, minimizing the generation of distortion associated with the synthesis.

A large power transformer of EI 111x100 size is used for the power supply.
This transformer uses a wrap-packed core. Normally, E-type and I-type magnetic steel sheets are individually laminated to form the core, and E-type and I-type magnetic steel sheets are stacked alternately to form the core. Although this structure requires time and effort to manufacture, it is advantageous in terms of sound quality. Since there are no faults in the magnetic path, leakage of magnetic flux is sharply reduced and the influence on the audio circuit is minimized.

The amplifier circuit, including the heat sink and input terminal, is mounted on the inner chassis and separated from the exterior chassis by the vibration surface. Furthermore, by using a slant-mount substrate, which is mounted with the substrate slightly tilted, the generation of standing waves is suppressed and resonance is reduced.
The inner chassis is a monocoque structure using a single seamless steel material.

The chassis uses FB chassis that absorbs and attenuates vibration due to loss of joints.

The heat sink adopts a newly developed "sf" heat sink with a vibration dispersion fin structure to suppress fin resonance.
Each fin of this heat sink is equipped with ribs in different positions to prevent tuning fork vibration, suppress split vibration, and minimize coloring to music.

A gold-plated input terminal is used for the input terminal, with careful consideration of sound quality in the substrate and processing method itself.
The speaker terminal is large enough to accommodate the Y terminal and banana plug.

Model Rating

Type	5-channel power amplifier
Audio input	5 ch : 1 system Extra2ch : 1 system
Maximum Practical Power (EIAJ)	Front : 155W + 155W (4/8 Ω) Front (BTL) : 240W + 240W (8 Ω) Center : 155W (4/8 Ω) Rear : 155W + 155W (4/8 Ω)
Total harmonic distortion factor	Front : 0.013% or less (8 ohm load, 100W + 100W, 20 hz to 20 khz)
Frequency characteristic	20 Hz ~ 20 kHz + 0 -0.5 dB 10 Hz ~ 100 kHz + 0 -3dB
Signal-to-noise ratio (A network)	118dB
Pwer	100 VAC, 50Hz/60Hz
Power consumption	300W
External dimensions	Width 430x Height 173.5x Depth 453 mm
Weight	Approx. 24 kg