High Current Amplification Achieves Low Impedance/ High Current Power from Input to Output.

The Importance of High Current

Although power rating is often the first thing customers look at in a receiver, high power output does not necessarily mean good sound. High current level is a much more important factor. Yamaha receivers has always had fairly high current levels, but with the RX-V640, we have further improved this performance.

What It Does

In brief, Yamaha High Current Amplification achieves low impedance, high current power from input (power supply circuit) to output (speaker terminals). This drives the speakers much more smoothly and dynamically, for better sound from all sources, including 2- channel audio.

Specific Improvements

The first problem to be overcome was the difference in voltage that ordinary receivers suffer between the power supply and amplifier circuits, caused by current

fluctuations. This was solved by using custom-made, high-grade block electrolytic capacitors and a copper grip for one-point grounding. Another current drop is generally seen between the amplifier circuit and the speaker terminals, caused by the cables, speaker output relays, copper circuit boards, and so on. To increase current here, we used an extra-large, low-impedance transformer and gold-plated speaker relay contacts.

6-Channel High Power,

Discrete Amplifier Configuration

The RX-V640 will deliver as much as 85W of power to each of six channels (two main, two rear, one center and one rear center). This is more than enough to fill even the largest rooms with vibrant music and Richter-scale sound effects. 6-4 mixdown is also provided, for enjoying 6- channel input sources from four or five speakers you already have on hand with or without a subwoofer.

High Dynamic Power Capability

The RX-V640 is capable of delivering large amounts of reserve power for accurate reproduction of the high energy peaks that are especially prevalent in digital audio sources. This emphasizes the music’s dynamic qualities and provides a sharper sound image.

Linear Damping (Main L/R Channels)

Level variations due to high amp impedance tend to reduce an amplifier’s damping factor, and frequency variations cause it to fluctuate. This circuit cancels the effect of these variations, maintaining a high, stable damping factor, for superior articulation of all sounds and better frequency response.

Anti-Resonance ToP-ART Base

Supporting the heavy heat sinks and circuit board is Yamaha’s ToP-ART base, which has exceptional anti-resonance and damping characteristics. Beneath this base is the bottom of power amplifier, part of the

High Current Amplification Principle

The voltage (A) of Block Electrolytic Capacitors and voltage (B) of Power Transistor Collector should be ideally at the same level. However, when the current become large, there will be a big difference in the level of each voltages.

There is also a level difference between Output of the Power Amplifier

(C)and Speaker Terminals (D), which is reflected by coppers of PCB, Speaker out put relays, cables and so on, resulting damaging the sound quality.

A

 

B

 

 

 

 

 

 

 

 

 

 

 

 

Power

 

 

 

 

 

 

 

 

 

GND

Amplifier

 

 

 

 

 

 

 

Supply

 

 

 

 

 

 

 

 

Circuit

 

 

 

Circuit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power

Supply

Circuit

C D

GND Amplifier

Circuit

Voltage level difference between A (power supply circuit) and B (amplifier circuit).

Voltage level difference between C (amplifier circuit output) and D (speaker terminals).

Conventional Amplifier

High Current Amplification

Conventional Amplifier

High Current Amplification

4/10 (R/L/T/K)

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Yamaha RX-V640 manual Importance of High Current, What It Does, Specific Improvements, High Dynamic Power Capability
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RX-V640 specifications

The Yamaha RX-V640 is a notable audio-video receiver that made its mark in the early 2000s, offering a robust feature set for home theater enthusiasts. This AV receiver is part of Yamaha’s RX-V series, known for delivering quality sound and versatile connectivity options. The RX-V640 merges both performance and functionality, catering to a wide variety of audio and video formats.

One of the distinguishing features of the RX-V640 is its powerful amplification system. The receiver is equipped with a maximum power output of 100 watts per channel across 5 channels. This ensures that it can drive a full surround sound system effectively while maintaining clarity even at higher volumes. The incorporation of Yamaha’s Digital ToP-ART (Total Purity Audio Reproduction Technology) is another highlight. This technology minimizes signal degradation and enhances audio fidelity, allowing listeners to enjoy music and movie soundtracks with exceptional detail and richness.

The RX-V640 boasts support for various surround sound formats, including Dolby Digital, DTS, and Yamaha’s proprietary DSP modes. With 17 different surround programs, users have the flexibility to tailor their listening experiences to suit specific genres, from cinematic blockbusters to immersive concert recordings. The built-in Yamaha DSP features create a realistic surround sound environment, making every action scene or musical performance come alive.

Connectivity is another strong suit of the RX-V640. It comes with multiple inputs and outputs, including HDMI, optical, and coaxial, allowing for seamless integration with modern devices. The receiver is also equipped with five audio inputs and two sets of speaker outputs, enabling users to set up a versatile audio system without the hassle of switching cables. The inclusion of a remote control further enhances convenience, giving users the ability to manage their audio-visual experience from a distance.

In terms of build quality, the RX-V640 follows Yamaha's tradition of durability and design elegance. With an intuitive user interface and an on-screen display, navigating through the various settings and configurations becomes a straightforward task for users of all experience levels.

In summary, the Yamaha RX-V640 is a solid choice for anyone seeking an audio-video receiver that combines power, advanced technologies, and versatile connectivity. Its performance characteristics make it especially suitable for both home theater enthusiasts and casual listeners alike, delivering an impressive sound experience that stands the test of time.
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