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-V740RDS, 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-V740RDS will deliver as much as 140W of power (DIN) to each of six channels (two main, two rear, one centre and one rear centre). 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 subwoofer.

High Dynamic Power Capability

The RX-V740RDS 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 heavy chassis which is also

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 caused by the copper of the PCB, Speaker output relays, cables and so on, resulting in reduced sound quality.

A

 

B

 

 

 

 

 

 

 

 

C

D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power

 

 

 

 

 

 

 

 

 

Power

 

 

 

 

 

 

 

 

 

GND

Amplifier

 

 

 

 

GND

Amplifier

 

 

 

 

 

 

 

 

 

 

 

 

Supply

 

 

 

 

 

Supply

 

 

 

 

 

 

 

 

Circuit

 

 

 

 

 

 

 

Circuit

 

 

 

 

Circuit

 

 

 

 

 

 

 

 

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

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