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4/10 (G/B)

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

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.

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

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

High Current Amplification

Conventional Amplifier

High Current Amplification

Conventional Amplifier

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.

GND

Power

Supply
Circuit

Amplifier

Circuit

A

B

GND

Power

Supply
Circuit

Amplifier

Circuit

C

D

High Current Amplification Principle

Summary of Contents for RX-V740RDS

Page 1: ...home cinema system Major features include 6 channel discrete amplification 140W x 6 DIN Yamaha s Digital ToP ART design concept Quad Field CINEMA DSP 24 surround programmes SILENT CINEMA On Screen Di...

Page 2: ...latest movie sound formats including Dolby Digital EX Dolby Pro Logic II DTS ES Discrete 6 1 and DTS Neo 6 Powerful 32 bit Yamaha LSI YSS 938 for CINEMA DSP processing 24 surround programmes 44 variat...

Page 3: ...ction with an ultra precise digital control circuit Yamaha original YAC 520 LSI The wide control range extends from 0dB to 99dB with narrow 0 5dB steps throughout the entire range for delicate control...

Page 4: ...ided 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 amou...

Page 5: ...he tone control circuit layout is straighter and shorter than ever Finest Parts Used Throughout In order to realize the goals of massive power and superlative sound quality Yamaha technicians complete...

Page 6: ...rom the presence front rear and rear sound fields you will hear sound with highly accurate localization smooth movement exceptional clarity and richness and startlingly realistic presence It will seem...

Page 7: ...Listening mode you can reduce the volume and still enjoy proper tonal balance and dynamic range You hear dialogue clearly and the music and action are just as exciting without the screams and explosio...

Page 8: ...ection quick and easy are Setup and Speaker Level while the Sound modes feature a Centre Graphic Equalizer Speaker Set Speaker Distance LFE Level Dynamic Range and Headphone Tone Control The Input mod...

Page 9: ...inals includes S video and optical digital input terminals for connecting game machines digital equipment and so on Fixed and Assignable Terminals Yamaha offers terminals that can be RX V740RDS Main S...

Page 10: ...d Damping Factor ToP ART Base for Reduced External Resonance High Performance Myca Capacitors and Film Capacitors Thick PC Board Wiring with 1 6mm Copper Jumper Cables Extruded Aluminium Front Panel E...

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