Yamaha RX-V440 - Manual (Page 4)

4/10 (R/L/T/K)
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-V440, 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-V440 will deliver as much as
95W 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-V440 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
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 reflected by coppers of PCB,
Speaker out put relays, cables and so on, resulting damaging the
sound quality.
GND
Power
Supply
Circuit
Amplifier
Circuit
A B
GND
Power
Supply
Circuit
Amplifier
Circuit
C D
High Current Amplification Principle