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effective heat dissipation and reduces the
impedance of the output stage.
Current feedback circuit topology prevents phase
shifts in high frequency range
The P-3000 employs the renowned current feedback
principle developed by Accuphase. At the sensing
point of the feedback loop, the impedance is kept
low and current detection is performed. An
impedance-converting amplifier then turns the
current into a voltage to be used as the feedback
signal. Since the impedance at the current feedback
point (current adder in Figure 3) is very low, there is
almost no phase shift. Phase compensation can be
kept to a minimum, resulting
in excellent transient response
and superb sonic transparency.
Minimal
amounts of NFB
are used to
maximum
effect, providing
natural energy
response.
Figure 4 shows
frequency
response for
different gain settings of the current feedback
amplifier. The graphs demonstrate that response
remains uniform over a wide range.
Robust power supply with "Super Ring" toroidal
transformer and high filtering capacity
The P-3000 features a massive toroidal power
transformer with a maximum rating of 700 VA. The
transformer is housed in a case filled with a material
that transmits heat and absorbs vibrations. This
Gain(Large)
(High) Frequency
completely prevents any
adverse influences on other
circuit parts. A toroidal transformer
uses heavy-gauge copper wiring on a
doughnut-shaped
core, resulting in
low impedance and
high efficiency while
allowing compact
dimensions, which
is especially useful
for audio appli-
cations.
Two ultra-large
aluminum
electrolytic
capacitors rated for
47,000 µF each
serve to smooth out
the pulsating direct
current from the
rectifier, providing
more than ample
filtering capacity.
BufferCurrent
adder
I-V
converter
Trans-impedance
amplifier Amplifier Output
Current NFB
network -“ Input
Buffer + Input
Fig. 3 Principle of current feedback amplifier
nPower amplifier assembly with
3 parallel push-pull transistor
pairs per channel mounted
directly to large heat sink,
MCS+ circuitry, and current
feedback amplifier
Fig. 4 Frequency response with current feedback(Response remains uniform also when gain changes)
