ALLNIC AUDIO L-4000 Panduan Pemilik - Halaman 4
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INTRODUCING THE L-4000 PREAMPLIFIER
The L-4000 is Allnic Audio's best line stage preamplifier.
Like all Allnic Audio products, it uses Permalloy (Iron and
nickel alloy) for its transformer cores. Allnic is grateful to
Mr. G.W. Elmen of Western Electric for inventing
Permalloy for transformer core use, and in so doing,
providing an enormous service to recorded music
listeners everywhere.
The L-4000 has the following features:
Single gain stage – A single gain stage circuit uses only
one tube for amplification ("gain"). This reproduces a
purer, more detailed, more spacious and more dynamic
sound than multi gain stages.
Line output transformer coupling – The L-4000 is
"transformer coupled". In tube amp circuitry, there are
two coupling methods; one is capacitor coupling and
the other is transformer coupling. Capacitor coupling is
the traditional, low cost method. It is somewhat stable
but transfers only voltage, not wattage (i.e., not real
energy). With transformer coupling, about 90% of real
wattage is transferred (there is still a transformer loss
of about10% of wattage – voltage is not affected).
Transformer coupling is superior to capacitor coupling.
However, all the advantages of transformer coupling
depend on the quality of the transformer and on the
choice of tubes. Allnic Audio manufactures its own
transformers and uses what it views to be the best core
material, Permalloy. Allnic Audio's unprecedented,
wide (16Hz ~ 75kHz, -3db), low distortional, and ultra-
flexible (up to 50kHz square wave response) output
transformer helps Allnic Audio to realize the ideal
transformer coupled preamplifier. Of course, gain tubes
are also carefully selected for three critical factors for
function with the Permalloy output transformers: high
gm, low internal resistance and high mu.
Constant and low output impedance – One of the
benefits of transformer coupling is that it facilitates
constant low output impedance. Low output
impedance is critical to the design of a good
preamplifier. The L-4000 has a 150 ohm (150Ω)
constant output impedance at all frequencies. In
capacitor coupling (C-R coupling), a "cathode follower
circuit" is usually used to lower output impedance.
Unfortunately, this method of lowering output
impedance is accompanied by high distortion and has
an "L" shaped output impedance curve. Please
compare the two graphs below, especially for low
frequency response.
No negative feedback design
Advanced tube technology voltage regulation - For
quieter and more dynamic operation, the L-4000 has
an ultra high speed automatic voltage regulation
circuit, utilizing vacuum tubes. This also protects the
amplifying tubes from change in the AC line supply
and copes with any abrupt, internal current demand.
New vacuum tube damping technology – Allnic
Audio's patented "Absorb GEL tube damper"
technology prevents harmful vibrations from
reaching the signal / gain tubes and, therefore,
prevents microphonic noise propagation in the tubes.
The Allnic Audio Absorb Gel damper technology
effectively solves a problem that plagues most tube
amplification systems. Provided other tube
components do not introduce microphonic noise into
your system, with the Absorb Gel damping system,
you will enjoy a degree of transparent sound that will
surprise and please you.
Precision attenuator volume control – The L-4000
does not employ a digital IC volume control or a low-
cost carbon film volume control with a motor. Allnic
Audio has developed a precision oil clutched
motorized attenuator; the L-4000 has no (± 0db)
channel unbalance at any volume level.
Pure Class A operation
Pure balanced operation
As are all Allnic Audio products, the L-4000 is fully
RoHS (EU Reduction of Hazardous Substances
regulation) compliant in construction and materials
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