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INTRODUCING THE HA-3000 HEAD AMPLIFIER
The HA-3000 is Allnic Audio’s pre-preamplifier, or
“Head Amplifier”. It is an active, tube based device
for amplification of low voltage signals from moving
coil cartridges to allow connection of moving coil
cartridges to the moving magnet inputs of a phono-
stage, such as the Allnic H-3000 or H-1500. The HA-
3000 is an active pre-preamplifier, not a “step-up
transformer” like Allnic’s HA-3000, which uses only a
transformer to boost the signal from the cartridge.
The HA-3000 has the following features.
Innovative Fixed Bias Circuit
In the HA-3000, two nuvistor 7895 tubes, the smallest
vacuum tube, perform as amplifying devices. They
magnify the tiniest signal in audio, the output voltage of
MC cartridges, to match to the MM input of phono
stages. Allnic applies its innovative, fixed bias circuit to
achieve quiet and stable operation of the extremely
sensitive 7895 tubes. The fixed bias circuit eliminates the
subsonics so harmful to phono stages and inherent in the
characteristics of the R.I.A.A curve, which requires
amplification of the lower frequencies. The fixed bias
circuit applies a sustained negative DC voltage to the grid
of the tubes and to the input coupling capacitors,
blocking capacitor “crossover distortion". This distortion
is a common phenomenon but, unfortunately, is often
neglected in pre-preamplifiers. The result of no "zero
crossover distortion" is, simply, clearer and more vivid
reproduction of the music.
Very High S/N Ratio
The above mentioned characteristics of the R.I.A.A curve
demand a hum-free pre-preamplifier and, therefore, a
silent power supply circuit. Even one micro volt
(1/1,000,000 of one volt) of hum noise (120Hz hum) in
the output signal of a pre-preamplifier will result 63mV to
the loud speakers. That is unacceptable, and Allnic has
overcome the issue through its automatic pure vacuum
tube voltage regulation circuitry. This voltage regulation
circuit minimizes power supply hum noise to inaudibility.
Extremely Wide Frequency Range
Though the HA-3000 has a single gain stage and no
negative feedback, its frequency range capability
extends from 15Hz to 125Khz(-3dB), revealing the full
richness of the musical information on vinyl.
Ultra Flexibility
The capability to follow an unpredictable musical
signal with ease is strongly believed to be the heart
of musicality for audio equipment. This ability can be
indicated by square wave response at high
frequencies, especially at 10Kh and the even more
rarely achieved 20Khz. Exceeding these
expectations, Allnic’s HA-3000 shows a response
shape that is, even at 100Khz, in a word, beautiful.
Micro-Phonic Free Tube Damping Know-how
Allnic’s Absorb-Gel® tube damping know-how
culminates in the HA-3000. In the HA-3000, an
extreme version of this mechanical technology
applied, reducing vibration induced noise in the
sensitive tube amplification circuit to a level never
before realized.
Variable Input Load Impedances.
The HA-3000 has four input load impedances: 50,
100, 200, and 500 ohms, selectable from a control
on the front panel. This allows loading according to
the output impedances of your MC cartridges.
Furthermore, these loads are purely resistive, not
the compound one of a step-up transformer,
resulting in a pure and clean sound.
As are all Allnic Audio products, the HA-3000 is
fully RoHS (EU Reduction of Hazardous Substances
regulation) compliant in construction and
materials.
The HA-3000 has been designed and manufactured to
work most synergistically with other Allnic Audio
products, for example the Allnic phono stages and
preamplifiers.
