A-2000 KT-120 Push Pull Stereo Power Amp.
◈ PRINCIPAL FEATURES
⊙ "Full Engagement" Output Transformers
Conventional output transformers use pre-set secondary windings to accommodate
4, 8 and 16 ohm loudspeaker loads. However, these conventional transformers utilize
only one secondary winding at a time, while the other secondary windings remain "idle".
This approach has two adverse effects. First, the output transformers are not working
at their maximum efficiency, reducing their output relative to their potential.
Second, the "idle" windings are not actually "idle" they are subject to parasitic
oscillations, producing their own "signal". This undesirable electrical information is
additive to the transformer's output, distorting the amplified signal going to the loudspeaker.
Allnic's "Full Engagement" transformers address these issues by having 4 independent,
secondary windings which are always fully connected, never "idled".
This means that all secondary windings are always connected to your loudspeakers,
regardless of which output switch position you use (4 ohms or 8 ohms or 8 ohms or 16 ohms,
depending on the factory configuration you have selected). The result is that there is neither
a loss of transformer output efficiency, nor the introduction into the output signal of
distortion from parasitic oscillations of the secondary windings.
⊙ Large Nickel/FeSi Core Output Transformers
As with our other models, Allnic uses very large output transformers (96 mm) with nickel,
mixed with FeSi, cores. This provides for higher inductance with fewer windings than other
designs can provide and results in the great benefit of an extremely wide range of output
⊙ Powerful Driving Circuitry
Allnic belives in the importance of using high-quality, low noise and powerful driving circuitry
in all its amplifying devices. Therefore, in the A-2000, we employ the E282F tube in triode mode
as the second stage driver tube, with a load of about 5 K ohm, and using 20mA of current.
The listener can easily hear and even "feel" the differences between this design and other,
more conventional, ones.
Please compare, in your imagine, it to conventional 12AU7 or 12BH7's driving force, 47K ohm loaded.
2 ~ 3mA current.
⊙ "Soft-start" Circuitry
Allnic uses soft start circuitry that, after sufficient warm-up only, provides the high voltage
supply to the plate of each tube. This protective design results in prolonged tube life and
fewer and less frequent issues with tube performance.
⊙ "Easy-lift" All Aluminum Chassis
The A-2000 chassis has a new handle design for easy-lifting and is all aluminum, milled
precisely in a sophisticated maching facility.
⊙ Analogue Power Tube Current Monitors
In order to provide constant current (bias) monitoring for the power tubes, Allnic uses a
separate analogue current meter for each channel. The meters make it exceptionally easy
to see the status of each tube at any time and to respond immediately to any variation
in bias by use of the bias control knob for the relevant tube. The meters offer a simple,
unambiguous indication of each tube's status compared to cinventional LED bias monitors.
⊙ "On-the-Fly" Triode/Pentode Switching
Switching between triode and pentode operation can be done "on-the-fly" at any time
while the amp lifier is in use.
Fig.1 Square Wave 50Hz Fig.2 Square Wave 1KHz Fig.3 Square Wave 10KHz
Measured by LEADER LAG-126 Audio Signal Generator & KENWOOD CS-4125 Oscilloscope
⊙ Output Power : 70w + 70w(8Ω load, at 1KHz)
⊙ Distortion : 0.2% at 1KHz, 10W
⊙ Frequency Response : 20Hz - 20KHz Flat
⊙ S/N Ratio : -80dB(CCIR, 1KHz)
⊙ Damping Factor : 8 at 8Ω load at 1KHz
⊙ Voltage gain : +24dB
⊙ Input Impedance : 100KΩ(unbalanced)
⊙ Input Sensitivity : 1.4V for rated power ⊙ Tubes : KT-120 X 4, E282F X 4, 6AK6 X 2
⊙ Dimensions : 430mm X 430mm X 240mm(W.D.H) ⊙ Weight : 40Kg net.