7
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-8000 DHT has a 120 ohm (120Ω) 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-8000 DHT 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, and especially DHT,
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-8000 does not employ a digital IC volume
control or a low-cost carbon film volume control with a motor. The L-8000 uses the
WORLD’S FIRST 61 step, constant impedance, “bridged” type attenuator. Allnic’s new
attenuator is now the most sophisticated on the market, and we believe, without a doubt,
also the absolute best sounding. With fixed impedance and no (± 0db) channel imbalance at
any volume level, this revolutionary and currently unique, oil clutched, motorized
attenuator will astound users with its elevation of the fidelity and purity of any system in
which it finds a home.
Output
Impedance
Frequency
(Allnic LCR Output Impedance Curve)
Frequency
(Traditional CR Type Output Impedance Curve)
Output
Impedance
