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INTRODUCING THE A-2500 211/845 SINGLE-ENDED TRIODE MONOBLOCK POWER AMPLIFIERS
The A-2500 is Allnic Audio’s most powerful, power tube flexible, single-ended monoblock power
amplifier model. Like all Allnic Audio products, the A-2500s have Permalloy (iron and nickel alloy) for
their 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 A-2500s use the superbly musical 211 or 845 (customer’s choice on ordering) power tubes in
single-ended configuration to provide the special musicality of the 211/845 tubes. The A-2500s have
the following features:
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The A-2500s are single-ended triode monoblock power amplifiers. Each monoblock provides 20 watts of
pure Class A, continuous power with either the 211 or 845 tube.
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Powerful Driving Circuitry. Allnic believes in the importance of using high-quality, low noise and
powerful driving circuitry in all its amplifying devices. Off-the-shelf design is not a part of the magic of
these amplifiers. Tubes and transformer characteristics are closely matched to complement each other
to achieve the most accurate and satisfying sound. In the A-2500s, we employ a new old stock (NOS)
6CM7 (for the 211 power tube) and a 6DR7 (for the 845 power tube) triode as the input tube for the
choke-transformer driving circuit. The listener can easily hear and even "feel" the differences between
these designs and other, more conventional ones. Please imagine, as you listen to the A-2500s, its sound
compared to the sound of an amplifier using conventional, for example, 6SN7, 6922, 12AU7 or 12BH7s.
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Fixed bias of both the 211 and 845 tubes for more power and less distortion.
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Direct-heated Vacuum Tube Rectification. The A-2500s use a 5R4 full-wave rectifier tube rather than a
semiconductor diode in the rectification circuit. This provides both sonic benefits and improved
protection for the 211/845 power tubes.
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Point-to-point hard-wired circuitry.
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“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 that 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
