4
INTRODUCING THE A-5000 NEO 300B SET
MONOBLOCK POWER AMPLIFIER
The A-5000 NEO monoblocks are Allnic Audio’s top of
the line power amplifier model. Like all Allnic Audio
products, the A-5000 NEO has 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 A-5000 NEO has the following features:
25 watts of pure class A high power output. The A-5000
NEO is a parallel single ended power amplifier. Almost all
other 300B amplifiers are under, and distortion, driven.
This is a result of the use of conventional "Resister-
Capacitor" circuits, which give only up to around a 70V
swing voltage, with high distortion. This means that an
already distorted signal of a lower than optimum swing
voltage is directed to the deep biased 300B grid. Allnic’s
powerful "Inductor Drive" circuit gives up to a 150V swing
voltage, with very low distortion (about 0.3%). It is this
drive delivered to the A-5000 NEO that allows for a
significantly higher output (25w) than the approximately
18 - 20w output that could be expected from standard
300B circuits.
Real power drive. The driver tube, a 6GV8, is a very strong
power pentode. We use this power pentode to drive the
300B’s via a choke plate inductor. Our choke inductor
(100% nickel permalloy PC core) has very low power loss
and infinitely high load impedance. This configuration is an
ideal drive stage for 300B SE.
Nickel alloy output transformer. Allnic uses sophisticated
ratio mixed nickel permalloy PB cored output
transformers. Because of their extremely high initial
permeability, it is possible to use lower turns on the
primary winding while retaining very high 'open circuit
inductance”. That means a resulting very wide frequency
range and low distortion bass response. This is another
reason why the A-5000 NEO excels over other 300B power
amplifiers. Allnic also uses a very big nickel core, so as not
to be magnetically saturated at a high current of level of
200mA.
Long life and trouble-free operation. Allnic employs a
“soft start circuit” to protect the tubes and other parts. It
applies the high B+ voltage only after tubes are fully warmed-
up.
Fixed bias control grid. Allnic prefers to use low distortion and
high output “fixed bias” rather than the relatively higher
distortion and lower output “self bas” method. That way, it is
possible to eliminate the use of cathode resisters and their
associated heat production.
Natural negative feedback. The A-5000 NEO applies about -
6dB of negative feedback. This is a very complimentary
amount of negative feedback that differentiates the Allnic
300B single ended amplifier from the standard, which has a
very coloured and weak speaker driving force. With this
natural feedback, the A-5000 NEO has a relatively high
“damping factor', very low distortion, and a higher S/N ratio,
without losing the signature single ended natural sound
quality.
Hard wiring. The A-5000 NEO is all hard wired; circuit boards
are not used.
Beautiful 20KHz square wave response. See Figures 1-3.
Fig.1 Square Wave 50Hz Fig.2 Square Wave 1KHz
Fig.3 Square Wave 20KHz
Measured by LEADER LAG-126 Audio Signal Generator
and KENWOOD CS-4125 Oscilloscope
As are all Allnic Audio products, the A-5000 NEO is fully
RoHS (EU Reduction of Hazardous Substances regulation)
compliant in construction and materials.
