ALLNIC AUDIO A-5000 DHT 소유자 매뉴얼 - 페이지 4

{카테고리_이름} ALLNIC AUDIO A-5000 DHT에 대한 소유자 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. ALLNIC AUDIO A-5000 DHT 9 페이지. 300b single-ended pure direct heated triode monoblock power amplifier
ALLNIC AUDIO A-5000 DHT에 대해서도 마찬가지입니다: 소유자 매뉴얼 (13 페이지)

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1. Tubes and Tube Bias

INTRODUCING THE A-5000 DHT

300B SINGLE ENDED, PURE DIRECT HEATED TRIODE

MONOBLOCK POWER AMPLIFIER

The A-5000 DHT monoblock, like all Allnic Audio products,

uses 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 DHT has the following features:

All Direct Heated Triodes – The A-5000 DHT monoblock



amplifier is a pure direct heated triode, tube rectified

power amplifier. It uses only direct heated, single ended

tubes from input to output. The first stage is a new old

stock Marconi HL-2; the second is a new old stock STC 3A-

110A (or equivalent); the third is the famous 300B. This is

an ideal combination of pure direct heated triodes,

resulting in unparalleled faithfulness to the incoming

signal, incredible musicality and detail, and quick,

articulate bass.

Real power drive - The driver tube is the 3A-110A (or



equivalent). Allnic uses this direct heated triode 3A-110A

tube to drive the 300B to its correct specifications via a

choke plate inductor. The choke inductor (with a 100%

permalloy core) has very low power loss and an infinitely

high load impedance. This configuration is an ideal drive

stage for the single ended 300B and produces 10 watts of

pure class A, extremely low distortion, high power output.

Nickel alloy output transformer - Allnic uses sophisticated



ratio

mixed

nickel

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 DHT 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.

 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 bias" method.

That way, it is possible to eliminate the use of cathode

permalloy

cored

resistors and their associated heat production.

 Natural negative feedback - The A-5000 DHT applies about

-6dB of negative feedback. This is a very complimentary

amount of negative feedback that differentiates the Allnic

300B single ended amplifiers from the standard, which

have a very coloured and weak speaker driving force.

With this natural feedback, the A-5000 DHT 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 DHT is all hard wired; circuit

boards are not used.

 Beautiful 20KHz square wave response - See Figures

1-3.

Fig.1 Square Wave 50Hz

Fig.3 Square Wave 20KHz

output

Measured by LEADER LAG-126 Audio Signal

Generator and KENWOOD CS-4125 Oscilloscope



As are all Allnic Audio products, the A-5000 DHT is

fully RoHS (EU Reduction of Hazardous Substances

regulation) compliant in construction and materials.

Fig.2 Square Wave 1KHz