ALLNIC AUDIO L-6500 Instrukcja obsługi - Strona 4

Przeglądaj online lub pobierz pdf Instrukcja obsługi dla Wzmacniacz ALLNIC AUDIO L-6500. ALLNIC AUDIO L-6500 14 stron. Line-stage preamplifier

INTRODUCING THE L-6500 LINE-STAGE PREAMPLIFIER

Immerse yourself in the original recorded space. The L-6500 is a single gain stage, transformer-

coupled, remote-controlled line-stage pre-amplifier.

The L-6500 is silent, except for the music emanating from the blackest of backgrounds. The

outstanding sonic quality is matched by the simple elegance, flexibility and ergonomic

functionality of the casework and connection options. Few pre-amplifiers can compete at any

price.

Like all Allnic Audio products, it 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 L-6500 has the following features:

•

Line output transformer coupling – The L-6500 is "transformer coupled. In tube amp

circuitry, there are two coupling methods; one is capacitor coupling and the other is

transformer coupling. Capacitor coupling is the traditional, low cost method. It is somewhat

stable but transfers only voltage, not wattage (i.e., not real energy). With transformer

coupling, about 90% of real wattage is transferred (there is still a transformer loss of about

10% of wattage – voltage is not affected).

Transformer coupling is superior to capacitor coupling. However, all the advantages of

transformer coupling depend on the quality of the transformer and on the choice of tubes.

Allnic Audio manufactures its own transformers and uses what it views to be the best core

material, Permalloy. Allnic Audio's unprecedented, wide (16Hz ~ 75kHz, -3db), low

distortional, and ultra-flexible (up to 50kHz square wave response) output transformer helps

Allnic Audio to realize the ideal transformer coupled preamplifier. Of course, gain tubes are

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-6500 has a 150 ohm (150Ω) 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.