Introducing Fujii Amplifier
Recently Mr hideo Fujii (Japan) are doing experiment about
Single ended valve amplifier with some special technical .
He said Amplifier with diode resistance loaded
He's calling "Mirror images drive" for valve amplifier.
(He is passed way on early 2006 so we can't to see any more
new his technical of electronics .)but I will introducing his technologies
around amlifiers to be good.
What effect has ?
Usually pentode valve originally have a non lineal distortion
when near cut off position under Ip – Eb curve each valves.
Generally Diode valve has no lineal resistance .many of single
ended valve amplifier has non lineal distortion and produce some
of 2nd harmonic. This type of distortion is under 3/2 multiple character.
Which meaning diode has 2/3 multiple character so when you have
to get output signal on plate,probably to get some no distortion signal.
Is idea of Mr hideo Fujii. He call it's Mirror Images Drive.
This idea produce around min 1/20 less distortion of general
pentod amplifier.(many DHT has lineal Ip-Ep curve)
Generally made up good amplifier with out minimal distortion by
some of NFB but this type of amplifiers does not need NFB.
I think good for
use a parts of KT88(6550)SE Amplifier
so you can get clear sound from Power Penthode Amplifier.distortion are divided by 10 or more.
Fujii Amplifier explane
single amplifier accompanies the essential non-linear shape which is
derived from 2/3 power qualities of input anti- output current of the
vacuum tube. Some device as for the vacuum tube amplifier which is not
10% distortion is generated from 5 to generality. In case of the triode
amplifier, it is possible to decrease the distortion rather by giving
the load resistance of 3 times from 2 of the internal resistance which
it has individually. And in the multielectrode tube doing the kind of
thing generally, that it decreases the distortion, it is assumed that
it is very much difficult. Generating the strain rarely with the driver
tube, making the secondary distortion decrease which occurs with the
output tube is usually done, but it is very much difficult thing, is,
but it is reduction method of the distortion which is used generally.
We call "offset of the distortion". It has been said Fujii the
multielectrode tube input/output relationship is stipulated in gm. As
for the multielectrode tube because it is the electric current output
device, as for effective amplification constant being consistent,
because it is gm, the quality which is obtained with that becomes 2/3
power qualities. It is assumed that it is difficult to escape from these
qualities. It is to insert the element where the method Fujii devising
here generates the opposite quality curve of 3/2 power qualities in the
circuit. The equivalent diode of a triode is chosen in the opposite
quality element. And that applying as the resistant element, being to
devise that it denies 3/2 power qualities, it does. It is first to be
announced to the Japanese technical magazine in 1994 by him. He has
died in New Year 2006, it stopped impossible already to look at the
vacuum tube amplifier of that original thought, but those where the
information regarding many vacuum tube amplifiers is left very are
important thing. As for also backbiting of the wicked road being heard
it is fact in the people of part, but as for me as for the vacuum tube
amplifier of that original thought you think that even from now on it
keeps living somewhere of the world. The very regrettable person is
thought the dying/fleeing paragraph is with. The 6L6GC single
amplifier which is announced in 1994 is a result of decrease of the
distortion of maximum of 20 decibels with this method. There are 3/2
power qualities in the equivalent diode of a triode. Being recent
years, he all the vacuum tube distortion decrease drivers which abolish
FET experimenting and succeeding. The advocate of the single amplifier
of dream being not to be, does, that already new technology is shown in
us but you try probably to leave on the eternal master and the edge of
heart. Furthermore the vacuum tube which is used has recorded when the
equivalent diode of a triode connection of 12AU7 has the best quality
(1)Use: Distortion decrease of acoustic amplifier of distortion reduction like a 6L6GC beam valuves.
(2)Transmitting tube use of multielectrode tube like a 811A SE
Right now does not need push pull Amplifier.
By Lagarto san D.I.Y single ended 2005-2009 amplifier
Ref : Hi End Audio Radio Gijutsu magazine
about how to build up 6L6GC and 811A Single Ended Amplifiers without NFB
by H Fujii
Hi End Audio Radio Gijutsu magazine
4D32 Single Ended Non NFB Amplifier how to build up
by H Fujii
Radio Gijutsu Audio Maazine by IA
Last up date 8thNov 2009 since Dec 2005