Luxman L58A / 2SK163-2SJ44?

[mlloyd1]

my japanese is not so good
heres an english version of the 2sj44 datasheet:
Download | Datasheet Archive

mlloyd1

Originally Posted by tiefbassuebertr

2SK163/2SJ44 datasheets now available from RENESAS:
http://www2.renesas.com/maps_download/pdf/TC-5409.pdf
http://www2.renesas.com/maps_download/pdf/TC-5466.pdf
Document Download | Search | FAQ / Support | Renesas Electronics

[KJ2005]

Originally Posted by mlloyd1

my japanese is not so good
heres an english version of the 2sj44 datasheet:
Download | Datasheet Archive

mlloyd1

Yes...easyer to understand in an english version. ....seems to be more than difficult to find several pairs of the mentioned fet's ( enough to match some of them).
....Did not had the time to search for replacements that could take the same voltage - and even with the same good sonic sound - if there are any??

... a lot of projects for the moment.

Kim

[KJ2005]

Originally Posted by tiefbassuebertr

I am not sure, what means "non feedback DC amplifier". I real life such amps don't exist.

Well ..... besides small local feedback..... "The End mk.II" comes as close to a "NO FEEDBACK" amplifier as possible.

The 1990 schematic is shown by kind permission of the man who designed the amplifier Mr. L.H.Clausen , and the company that owns the copyrights for "The End mkII", 800XE power modules and more.... the company LC Audio, Denmark.

Find "The End mk.II" schematic at: leakstereo20

...and the button "The End circuit"

rgds.

[tiefbassuebertr]

Originally Posted by KJ2005

Well ..... besides small local feedback..... "The End mk.II" comes as close to a "NO FEEDBACK" amplifier as possible.

The 1990 schematic is shown by kind permission of the man who designed the amplifier Mr. L.H.Clausen , and the company that owns the copyrights for "The End mkII", 800XE power modules and more.... the company LC Audio, Denmark.

Find "The End mk.II" schematic at: leakstereo20

...and the button "The End circuit"

rgds.

I don't find the schema about
leakstereo20
but I think, you mean this amp topology:
leakstereo20
L C Audio Technology/The End Millennium (predecessor)
this is indeed called "No Feedback Amp" from Mr. L.H. Clausen.
Actually Mr. Clausen means "No Global Feedback Amp", because there are three independend feedback-loops:
A: Voltage gain stages (open loop gain = closed loop gain):
1) Serial feedback R1+2
2) Serial feedback R32+32
B: Power Buffer stages (pre-Driver Buffer + PP Sziklai Darlington)
very high hfe/ typical combinations of local serial feedback from a power follower/local NFB of a Sziklai-Darlington.

If you check only the power buffer of this topology by changing the output and GND, you will see the amount of the open loop gain factor.

At my opinion this design is to prefer for applications in the upper frequency range (> 1000 Hz), while NFB designs is to prefer for the frequency range below 1000 Hz. Full range (single amp) applications, used from the most music lowers, still a compromise between clear and tight bass and smooth/musical midrange/height (voices e. g.).

Presently I think about an evaluation amp PCB design, where I can realize (e.g. through jumper change) Mr. Clausen's amp design so as various NFB amp designs for directly comparable on various speakers/complex loads. So I can more talk about the pros and cons. But at whole I get still too much posibilities of combinations.

[KJ2005]

Originally Posted by tiefbassuebertr

I don't find the schema about
leakstereo20
but I think, you mean this amp topology:
leakstereo20
[url=http://octave-electronics.com/lcaudio/temil.shtml]
this is indeed called "No Feedback Amp" from Mr. L.H. Clausen.



But at whole I get still too much posibilities of combinations.

... think I wrote press the "The End circuit" button.

.... Also wrote small local FB used at the mk.II version.

forget all about the circuit possibilities... think that one has to keep both legs on the ground, and follow whatever long experience has told you.

The sonic sound of the last analog amplifier Millenium , in my opinion, can't quite compete with the "The End mk.II and mk.III" version - and don't tell anyone about a choice between a tight bass and musicality in mid-and high frequences when talking "The End mk.II and III" ..... you get both when you built these amplifiers.......say - built very accurate with matched transistors!!

You need to built at least 10 of these amplifiers before it is possible come up with any statements about their musicality.

[tiefbassuebertr]

Originally Posted by mlloyd1

my japanese is not so good
heres an english version of the 2sj44 datasheet:
Download | Datasheet Archive
mlloyd1

Thank you for this URL. I am looking for the associated NEC databook from 1981
Who know the exactly title or can post a cover image like examples by post #34 and #37 about
Vintage Transistors

[Gudmund]

Originally Posted by tiefbassuebertr

I don't find the schema about
leakstereo20
but I think, you mean this amp topology:
leakstereo20

Search for no-feedback amp.

Could not find anything about no-feedback amp on your link, but found several pics on: TUBEAMP


rgds

[scott wurcer]

Interfet lists an IFP44 which in their coding scheme would be a 2SJ44 which looks similar to a 2SJ74, but there is no evidence of it being actually available.

[tiefbassuebertr]

Originally Posted by Gudmund

Search for no-feedback amp.
Could not find anything about no-feedback amp on your link, but found several pics on: TUBEAMP
rgds

There are no so called "no-feedback" amps, both as commercial amps and diy amps.
Please explain us more exactly, what kind of amplifier topology you want to find.
Perhaps such an amp like this?
Zero Feedback Impedance Amplifiers

[jacco vermeulen]

Originally Posted by scott wurcer

Interfet

You don't think they buried ProJect 99 at Area 51 ?