Choky Susy F3 for LU1014's

[Tea-Bag]

For those who have been hording LU's or waiting for a balanced F3 amp, ZM proposed the following.

[Tea-Bag]

For those who want to build a simpler PS. Could be me...

[steenoe]

Great mithomas
The adventure started here, after ZM worrying about my nerve-system, and a few pm's later came up with a cure

Start of Susy F3.

ZM sure is a man of many talents

[EUVL]

If you would forgive me :

1) It depends on what your definition of Super Symmetry is. As it is the proposed schematics is basically 2 identical inverting amps joint at the frontend by a current course to form a diff pair. But there is no cross feedback, as in the Pass patent.

2) I would perhaps consider adding an output decoupling cap at each end.

3) To get the LU1014D to operate in triode mode at around 1.5A, the source resistor wants to be somewhere between 0.6 to 0.7 ohm. Maybe you can also get a triode mode with 0.1 ohm Rs (I have not tried), but I guess you need to play with the cascode voltage, and you bias current would go up by lots, so the IRFP240 might struggle with heat.

Just a few minor issues.




Patrick

[Zen Mod]

Originally posted by EUVL
If you would forgive me :

1) It depends on what your definition of Super Symmetry is. As it is the proposed schematics is basically 2 identical inverting amps joint at the frontend by a current course to form a diff pair. But there is no cross feedback, as in the Pass patent.

2) I would perhaps consider adding an output decoupling cap at each end.

3) To get the LU1014D to operate in triode mode at around 1.5A, the source resistor wants to be somewhere between 0.6 to 0.7 ohm. Maybe you can also get a triode mode with 0.1 ohm Rs (I have not tried), but I guess you need to play with the cascode voltage, and you bias current would go up by lots, so the IRFP240 might struggle with heat.

Just a few minor issues.




Patrick

tnx for input

1) I see it as SUSY ; tail in LTP is what brings crossed feedback ;
anyway - only Papa can tell is it or not

2) caps on output are needed same as in SOZ or F1

3) thing to try ; less degeneration - better ; we'll see where triode begins

[Zen Mod]

Magura sez :
big donut ; either 1KW donut , where two 110V primaries are used as split choke , or 2KW 220V:110V autoformer ( it have same core as 1KW plain xformer)

and yes - Magura also sez ( but we know that he's pretty nutz ) - use air core bifillar wound choke

[steenoe]

A study in simplicity, and typical Magura. His amps fit in a 20' container I bet those aircore-chokes weigh at least 20kg each.

[Zen Mod]

Originally posted by steenoe
A study in simplicity, and typical Magura. His amps fit in a 20' container I bet those aircore-chokes weigh at least 20kg each.

nope ;
this one is mucho simpler than Magura's dreks

[steenoe]

Originally posted by Zen Mod

big donut ; either 1KW donut , where two 110V primaries are used as split choke , or 2KW 220V:110V autoformer ( it have same core as 1KW plain xformer)

I guess that version could be a serious contender.

[Vix]

Originally posted by Zen Mod
Magura sez :
big donut ; either 1KW donut , where two 110V primaries are used as split choke , or 2KW 220V:110V autoformer ( it have same core as 1KW plain xformer)

and yes - Magura also sez ( but we know that he's pretty nutz ) - use air core bifillar wound choke

And...how about big donut with a single supply?

Or, a Sysy F3-lite?