VFet F5

[cygnus x1]

I may have missed this somewhere, I got lost in all the F5 posts, but has a Sony VFet F5 been tried or built? I'm referring to the 2SK82/2SJ28 set. I found several amps referred to on the web, but they all had capacitors in the output stage. I would like to avoid that if possible.

 

[Zen Mod]

search for meaning of depletion and enhanced mode biasing

those Vfets , being depletion mode , aren't so convenient to implement in F5 concept

 

[cygnus x1]

I guess I should have said a simplistic amp design using the Sony VFEts, without caps in the output stage. The amp I was referring to was designed by F. Corrado.

 

[Zen Mod]

link?

 

[vdi_nenna]

http://www.amplimos.it/images/2SJ28 SE AMP2.bmp

AMPLIMOS one stage amplifiers, amplificatori audio monostadio

 

[cygnus x1]

I was thinking of a simplified Sony TAN5550 or similar, since it did not have caps in the output. This is the amp I referred to.

 

[Zen Mod]

I know that one

nothing wrong with cap position - sort of part of Transnova circuit by Kirkland

whatever - even in common PSU arrangement , caps are in signal path ......

 

[Nelson Pass]

I have built an F5 type circuit with the Sony parts. It works fine, but the
heavy depletion bias voltage makes the circuit more complicated, so I'm
not rushing a DIY project out.

 

[cygnus x1]

I would be interested when you do, and interested in a few clues/guidelines. Still looking into reworking the Sony TAN5550 with these parts and simple circuit.