I was comparing to Schade or triode N fdbk which are often used to lower the output Z. The 50% feedback at g2 will only reduce the pentode Rp to about a third, since g2 is rather insensitive. Damping factor might be kinda low.
I also thought it was doing UL mode at that point, with missing screen current, so the low N Fdbk would not fix the high harmonics of missing screen current. But the divider to ground scheme does not have that problem (screen current proportional to plate current instead). So all is well there.
I also thought it was doing UL mode at that point, with missing screen current, so the low N Fdbk would not fix the high harmonics of missing screen current. But the divider to ground scheme does not have that problem (screen current proportional to plate current instead). So all is well there.
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Hi Mona.... that's interesting! What will I achieve with that mod?
My main intention for starting this thread rolling was hoping some helpful guy will come forward to give a helping hand. Thanks, Mona!
I know I've a bird in hand and am not disturbed by the initial negative comments.
OK, I'll do the changes tomorrow and report back.
My main intention for starting this thread rolling was hoping some helpful guy will come forward to give a helping hand. Thanks, Mona!
I know I've a bird in hand and am not disturbed by the initial negative comments.
OK, I'll do the changes tomorrow and report back.
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I like the KISS approach. The screen voltage can be taken from the B+ by using a simple C-R-C network that provides a stiff stable supply. EL156 doesn't really needs a lot of voltage to drive it and make it sound great. A quality set-up input transformer with 1:8 ratio should able to do the trick. Of-course, with this approach, the source impedance needs to be low.
Hi Mona.... Your contribution to my built is fabulous 
.
The configuration around 6CG7 is spot-on as well as it's unusual heating technique. I was totally astonish by the high voltage of 301v at the junction of the two 22K, connected to the filament.
All this, is to me a class act of technical competancy. I like your down to earth style helping newbie like myself. A sketch or drawing goes a long way!
Sonic is awesome! Sweetie high with deep bass!
I'm exhilarated and this project have truly enliven me.
Mona, wish u're nearby, where I can come over with champagne, to thank you personally for helping me.... THANK YOU!
Best Regards,
Zekk.
.The configuration around 6CG7 is spot-on as well as it's unusual heating technique. I was totally astonish by the high voltage of 301v at the junction of the two 22K, connected to the filament.
All this, is to me a class act of technical competancy. I like your down to earth style helping newbie like myself. A sketch or drawing goes a long way!
Sonic is awesome! Sweetie high with deep bass!
I'm exhilarated and this project have truly enliven me.
Mona, wish u're nearby, where I can come over with champagne, to thank you personally for helping me.... THANK YOU!
Best Regards,
Zekk.
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