I have seen now the schematic on forum pag. 49
There is a current locker so these mosfet are not like lateral
There is a current locker so these mosfet are not like lateral
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This one?
http://www.diyaudio.com/forums/pass-labs/151909-firstwatt-j2-50.html#post2175400
Not mosfets but power Jfets
http://www.diyaudio.com/forums/pass-labs/151909-firstwatt-j2-50.html#post2175400
Not mosfets but power Jfets
What is a "Current Locker"?
These SiC JFETs are lower threshold like Laterals though. And that seems to be an issue with the output biasing that is not quite typical Pass? Even the 1.25V version of TL431 might not cut it? Or maybe no one makes it anymore???
These SiC JFETs are lower threshold like Laterals though. And that seems to be an issue with the output biasing that is not quite typical Pass? Even the 1.25V version of TL431 might not cut it? Or maybe no one makes it anymore???
O.K. Page 50 explains a little more. A TL Reg may work but Papa says it is less stable or "would need adj..."
"Current Locker" you mean the over current protection Q1?
"Current Locker" you mean the over current protection Q1?
let's say just that Mighty ZM measured that
not thoroughly with CCS biasing , but with plain power resistor between PSU and drain
gate was tied to drain , of course
in any case - let them bleed ......... and do not worry too much
not thoroughly with CCS biasing , but with plain power resistor between PSU and drain
gate was tied to drain , of course
in any case - let them bleed ......... and do not worry too much
yes, the FirstWatt J2 use a CCS on output stage to fix the current also when temperature increase.
Here is all one need to know about the output stage topology used in the J2 in order to make a clone that's close enough to contain the interesting characteristics!
The Good Old Days & More SRPP
(Scroll down to "Even More Impedance-Multiplier Circuitry")
The Good Old Days & More SRPP
(Scroll down to "Even More Impedance-Multiplier Circuitry")
let's say just that Mighty ZM measured that
not thoroughly with CCS biasing , but with plain power resistor between PSU and drain
gate was tied to drain , of course
in any case - let them bleed ......... and do not worry too much
Very good ZM! Time to get back to the Circlotron circuit. With JFETs this time...
