probably it will not oscillate , but gate stopper is conditio sine qua non , at least in my head
so , no need to draw it all the time , especially when I forget .....
(so , that was good question!)
rationale for output resistors arrangement is nothing else than THD spectra ( and dynamic behavior of mosfets in output)
it looks best this way
edit: just checked - both gate resistors are included on pcb
so , no need to draw it all the time , especially when I forget .....
(so , that was good question!)
rationale for output resistors arrangement is nothing else than THD spectra ( and dynamic behavior of mosfets in output)
it looks best this way
edit: just checked - both gate resistors are included on pcb
I think I covered (also commented on) all possible iterations I could think of ....... so , no - Shade amp must have source resistors , to have what I need of transfer characteristics and behavior of outputs (DEFiSIT being ethalon for that)
regarding your question , I believe it's covered with :
Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans
and - last but not least:
Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans
regarding your question , I believe it's covered with :
Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans
and - last but not least:
Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans
btw ....... made sanity (sim) check of 2SK180 based DEFiSIT , made with ACS chips
nada - not big enough (voltage) window between gates of 2SK180 and IRFP9xxx to keep current in sane bracket
same case with SJDP
Sorry to quote a relatively old post, but the "1, 2, SIT3" thread triggered me to ask again.
I have some 2SK180D, that gives Id of around 1.5A at Vgs of -3.2V (Vds=20V), would they be feasible devices for the DEFiSIT. (attached are the measurements of the 2SK180D).
Attachments
if you go back in thread , you'll find (simulated) iteration with 2SK180
I can't do more , further development demands having actual part on bench
edit: found exact post : Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans
I can't do more , further development demands having actual part on bench
edit: found exact post : Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans
Last edited:
I have some 2SK180D, that gives Id of around 1.5A at Vgs of -3.2V (Vds=20V), would they be feasible devices for the DEFiSIT. (attached are the measurements of the 2SK180D).
All you need is a P channel Fet with Vgs of 3.2V at same current and temp.
Maybe P Fets in parallel.
There are adjustments that can be made if it's not exact.
Thanks Mr. Pass and ZM . It seems quite possible to find a matching P FET, but I'll need to get familiar with the SPICE circuit first.
I have another question though, if you don't mind. In the "DEF Amp" thread, it describes a way to adjust the Vgs matching through 3 resistors. In the DEFiSIT amp, opto-coupler is used - what is the reason for the change.
I have another question though, if you don't mind. In the "DEF Amp" thread, it describes a way to adjust the Vgs matching through 3 resistors. In the DEFiSIT amp, opto-coupler is used - what is the reason for the change.
- Home
- Amplifiers
- Pass Labs
- Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans