Most Greedy Boy, of them all... or (there is no) DEFiSIT of Papa's Koans

Official Court Jester
Joined 2003
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it's possible to to catch that wabbit in more than one way

one way is , as shown by Papa with that pcb screenshot (Soundwakoo posted) , implementing depletion one and enhancement one in M2 like circuit

just pulled out old M2 sim , slammed Pass-SIT-1 in it , changed few things and values and got workable solution ; which means that there is proper leeway to have it functional in vivo , with Tokin or similar , instead of PapaSit

price , besides loosing obvious visual elegance of schematic itself (which is only important as visual presentation of inner elegance and beauty of mental construct) is - introducing source resistors , thus loosing/changing pure transfer characteristic of parts used ......... which is , if we don't know better , important even just because Pa found it interesting to include in newest PL amp - XA25
other part of price is introduction of several parts for biasing mechanismus , introducing rail(s) in game and complication of offset behavior during startup
(not a problem if deciding to use one-sided PSU and capacitor on out)

second way - resorting to XA25 biasing approach , to avoid source resistors at all costs

more I think of all that ....... I'm more appreciating beauty of this simple DEFiSIT ........ and last but not least - Papa's work involved in .........
 
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more I think of all that ....... I'm more appreciating beauty of this simple DEFiSIT ........ and last but not least - Papa's work involved in .........

Yes this was my secret brilliant idea in f4 beast builders thread to combine ixth40P50P with an appropriate depletion mode mosfet, or combine depletion mode device with stack of P channel lateral fets.
I'm a sucker for simplicity wherever possible.
 
Official Court Jester
Joined 2003
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tnx

this is proof of a pudding ....... not exactly proof in a pudding :)

si , it is doable , Iq around 1A6 as predicted per spice

it'll need sort of speaker delay , just because there is nasty voltage peak in startup sim

this is far from optimised** , THD is 0.1% at 1W , though THD spectra is schweeeeeeeeeet :clown:

**demanding both more time with LTSpice and then real deal - playing with it in vivo
 

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