@Antoinel the second suggestion is similar to the one I found in your DEF thread.
This resistor network from gate stopper to output works really, but I cannot use your complete suggestion because you have a cap.
I cannot use a cap because the auto former gives the biasing voltage to the semiconductors.
Using a cap in this place would stop the biasing voltage.
This resistor network from gate stopper to output works really, but I cannot use your complete suggestion because you have a cap.
I cannot use a cap because the auto former gives the biasing voltage to the semiconductors.
Using a cap in this place would stop the biasing voltage.
did something .... though no way that I can wrap my head about that , at least not in this moment
it'll work , at least semi-decent , as this :
though , there must be more elegant ways ( and we know there are , even if I can't remember where they're posted
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Lhquam, could you explain in simple words what you found....?
)
What I found is really nothing more than what Papa said in post #539. Here is another presentation of that, plotting the in-circuit transconductance d(I(PapaSIT)/d(Vgs(PapaSIT) of the PapaSIT at different values of Rload at 1 Watt output.
- Green: Rload = 4R gm=-33mS push-pull
- Blue: Rload = 6.56R gm=0mS similar to CCS
- Red: Rload = 8R gm=+25mS similar to resistive load
- Cyan: Rload = 16R gm=+55mS ..
- Magenta: Rload = 100R gm=+80mS ..
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Fearless and dumb.. it's me
I did make a mistake today and my DEFiSIT amp worked!
I used my last pair of 2SK82 and IRFP9240, the resistor at the Source is 0.66 ohm. (2ohm+1ohm in parallel) Is this too high a value? 30V supply 1.5A bias. Both channels the same Source resistor value is used.
I have no idea whether this is working right or not but it makes the sound.
Please enjoy the poor and crappy build. I do not have the time and I wanted to try as soon as possible.
Yes the words are right it is single ended tone with power and damping, and lively. Best sound until now with my Altec Valencia(16 ohms). I am happy. I wonder what the real SIT-3 would sound like...??
The heat sink size is not enough. Temperature between SIT and FET is 57 degrees C.
I get the feeling that the voltage across SIT needs to be higher than FET. I tried to make it half the supply voltage. But this is all I can do..
I did not listen to 4 ohm or 8-ohm speakers.
I would like to thank Gerd and others for encouraging..
I did make a mistake today and my DEFiSIT amp worked!
I used my last pair of 2SK82 and IRFP9240, the resistor at the Source is 0.66 ohm. (2ohm+1ohm in parallel) Is this too high a value? 30V supply 1.5A bias. Both channels the same Source resistor value is used.
I have no idea whether this is working right or not but it makes the sound.
Please enjoy the poor and crappy build. I do not have the time and I wanted to try as soon as possible.
Yes the words are right it is single ended tone with power and damping, and lively. Best sound until now with my Altec Valencia(16 ohms). I am happy. I wonder what the real SIT-3 would sound like...??
The heat sink size is not enough. Temperature between SIT and FET is 57 degrees C.
I get the feeling that the voltage across SIT needs to be higher than FET. I tried to make it half the supply voltage. But this is all I can do..
I did not listen to 4 ohm or 8-ohm speakers.
I would like to thank Gerd and others for encouraging..
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Last edited:
Great ChulI did make a mistake today and my DEFiSIT amp worked!
I used my last pair of 2SK82 and IRFP9240, the resistor at the Source is 0.66 ohm. (2ohm+1ohm in parallel) Is this too high a value? 30V supply 1.5A bias. Both channels the same Source resistor value is used.
I have no idea whether this is working right or not but it makes the sound.
Please enjoy the poor and crappy build. I do not have the time and I wanted to try as soon as possible.
Yes the words are right it is single ended tone with power and damping, and lively. Best sound until now with my Altec Valencia(16 ohms). I am happy. I wonder what the real SIT-3 would sound like...??
The heat sink size is not enough. Temperature between SIT and FET is 57 degrees C.
I get the feeling that the voltage across SIT needs to be higher than FET. I tried to make it half the supply voltage. But this is all I can do..
I did not listen to 4 ohm or 8-ohm speakers.
I would like to thank Gerd and others for encouraging..
I am following your every step ..... with great care.
After the good experience with MOFO this will be my next madness.
The defisit is a follower but very special....I have a pair of SK180s that I would like to work with