Greetings to everyone,
as some of you already known, I have in the past tried solutions that could make the V-fet amplifier circuits simpler. Especially I want to remember that on this forum I presented the circuits of the BabySit series which in the simplest version use a single mono power supply. As some already known, V-fet, similarly to tubes, need a polarity of Gate voltage opposite to Drain.
But, meanwhile with tubes it is often possible to use autobias with series cathode resistance, this practice is almost impossible to use with the V-fet due to the large signal losses needed and a consistent increase in output resistance of circuit in relation to the load resistance, with a value comparable to the latter. This problem is not so much felt in the follower schematic, with source output, where it typically needs a single dual voltage, but if you try to use a common source scheme with Drain output, if you want to avoid unacceptable performance losses, to properly polarize the devices, it is really necessary to have 4 power supplies (with few exceptions).
One of these exceptions is to use a Transnova scheme and myself in the past have presented some project with this solution, but I must confess that they have received (wrongly in my opinion) little consideration.
Now, I have developed two new complementary push-pull output circuits, designed for V-fet applications and all other Depletion types as SIT, and Depletion MOSFET, which, although configured as common source amplifiers, they need only one dual power supply and not four different power sources.
I think a lot of simplification for using these devices.
For now I attach the two principle schemes used and then follow some simulations I think interesting.
I obviously look at your considerations on this and good V-fet amplifier at all.
Francesco
as some of you already known, I have in the past tried solutions that could make the V-fet amplifier circuits simpler. Especially I want to remember that on this forum I presented the circuits of the BabySit series which in the simplest version use a single mono power supply. As some already known, V-fet, similarly to tubes, need a polarity of Gate voltage opposite to Drain.
But, meanwhile with tubes it is often possible to use autobias with series cathode resistance, this practice is almost impossible to use with the V-fet due to the large signal losses needed and a consistent increase in output resistance of circuit in relation to the load resistance, with a value comparable to the latter. This problem is not so much felt in the follower schematic, with source output, where it typically needs a single dual voltage, but if you try to use a common source scheme with Drain output, if you want to avoid unacceptable performance losses, to properly polarize the devices, it is really necessary to have 4 power supplies (with few exceptions).
One of these exceptions is to use a Transnova scheme and myself in the past have presented some project with this solution, but I must confess that they have received (wrongly in my opinion) little consideration.
Now, I have developed two new complementary push-pull output circuits, designed for V-fet applications and all other Depletion types as SIT, and Depletion MOSFET, which, although configured as common source amplifiers, they need only one dual power supply and not four different power sources.
I think a lot of simplification for using these devices.
For now I attach the two principle schemes used and then follow some simulations I think interesting.
I obviously look at your considerations on this and good V-fet amplifier at all.

Francesco