Recently I sumbled over an old idea: the upper transistor is depletion-mode, the lower is enhancement mode.
It can be easily converted to n-channel transistors and scaled up to more power.
Not having the right transistors at that time, it was tested with a triode as the enhancement-mode device and a high-voltage BJT (video driver for CRT b/w TV sets). It could also serve as an inspiration for OTL amplifiers with 6C33 triodes.
Unlike the DEF, it has voltage gain.
It can be easily converted to n-channel transistors and scaled up to more power.
Not having the right transistors at that time, it was tested with a triode as the enhancement-mode device and a high-voltage BJT (video driver for CRT b/w TV sets). It could also serve as an inspiration for OTL amplifiers with 6C33 triodes.
Unlike the DEF, it has voltage gain.
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Hello all,
I hope that you are well and safe.
I had used the circuit of the attached schematic in Class aP prototypes. It is structured different from that shown by franzm. It idled at 0.1A, and had a Vgs =~13 V for SIT.
I did not consider [then] to idle the semiconductors at a higher amperage because this defeats the purpose of Class aP.
But, one can lower the value of the degeneration resistor and boost idle such that Vs of SIT settles at ~6 VDC. Next feed NMOS an AC instead of an aP signal and take [Vout] at the source of SIT as shown. The resultant dynamic range of the resultant output signal [Vout] maybe a max of 12 Vp-p.
Best
Anton
I hope that you are well and safe.
I had used the circuit of the attached schematic in Class aP prototypes. It is structured different from that shown by franzm. It idled at 0.1A, and had a Vgs =~13 V for SIT.
I did not consider [then] to idle the semiconductors at a higher amperage because this defeats the purpose of Class aP.
But, one can lower the value of the degeneration resistor and boost idle such that Vs of SIT settles at ~6 VDC. Next feed NMOS an AC instead of an aP signal and take [Vout] at the source of SIT as shown. The resultant dynamic range of the resultant output signal [Vout] maybe a max of 12 Vp-p.
Best
Anton
