I will try to design a NGNFB amp with an OPS with no EC, as this is also a kind of NFB. I would like not to use negative feedback except local degeneration.
I chose IPS(input stage) a current conveyor very similar as in GainWire mk2 but with higher gain of about 32 dB. Characteristic I like about current conveyor is that the gain is defined with resistors only. The volume control is at the output of the current conveyor. In this case SNR is always the same independent of the volume settings. Disadvantage is that distortion is the same on all volume settings(for IPS only).
First OPS I choose is non switching design by Edmond Stuard. Interesting thing about that OPS is the same THD on almost all levels, it drops only below 1 - 2 W on output. I expect some more ideas for OPS, preferable Class B(AB).
Damir
I chose IPS(input stage) a current conveyor very similar as in GainWire mk2 but with higher gain of about 32 dB. Characteristic I like about current conveyor is that the gain is defined with resistors only. The volume control is at the output of the current conveyor. In this case SNR is always the same independent of the volume settings. Disadvantage is that distortion is the same on all volume settings(for IPS only).
First OPS I choose is non switching design by Edmond Stuard. Interesting thing about that OPS is the same THD on almost all levels, it drops only below 1 - 2 W on output. I expect some more ideas for OPS, preferable Class B(AB).
Damir