Greg Ball SKA
Hafler Transnova topology (uses more or less the same principle)
various AM Audio (Italy) power amplifiers, with massive banks of parallel latfets
Selectronic Profet (which originated Pass F5 and the AM Audio power amps)
Musical Fidelity A370
BJT examples:
various Musical Fidelity power amps such as A1, A100
Blomley Class B amplifier (uses a CFP triple and the "emitters" of the compound connect to the rails)
Hafler Transnova topology (uses more or less the same principle)
various AM Audio (Italy) power amplifiers, with massive banks of parallel latfets
Selectronic Profet (which originated Pass F5 and the AM Audio power amps)
Musical Fidelity A370
BJT examples:
various Musical Fidelity power amps such as A1, A100
Blomley Class B amplifier (uses a CFP triple and the "emitters" of the compound connect to the rails)
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In most of these power amps where the outputs are operated with voltage gain, there's an outer NFB loop and inner NFB loop, to achieve stability. You can look at everything to the right of the opamp as a building block with a current input rather than a voltage one.
As you can see from the schematic, the inner NFB on this example is from the drains of the outputs to the bases of the "cascode" (it is a sort of cascode because the input to the emitters is a current and the voltage stays more or less fixed at that node, allowing low voltage opamps to be used - they only have to swing a few milliamps).
If you were to analyse the loop and break only the outer NFB then the OLG will not be all that high. This is the case in all the examples I cited above, although the composite/nested NFB is done differently in each one.
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ok so I have been doing some reading and things are becoming clearer why the odd arraignment... This is part of a BASH system...which i was not familiar with. i thought that the BASH part of this was just the power supply. which is odd as well. it has a SMPS that develops the positive rail. and then the negative rail is switched On and off I thought. but as i am reading more about BASH. i believe the negative rail is actually modulated. there is no CT reference so they can swing the rails around for more power with more efficiency and less heat. its all becoming clearer to me now...