Here an theoretical possible for select between two kinds for reduce of distortion. Anybody tested?
Hi,
I've build some hawksford ec amps, but not tested this specific topology, and I have trouble understanding the Hawksford ec case. Can you post the schematic for 'Hawksford ec' like you did for 'nfb' please?
Edit: I now see, it's the upper case. Forget my post ....
jd
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I don't think that ec case works. Assume the opamp has gain A, the buffer is ideal and the load voltage is Vo. We see that the opamp Vout=Vo.
The inverting input is also Vo. The non-inverting input is also Vo. Vout opamp = A(-Vo+Vo)=Vo so Vo = 0. Independent of Vi.
jd
The inverting input is also Vo. The non-inverting input is also Vo. Vout opamp = A(-Vo+Vo)=Vo so Vo = 0. Independent of Vi.
jd
The OP-Amp must be a diamond transistor, not a normal type (see datasheet for AD844 e. g.)
http://www.analog.com/static/imported-files/Data_Sheets/AD844.pdf
The buffer symbol in my simplefield schematics represented the internal buffer of the op amp so as an external power push pull buffer.
http://www.analog.com/static/imported-files/Data_Sheets/AD844.pdf
The buffer symbol in my simplefield schematics represented the internal buffer of the op amp so as an external power push pull buffer.
Ahh yes, I used that too. You must have read my article on the Hawksford ec amp in Elektor or AudioXpress...
So the opamp non-inverting input is a high-impedance voltage input, the inverting input is a low-impedance current input, and this current comes out of the opamp output in reverse polarity? Is that what you mean?
Yes that'll work.
jd
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