op-amp + op-amp buffer combinations

[eccdbb]

Assuming the buffer is faster and that this will be used as the power amp for driving speakers,

if you have a op-amp with good THD+N performance and one with bad, in addition to a buffer that has good and one with bad, and you put the buffer inside the feedback loop of the op-amp, what will the THD+N of the combination be like for the different combinations:

good op-amp + good buffer
good op-amp + bad buffer
bad op-amp + good buffer
bad op-amp + bad buffer

Has anyone tried this before?

 

[lineup]

and you put the buffer inside the feedback loop of the op-amp

The best opamp should be the one outside, the total feedback loop.

See my topic: http://www.diyaudio.com/forums/chip-amps/187156-hifi-combo-opa445ap-opa541ap.html
OPA445 is +/-45V opamp for hivolt
OPA541 is +/-40V power buffer chip

 

[eccdbb]

Hi lineup, posted in your thread.

Which parameters will be closer to the op-amp on the outside, and which will be closer to the buffer? (I only know the buffer increases Io).