Multiloop and inverting configuration

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Thanks for pointing this out; I was half asleep when I post it.

I hope now the circuit is correct, the idea is to use two inverting opamps to get non-inverted signal.
Get inner loops to stabilize opamps and outer loop to adjust required gain.

Link:
http://www4.head-fi.org/forums/attachment.php?s=&postid=312845


But I think, since this circuit is to be used as a "gain clone", let’s say gain about 100, the function of the outer loop losing functionality.
 
Do I have this correct now?
Yeah, that's the way I meant.

Another thing - what is the gain of U3 going to be set at? Placed where it is, the overall cct gain is going to be something like the inverse of U3 gain. e.g. if U3 has a gain of 5 then the overall gain is about 0.2 :dead: Not entirely useful. If you want a gain of more than 1 then you want a voltage *loss* in the feedback path, not a voltage *gain*. I think at this point seeing you have three opamps why not just string them all in series as inverting stages and use simple resistive feedback on the resulting inverting amplifier?

Does anyone know what the closed loop phase response of an opamp is compared to it's open loop phase response? How does it vary with gain?
 
Looks like multiloop and inverting input don't mate:(

Instead of playing with third opamp in series I would prefer to use two inverting opamp to get non-inverted signal, set gain of U1 to 10 and U2 to 10, clear and simple.

The aim of this post was to simply implement Jung's multiloop theory to a inverting input of the opamp.
If it doesn't work very well there is no point in complicating basic schematic.
 
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