I am about to wire up some LM1875s for a subwoofer amp. I know, relative low power for a sub, but it's for my flea amp setup.
I would like to try the current feedback topology instead of the voltage feedback.
So, I try to sim, using a high current output opamp because I dont have LM1875 model. The circuit is modded for 10x higher load impedance so the opamp can drive it realistically.
I have a LCR load in parallel to give a 'difficult' load. I would expect the current feedback version to have a smaller dip in the response, but they seem to be identical.
Why no difference in the voltage vs current feedback.
I must be doing it wrong.
Are my values off? I am giving same gain to easier compare. (EDIT: the feedback res on VFB should be 21400 not 21500 ohms, sorry)
I would like to try the current feedback topology instead of the voltage feedback.
So, I try to sim, using a high current output opamp because I dont have LM1875 model. The circuit is modded for 10x higher load impedance so the opamp can drive it realistically.
I have a LCR load in parallel to give a 'difficult' load. I would expect the current feedback version to have a smaller dip in the response, but they seem to be identical.
Why no difference in the voltage vs current feedback.
I must be doing it wrong.
Are my values off? I am giving same gain to easier compare. (EDIT: the feedback res on VFB should be 21400 not 21500 ohms, sorry)
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In the current feedback case, you should return the L-R-C to the top of the sense resistor instead to ground, as it is supposed to be in parallel to the load I guess.
Then you'll see the difference.
Jan
Then you'll see the difference.
Jan