CMRR of LM3886 vs LM4562 - which one is better to choose as a summing amp?

[nigelwright7557]

As far as I understand, 5532s will have some DC leaking to its outputs. LM3886 is then AC coupled with C3 and C4. Those are missing DC drain resistors in my opinion.

Another difference that I see is 5532s are not configured as voltage followers like in the article. Will that affect DC biasing? I'm not sure, I'm afraid my knowledge lacks in that area.

Care needs to be taken with input current.
I used a none inverting op amp stage for a scope with 1 meg to ground.
Ended up with a couple of volts bias when I used a high input current op amp !
So I picked an op amp with 1pA input current and that fixed it.

You also have to be wary of gain bandwidth products.
As usually it is for a small signal only and the results are often worse than expected.