LM3886 + volume control - Rb & Rin swapping

[marcobobo]

Hi All... yes another LM3886 under construction.
I'm doing it with active volume control like suggested by TI:
https://www.ti.com/lit/pdf/tidu034
The only thing that I'm going to change is the ratio on the R3/R4 just to have a little bit of gain from the audio source.
The circuit for LM3886 is the same suggested by TI's datasheet.

My thoughts are relative to:
1) DC should be blocked from the RF filter + Baxandall circuit, so for the "less is more rule" I think to remove the cap on the 3886 input, I'm wrong?

2) If 1) is ok, can I use a 22uF cap in the feedback path as suggested by TI?
In this case, I can use a not polarized cap for better quality.

3) I know that the inputs of the 3886 should be balanced, so the R from V+ and ground and the feedback loop should be the same.
In my example is 20k.

Assuming that the OP-AMP used in the Baxandall circuit is capable of delivering the right amount of current, if I swap values of Ri and Rb, I have a different DC offset.
Am I getting lost somewhere?

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Thank you!

 

[mjf]

ad 3:
Rb = 20k is an unusually high value res in the signal path, should be 1k or so what, makes less noise.........

hint from page 9:
100 Ω is chosen for the value of R 5,
as the resistor is in the signal path and should be as low of a resistance as possible to minimize noise.