Newbie question about gain resistors

[diyloveman]

post4 pic looks like the sch shown in the National datasheet.

That sch is very misleading !
You have a number of missing circuits/components.
Add DC blocking to the input.
Add RF attenuating filter to the input.
Add output Inductor with it's damping resistor to the output
Pay attention to getting Cs close to the power pins and particularly getting the X7R VERY close to, or attached to, the power pins.
Ci is far too small to avoid distortion of the bass signals. and it's not optional !
And go read Tomchr for info on how to properly implement Cc connected to the -IN pin. If you don't do it that way then omit it completely.

Consider, as optional, adding RF attenuating capacitors to all the inputs and outputs.

and BTW,
the 25k vol pot is too high a value for the shown input impedance of 23k (1k+22k)
Use 10k maximum for 23k, or even increase to 40k (1k+39k)

Is it really necessary for DC blocking for OPamp config?

 

[AndrewT]

that's going back a bit.
I have trouble remembering last week, never mind last year !

AC or DC coupling of an amplifier is a choice that the Designer must make.
As Designer, they make an informed choice and accept what baggage comes with the decision.

As Builder, you take the whole package, with good and bad baggage.