[sdiy] Final-stage mixer module?

[Oren Leavitt]

On 3/9/2012 12:51 PM, Mark Rivera wrote:
> I'd like to make a simple (TL07x) mixer for the final output of my
> modular. I want it to block DC. I recall seeing a schematic that
> showed two electrolytics back-to-back to achieve this. Is it as simple
> as that? Or is it better to have small ceramics on each input instead?
> Both?
>
> Mark

Sometime back, I did an output interface module that has a 3 input 
mixer, master level control and an output section with bass/treble tone 
controls. The output is attenuated to reasonable line level.
The mixer is AC coupled to the output section via a 0.1 uF capacitor. 
The output section input impedance is 100k which makes the low cut-off 
freq about 16Hz.