I'm working on an interface that will be connected instead of a speaker, input of my interface is differential, and output is single ended.
R3 is the load to simulate the speaker, the R1/R7/R4 group is here to decrease the level.
I would like to easily adjust the gain by acting on R2 (knowing that I should act the same on R5) but I need a major value change to see a minor change on the output, I'm using Proteus to do the simulation.
Do you see an alternative to my scheme? or can I use a transformer to move from differential to single ended then use an AOP to adjust the gain?