[sdiy] Auto Center waveforms

[David Anderson]

Jerry Gray-Eskue wrote:
> I have been thinking about centering arbitrary wave shapes on 0 volts.
> 
> The issue with this approach is cost and complexity. It seems like there may
> be a "Slick" way to do this without resorting to expensive ICs and still
> give good offset removal performance.
> 
> Any thoughts, or ideas on a better method ?

Funny you should ask. I just reworked an old guitar effect from E&MM 
that uses a voltage divider to create a ground. The signal input and 
output shields ("ground" relative to the guitar signal) are connected to 
the V- of the circuit. Since it's powered by a single 9v, the circuit is 
powered by +/-4.5v. Of course, this analog. Not sure what the equiv 
would be for digital except some input signal buffering and offset.