[sdiy] buffer opamp configuration [was: 1/8th inch questions]

[Grant Richter]

> Now here's a point which I haven't quite worked out yet .. how to get the
> required current limiting / short circuit protection when using a unity gain
> buffer.  It seems to me that by using configuration (b) and connecting the
> output jack to the inverting input of the opamp, then the feedback resistor
> will act as a current limiter.  However, this sounds a little wrong to me
> (running an output directly from an input - static discharge could damage
> input, other reasons I can't think of?) .. probably it's better to use 2
> resistors in the feedback loop and connect the output jack to the node between
> the resistors?  I'd welcome any comments on this ...
> 

This is exactly what Chris Macdonald and I did for the outputs of the unity
gain buffers for the Mini-Modular (http://www.minimodular.com) MIDI to CV
converter. Using two 1K resistors with output taken from the center tap.

Works fine, doesn't blow up.