Odp: [sdiy] 1/8th inch questions

[Tony Allgood]

> So why use a resistor on the output at all if the buffer opamp can
withstand indefinite short circuits?

They maybe able to withstand shorts, but in a modular it is quite
possible that one output may be connected to another. +10V on one output
meeting a -10V on another is very likely to sentence your little op-amp
to death.

I use 1K as standard since this it seems is what everyone uses....

On more CV lines like pitch CV I use the output resistor within the
feedback loop, and include a small value cap around the op-amp itself.

An example of which can be found on the schematic of the midiDAC on my
webpage.

www.oakleysound.com/mididac.htm

Unity gain buffers are harder to stabilise/protect. Bob Pease has a nice
section in his book about this if I remember correctly.

Regards,

Tony Allgood                       Penrith, Cumbria, England

Oakley Sound Systems                     www.oakleysound.com
Modular projects            www.oakleysound.com/projects.htm