Input and Output buffer design

[burningman]

Aside from placement in a rig. Can anyone explain to me what differentiates an input buffer from an output buffer? Are there any technical considerations to look at?
Jack Orman (AMZ) notes usage of Jfets for input buffers and bipolar transistors for output buffers. Aside from this note, I have not heard of any component differences between the two types of buffer applications.

[JKowalski]

Aside from placement in a rig. Can anyone explain to me what differentiates an input buffer from an output buffer? Are there any technical considerations to look at?
Jack Orman (AMZ) notes usage of Jfets for input buffers and bipolar transistors for output buffers. Aside from this note, I have not heard of any component differences between the two types of buffer applications.

They aren't really any different in theory. Input and output buffers essentially both do the same thing. However, in some cases you might want a very high input impedance, and in that criteria JFETs are superior.

[Processaurus]

Boss for instance seems to favor JFET's for input buffer's and BJT's for outputs: the JFETs for the reason above, and regular transistors for being able to drive higher loads (or even possibly because they are cheaper, but perform well in that position?).  The JFET's are fine for either, as instrument inputs and even modern mixers don't present a low enough impedance to demand heavy lifting in the current department. I've noticed the JFET buffer at GGG sounding nice in the circuits I've grafted it onto, including some buffered bypass pedals.