would a buffer distort?

[kvb]

Some time ago I posted a question about buffers, because I was confused by the fact that the mosfet boost can be used as a buffer and the mini booster has a buffer after the fets (no response). Now I know that these are two different scenarios for a similar but different purpose.
I've read enough to have a relatively solid grasp on the purpose of a buffer. (high z in > -unity g- low z out >)

The question is: If the buffer is at the end of the fx chain and one of the effects is a booster does the buffer distort, or does it send the boosted signal along on its way at this higher level unchanged?

If so, then one could make a bypass box with a buffer going out to the fx (send) and another buffer at the fx in (return) and have everything connected at this single junction.

[Transmogrifox]

The issue with the buffer is headroom.  Typically an op amp buffer would not distort unles your booster pumped the signal level to the rails itself (in which case it would probably be distorting anyway).

If you want to guarantee the buffer does not distort, then use a supply voltage that is much larger than the highest supply voltage in your FX chain.  For instance, if you are using all 9V pedals, then use a 15V supply for your buffer.

For most of the boosters I have seen, you don't need to worry about it.  Just use a 9V supply on your buffer as well.

For JFET and BJT source/emitter follower type buffers, you'll have some distortion at high signal levels no matter what.  These circuits are only considered linear for small signals.

[kvb]

sounds like it would be a FET based buffer for the beginning of a chain and a Super buffer for the end.
I can get tl072s at the local elec-store. 

[Transmogrifox]

If you're doing this as a looper in a single box, then use the TL072 for both  beginning and end of the signal chains.  You have 2 opamps in the TL072 package---just as well use both of them.