Blender: Bypass necessary?

[insomniac2295]

So, I'm thinking of building a splitter/mixer to blend my bass with my various distortion pedals. I'm looking at this JFET Parallel looper- http://tagboardeffects.blogspot.com/2010/11/jfet-parallel-looper.html
My question is- if I don't include a bypass switch for the blender, will I experience a potential volume drop when the blended effect is disengaged? For example, say I'm blending my clean signal with a fuzz, with the fuzz at unity. When disengaging the fuzz circuit, while still having the blend circuit running, will could there be a volume drop?