Blend control

I'm wanting to build an overdrive pedal with a knob to blend the clean signal back into the overdriven one. (Like the Sparkle Drive) Should I put the blend before or after the level control? I'll be putting a buffer in the clean signal that is being blended.
Before the level control seems correct?
Am I wrong?
Thanks in advance!
-Foster

The only schematics I've seen for a blend have tied in before the level knob.

I´m looking at an old digital reverb rack effect from where I am sitting.The last knob says "output".The one before that says "direct/reverb.It is as Justin says.Blend them first to get the right sound,then set the output level.

Alright that makes sense!
Should I include an effect level AND master level? (controls would be Gain, Tone, Effect Level, Clean Level, Master level)
And do you have any of those schematics?
Thanks!

Found this schematic a while ago and thought it was interesting.