How do I add a depth control to this circuit?

[Marc.yo]

It's the kay T-1 tremelo circuit and I'm wondering where to add a pot so there will be a depth control on it.

[petemoore]

  Mixing clean with the tremolo is an option.

[Marc.yo]

If I remember correctly, when I asked this on a different forum, someone told me it should go between the two transistors that are hooked up through their emitters and collectors. I can't remember though.

[Marc.yo]

BTW, I made the link work. It had the wrong link. 

[Marc.yo]

Found the old post. link!

[Sir H C]

You could put a 100k off the emitter of the top or bottom transistor in that series set up.  Then that would limit how much it could pull down thte output.