[font=trebuchet ms]I used to have a Boss OC-2 so I can vouch for the mix controls on that. The Danelectro pedal I have now also has this feature. Both of these units allow you to blend the original signal with the effected signal at any balance you want, including shutting off the original signal and passing only the octave-down sound. No problem. I haven't used anyone else's octavers, but I would expect to find that they all have some way to do what you're asking for.[/font]