Phase issue

[pardonmybass]

I'm looking for a way to be able to blend a signal pre and post effect. How can I do this without phase cancellation?

[psychedelicfish]

http://geofex.com/Article_Folders/polarity_reverser/polarity_reverser.htm

[blackieNYC]

The reverser is great.  If this is an fx looper, make it switchable like the schematic. But- if you are talking about 1 specific effect, see if it inverts phase first.  You could skip the inverter altogether.  It has been said that the odds are your effect pedal is in phase. Or maybe it's a circuit not a pedal.   I guess I you don't have a scope, or a mixer, or a schematic, to see if you effect flips phase, you might just have to build the inverter.
If they are out of phase you will lose some bass., if not everything.

[pardonmybass]

Thanks

I was told that something called a summing amp would do the trick. What's the deal with those?

[GibsonGM]

Thanks

I was told that something called a summing amp would do the trick. What's the deal with those?

Nah, use the Geofex circuit if your signals are out of phase.  You need to really flip the signal, not mix it, and that one is selectable rather than 'hard-wired' to just invert. 

Perhaps the comment was meant for how you're going to recombine them?  Then of course the summing amplifier will do that, it's what it's for.   As stated, first you need to know if the signals are out of phase.  Look at the schematics.  Consider the phase shifts introduced by gain stages and capacitors...you can just throw the signals into the summer and listen, too.   

You'll probably notice if they're not in phase!

[moosapotamus]

You can also use a transistor set up as a phase splitter, something like this...

http://electriciantraining.tpub.com/14180/css/14180_40.htm

...then just use a toggle switch to select either the inverting or non-inverting output.

You can see one used in a complete design here...



Q3 is the phase splitter.

~ Charlie