Build effects in stereo

[letsgocoyote]

Building a stereo effect requires duplicating the circuit twice, does it not?  My question is thus:  if I want to build a mono in, stereo out effect, will I need to use some sort of buffer up front, or can I just run both ins of each stereo effect channel from the same source?
will i need to use a 4pdt for bypass?
this is the first ive considered a stereo effect.

[dano12]

Not necessarily duplicating the same circuit twice... Many modulation effects, say chorus and phasers, can send out a stereo spread without duplicating the primary circuit.

If you split your mono signal into a buffer, and then build two of the same effect, the result is certainly two channels, but I doubt there would be much interesting in terms of stereo spread.

One that's in between is a stereo panner: http://www.schematicheaven.com/effects/ibanez_st810_stereopan.pdf

4PDT is the way to switch it if you want true-bypass. That or use a buffer.

[letsgocoyote]

ah i see what your saying.  i guess i should be more specific abotu what i want to accomplish.

using some sort of filter (liek the dod 440 in this case) hooked up to an LFO you get a neat modulated wah sound (which I have done before).

so what i am wanting to do is make it a stereo effect. the lfo i used before is able to send out opposing pulses from two seperate LEDs, one coming off an npn and one off a pnp transistor.  so as one led lights, the other fades.  ive used this lfo in mono form for the modulated wah sound (just hooking up to the vactrol of a 440 instead of an LED).  so i am thinking it would be cool make it stereo, that wya while the left channel is at the treble end of the sweep, the right channel is at the bass end up the sweep.  coul sound very cool i think!

but i would like it to be mono input.  so would i go:

              /--------buffer------left channel
guitar----|
              \--------buffer------right channel

would I be using one or two buffers?

[dano12]

ah i see what your saying.  i guess i should be more specific abotu what i want to accomplish.

using some sort of filter (liek the dod 440 in this case) hooked up to an LFO you get a neat modulated wah sound (which I have done before).

so what i am wanting to do is make it a stereo effect. the lfo i used before is able to send out opposing pulses from two seperate LEDs, one coming off an npn and one off a pnp transistor.  so as one led lights, the other fades.  ive used this lfo in mono form for the modulated wah sound (just hooking up to the vactrol of a 440 instead of an LED).  so i am thinking it would be cool make it stereo, that wya while the left channel is at the treble end of the sweep, the right channel is at the bass end up the sweep.  coul sound very cool i think!

but i would like it to be mono input.  so would i go:

              /--------buffer------left channel
guitar----|
              \--------buffer------right channel

would I be using one or two buffers?

I'd imagine that it would work fine with just a single buffer, but breadboarding it would be the best test. Have a buffer in mind yet? I've had great success with Jack Orman's jfet buffer. Here's what I use:



The modulated 440 idea sounds very cool!

[letsgocoyote]

ill have to give it a shot then!  thanks dano!

[frequencycentral]

using some sort of filter

What does sound cool is panning lowpass and highpass outputs of the same filter - lowpass to the left, highpass to the right. When the filter sweeps it also creates frequency panning. Its pretty easy to get a highpass output from a lowpass filter by mixing the source signal with the lowpass filtered signal into an opamp buffer, you just need to tweak the relative volumes to unity. Providing they are out of phase, the low content from the filtered signal will cancel the low content from the source signal - hey presto - a highpass filter. This is how many synth multimode filters work, such as the Oberheim SEM.

I've been thinking of a stereo vibrato, the doppler effect may sound similar to a Leslie. I pretty much decided I would need a 3PDT plus a Millenium bypass, as I don't have a ready source of 4PDT.