DIY Ping Pong Effect

[Ofek Deitch]

Hi,
Does any one remember that cool part in Led Zep's song "What is and What Should Never Be", where Jimmy Page plays in about 3:30 a riff that goes from left speaker to the right?
Is it possible to build this kind of effect into a pedal? If I'm not mistaken it is called Ping Pong Effect.

I thought it would be really cool to make maybe an a/b switcher that is actually a "blend" effect built into a wah pedal that is connected to two different amps or has a Stereo out, and the treadle will play with the blending - When your heel is all the way up you only get signal from the right, and heel down is only left, and then you can sweep in between! 
Is this possible?

You can also add another section to the circuit that does the blending effect automatic, just like an auto wah !

[psychedelicfish]

I may be mistaken, but isn't that just a stereo panner?

[Brian_L]

I just did something similar with a stereo tremolo pedal.  (stereo panner)

It uses an LFO and an inverting opamp to give me leds that blink back and forth, then I just used a tremulus style circuit and split it before the LDRs.

one goes to each amp. Sounds so sweet! The LFO is the TAPLFO from Electric Druid. It really has a phasery/vibey kind of thing with some settings.

[Ofek Deitch]

Ok, so I just found out that, apparently, ping pong effect is just a stereo delay.
I'm not trying to make this sort of effect - I just want to pan the signal from left to right using the treadle

[wavley]

Ok, so I just found out that, apparently, ping pong effect is just a stereo delay.
I'm not trying to make this sort of effect - I just want to pan the signal from left to right using the treadle

http://www.effectsdatabase.com/model/morley/telray/pvl

[Mark Hammer]

Do you want that exact effect, or is that simply an example of something like what you're imagining?

[defaced]

Might be worth looking at for reference: http://buildyourownclone.com/effects-pedals/soaringskillet.html

[R.G.]

http://www.geofex.com/Article_Folders/panner.pdf
Replace the pan pot with a fixed resistor and a CMOS switch to analog ground at each end and drive them out of phase; or use 1/3 of a CM4053.

[midwayfair]

Anderton Stereo Trem.

There are other effects that could be adapted, but that's an existing and venerable project.

You could also repurpose any of the harmonic tremolos posted recently to be stereo instead of summing at the output.

[gritz]

Any auto-thinger may be nice for an afternoon, but without knowing the tempo of the song you're playing it might get old pretty soon after that.  

http://www.geofex.com/Article_Folders/panner.pdf

Take a look at the last illustration in the pdf - the one entitled "pan between outputs". A wah shell, or volume pedal, or MIDI keyboard expression pedal with the original potentiometer replaced with a 10K linear pot will do the job of the 10k pot in the diagram and should provide a big enough home for the circuit board, battery and jacks. I'm not sure why the first opamp has a 100k resistor in it's feedback loop rather than just being directly wired (it's a simple unity gain buffer after all), but hey ho. Hope this helps.

[lespos]

Take a look here http://www.spinsemi.com/forum/viewtopic.php?t=104&highlight=ping+pong+delay This is FV-1 chip based delay.

[Ofek Deitch]

So far R.G's Output Panner and that Morley PVL Panner look like they can provide me the effect I'm looking for.
Has anyone made one of these before?

One problem though - I have only one amplifier..

[mistahead]

Unless its a stereo amp with dual cabs you're going to end up shitouttaluck mate.

See this is the killer issue when stepping to stereo - do you sacrifice the stereo on stage (as its trivial to record stero DI) or start upping the ante on your gear.

I'd replace the amp with a good stereo PA, DI to it and rent out plug'oles in the PA to bandmates to pay it off 

[Ofek Deitch]

I have a friend which I can borrow his amp to try this thing out once it's done.

[R.G.]

Has anyone made one of these before?

I incorporated a variant of the panner into a commercial product. It's an adaptation of an application note from the National Semiconductor Audio Applications Handbook from about 1975.

You would want the variation to the right of the circuit inside the box. It says "pan one signal to two different places". The signal source at "A" needs to be low impedance, so you may need to put a third opamp as a buffer before "A". Note that the pot needs to be linear taper.

An interesting variation would be to use two dual opamps and use the fourth opamp to make the output of one of the signals fully differential. This would let you get rid of some hum problems in many situations.