a quad panner?

[paguitarist]

Hopefully one of you can help me with this. I was listening to a Pink Floyd bootleg of Money from the Animals tour, and David Gilmour's guitar was panned through the quadrophonic PA so that it swirled around the audience. Anyway I was wondering if any of you know of a schematic or a way to build a pedal that can pan across 4 different amps so I can achieve that effect. Any and all help would be appreciated.

Thanks

[Paul Perry (Frostwave)]

Normally,  I believe one uses four voltage controled amplifiers.
And one arranges the joystick (which has two pots, for X and Y)
to control two normal panning circuits.

Call the outputs from these XL for X left, XR for X right, YF for Y front, YB for Y back.

Now you need four little mixers, so you can assign those outputs to the speakers:

XL + YB for the left back speaker.
XR + YB for the right back speaker
XR + YF for the right front speaker
XL +YF for the left front  speaker.   I think.

Now that isn't EXACTLY equal power mixing, but I thnk it will get you thrrough the gig.

traditionally in E-Music you do all this with four voltage controlled amps, in a kind of analog synth circuit.

[Paul Perry (Frostwave)]

Thinking about it a bit more, I think there is a cheap way to do it, without a joystick:

If you have two panners, then have one for L-R, one for F-B.

And now all you need, are four very simple 2 to 1 mixers for assigning the two L-R outs and the two F-B outs as in the post before.
In fact you could do all that in a 4 in, 4 out mixer.
Or in a 4 in 2 out mixer, if you can cheat & use the aux sends as two more outs.

[ambulancevoice]

try this
a few months ago, i asked around for a simple panning circuit
the one i had in mind would not have alowed hard panning
but luckily, Dann Green gave me his extremely effective and extremely simple hard panning circuit
so i used the same circuit, except to pan to four channels
here it is
sorry for the mess and image size
http://www.geocities.com/deathtomusicrecords/4amphardpanner.jpg

[StephenGiles]

Don't you need the VCA arrangement from an analog barberpole phaser whatever that is......
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[Paul Perry (Frostwave)]

Nice one, Dan Green & ambulancevoice! that's a 100K joystick I presume.

[Gladmarr]

I hope that's a joystick, otherwise, it looks like a dual ganged potentiometer.  That would be simply a four-output panner that's still stuck in L-R mode....

[Sir H C]

Occasionally you will see one come up on e-bay, from Neve or API that does the quad panning.  I have an old quadraphonic mixing console that uses the L-R and F-R arrangement.  The trick is that when you go F-R from the L-R you need to have two F-R pannings, one for L one for R.  Orban had a good one pot panner (thread somewhere here on it), so the second one could use a stereo pot and be cool with it.

[puretube]

Stephen: add one more: "quadrature"... 

[StephenGiles]

Don't you need the VCA arrangement from an analog barberpole phaser whatever that is......
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whatever


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whatever

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whatever

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[Mark Hammer]

I have a couple of scanned documents from POLYPHONY on my site that cover that.  http://hammer.ampage.org

[ambulancevoice]

eh, try a joy stick
i was using a dual gang linear 100k
you could use different amp out combinations so when you turn the pot the paning goes all weird
like, having speaker one at the back left, and two at the front right etc
so as you turn the pot (maybe in a wah enclosure?) it will pan into the different speakers blah blah

[RickL]

Most of the previous replies seem to be about manual panning. If the OP is looking for automatic panning I wonder if it could be done with three regular panners (4ms Pannuer maybe) run off the same clock signal?

P1 run at half speed, L output into P2, R output into P3. Just build three identical boards, use the half speed mod into P1 and normal speed into P2 and P3. If you want it (relatively) simple replace most of the controls, except speed. with fixed resistors. I wouldn't though, imagine turning the depth control and hearing the circle widen out or having soft panning left to right but ping pong from back to front..

I'm definitely going to have to try this.

[Paul Perry (Frostwave)]

http://www.wiard.com/1200/JAG/jag.html

commercial unit that ties in with an analog synth

[paguitarist]

I might try those, however what I was looking for was like an automatic pedal instead of a joystick controled one, so I could just turn it on and play the guitar and have it go from one amp to the next all in a circle.

[ambulancevoice]

555/556 timer maybe?

[Paul Perry (Frostwave)]

The simplest way, if you just want to go in a circle, is to have four light dependent resistors arranged as you would in a LED/LDR tremolo.
And a small electric motor arranged with a disc or cylinder with holes in it so that light falls on them sequentially.

[Sir H C]

Well you could get two stereo panners, but the curse is syncing the LFO for a 90 degree phase shift between the two.  There are some allpass networks (and Polyphase filters) that can create a relatively fixed 90 degree phase shift for two signals, ARRL has several in the old books, and so running the LFO through this would get you the needed LFOs for the two panning circuits, and then you should be all set.

[R.G.]

The setup is
Signal -> L/R panner (controlled by L/R pot)  : L -> F/B panner 1 and R - > F/B panner 2.

The simplest possible setup has to have two controls, a L/R control and a F/B control. A panner is usually a 1:2 setup, and you have four destinations, so you need three panners: one to pan left/right, and one each on left and right to pan that signal front/back. Or you could have one F/B panner and two L/R panners.

The simplest control is probably a joystick with a single pot on one axis and a dual on the other. The single controls the single panner and the dual controls the two other panners.

Panning circuits are shown at GEO: See "Panning for Fun", 7/22/06. A suitable panner can be made from one pot and one dual opamp, as shown in the first illustration.