Phantom Wah schematic?

[MR COFFEE]

Hi all,

Anyone out there have a schematic for the Phantom Wah?

You just put your heel on the back of it and move your foot up and down in the air, no rocker or anything. No longer made I understand.

Anyone played with one care to comment on it?

Thanks

[Paul Marossy]

Who made it? Hmm... that sounds a lot like the Z. Vex Fuzz Probe. I've never heard of the Phantom Wah before, though. 

[ncc]

Hi all,

Anyone out there have a schematic for the Phantom Wah?

You just put your heel on the back of it and move your foot up and down in the air, no rocker or anything. No longer made I understand.

Anyone played with one care to comment on it?

Thanks

A simple search on google returned this link.
Is this what you wanted?
(even comes with a PCB layout)

http://forum.musikding.de/gallery/displayimage.php?album=121&pos=0&PHPSESSID=bc3705eba4b56f2ae425798dc2fe7403

ncc

[Paul Marossy]

Well, it's a John Hollis project, eh? It's probably also at his website as well.

EDIT: It's also in the schematics section here at the forum! 

[MR COFFEE]

Hi Paul,

I can't remember a company - I think it was one of those one-product companies that came and went. It never caught on big, and I've never seen one in person.

I don't know about the Z. Vex Fuzz Probe - does it work on light or proximity? I got the impression the Phantom wah was controlled by proximity of the human foot to the plate (capacitance, I presume).

Hi RCC,

Thanks, but different animal of the same name. It wasn't a DIY project, and it didn't have a treadle that turned a potentiometer.

I read an interview a few years back of some guy who put one on his guitar with duct tape and worked it with his hands (like playing a bongo or something, I suppose). It was one of those "industrial" noise-maker type bands.

I read a review of one many years earlier (1980s somewhere - maybe in Polyphony or Electronic Musician?), and assumed from the description it used a capacitative sensor to control the VCO controlling a SCF (switched-capacitor filter) chip to create the Wah filter. From the picture it looked like a 1590 box with a smaller box attached to the narrower end of it by two (I presume, insulated) spacers. The smaller box was where you rested you heel.

I guess it's a nostalgia thing

I just always wondered about the thing, and I guess I just got the jones for a new schematic to study today .

Hasn't anybody here seen one or (I wish, I wish) have a schematic for it?

[John Lyons]

So the frequency is controlled by capacitance...Does this just work on the capacitance of you foot/body capacitance?

How dodes this thing work?

John

[ncc]

Hi RCC,

Thanks, but different animal of the same name. It wasn't a DIY project, and it didn't have a treadle that turned a potentiometer.

Thanks for the follow-up. I didn't expect there would be more than one "phantom wah" and
I was hoping to learn how it works (how to operate it);
unfortunately, this wasn't the one

[MR COFFEE]

So the frequency is controlled by capacitance...Does this just work on the capacitance of you foot/body capacitance?

That's the deal.

How dodes this thing work? 

That's why I was hoping to see a schematic. My best guess is in the post I wrote earlier.

Nobody here has seen one? Not even to play through?

[theblueark]

Sounds just like a wah probe:

http://media.zvex.com/wahprobe.mov

[darryl]

Check this out I found a Picture of it.

http://www.sonicflux.com/index.htm

D.

[darryl]

Scroll down the page to Phantom Wah     

D.

[amz-fx]

That's why I was hoping to see a schematic. My best guess is in the post I wrote earlier.
Nobody here has seen one? Not even to play through?

Somewhere I have a magazine with a review of the Phantom Wah, but a quick look through my archives did not turn it up. It was a commercial pedal available in the early 1980s and it's quite rare now.  I would love to have a look inside one.

-Jack

[MR COFFEE]

Hi darryl,

Nice pic - yup, that's the sucker!!! Notice it doesn't even have an on-off stomp switch.

Hi theblueark,

It's similar, but it sound like there are some differences, anyway.

The probe circuit generates a small (one or two inches high) "bubble" of RF energy at about a million cycles per second above the copper plate. As your foot or hand (or any wet or metallic object, for that matter) approaches the copper plate, the RF field is disturbed and the circuit reacts by increasing the brightness of an LED, which drives a photoresistive cell and controls the Z. Vex wah circuit. The wah circuit is actually the Seek-Wah sound circuit without the sequencer control. It's also the same wah circuit as the one in The Drip guitar that I make. The only difference is the boost circuit in this Wah Probe model.

Sounds like Zach converts the frequency shift into a control signal for a LED-photoconductor that controls the wah circuit. I'm not sure if this is how the Phantom Wah does it or not ('course it could be the same idea, but that's not the only way to do it - see my speculation in the previous thread above).

Hi Jack,

Somewhere I have a magazine with a review of the Phantom Wah, but a quick look through my archives did not turn it up. It was a commercial pedal available in the early 1980s and it's quite rare now.  I would love to have a look inside one.

Me, TOOO!!!!!

I was hope somebody around here had gotten one in to repair and got interested enough to trace it out.

I suspect there were two different RF field proximity sensors, since there was no on-off stomp switch like the version Zach makes; one that sensed when you put your heel on the back box, and one that sensed how close the sole of your shoe was to the main box.

I also just like to hear the experiences of anybody playing through one - or the Wah Probe, for that matter.

I wonder if the lack of a treadle to rock with your foot makes it hard to control or not, and whether it tires your lower leg out playing it for a song or so - or not. You could sure do those fast flutter Hendrix-y end-of-solo things easier than with a regular pedal.

Doesn't seem like it'd be a bear to design or anything, but would I like it if I did?

Nobody here played through one? Or Zach's version?

[Paul Marossy]

I wonder if the lack of a treadle to rock with your foot makes it hard to control or not, and whether it tires your lower leg out playing it for a song or so - or not. You could sure do those fast flutter Hendrix-y end-of-solo things easier than with a regular pedal.

I haven't tried a Wah Probe, but I would think that my leg would get tired rather quickly. But, OTOH, I wouldn't know because I have never tried one!

[theblueark]

I have the wah probe in fact. It's really neato.

If I place my heel right at the base of the plate, then it tires easily. The beauty is the versatality of this thing. If I place my heel further away, such that when my foot is down, only my toes plus a little of my foot touches the plate, I am able to do very quick wah-ing and my foot is better rested because I don't have to move it much to go from fully 'un%^&*ed' to fully '%^&*ed'.

If I want a more traditional wah sweep, I can place my heel closer to the base, and my foot will naturally create less of a sweep. The starting point of the sweep can also be adjusted this way. Because the closer my heel is to the plate, the more I'm affecting the RF bubble already, and hence putting the wah in a slightly 'half %^&*ed' position.

The wah probe is definetely capable of faster wah-ing than the normal wahs. You can wah as fast as your feet, or even your fingers can move. Maybe only a wah with the 'woodpecker' mod, or something like the behringer or morley wahs can come close.

[The Tone God]

If you would like this type of wha depends on what kind of wha player you are.

Some players like to put their alot of their weight on the pedal trying "balance" themselves on the rocker shaft. With their weight on the shaft very little movement or effort is needed to cause a change. Other players put very little weight on the pedal instead placing their foot on the rocker gingerly and using their ankle joints/muscles to rock the pedal.

The lack of mechnisim would probably throw off the first group but almost be beloved by the second.

Also how they wha is normally used would affect the preference. If there is alot of quick swinging then they would probably like it. If on the other hand their is little swinging but instead an emphises on one area of the sweep wagging the foot in that spot everytime could become anoying.

There is also the lack of removing the foot and having the pedal hold its posistion which some players enjoy.

Andrew

[soggybag]

This questions has come up a few times on the forum. I have even brought it up myself. I had been thinking aout this for a while and I suspect that this could be done with a PLL. Using the phase detector. If I understand correctly the PLL can produce a control voltage based on the difference between two frequencies.

[Paul Marossy]

Other players put very little weight on the pedal instead placing their foot on the rocker gingerly and using their ankle joints/muscles to rock the pedal.

That would be me. 

[MR COFFEE]

Hi thebluearc,

Thanks for the description of the wah probe playing "feel". Sounds like it is most suited to intense rhythmic effects than the Hendrix-y tone shaping, correct?

Obviously, you can't do the fixed position thing, but can you get a "vocal" thing without the feedback of the pedal to help you stop your frequency sweep when it gets to the right point?

Hi Soggy,

I would think a simpler approach would be to use a fixed pulse width and then integrate it to derive a dc control voltage. As the frequency goes down, the control voltage decreases - less frequent pulses average out to a lower voltage. An inverter would give you a rising control voltage as your foot approaches the plate. PLLs are more oriented to locking on to a particular frequency.

[theblueark]

You can get the shaping done, but It's not as stable as with a normal wah. Becuase my foot has to be left at certain positions if I want to do subtle tone shaping. Maybe some other people can do it, but when I leave my foot like that it tends to wobble a little and it's quite hard to make small controlled movements.

Obviously, you can't do the fixed position thing, but can you get a "vocal" thing without the feedback of the pedal to help you stop your frequency sweep when it gets to the right point?

I don't really understand this question, sorry can you rephrase it?