Ludwig Phase II Clone Tech Notes

[R.G.]

R.G., don't get bent out of shape with sliders, pots, switches, etc. Personally, if one is to create his/her clone, just offboard wiring from the board would be the best option. They can create their own control scheme then. Let's keep it simple.... and compact.

Yep. That's why I stopped.

[pinkjimiphoton]

i agree too...unless we're gonna get some chinese company to clone them commercially, there's no need to try and make an exact clone.

we only need to make a work/soundalike...then figure out how to improve on it. 

[pinkjimiphoton]

bumpage...any news, keppy? r.g.? dino?

[Keppy]

bumpage...any news, keppy? r.g.? dino?

I've collected (almost) all the parts for the build, but I'm heading out of town tomorrow, so I won't start building until the end of the week sometime.

You know how you always fail to order one essential part? I'll be looking for a B5K long shaft knurled pot while I'm in KC...

[digi2t]

You know how you always fail to order one essential part? I'll be looking for a B5K long shaft knurled pot while I'm in KC...

Yup... kinda like forgetting the can opener when you go camping 

It's been pretty loose on my end. Thanks to R.G., I've been investigating the principles of formant filters. Been working on the Colorsound Vocalizer in the meantime, checking out a EH Talking Pedal, and the new EH Talking Machine.

It seems that this Phase II project has sent my tone interests into a whole new dimension.

Now I just need to find a new place, where I can unpack all my gear, and get back down to business!!

[pinkjimiphoton]

cool, cool...thanks for the updates!

yah, i wish i understood a bit more about it, but rg's got my head spinning, too...trying to find a busted crybaby  or volume pedal so i can get it going on that vocalizer.

my phase II i've decided i can live with at this point, so for the moment, unless someone needs me to take pics voltage readings or whatever, it's chilling.

i AM gonna use it live, too, i've decided...depending on the gig. i've gotten addicted to it!!

keppy...can't wait to see what ya come up with, cuz i'd rather build a clone to take to gigs than the real mccoy!

anyways..be well my friends, talk soon..

namaste

[R.G.]

For added fun, when you get your parts for the colorsound, temporarily hook up individual pots to the formant filters and play with them. The combinations of the filter frequencies can hit all the human vowels, but the way the controls are hooked up on that can only hit a few of them because of the "path" the controls take. by dinking with the controls individually, you can hit them all.

[pinkjimiphoton]

i may just do that, r.g.....i just got a cheap pos pyle wah pedal on amazon shipped for like 23.90....so i figure i'll gut it, and add some pots to it, maybe a couple switches to have some "presets".

this is gonna be a blast, and a lot of fun!!

[digi2t]

Hmmm, once the different combinations are figured, would it be possible to use a rotary switch to flip between different vowels? Actually, I'm asking this question not only on my behalf, but Erik as well. New member, he's trying the build as well.

Or maybe a dual pedal setup (with ganged pots), to sweep through the vowels. 

Or maybe I'm just plain nuts 

R.G., god damn you. Now I won't be able to sleep tonight! 

[pinkjimiphoton]

i'm thinking maybe measuring some pot values, and adding a remote box with a couple foot switches mounted in it that plugs into the wah wah shell
so you can switch the values and get anything ya want?

this could be VERY sick!!

[R.G.]

Hmmm, once the different combinations are figured, would it be possible to use a rotary switch to flip between different vowels? Actually, I'm asking this question not only on my behalf, but Erik as well. New member, he's trying the build as well.

Yes, you can flip between vowels with a rotary. The combinations are here:http://geofex.com/Article_Folders/sing-wah/sing-wah.htm
See that chart? You want to try to hit the middle of the regions, perhaps fudge them a little to taste. That was taken from a similar chart in the book "Speech Synthesis" by Bell Labs, 1963. I believe it was actually from earlier work at Bell Labs. Neat book. I've always been a little surprised that no one followed up on that chart and the info in the article with a commercial product. Although I do admit that fixed filters like the schemos suggest are a little tough to get working right... 

For reference:
oo = 250,800
aw = 600,800
ah = 900,1300
uh = 800,1700
ae = 900,2100
eh = 700,2500
ih = 450,2800
ee = 300,2800
er = 500,1800
where all the "=" are approximate, and guesses, but near the centers of the regions.

If you graph that, you can see, the "path" for the frequencies of the formants are non-linear for both F1 and F2. That's pretty much why the Ludwig does an alternation between only two of them, as in ee-oh-ee-oh, or other pairs depending on how you adjust the relative responses of the formant filters. The control voltages of the Ludwig are linear ramps, not able to follow the paths for hitting most of the vowel regions.

That's what I've been doing - messing with opamps, breakpoints, waveshaping, etc. to make control voltages that send a pair of filters through as many of the vowel regions as possible. I *think* I have the "outer loop" (oo-aw-ah-uh-ae-eh-ih-ee) down pretty well. I need to mess the hardware some more to be sure I have a good fit on the center and range of the filters as well as the control voltages to get a foot rocker to sweep that range. That's what I was blathering about in some of those earlier posts.

It was a tossup whether I did it with opamps or programmed a microcontroller to put out a pair of PWM'd DC control voltages. That last had the advantage that I could stick the info in a table for what vowel targets came in what order, but had some other complications. In the end I went with opamps.

Or maybe a dual pedal setup (with ganged pots), to sweep through the vowels. 

The old Fender fuzz-wah had a dual-axis rocker which let you rock fore and aft as well as twisting. However, the problem is that not all combinations make vowels. The brain only recognizes the certain regions and anything off the combinations just sounds like tone-controlled music, not vowels.

Or maybe I'm just plain nuts 

One of my favorite aphorisms is that a monstrous mind is a toy forever.

R.G., god damn you. Now I won't be able to sleep tonight! 

Welcome to the village of the damned.   

[pinkjimiphoton]

as always, bro, you have blown what little is left of my mind...i'm surprised there's anything left!

are you gonna eventually post this creation? cuz man, i'd sure love to build it!!!

[R.G.]

Will I post it? Hmmm... maybe. It's gotta work first.   

[pinkjimiphoton]

DUDE! I GOT FAITH IN YA!!! 

[pinkjimiphoton]

r.g., i have a question...is there any way to make the modulation of the formant filter SLOWER? i'd love to get it down on the slower settings to about half the speed it is now.
could i replace one of the caps with one maybe with 2-3 times the value to make it slower? or am i barking up the wrong tree? it'd be great to be able to make it sweep really slow.. i have a feeling it would make the treadle more expressive, too.

[R.G.]

Sure. It's a little clumsy because of the way they did the modulation, but do-able.

C2, C6, and C12 on the console board control various aspects of the modulation speed. C2 (1uF) controls the basic rate of modulation. It sets how fast the basic "tick" of the thing works. C6 (1uF) sets the slew rate up and down on the formant control sweeps, and C12 controls in a gross fashion the size of the signal to the formant sweep. Doubling all of those should cut things down by half.

For slower pedal expression, just doubling C6 will do a lot. It will also make the modulation move less fast, but not do anything about the time between when it changes directions.

[pinkjimiphoton]

hmmm, sounds like c6 is the one to change...it may be blasphemous, but i'm thinking of maybe doing a couple mods to the pedal, as it's in far from pristine condition already..

so maybe putting c6 and a double sized version on a switch would be cool. the other thing i'm thinking about is adding a momentary switch to the animation pedal, so it can be just stepped on occaisionally  and only engages the modulation...and the ramping effect...while the switch is depressed.

or maybe i should just chill til the clone gets realized...

too much coffee...the world is wobbling nicely!!

[digi2t]

If you mean slowing down the RATE, then trimmer R4 on the console board should do the job for you. I've played with that one, and it moves the hi/lo range of the Rate. If you slow down the Lo, the Hi will come down with it, and vice versa. Expanding the range will require a mod, but moving the range, try trimmer R4. Pretty sure it's that one.

IF.... that's what you mean 

[pinkjimiphoton]

that IS what i mean...i'll try it later!! thanks dino!!

tho it would indeed be nice to adjust the usable range some, for sure!!

[artifus]

switchable parallel cap of same value?