Wah-wah-yaow-moe-pedal question. I mean, auto-wah.

[JimRayden]

The thing I'm looking for, is simple -- a great show. I'm looking for whacko pedals to make it simpler to make the people go "woah!".

Should one want to spend a little less time thinking about foot movements, and a little bit jore time thinking about note choices, though, withing the context of an "automatic" device, the dual filter thing, as I laid out with Sean's help, can yield some really interesting possibilities.

Yes, and actually I'm not used to controlling a wah-pedal. I just happen to have one hanging around. I actually would feel much more comfy with a real mad talk-generator I could switch on.

How random would the double-Q sound?

Also, how difficult would it be modding one of the channels to an LFO-controlled one? (I feel another tutorial coming up. And a schematic. )

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Jimbo

[puretube]

for the late-comers:
http://diystompboxes.com/sboxforum/viewtopic.php?t=31274

http://diystompboxes.com/sboxforum/viewtopic.php?t=28585

[JimRayden]

Ye that double-manual-wah of mine is still a pending project. Haven't got the time yet.

Time passed on and I dropped the idea of total manuality and now I'm looking for a more randomally talking box to pull off some cool solos. (and to cover my crappy playing )

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Jimbo

[JimRayden]

Hey, are those P3, P7 actually 500 ohm pots? And what are P4, P5?

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Jimbo

[Mark Hammer]

Hey, are those P3, P7 actually 500 ohm pots? And what are P4, P5?

P3 and P7 are optional pots that will serve to increase the attack time.  The 47R resistors make the attack pretty damn fast.  I'm in the midst of putting one of these together right at this very minute since it's pretty easy to perf.  I've gone with 47R alone for the lower filter but will stick in the pot for the upper filter.  The idea is that  different attack and decay times for the upper and lower filters will mimic formant production.  Say the word "Are" to yourself very slowly and pay attention to how your mouth moves.  You will note that there is an initial low formant as your mouth moves into shape that seems to decay quickly, with a slight movement of an upper formant as you bring the sides of your mouth together to make the R sound.  It's that asynchronous aspect of the filters I'm trying to mimic.  My hunch is that being able to tinker with attack and decay in the upper filter is more important for producing different sounds than tinkering with the same parameters in the lower filter.  I suppose it is an empirical question and if I can post samples, maybe you can decide if it does what you want.

The others (P4, P5) are required trimpots, as found in the Dr. Q, Dr. Quack, Nurse Quacky and Baseballs.  These can be left as trimpots on the board OR can be panel mounted as filter-tuning controls.  In the Baseballs they seem to have some useful range whereas in the DQ they are only useful for about 30-40% of their range.  I leave it up to you.  If you feel like it, panel mount the attack and range controls for the upper filter and leave the lower one as a kind of preset.

Note that this will ALSO do conventional auto-wah sounds with some options not available on the Baseballs (mixing) but with others absent (fuzz).  The Baseballs I made for myself uses panel-mount pots for tuning each filter section, and that yields a much broader palette of sounds than the original does.  Adding some time-stagger as well as some centre-frequency stagger will be sure to expand that palette even more.

[Mark Hammer]

Hey, are those P3, P7 actually 500 ohm pots? And what are P4, P5?

P3 and P7 are optional pots that will serve to increase the attack time.  The 47R resistors make the attack pretty damn fast.  I'm in the midst of putting one of these together right at this very minute since it's pretty easy to perf.  I've gone with 47R alone for the lower filter but will stick in the pot for the upper filter.  The idea is that different attack and decay times for the upper and lower filters will mimic formant production.  Say the word "Are" to yourself very slowly and pay attention to how your mouth moves.  You will note that there is an initial low formant as your mouth moves into shape that seems to decay quickly, with a slight movement of an upper formant as you bring the sides of your mouth together to make the R sound.  It's that asynchronous aspect of the filters I'm trying to mimic.  The attempt to create two "filter events" that do not move synchronously but occur together close in time.  

My hunch is that being able to tinker with attack and decay in the upper filter is more important for producing different sounds than tinkering with the same parameters in the lower filter. I suppose it is an empirical question and if I can post samples, maybe you can decide if it does what you want.  Note as well that the added series resistance of an attack control alters the amount of drive available - longer attacks do not sweep quite as wide due to the current limiting of the added resistance.  In some respects, that can also be treated as a plus since the two filters will not sweep equally, further expanding the discrepancy between the two "formants".

The others (P4, P5) are required trimpots, as found in the Dr. Q, Dr. Quack, Nurse Quacky and Baseballs.  These can be left as trimpots on the board OR can be panel mounted as filter-tuning controls.  In the Baseballs they seem to have some useful range whereas in the DQ they are only useful for about 30-40% of their range.  I leave it up to you.  If you feel like it, panel mount the attack and range controls for the upper filter and leave the lower one as a kind of preset.

Note that this will ALSO do conventional auto-wah sounds with some options not available on the Baseballs (mixing) but with others absent (fuzz).  The Baseballs I made for myself uses panel-mount pots for tuning each filter section, and that yields a much broader palette of sounds than the original does.  Adding some time-stagger as well as some centre-frequency stagger will be sure to expand that palette even more.

[JimRayden]

Any news?


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Jimbo

[sean k]

Hey Mark,I'm about to turn 43 in a few days,and though I haven't been into this for that many years I can still appreciate what it was like in the old days when there wasn't an internet for sharing of information and relative skills but I did learn early that giving away knwledge and secrets is the absolute best way to learn more as the people you give your ideas to come back with their own original perspectives and help one to avoid complacency.Anyways I've got my own PCB drawn up,not inked yet though,and have it down to 65mm x 70mm and also found some nifty switches that will be used for the range.They are of the type that make 6 different on off connections and can be used as 6 different voltage dividers instead of P4 and P5 and as they look like slider pots then range will be easier to see at a glance.Actually they might work well for R13,P3 and R15,P7 as these too will be easier to understand in slider format.I'm also going to try and find a 250kB dual pot to use as the balance pot instead of two individual pots.I'll put resistors accross the legs to semi log the "reaction" and hopefully I'll be able to calculate the resistor values to get an even volume sweep accross the two outputs and not have either a dip or a peak where the two crossover.Maybe this setup "on the roof" of the effect will make its workings within more ergonomic as to available outcomes...

[Mark Hammer]

I've got it all perfed (last decent drill bit snapped, so perf it is :cry: ), but like many perfed projects, first go is a no go.  Took a bit of twiddling to realize the FET was in backwards.  Turned that beast around and found acceptable envelope signals coming out.  Unfortunately, I'm not getting acceptable audio just yet.  Soon...I hope....soon.  Ran out of TL074's so I have an MC3403 in for the moment.  Tried it with an LM348, but that didn't change anything.

Thought the chassis bviously is rather unfreindly to the number of controls I'd like to have, I was surprised by howeasily the perfed version cold fit in a 1590B  I stuck with Sensitivity, Low Filter Level, High Filter Level, and High Filter Attack controls.  I left the low filter envelope fixed, and kept the tuning as trimpots...for now.  I *might* move the upper filter trimpot to a chassis mount.  First I need to get the damn thing running and see/hear what difference it might make.

[JimRayden]

Lol, I'm starting to think there's someone more attached to this project than me.  :lol: Anyway, get those clips ready as I'm really anxiously waiting to hear it.

Don't be modest on those clips, show the circuit's full potential.

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Jimbo

[Mark Hammer]

Lol, I'm starting to think there's someone more attached to this project than me.  :lol: Anyway, get those clips ready as I'm really anxiously waiting to hear it.

Don't be modest on those clips, show the circuit's full potential.

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Jimbo

You might be right about that!  :lol:

BTW, not to take anything away from Sean's above-and-beyond-the-call-of-duty drawing, but there is a missing resistor.  The input buffer shows only a 1M resistor between drain and gate.  There should also be a 1M resistor between gate and source/ground.  Other than that, seems as error-free as my verbal description allowed.

If I can get it running, I'll be sure to include comparison samples of a Dr Quack, a Bi-Filter Follower, and a modded Baseballs.  As helpful as samples can be, often by the time you've opened up another file to hear pedal B, your memory of the tone of pedal A has drifted a little.  Some attributes are still well-preserved in memory, but others have blurred in the 5 seconds between.  Immediate comparison is a nice way to draw attention to differences.

[JimRayden]

Cool.

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Jimbo

[sean k]

Oh,so there is...oops,bit too quick off the mark,eh!(NPI), but I've had a look at my inked but not net etched PCB and theres room to put one in on the bottom of the board from the gate to some spare earth nearby.Thanks for that Mark.I'm still a few days off on mine as I'm doing a 2540 trip looper and getting really excited about making knobs and boxes and forgetting about schematics sooo fast!

[JimRayden]

Any news? With every day of you debugging it, I'm getting more and more scared of building one.

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Jimbo

[JimRayden]

Bump.

Just keeping the topic in your face until you finish

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Jimbo

[Mark Hammer]

My wife's new mobo install took priority last night, and may do so again tonight if I can't fix the screwup with the ethernet connection

[JimRayden]

Family comes first, take your time.


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Jimbo

[JimRayden]

Phew, that was close. Almost fell into the dark depths of a place called The Second Page  :roll:

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Jimbo

[JimRayden]

Knock-knock.


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Jimbo

[Vsat]

Hey gang,
Here's a very capable vocal filter.. produces a succession of vowels under voltage control:

http://www.oldcrows.net/~patchell/vocalfilter/vocalfilter.html

(watch the wordwrap)

With a bit of work can probably be made to fit into a Hammond 1590DD!!
Cheers, Mike