Looking for auto-wah (with LFO) suggestions.

[strungout]

Hey, as the title says, I'm looking for a cycle-wah to build.

I already have some ideas of some wahs I could just tag an LFO on, but hit me with up with your favorites, I'll check 'em out and maybe find a sound I like better. I thought about deadastronautfx's Pendulum Tremolo. Just remove the tremolo part. It sounded good when I was messing with that circuit. There's the Karate Shop (Harmonic Energizer) too. I remember Mark Hammer making one with an LFO...

Anyway, looking for suggestions!

[blackieNYC]

https://www.diystompboxes.com/smfforum/index.php?topic=119927.0
I built this and it is great.
As Garcho suggests in the thread, I did put a simple compressor on the output to level out the resonant peaks. I used an orange squeezer but any very simple compressor would do. I think any filter with an LFO would improve with this. 
I like the random LFO. It sounds just like someone is operating your wah for you.

[ElectricDruid]

I support Blackie's suggestion!

The FilterFX is a design I'm pleased with. The filter is simple and quiet, and the StompLFO gives the pedal a lot of options beyond the typical, including tap tempo. Plus you can add a sync input and an expression pedal if that's your thing. Sometimes things just work for you, and the FilterFX was one of those times for me.

[strungout]

Thanks both!

This is very cool sounding wah, Tom, and the waveform modes allow for a lot of variety and wierdness. I really like that stuff (like the Echo Base or the Abductor Delay, which I'm waiting on parts to build). It's experimentation begging to happen and create atmospheric music. I'll have to order the stompLFO and some other parts I think, but I'm impressed with the FilterFX.

Keep the suggestions coming! Whenever I search, I only find envelope-controlled wahs...

[Kipper4]

Here's another Stomplfo design.

https://www.diystompboxes.com/smfforum/index.php?topic=123551.msg1168957#msg1168957

[duck_arse]

It's experimentation begging to happen and create atmospheric music.

the uglyface. be the first to build it with a second led connected to an lfo and shining on the [main/single] ldr - then you can auto sweep between lfo peaks. or not/either, if switch selected. or lfo sweep [up or down] the control voltage pin of the 7555 .....

[strungout]

@kipper: Very nice. When I get my parts, I'll breadboard it


@da: That's a good idea! I never actually boxed it up, but I had the ugly face on my bb for a long while. That'll sound gnarly.


Thanks!

[strungout]

EDIT: I figured it out. Was thinking about it wrong. I was trying to figure out how to do it with the LDR, when all I needed to do was to take the control voltage straight from the LFO output. 

It sounds a LOT better: https://soundcloud.com/user-165425177/may-31-005/s-UZNm8L0nyhD

----------

Little update.

Added the second LED to the ugly face + LFO. I used the Lune's LFO. This is what it sounds like:

https://soundcloud.com/user-165425177/may-31-004/s-uiWj0J4uoza

The LFO sweep only seems to 'come out' as the filter settles back down.

As for controling pin 5 of the 7555, I don't know how to go about it. Pointers?

[ElectricDruid]

It sounds a LOT better: https://soundcloud.com/user-165425177/may-31-005/s-UZNm8L0nyhD

That sounds fantastically broken, in a good way

[strungout]

It does!

Here's a schemo for those who'd like to try it. Probably could use some improvements, maybe some stuff doesn't need to be there...



For some reason DIYLC stopped working after I installed a new version :/

[duck_arse]

control voltage pin - you can stick a cap on and feed in an ac signal, will warble about the set centre freq. that pin has a resistor to supply and two resistor to ground, all equal values. doesn't mind if you mess with it, so you can sling an ldr between pin 5 and supply, and it sweeps one way, or pin 5 and ground, and it sweeps twice as wide the other way.

geeze looise, you don't want it sounding any better than this one ....

https://soundcloud.com/user-165425177/may-31-005/s-UZNm8L0nyhD

[strungout]

@ da: I'm having a hard time picturing how to do it, but then I'm tired. But if I understand you correctly, the CV would sorta spiral around the frequency that increases as the filter sweeps. And I could get it to reverse sweep...

...sounds really damn cool! I'll mess with it some more tomorrow, with a fresh mind.

[duck_arse]

try this


I should probably point out that sweep up and sweep down may not sound exactly like that. from memory, it werks, but is somewhat more complicated to describe. the three resistors in the 7555 are shown on datasheets as being 100k each. the B250k is off the top of my head, you might get better knob response with a B100k and a 150k or 180k in series. run the led flashing the ldr at whatever brights you like, you don't really need a depth control on that [the oscillator] end.

have fun. post results, please.

[strungout]

Sooo...

The LFO part works indeed, and well. A bit of a different effect than the 2 LEDs to one LDR setup since the two LEDs aren't interacting against only one LDR. I'd just say it doesn't warble the same. That's not bad. Probably due to LED and LDR choice. My Ugly Face's opto combo is a red LED and 500-10M ohm LDR. The LFO's, I think, is blue and also 500-10M ohm.

The effect is more subtle/smooth in the up position and more pronounced/choppy in the down position. You're right, it's kinda hard to explain what it actually sounds like though, so here's some clips:

Up position: https://soundcloud.com/user-165425177/lfoglyface03-up-jun-02-002/s-nE7vtIsw4C9?in=user-165425177/sets/lfogly-face/s-6xPkTozqCnC

Down position: https://soundcloud.com/user-165425177/lfoglyface02-down-jun-02-001/s-DGlVVHWxB7u?in=user-165425177/sets/lfogly-face/s-6xPkTozqCnC

I'll change the depth pot to 100k like you suggested. The 250k cuts off a some point.

I like how it sounds. I'm starting to wonder about a clean version of this...



As for the AC modulation, I'm lost. I need an AC function generator?

[duck_arse]

that's wild. fantastic, you've sold me.

for the AC modulation, you just need a low freq osc, any type you like, square wave, triangle, sine, sawtooth, whatever. first thing, tho, that cap will prolly need to be at least 470nF and up. then just feed the oscillator output into the cap. done.

[strungout]

that's wild. fantastic, you've sold me.

XD


Ok, so, built a simple function generator on my bb, cause, why not. More waves, more variations. The 470nF was a good estimate. Without it, it sounds very nasal and hissy. Has some worth, I think. Could easily just switch in different caps for tonal variety. I'd say it sounds similar to using the other LFO in up mode (with the 470nF cap). Here's a clip. It goes Square > Triangle > Sine. When I stop playing, I change wave:

https://soundcloud.com/user-165425177/lfoglyface04-acmod-jun-03-003/s-Q9gsTtvGTwj

I used this: function generator:

[deadastronaut]

lightwah..... basic opamp wah T-filter with lfo.... and optional ldr sensor... (which nowdays i would do IR instead)

[strungout]

lightwah..... basic opamp wah T-filter with lfo.... and optional ldr sensor... (which nowdays i would do IR instead)

Checked out the demo. Sounds awesome, man, and it's a good idea! I'm thinking lightwah + taplfo with 8 waveforms... That should be all kinds of versatile, from classic to straight freaky.

[deadastronaut]

yeah sounds like a good addon....

[strungout]

Just a little update: I'm still waiting for parts so I'm still messing around. BB'ed the Lightwah. After some 'figuring out', works well. It'll take some getting used to controlling the amount of light the LDR gets.

Also found out, I can plug both the foot LDR and the LFO LDR in parallel, for some interesting interplay. Reminded me of when I was trying to add an envelope follower to the karate shop (systech harmonic energizer). So I added one to the Lightwah, sounds like this:

https://soundcloud.com/user-165425177/cleanauto-wahandlfo-jun-09-001/s-Pk14dHN6i9h

The foot LDR and LFO LDR together do the same kind of thing, except you can control how the filter moves more precisely. I'm eager to try the STOMPLFO on this, the random step should make thing pretty chaotic.