'LIGHTWAH'

[claytushaywood]

Wasn't this originally a vero layout?  I cant find it if so!

And I'm a bit confused on this perf layout (i really wanna build this and really hate perf so I'm hoping there's a vero!) So what kind of LDR's work best here?  where did you get yours?  I've had bad luck building effects with homemade optocouplers, I always just like to pay the extra dough for the vactrols or the nsl32's.  But if you know the exact LDR you used that would be awesome!!!

Thanks for this awesome project... agian where can I find the vero layout?

Claytus

[deadastronaut]

i never made a vero layout, only pcb...

i rolled my own led/ldrs...works fine...  mine iirc were a few k' to 1M ...


iirc someone said there was a vero on the 'other' forum...someone might chime in and help you on that!..

[J0K3RX]

Seen this?

http://www.ehx.com/products/crying-tone

[deadastronaut]

yeah i saw that......a few design flaws imo....you have to calibrate it everytime you move it....and you can't have half c.ocked either...jacks always moving etc....nahhhhhhhh!!!!!!!!!!...

there was a discussion on that a while back..

[Gurner]

yeah i saw that......a few design flaws imo....you have to calibrate it everytime you move it....and you can't have half c.ocked either...jacks always moving etc....nahhhhhhhh!!!!!!!!!!...

there was a discussion on that a while back..

I saw a youtube video justifying the design as "building a better mousetrap" (on the basis of no exposed parts to get scratchy over time), but that to me ain't a better mousetrap...sure it might solve the problem of dust, dirt getting into the main pot, but by the looks of it introduces quirks which could be a real annoyance.

[Jdansti]

Great work Rob!  I'm going to have to build this after the competition!

[threepwood]

Hey there.

Just wondering if I would need to make any changes to resistors etc if I wanted to use 5mm external LEDs rather 3mm as usgested in the layout?  Also would it be possible possible to add a second sensor LED?

Thanks in advance.

[midwayfair]

Been looking for an effect that does the auto mode on this one, so this is on my build list. Am I correct in assuming I just need to leave off the external LED, external LDR, and the LDR/LED pair that connects to switch 1? It's a little hard to tell from the schematic (which is cut off?) whether LED2 and that LDR are part of the footwah part.

[deadastronaut]

Hey there.

Just wondering if I would need to make any changes to resistors etc if I wanted to use 5mm external LEDs rather 3mm as usgested in the layout?  Also would it be possible possible to add a second sensor LED?

Thanks in advance.

probably be ok using 5mm's..

2nd sensor led, yep again probably be ok in series...(but build the pcb and try/test it first before drilling box ok...might be dimmer....)

[deadastronaut]

Been looking for an effect that does the auto mode on this one, so this is on my build list. Am I correct in assuming I just need to leave off the external LED, external LDR, and the LDR/LED pair that connects to switch 1? It's a little hard to tell from the schematic (which is cut off?) whether LED2 and that LDR are part of the footwah part.

heres the schematic without the foot sensor etc.., there is a trem/swell mod too (sw2) that i never actually tried, but the rest will be ok...

[midwayfair]

So ... built an auto-only version up tonight (on my own layout) and the LFO wasn't working -- full brightness the whole time (the dry path is also dead, but I think it's because the LDR is just dumping my signal to ground since it's on all the way). After much trouble shooting and unable to find any mistakes, I went back and compared the previous layout and older schematics. Long story short, there's a mistake in the most recent schematic; the 150K going from the speed pot back to IC2 should connect to pin2, not pin 1, according to older schematics.

--The wah mode is working now. It sounds really, really nice! Much more rich in person than the demos. However, the tremolo mode doesn't work at all -- no sound except the LFO ticking. I think that's another mistake in the schematic -- that's should be a ST switch, so that flipping it connects all three switch terminals and keeps the feedback loop in the circuit, right? It's a little too late at night here for me to experiment.

--I'm getting some LFO ticking, even after I electronically separated the LFO from the wah via a 100R and 47uF to ground at depth settings above ~3:00. I had to use a jumper to connect the second voltage source to the LFO IC, but I'm not sure that's the culprit. Could it be that I'm using a vactrol (VTL5C1), so the depth is just much more extreme? A small resistor between the series LEDs squelched it, but it also deadens the effect. Does anyone have any more ideas?

--Finally, I think it's possible (and easy) to cop some controls from the Lune and add e.g. a wave form knob for sine <> square forms. This could be fun for anyone who wants to play with the auto mode exclusively. I'll report back after further experimentation tomorrow.

[deadastronaut]

hi jon, sorry to hear about your probs....yep you are correct on the 150k...oops..

heres the full layout to reference to.., i never tried the trem/swell mod, it was just a quick idea i had..(just being greedy)

i ike the idea of poaching the lune bits....cool.

[midwayfair]

Thanks! It's all better now, except for the LED ticking, but that's pretty minimal even with a red LED when using the vactrol (I swapped out a few and tried the roll my own method ... the Vactec sounded the best to my ears, a really rich full voweling with the least amount of ticking).

This was a really cool project, so thanks for working so hard to get it to its current state.

I made a perf layout for the auto mode only that fits in a 1590A:

PDF: http://jonpattonmusic.files.wordpress.com/2012/09/lightwah-auto-only.pdf

This layout is not fully verified (I'm working on it), but it has been thoroughly checked and was adapted from a verified layout. I used a slightly different layout for the perf one I built yesterday, then redrew it today. This one is much cleaner.

I also made a few other changes (some simply to get the circuit smaller for the mini build) and discoveries:

Waveform mod did not work, at least, not in a way I can get working. Someone smarter than me might be able to figure it out. The topology is just different enough from the Tremulus Lune's LFO to make it not work regardless of the wiring.

However -- very exciting! -- a ramp mod is possible! It's really easy and it sounds very cool. Just use an on/off/on switch and wire the center lug to one of the speed pot's lugs, then put 1N914s on the other lugs (one is backwards) and then wire their other terminals together and back to the other lug of the speed knob. This trick general works in any LFO, so no surprise that it works here. In the "ramp down" mode, it sounds more like an envelope filter. In the "ramp up" mode, it's just a little different. For added thrills, I stuck a Nurse Quacky after it and let the ramp's "stabs" active the filter. Very crazy. It might be worth combining the circuits at some point ....

3. I found the input loading to be a bit extreme unless there was a gain pedal in front. The high e string was just disappearing on any depth settings below maximum (even with a vactrol doing the heavy lifting and a red LED [instead of the blue] for the external -- the LED affects the overall tone). I can understand why it was designed that way -- from your demo it's pretty obvious that you use a lot of gain -- but I found that just using a 1nF cap at the input was sufficient. Similarly, a volume (trim)pot on the output was sufficient for my purposes, and without the 3.3K and 6.8K it was necessary to reduce the output cap and volume pot size to keep a cutoff frequency similar to the original.

[deadastronaut]

good work jon,  seems like you've had a right good time of experimenting on it,

yep i tried lots of led colours too...

sounds like the ramp idea is a cool mod too...

clips?#


edit: i laways wanted to add an envelope filter to it too....just never got round to it...

[midwayfair]

Sure thing, clips as soon as I can get it boxed and have some time to play my electric without annoying the neighbors! I can't shred like you can, but I'll try to come up with something cool for it.

Small layout's verified -- I just finished it about an hour ago and it works really well. Sounds almost identical except NO TICKING! Woohoo.

Oh ... discovered another possible mod, not sure how useful it is, because it precludes using the rate LED as an indicator: You could get a parked wah/filter by switching in a Germanium diode across the rate LED (same orientation). It still moves a VERY VERY small amount, almost imperceptibly, and sounds just like a parked wah. The depth knob becomes a frequency control in that mode. It has to be germanium -- silicon clips too high to work this way.

I have a question if you don't mind, if one wanted to shift the sweep to be more trebly, it's just a matter of reducing the 6n8 and 4n7 caps -- to, say, 4n7 and 2n2? I'm still trying to get a handle on filters.

Again, thanks for such a cool circuit. It's really made the weekend fly by.

[deadastronaut]

cool, glad you got your head around it,  yeah IIRC those cap swaps should work....(in the ''T'')

look forward to ya clips...sounds interesting. 

[shay1510]

Hey everyone,
is someone making PCBs for this awesome pedal? (or have a spare 1?)

Thanks.

[deadastronaut]

^ yes.  £8.00 GBP each. (paypal) includes postage,

pm me ok....

[haveyouseenhim]

I'm so excited to get started on this. I think I'm going to put this in a wah shell as to control the footwah part without having to depend on the available surrounding light.

[deadastronaut]

yeah cool idea, just use the sensor inside it instead....no scratchy pot.