'LIGHTWAH'

[vendettav]

Rob, dammit i'm also experiencing issues.
I just built the dark light bit. 2 working LEDs a 2n3904 (checked the pinout thrice) a pot and a LDR. the LDR is working on it's own, changing the resistance. ut in the schematic it doesnt do anything at all
are you sure you did it this way cause i understand the concept behind this but the fact that there is a already a connection between the pot's lug 1 and base of the tranny, an additional resistance parallel to the one from the pot's lug is just pointless. ive tried bunch of combinations and still cant get it work (i got it responding on one but the LEDs would go dark when i'd darken the LDR (as if cut the light from it) but it's not how it's supposed to funcion right?

[vendettav]

ok an update here

I did some research and found this http://www.kpsec.freeuk.com/trancirc.htm
go down til the end and scroll up a bit it says 'Using a transistor switch with sensors'
now see the schematic, i did the LDR birght = LED bright one and it works
the other one doesnt want to work with me for some reason!
what the ...

[mattthegamer463]

ok an update here

I did some research and found this http://www.kpsec.freeuk.com/trancirc.htm
go down til the end and scroll up a bit it says 'Using a transistor switch with sensors'
now see the schematic, i did the LDR birght = LED bright one and it works
the other one doesnt want to work with me for some reason!
what the ...

The sensitivity pot in rob's circuit is in parallel with the LDR, maybe it is causing the LDR resistance changes to become negligible compared to the 10k pot value.  10k in parallel with 1M is not much different than 10k in parallel with 100k, etc.  Maybe thats the issue.  I'm concerned that much of this circuit's success is dependent of the light/dark resistances of the LDR.

[vendettav]

ok an update here

I did some research and found this http://www.kpsec.freeuk.com/trancirc.htm
go down til the end and scroll up a bit it says 'Using a transistor switch with sensors'
now see the schematic, i did the LDR birght = LED bright one and it works
the other one doesnt want to work with me for some reason!
what the ...

The sensitivity pot in rob's circuit is in parallel with the LDR, maybe it is causing the LDR resistance changes to become negligible compared to the 10k pot value.  10k in parallel with 1M is not much different than 10k in parallel with 100k, etc.  Maybe thats the issue.  I'm concerned that much of this circuit's success is dependent of the light/dark resistances of the LDR.

actualyl that's what i was trying to explain in my post

however hmm hey i get another idea how to wire this thing up, will try it asap and let you know guys

[deadastronaut]

yeah i know, yawn!......i built another 2 lightwahs......









works fine!...

tip. use low profile miniature electro's ...with the switch in the middle...

[nocentelli]

looks great, Rob. I'm still waiting for the b@sta@rd LDRs to arrive so I can build this.

[deadastronaut]

cheers man, yeah i hate waiting foir bits, but its nice when they arrive,...

ive whacked this into my little roland micro cube and it kicks serious butt...sounds great...proper

[nexekho]

I love it!  Want to build something functionally similar, but simpler.

My signal chain is almost all-digital and quite hot with a lot of volume headroom.  (I run my POD at ~30% volume)  Do you think it might be feasible to build a passive wah?  As far as I can tell, a wah is basically an adjustable bandpass, filtering out everything outside a certain range, am I right?  If I built a passive bandpass filter with the right values, could it be LDR-controlled by putting the LDRs in series with the resistors?

[kinski]

So I built this pedal a while back. Sounds great! However, I was wondering, would it be possible to add an expression jack, so I could use and expression pedal to control the manual wah? I guess at that point, I could just build a true wah pedal, but I'd still like to know if this would be possible.

Thanks for the help, and sorry if this was mention already in this thread. I tried to sift through to see, but its pretty long and may have missed it.

[cab42]

So I built this pedal a while back. Sounds great! However, I was wondering, would it be possible to add an expression jack, so I could use and expression pedal to control the manual wah? I guess at that point, I could just build a true wah pedal, but I'd still like to know if this would be possible.

Thanks for the help, and sorry if this was mention already in this thread. I tried to sift through to see, but its pretty long and may have missed it.

You could add a three way switch instead of the present switch and route the wire to a mono jack. Or alternatively use a switching jack that cuts the connection to the switch. At least that was how I thought about doing it.

I was thinking about building the thing into a wah shell, and leave out the sensor part. I'm fairly sure that I'm not able to stand on one leg, waving my foot in the the air and play guitar at the same time without some yoga training.

Regards

Carsten

[Gurner]

Or alternatively use a switching jack that cuts the connection to the switch. At least that was how I thought about doing it.

I reckon that's the way to go...just find a pot that matches the dark resistance of the LDR.

Anyone considered a ldr (on a socket/jack)...long lined up a mic stand taped to the top for cool mouth wah?!

[kinski]

Very cool. Thanks! I'll see what I can do.

[deadastronaut]

So I built this pedal a while back. Sounds great! However, I was wondering, would it be possible to add an expression jack, so I could use and expression pedal to control the manual wah? I guess at that point, I could just build a true wah pedal, but I'd still like to know if this would be possible.

Thanks for the help, and sorry if this was mention already in this thread. I tried to sift through to see, but its pretty long and may have missed it.

I'm fairly sure that I'm not able to stand on one leg, waving my foot in the the air and play guitar at the same time without some yoga training.

Regards

Carsten

get another leg...

but seriously, i thought about the expression a while back, good idea,...... if i were to build it in a wah shell, i would have switching between caps too...bright and normal etc...experiment with the 'T'....

[askwho69]

Just Built it from 10:30 to 2am i used perf and followed the pcb above.. its fricking hard man its so compacted! but focus is the only thing that makes my build 90percent working in first try! i was experiencing the LDR foot sensor " the thing doesnt work" but when i read about dark/light resistance and measure a ldr that is 800k - 1M turned the sensor and  "boom" wah wah! it worked!

While doing the perf i forgot the c8 i installed 1 uf "damn" and i dont want to desolder my beautiful perf "i was trying to make like "FC" as clean as possible "
SO! i paralleled 10 uf instead and the effect is very cool my speed pot was 500k and c8 is 11uf im getting a slow speed and high speed that is usable and really kicks in when turning the pot ... another changes was the "TLE2072" superb IC i just replaced the TL072 and the beast becomes "beastiality " PLEASE TRY AND COMPARE TO HEAR THE DIFFERENCE" for me the pot speed becomes easy to dial and more speed and super slow speed try it

By the way im sleepy dont mind my terms and wrong grammar im tired! need to wake up early hahahahha

this is a good night sleep!


THANK YOU ROB!


last question where can i install or insert a jack for manual wah? i have expression pedal laying around.. and also the pot value?

thanks once again!

[deadastronaut]

well done,..... on perf?..your brave ...

glad you got it going man.......now have a good kip!..night night....

[askwho69]

hahhaha Rob yah im so desperate to make one and for me making pcb is more job and hard work to me! hahaha glad i modify my post about expression pedal

anyone wants to perf it ? just follow the pcb and count the dots hahahahha

Thanks again rob!

[Dork]

Hi Guys!

So, this PCB is verified, right?
And C8 is 100µF and the speed Pot is 500K (470) lin?

I want this effect so bad, definately gonna make it asap! Many thanks Deadastronaut!

if anyone is remotely interested.... YAWN!...

and fancies giving this a shot, heres the layout pdf, and pcb pdf ok....

ive made a pcb of it, (and one for armando ) but wont have time this weekend to build/verify  it....ive checked it over many times and it all looks ok...

i re-breaded the lfo especially, and it looks cool to me!...blood sweat and many tantrums  went into this @#$%er!!!!....but it looks ok now!...

http://dl.dropbox.com/u/7464107/LIGHTWAHPCB2.pdf

http://dl.dropbox.com/u/7464107/lightwah%20layout.pdf

[deadastronaut]

hi dork,  glad you like it , i do a lot... C8 is a 10uf..ok...and pot is 470k lin.

ive built a few so yep!..its very verified ok.

i'm currently working on a lightwah+distortion+fuzz in a 1590d, basically metallica+hillage in a box..

[Dork]

Thanks Robert for the fast reply!

I still have a few questions:

I can´t find the 9V spot, and two resistors have no values. I added a Picture, so you can see what I mean:


Are both trannys 2N3904´s ?

Thank you, I already etched the PCB, ready to start in a few days (I have to take a look, if I have enough LDRs @ home).

I can´t wait, to start. I finished my Snow white Auto wah a few days before, but your Lightwah is definately much more interesting!

[deadastronaut]

hi dork, i just updated the pdf, download it again its all ok now.....all corrected and those resistors have values on the layout too ok...

let us know how ya get on. good luck man. rob.

edit: yep thats the 9v...