WAH pictures- diy , modded & etc.

[deadastronaut]

cheers joe...i knew you'd know..i'll grab one then..

[peterg]

Joe

Since you brought up switch popping I have questions. I recently modded a crybaby (see above). It was my first time working on one. I added a number of switches and have popping when using the gain/bass, mid and sweep switches. The gain/bass and mid switches produce the loudest pops.

1. I sort of understand why the sweep switches pop since they are switching caps. Where should the pulldown resistors go?
2. Which cap is causing the pop when the mid switch is used? The 10n at the first transistor and/or the caps on the sweep switches? Where should the pulldown resistors go?
3. Since the gain/bass switch is not directly connected to a cap what is the pop caused by? How can this be fixed?



Thanks

[joegagan]

i use the GM arts schematic for that, it works like a charm

[joegagan]

part2 - peterg ,nice drawing by the way!

for questions 2 and 3, there is DC on those switches as you are using them, causing the noise. not sure if ' break before make' switches would help, i suspect they might.
i also think using two Rs in parallel, with both  Q1 side legs tied together would be preferable as far as noise when switching is concerned - using an spdt on the far side to add the 2nd r in parallel to make the second R position. you'll have to do the math on the r values , there are online calculators for that.

i will be interested in your results if you try one or both of these ideas.

[peterg]

Thanks Joe. I'll explore!

[tubelectron]

ended up making a lightplate for my vol too...

@Rob aka deadastronaut : I am tempted to copy you lightning "trick"... So I have some questions :

- How many LEDs did you use for those lighted bottom-coverplates ?
- You probably drill a hole for each LED in the thickness of the plate to radiate light (it is what I would have done, but...) ?
- Did you measured the current draw by the lightning function ?

Thanks !

[deadastronaut]

hi bruno,

yep its 4 leds,  front, back, left/right side..

i use flat top leds, you can scuff/sand them down a little to diffuse the light more evenly..

never bothered measuring as i have a nice psu...

[tubelectron]

Thanks Rob, fine :

- did you flatten the top of the LED by yourself (filing ?)
- is the flat top looking the thickness of the plexi or looking to the floor (the led being put in a circular hole) ?

Oh, I should make a little drawing to explain my purposes... Here is a picture of my Tubelectron Tube Overdrive, my sole attempt to light a plexi in its thickness :



- the plexi is drilled to the exact diameter of the led (it is a 3mm blue 8000mcd led).
- the led is mounted vertically, by the underneath.
- the led emitting junction is placed at half the height of the thickness of the plexi.
- the plexi being 3mm thick, I didn't needed to flatten the top of the led.

Did you placed the led vertically (like me here) or horizontally ?

If you don't see what I mean, I'll do a drawing for clarity ...

A+!

[thermionix]

^Deluxe Reverb schematic?

[Ben Lyman]

My first attempt at a Wah, broken 1987 Dunlop Crybaby for $15.


all goes except the pot, which seems fine, cut the perf, 1960's Vox style inductor courtesy of Joe Gagan

Found this schematic online, somebody found it inside his Vox.

Figured my own layout using many of Joe's recommendations.

Then from this...

...and this...

...to this...

New tires and it's done, sounds awesome. Battery only for this one, 5mm LED fits in the former DC jack hole without any drilling.

[thermionix]

Very cool.  You're lucky the inductor fit down at the shallow end.  My wah build (same circuit, different components) was just a tad too bright, changing the sweep cap to .012 put it spot on, sounds pretty much identical to my buddy's '69 stack-o-dimes.  Actually I added a .002 in parallel with the .01, same difference.

I also omitted the wall wart jack, but put a Q control there, a 50K pot in series with a 33K resistor on the board.  It's pretty subtle but there's a noticable difference between min and max.  A pushbutton switch might make more sense but I already had the pot.



Edit: Just noticed that Vox schematic says 68 instead of 68K for the input resistor, oops!

[Ben Lyman]

Wow! that looks great therm! and yes, lucky indeed that the inductor fit, I tested before soldering but I really didn't want to have to rework my DIYLC layout, it was hard enough. Joe told me to socket my sweep cap and I probably should have listened but it sounds great almost anywhere I turn the trimmers. You can probably tell from my layout what they all do. The treble bleed on the input is interesting, it's the only one that has a weird spot, let too much treble thru and I get a strange low octave tone if I rock the pedal back to a certain spot. It's easy to adjust it to fix that sound though so I'm really happy with the sounds this thing makes.
Also yes, 68r on the schematic instead of 68k, I used a trimmer there as well. After looking at a billion schematics I noticed some have a different value and Joe recommended the trimmer, it has a great affect on the range of tones. The difference in all the schematics that really threw me for a loop was that half of them show the 68k on one side of the 10n and the other half show it on the other side. I went with my 200k trimmer after the 10n but I don't know what is preferred or why

[thermionix]

Wow! that looks great therm! and yes, lucky indeed that the inductor fit, I tested before soldering but I really didn't want to have to rework my DIYLC layout, it was hard enough. Joe told me to socket my sweep cap and I probably should have listened but it sounds great almost anywhere I turn the trimmers. You can probably tell from my layout what they all do. The treble bleed on the input is interesting, it's the only one that has a weird spot, let too much treble thru and I get a strange low octave tone if I rock the pedal back to a certain spot. It's easy to adjust it to fix that sound though so I'm really happy with the sounds this thing makes.
Also yes, 68r on the schematic instead of 68k, I used a trimmer there as well. After looking at a billion schematics I noticed some have a different value and Joe recommended the trimmer, it has a great affect on the range of tones. The difference in all the schematics that really threw me for a loop was that half of them show the 68k on one side of the 10n and the other half show it on the other side. I went with my 200k trimmer after the 10n but I don't know what is preferred or why

Yeah on the input, the early Clyde McCoys had the cap first, then the 68K, but within a few years it was switched the other way around.  I tried it both ways and didn't hear much difference.  I started with a 56K input resistor, as is often recommended for true bypass wahs, but I ended up liking a 68K better.  Seemed to help tame highs just a tad, and I don't notice a volume drop when I engage the wah.  I'm using a .02 input cap, because I broke the .01 when I was experimenting and swapping parts around.  The .02 didn't sound much different, if at all.  Sounds good so I just left it.