Wah issue

[kierc]

Hi,

Firstly I'd like to say hi and a big thanks to everyone as I haven't introduced myself yet 
Great forum, with a great community going on!

I'm not only new to DIY guitar pedals, but new to electronics altogether, but seems really fun so far other than waiting for the parts to come! (terrible here in the UK! )

Anyways, on to my problem..

I've recently took on the Clyde McCoy Wah from fuzz central as my first project after the beginner project on here, and well I've populated the board with carbon comp resistors, xicon greenies and styroflex caps, and a whipple and icar pot from the whipple guy, wired it all up according working from this image : http://www.fulltone.com/vox6080.html
The switch I have/came with my chassis is a rectangular Carling one with 6 upward-facing pins

Well I plugged it in after wiring it up, it bypasses fine, then when i switch it on it seems to act like a volume pedal rather than a wah...
As in it's quiet when the heel is down and normal when the toe is down...

Now I've never used a wah in my life and i'm not particularly good on guitar either but I'm pretty sure this ain't what a wah is supposed to sound like?!

I'd really appreciate any help with this, I can take photos if needed, but I don't have a multimeter or any testing equipment 

Thanks,

Kier.

[John Lyons]

I believe this has something to do with the 4.7uf cap.
Make sure your cap is put in correctly.
On that board (that I made you) there are two pads different size caps.
One pad is for an axial cap and one is for a radial cap.
The cap may not be put in correct and this would cause it to function as a volume pedal if I'm not mistaken.

john

[kierc]

Cheers for the reply John,  I thought it didn't matter which way the 4.7uF cap was due to it being non-polarised?
Well I checked it, removed it, and solderd it in the other way, but it's still the same as before 

Any other thoughts? I'm away 'till tomorrow so I won't be able to try anything else til then 

BTW John the board you made me is great, i'll have to take some photo's and post 'em up 

[John Lyons]

On the Fuzzcentral McCoy layout the 4.7uf cap is polarized.
I'm not sure this is your problem but...

john

[liddokun]

The 4.7uf should be the problem.  When it's not connected to ground, the wah becomes a volume pedal.  Like John said, check polarity, and compare it to the schematic to double check.

[kierc]

Well I've checked again, on the PCB layout image it does show polarity, but the parts list, schematic and the Mouser P/N for the cap that he recommends is a non-polarised cap?  Even the image of his own clone has an NP cap..

I dunno what i should do, as I believe you two are most probably right, but he does infact state that it's an NP cap?

Should I just order a polarised replacement and see how that goes? (I'm new to this so I don't have loadsa spare parts around )

Thanks,

[Paul Marossy]

I do not think that the 4.7uF cap absolutely has to be polarized. Are you sure that your inductor is actually connected into the circuit? If you take the inductor out of the circuit, it will act the same way as not having the 4.7uF cap in the circuit.

From your description of the problem, it sounds to me like the inductor isn't doing anything in your circuit.

[John Lyons]

That's true paul.
The inductor should fit more than one way so check to see
that you have one pin form each side of the inductor in each trace.

john

[geertjacobs]

I was lucky enough to get one of the Vox 847 wah's from the batch that Finlay found.
After some mechanical adjustments i was able to test it today and had the same issue as mentioned here:

the 847 worked fine in bypass, but it worked as a volume control in the wah mode.
I replaced the 4.7uF polarized cap with another one from my parts bin (checked it first with my DMM).
At the first test with the pcb dangling around it worked fine. Instant Voodoo Child! (or something that sounded somewhat like it  )
However with the pcb mounted I seem to have some issues. The wah effect was again a volume control.
Moving the pcb around fixed it again.
I probably need to be careful when mounting it (wiring pushes the pcb too close to the chassis, probably shorting traces to the chassis or so).

my 2 eurocents...

[kierc]

Cheers for the replies,

I'll triple check the inductor tomorrow when its light and also check it out of the chassis too, can be tricky without a de-soldering tool! Gonna order one tomorrow too!
Does it matter which orientation the inductor is as long as pin 1 and 8 bridge the traces?

Thanks, really appreciate all your help guys 

[kierc]

Well I tried it with the pcb hanging out the chassis, same thing still.. and I can't check the inductor until I get a de-solder pump (hopefully tomorrow if i order one now)
I've placed some foam under the pcb in the chassis just in case

I've took a few quick photos of it as it is, along with some of my sketches of the wiring and layout, and can be seen here : http://www.kierc.co.uk/Wah/index.html

Does the wiring look right? Also, my soldering ain't that good yet as you can see, but is it ok like that? (I dunno what it is but some amber/orange liquid appears from the solder? I scratched in between some of the joints to remove it just in case?)

I'm gonna order some polarised 4.7uF caps and a de-solder pump now 

[Paul Marossy]

Your soldering looks fine and the wiring looks good to me, but it doesn't hurt to double check everything. That amber stuff is rosin, that wouldn't cause any of your problems, either.

I still think the problem is with your inductor not actually functioning in your circuit.

[kierc]

I'm pretty sure I put the inductor in right, about 90%, but I will still check when I get the pump

TBH I thought it was wierd that the inductor had been painted..as all the other Whipple's I've seen look standard and black, whereas this one was painted a sortof blue, and spray painted i think aswell as you can see the paint on the coil inside and some spray around the bottom edge..

This wouldn't damage it or anything would it?

I'll check it when I can anyway and hope that I put it in wrong!

[Paul Marossy]

Hard to say if the paint damaged it or not. Probably not, but not impossible, I guess.

An easy test is to pull out the inductor and do a continuity check on it. It you get nothing, then the inductor is open, meaning that there is not a physical connection between the two pins. Or, the other possibility could be that the paint ate thru the lacquer on the windings so now some of the windings are now making physical contact and it's not functioning as an inductor anymore.

I think either case would have similar results. I am still not convinced that your problem is due to the 4.7uF cap from the info you have given regarding the inductor.

[kierc]

Well I got a de-solder pump today!

Damn it was hard getting that inductor out lol! never used a de-solder pump thing before 

Anyways... I FIXED IT    arhh i'm so happy lol

Here's what happened:

Took the inductor out, it WAS in the correct way, so I just put it back in but the other way round just to check, fired it up but still the same thing!
Then I swapped the 4.7uF cap for a polarised one, same thing still! This was when it started annoying me!

Anyways I started to think what everyone was saying about either the cap or the inductor not connected right, so I looked at all the pcb traces and thought about how they have missing specks in them, so I soldered over a couple of the traces, then i found the other hole for the 4.7uF cap (the second positive one), and just before the square it looked as though the trace had been cut through, so I soldered between the trace and the hole and fired it up again and voila!

Such a simple thing in the end 

Sounds pretty darn good to me, being the first wah i've ever heard in person or even used 

I'd like to say a big big thanks to everyone for your help and to John for making the PCB 

Also, Paul, I love your Nitefly    I have a P-44, and am reaally impressed with Parker's so far!

[Paul Marossy]

Yay! Glad you got it fixed. Turned out to be a simple thing, eh? 

Yeah, I love my Parker Mojo Nitefly. It's awesome. 

[John Lyons]

Kier

Hopefully that wasn't my fault...Didn't notice any break in the PCB trace.
I was thinking that you had the cap somehow wrong since there are two pads for the + cap
side depending on the size of the cap you use.

Glad you got it working anyway!

john

[kierc]

Don't worry about it John, i'm just happy to have found someone to make the pcb for me as I don't have enough funds to make my own..
I'll probably be hitting you up for some more in the future 

As for the (maybe) break in the trace, i'm actually glad it was there! I would've been so bummed if there was a problem with one/some of the components or something 
It's all stuff to learn from in the end.

Now then.. what to (*want*) to build next then...

[kierc]

Hey again!

Didn't know if I should make a new thread so I'll chuck it in here...

Basically, when I bought my wah chassis, the guy also threw in a red fasel inductor, and I was wondering if I could somehow mount the red fasel on some perfboard or something and add a switch to the chassis (hopefully in the DC jack hole?) that could switch between the two inductors, or even run both together or just the whipple?

I think it's possible, I've done some searching on here and google but can't anything definitive about how...could anyone help me with this?

Also, now I've played the wah some, i'm starting to feel that there isn't enough clarity or low end when the heel is down, and when the toe is down it can be a bit harsh, but the actual "wah" seems really fun!
I'm pretty sure theres mods out there for this, but most of the ones i've seen have trim pots?  Is there anything I can do with my board (fuzz central mccoy) to adjust this?

Really appreciated!

Kier.