madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: murdog47 on July 03, 2012, 07:33:11 PM

Title: Help with a WIIO RAH
Post by: murdog47 on July 03, 2012, 07:33:11 PM
So i finished this etched board of the RAH and am having some troubles. First off, I have gone back and checked all my solder points for cold joints and solder bridges and they are all good. I have checked and double checked all of my component values and they are all good. This is the problems

1. Volume is SUPER low. I have to crank my amp to hear the effect, but what I can hear sounds great!

2.I'm getting a bad hum when I touch some of the pots. I haven't boxed this yet, just running it through my testing rig.

Here is a video and pictures....any ideas??



(http://i1077.photobucket.com/albums/w466/pmurray47/IMAG0509.jpg)

(http://i1077.photobucket.com/albums/w466/pmurray47/RAH.png)
Title: Re: Help with a WIIO RAH
Post by: k.rock! on July 03, 2012, 07:47:57 PM
That sounds like a nice ground problem to me hehe

The first thing I assume you checked, are any of the pots touching anything on the solder side of the board? That may be causing some of your signals to go to ground, causing it to be low in volume and will cause that buzzing as well.

Check all your ground paths, from your board out to your hardware (pots, switches and jacks).

That's just the first things that popped into my head for now :)

We'll figure it out!  :D

-Kaleb
Title: Re: Help with a WIIO RAH
Post by: k.rock! on July 03, 2012, 07:49:59 PM
Looking at your video again, I'm 95% sure your problem is that you need to isolate the back of your pots from the board...

-K
Title: Re: Help with a WIIO RAH
Post by: night-B on July 03, 2012, 08:02:15 PM
I think the same as Kaleb. It's a grounding problem.
Maybe you can slip a little piece of plastic, cardboard, or anything that can isolate electricaly, between the body of the pots and your PCB.

Julien
Title: Re: Help with a WIIO RAH
Post by: murdog47 on July 03, 2012, 08:06:07 PM
Already did, I always use an old iTunes gift card to create a gap when soldering. I also added some electrical tape to the back of the pots to be sure.
Title: Re: Help with a WIIO RAH
Post by: mgwhit on July 03, 2012, 08:10:26 PM
Since you're unboxed, do you have both of your jacks grounded?
Title: Re: Help with a WIIO RAH
Post by: murdog47 on July 03, 2012, 08:17:22 PM
Yep, both grounded.
Title: Re: Help with a WIIO RAH
Post by: pryde on July 03, 2012, 08:32:54 PM
Hmm Bummer.

I built the exact same project/pcb and it works great. Let me know if you need some voltages (if it comes to that). Hopefully it is a simple grounding issue.

Title: Re: Help with a WIIO RAH
Post by: murdog47 on July 03, 2012, 09:06:56 PM
I hate to desolder especially on an etch but it looks like I'm gonna need to get those pots off of there and do some detective work.
Title: Re: Help with a WIIO RAH
Post by: k.rock! on July 03, 2012, 09:45:34 PM
I know this may sound stupid, but check that you're plugging your guitar to the input and not the output on the board. Silly as it is...it happens and can produce similar symptoms.

-K
Title: Re: Help with a WIIO RAH
Post by: murdog47 on July 03, 2012, 09:49:00 PM
Checked that too...been there, done that  ;D
Title: Re: Help with a WIIO RAH
Post by: JakeFuzz on July 03, 2012, 09:50:19 PM
I would check the lug resistances of the volume pot. It's in the circuit so you wont get the quoted value on the pot but you can usually see if something is wrong by checking and sweeping. It sounds to me like you may be shorting something to ground either inside the pot or around the lugs.

Edit: I see you have already taken that pot out. In that case check the resistance on the outer lugs and then check continuity between the lug 2 pad and ground and between the lug 3 pad and ground (actually check resistance)