This pedal is killing me, any help would be great

[McGhie]

So I found this layout on some site I can't even remember. Tried googling it after saving it, nothing relevant came up. I don't think the layout was verified, but I do know that I wired everything as it said. Using my not-that-extensive DIY-knowledge, I've wired it and boxed it the way I've shown below. And all it does is hum. Really damn loud. It does it all the time, bypassed or not, EXCEPT (how's this for weird) when the DPDT switch is manually depressed, then it just shuts up completely. No guitar signal gets through at any time either.
To the point, here's how I've wired everything (everything in the box is in this picture,) and I'd really love if any of you would take the time to look it through for any mistakes or problems.

[gutsofgold]

I always thought DPDT's switched from the center lugs to each outer set (up and down). If that's the case you would want your in and out jack tips to go to the center/middle set of lugs.

[PerroGrande]

Yeah -- the switch wiring looks a little amiss.

Connect the blue line from the IN jack to the left center lug of the switch.
Connect the green line that runs to the board INPUT to the lower left lug of the switch.
Connect the gray line from the OUT jack to the right center lug of the switch.
Connect the green line from the P1 center lead to the lower right lug of the switch.

[23]

if you get it up , let me know what it sounds like....>>>>>>>>>>>>>>

[Barcode80]

even so, he should still get sound when the switch is in the lower position.

[McGhie]

Haha I did miss that part, silly mistake, fixed now. Thank guys.
It still does the same thing though.
crapshit...

[gutsofgold]

I've never built anything like this before but I don't see why it wouldn't work. Did you make sure to bridge pins 1 and 8?

[Dragonfly]

In case anyone is interested, here is a PCB layout. I added a pulldown resistor, input and output caps, and power supply filtering for better performance and more stable operation.

[McGhie]

Holy **** nice one Dragonfly! Thanks! (Will have to convert those traces to wires on perf)

ALSO, I've found the "site" where I got it from.. I'm sure you'll find it as ironic as I do. Anyway:
http://www.aronnelson.com/gallery/main.php/v/zond/GEARBOX/

[Cardboard Tube Samurai]

Lugs 1 and 3 on the pot are back to front too

[McGhie]

As a matter of fact, I think I won't build the improved version, I cut my perfboard rather tight.

Lugs 1 and 3 on the pot are back to front too

Cheers!

[McGhie]

http://www.diystompboxes.com/smfforum/index.php?topic=63976.0

Found this too.

The last post describes the exact sound of my try at the Underfuzz.

[Renegadrian]

I think I'll try this one...Seems a quick one...

[newfish]

Have one of these on my Breadboard right now.

It doesn't work (yet) - all I get is a ticking noise.

More brainwork is required...

I'll be sure to read these threads though.  Cheers Guys!

Does it matter which flavour of 386 is used?  I've checked pinouts and it *seems* correct - I think mine are LM386Ns...

[McGhie]

Have one of these on my Breadboard right now.
It doesn't work (yet) - all I get is a ticking noise.

This starts to seem like it isn't a coincidence.. Three people with the same noise from the same layout..

Does it matter which flavour of 386 is used? - I think mine are LM386Ns...

So are mine.

[petemoore]

  Are you using DC blocking caps ?
  The first layout doesn't show any.

[McGhie]

  Are you using DC blocking caps ?
  The first layout doesn't show any.

In that case, nope. What kind of value are we talking about, and would that explain the signal not getting through and the crackling noise? The last one yeah, I reckon..

[McGhie]

By the way Dragonfly, can you confirm that the/your Underfuzz circuit works as it should?

[McGhie]

bump

[newfish]

I'm due some 'solder-time' tonight - so will try decoupling caps.

My 'stock' caps are 0.01uF on the input - and think i'll try a 0.1uF on the output - as there's a bit more bass coming out (hopefully).

Am now kicking myself for not putting the most basic of DC filters on.

Talk about a blonde moment...