madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: stazinish on October 23, 2010, 06:04:28 PM

Title: Snack Shack Meathead not working
Post by: stazinish on October 23, 2010, 06:04:28 PM
Hey all. I started this project quite a while ago. Never worked. I compared the wiring to the diagram but could never find an error. I figure it has to be with my board. See any mistakes? Any help would be appreciated.

(http://img97.imageshack.us/img97/461/topsj.jpg)

(http://img169.imageshack.us/img169/807/bottomfp.jpg)

I can take some different pictures if these aren't very helpful.

-Tyler
Title: Re: Snack Shack Meathead not working
Post by: madbean on October 23, 2010, 06:16:00 PM
Cap and transistor orientation looks correct. You have the wrong value for C2, though. It looks like you've used a 470n and it should be 470pF.

The traces and soldering look good. What transistors did you use?
Title: Re: Snack Shack Meathead not working
Post by: stazinish on October 23, 2010, 06:35:32 PM
I used the transistors called for in the document. Would a wrong cap value lead to me getting nothing? When I would turn it on I wouldn't even get the led to work.
Title: Re: Snack Shack Meathead not working
Post by: jkokura on October 26, 2010, 04:19:02 AM
when you're like 1000 times the capacitance? Probably. Think of it this way... it calls for a 470pf cap, and you used a 470,000pF cap. That would be like paying 470 grand for something that should cost you 470 bucks...

Well, it's not quite like that, but using wrong parts can be drastic. I used the wrong resistor value in a tubescreamer and got the most bizarre volume drop. I used a 100k instead of a 100R (same ratio as you) and it brought the volume down to almost inaudible.

Jacob
Title: Re: Snack Shack Meathead not working
Post by: madbean on October 26, 2010, 03:36:41 PM
stazinish...one other thing. If you used the BC182 did you twist the leads around to fit the correct pin-out on the board as indicated on the build docs? Kinda hard to tell from this pic.
Title: Re: Snack Shack Meathead not working
Post by: stazinish on October 30, 2010, 06:34:50 PM
I believe I have them bent the right way. I'm waiting on a new cap for C2 from smallbear. Should be here in a few days. Hopefully I'll get this little guy working.  ;D
Title: Re: Snack Shack Meathead not working
Post by: stazinish on November 02, 2010, 12:25:59 AM
So I'm thinking the problem is with my wiring. I'm still getting nothing with the new cap. I have clips where the wires would be attached to the jacks for now.

(http://img263.imageshack.us/img263/7166/bleht.jpg)

Any ideas?
Title: Re: Snack Shack Meathead not working
Post by: jkokura on November 02, 2010, 12:47:51 AM
Yeah, hate to say it, but your wiring looks bad.

My suggestion would be to start over, and be really careful about it. Another suggestion is to hook up the board to power, ground, and your input and output jacks OUTSIDE of the box. If it works outside of the box without the switch, you know it's the wiring. If it doesn't work, then the problem is on the board! Don't forget to ground everything that needs ground...