Author Topic: A few n00b questions. parts and problems.....  (Read 7967 times)

aab0mb

A few n00b questions. parts and problems.....
« on: June 10, 2007, 10:44:35 PM »
I'm building the NPN boost.
First, I have jacks from a crybaby wah.  I assume these are ok for this build and there's nothing special about them. (one stereo, one mono)
Second, I have a radio shack audio taper 5k pot. Is this ok?  Third, where would I put the 47uf cap on the board? Between the 22uf and ground? I want it off of the pot.
     I've checked the wiring multiple times and it all appears correct.  I'm hardwiring it to the board w/ no switch. Just jacks, power, and pot.  With no switch, I assume that all three connections on the stereo jack are still required, correct?  The soldering is nice and neat.  The problem I'm having is the old  "the pot doesn't do anything" number.  I've read all the posts with no luck finding a solution.  It has a kind of "loading feel"  effect on my guitar volume knob.  It passes signal w/ or w/out the transistor (3904).  Could it be blown?  I checked it both ways but yielded no results.  Any ideas?
     On a side note.  This is a great place.  Thanks to all contributing members.

respect,
Aaron

aron

Re: A few n00b questions. parts and problems.....
« Reply #1 on: June 10, 2007, 10:56:21 PM »
It's the same answer. Somewhere there's a wiring mistake. It could be on the jacks, it could be in the board itself, but there's a mistake for sure or else it would work. Carefully look over the board and trace out what you have on paper against what you see on the board - not what you expect to see. Something this will help you find your mistake.

Check out this page:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #2 on: June 11, 2007, 08:33:09 PM »
I read a thread about a jack that was not an actual stereo jack and they had to hook it up a little differently.  Could this be the case w/ old crybaby wah jacks?  Also the 2n3094 should have the flat side facing the input cap, right?  Their should be no crossed pins on the 2n3094 for insertion right?
     Sorry to beat a dead horse (or pedal) but I built it twice while strictly following the layout.  And wired it just like the pics and the schematic.  The wires are all going to the right spots.  It leads me to believe that one or both jacks may be a little different than what I need. 
     Could I wire it for non-bypass for test purposes?  How would I do that?
Trying not to enter frustration phase.  I'm keeping the faith because I really want a booster and the feeling of accomplishment.  :)

thanks,
Aaron

aron

Re: A few n00b questions. parts and problems.....
« Reply #3 on: June 11, 2007, 11:41:41 PM »
You need a meter and need to figure out the "stereo" jack. In any case, for the "stereo jack", just connect the battery black to the sleeve instead of the ring. That will treat it like a mono jack and the battery will be on all the time.

aron

Re: A few n00b questions. parts and problems.....
« Reply #4 on: June 11, 2007, 11:42:13 PM »
BTW: did you check out that debugging page I linked to?

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #5 on: June 12, 2007, 01:51:29 AM »
     Yeah I looked at the trouble shooting guide but didn't have access to the MM until today.  One thing I noticed is that with the one lead from the top lug of the pot as shown, to the 22uf cap and one to the bottom to ground and the 47uf cap across the middle lug to the bottom lug (positive to the middle)  it just makes the signal pass unaltered.  So, I removed all the connections on the pot and did ground to the bottom lug and the 22uf lead to the middle lug, suddenly the pot worked but no boost.  I put the 47uf cap back on in the required fashion and it turned it to the type of pot that comes on at the last part of the rotation (in a bad way)  but still no boost.  Could the diagram have a flaw? It seems that all of the problems stem from the pot issue.  I'll keep plugging away, and I now have my MM back so hopefully it goes a little better.

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #6 on: June 12, 2007, 02:25:16 AM »
yeah OK, if the ground and 22uf cap are connected to the outer lugs wouldn't that just pass signal unaltered.  The wiper wouldn't have any effect, right?  Or, is that what the 47uf cap is for.  Ugggggg. 

still trying........

aron

Re: A few n00b questions. parts and problems.....
« Reply #7 on: June 12, 2007, 04:53:26 PM »

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #8 on: June 12, 2007, 05:55:58 PM »
     Yeah the cap on the pot.  It seems like it actually makes the pot function way worse.   I've systematically tried all the alternate wiring ideas for the pot and the jacks but no luck.  I've  triple checked the component placement everything follows the schem.  There are no solder bridges, I've used a pin between anything that is a possible bridge.  Really having trouble getting solid readings from the MM but the continuity function indicates that all the connection are good.  I've tried a different tranny both ways w/ no luck.  Maybe my socket is attached badly.  It was a little hard to keep stationary.  I switched from the log pot to a linear of the same value just in case.  I replaced the 47uf which was mangled w/ a fresh one.  I guess if all else fails I'll build #3 but i'm gonna run out of money, solder, parts and soon.   Patience... I do have a little left.  Hopefully just enough to get my guitar really loud.  :)

hmmmmmmmm???

Has there ever been a thread that has a comprehensive overview of potential problem after construction.  What I mean is people post what their problem was and how they figured it out and fixed it.  Yeah, the debugging page is great and helps a lot.  Just thinking out loud (on the page) I guess.

Thanks Aron.

aron

Re: A few n00b questions. parts and problems.....
« Reply #9 on: June 12, 2007, 10:00:36 PM »
> if the ground and 22uf cap are connected to the outer lugs wouldn't that just pass signal unaltered.

But the cap is not connected to the outer lug like you say.

Aron

aron

Re: A few n00b questions. parts and problems.....
« Reply #10 on: June 12, 2007, 10:01:03 PM »
Can you take a picture?

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #11 on: June 12, 2007, 10:47:16 PM »
I meant the red line on the top lug which goes to the 22uf cap on the board on the picture and the black line that goes to the ground rail.  I didn't mean that I have the 22uf actually on the pot.  Sorry for the confusion.  I do have the 47uf cap on the bottom and middle lug with the neg. going to the bottom just as indicated.  I'll try to get a pick up.

thanks.

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #12 on: June 12, 2007, 10:58:44 PM »
ok. uuuhm. I had the 22uf backwards. so...I'll switch that and see what happens.  oops.  duh.   The joy of trouble shooting, huh.  I'll be back with good results hopefully. ;D

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #13 on: June 13, 2007, 12:49:28 AM »
<a href="http://photobucket.com" target="_blank"><img src="http://i155.photobucket.com/albums/s289/aab0mb/Pot1.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

The bottom goes to ground.  The top goes to the board output.  the positive side of the cap is on the middle lug.

<a href="http://photobucket.com" target="_blank"><img src="http://i155.photobucket.com/albums/s289/aab0mb/Inputjack1.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

From left to right it goes Battery ground lead (black), middle lug to board ground, right hand side goes to negative side of the 22uf cap on the board.

<a href="http://photobucket.com" target="_blank"><img src="http://i155.photobucket.com/albums/s289/aab0mb/Outputjack1.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

The 22uf cap when turned around to the correct orientation didn't seem to do to much for my particular problem.  Do these look correct?

Left side is to the board output, right is to ground.

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #14 on: June 13, 2007, 12:52:01 AM »
Sorry about the phone camera picks.  It's all i got.....

aron

Re: A few n00b questions. parts and problems.....
« Reply #15 on: June 13, 2007, 01:16:23 AM »
<a href="http://photobucket.com" target="_blank"><img src="http://i155.photobucket.com/albums/s289/aab0mb/Pot1.jpg" border="0" alt="Photo Sharing and Video Hosting at Photobucket"></a>

The bottom goes to ground. 

Correct.

 The top goes to the board output.  the positive side of the cap is on the middle lug.

Correct about the positive side of the cap, wrong about the top going to the board output. It should go to the emitter of the transistor.



>From left to right it goes Battery ground lead (black), middle lug to board ground, right hand side goes to negative side of the 22uf cap on the board.

Well for debugging you could connect the battery ground to ground itself on the board. Also the sleeve of the jack should go to ground as well. The “right hand side” should connect to the .1uF cap on the INPUT.


Impossible to tell with the pics, but correct the above for starters and look at the pictures of the way I hooked mine up.

http://www.diystompboxes.com/beginner/offboard.jpg

Aron

aab0mb

Re: A few n00b questions. parts and problems.....
« Reply #16 on: June 13, 2007, 05:35:02 AM »
ok. Got it. We win!  Aron you are a prince among men.  Thank you sir.  See my next post for details.  ;D :icon_biggrin: :D