Author Topic: NPN Booster PROBLEM  (Read 5741 times)

Barcode80

NPN Booster PROBLEM
« on: September 22, 2006, 05:06:36 AM »
I wired the circuit, soldered, added everything accourding to specs. However, when I plug it in and fire it up, it's like it is on permanent bypass. I have normal signal coming through from my axe, but no matter what position the switch is in the effect doesn't turn on and the pot won't work. Interestingly, When I unplugged the pedal from the power supply (i replaced the battery leads with a wall wart jack since that is how i power all my pedals), nothing changed. It is as though I wired a very fancy barrel adapter! HELP!

pyrop

Re: NPN Booster PROBLEM
« Reply #1 on: September 22, 2006, 06:17:00 AM »
Hi Barcode80 and welcome to the forum.
Sounds like your foot switch wiring is wrong.
I suggest using the search button and search for wiring footswitches or look at General Guitar Gadgets for wiring information.
http://www.generalguitargadgets.com/index.php?option=content&task=category&sectionid=4&id=23&Itemid=200
Also read up the what to do when it doesnt work thread for more help.
http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
good luck

pyrop ;D

Barcode80

Re: NPN Booster PROBLEM
« Reply #2 on: September 22, 2006, 01:27:30 PM »
woops, after reading the "what to do when it won't work" thread, I feel i should amend my "to specs" statement. There are 4 slight differences between the schematic and my build:

1) subbed a .33uF electro cap in place of the .22 as i had no .22's and a post elsewhere in the forum stated this would be fine.

2) subbed a metalized film .1uF at the input instead of the one pictured.

3) in the schematic it appears that the 47uF cap on the pot is an electro, i used a film cap

4) I have wired the 9v + and ground to a power supply jack instead of a battery lead


if i posted this right, the pic (in crappy 5 minute ms paint format) shows how i have wired the switch and the jacks.

Barcode80

Re: NPN Booster PROBLEM
« Reply #3 on: September 22, 2006, 01:28:59 PM »
dang it, can anyone help me as to how to post an image?  :icon_biggrin:

aron

Re: NPN Booster PROBLEM
« Reply #4 on: September 22, 2006, 04:05:49 PM »
Quote
in the schematic it appears that the 47uF cap on the pot is an electro, i used a film cap

Hmmm, doesn't seem likely. A 47uF film cap would be HUGE!

It really sounds like your problem is with your switch wiring.

Info on how to post pics are in the About this forum:

http://www.diystompboxes.com/smfforum/index.php?topic=21.0

Barcode80

Re: NPN Booster PROBLEM
« Reply #5 on: September 22, 2006, 08:07:58 PM »
here is how i have it wired. maybe i overheated the internal switching mechanism while soldering...


Barcode80

Re: NPN Booster PROBLEM
« Reply #6 on: September 22, 2006, 08:45:45 PM »
hmm, maybe i used a .47 instead of a 47 cap. my conversions are sometimes shakey  ;D Though you know WAY more about this than I do (I literally started building circuits like a week ago), the switch and jacks are built into a test box, and I think I remember them working for the last build, but on the other hand, I never got that one to work fully either.

Barcode80

Re: NPN Booster PROBLEM
« Reply #7 on: September 24, 2006, 03:58:53 PM »
okay, i have now attempted to build this NPN booster, another simple clean boost i found <a href="http://www.kilback.net/homebrewtweaks/pedals/cleanboost.htm">here</a>, and a fuzz i found <a href="http://personal.inet.fi/koti/holmberg/images/sfuzz.gif">here</a>. I have failed at all three, and I am about to yank my hair out, as I don't know what I'm doing wrong. I've attached everything properly to ground, I have a fresh battery in the test box, everything. I even checked the test box components (which is hard to screw up as it is just a couple of mounted and wired jacks)My only hope is that I am frying a component, using some bad ones (i cannabalized a danelectro fabtone for a bunch of caps and trannies, although the pedal worked perfectly before i dismantled it), because otherwise none of this is making nearly as much sense to me as i thought.at least on the last fuzz i tried to build i got signal. but the signal was so weak i thought the battery was dead in the box. replaced it, no dice. something is wrong with the wiring. any pointers would be great.

ps - Aron, i totally removed the switch from the circuit per your advice about the switch wiring. no dice!  :(