Author Topic: NPN Boost - Problem wiring 3PDT switch  (Read 5369 times)

jcwillow777

NPN Boost - Problem wiring 3PDT switch
« on: February 06, 2007, 06:58:17 PM »
I did the NPN boost today. I had it working for a while. After I got the board wired, I just hooked up a battery and mono input and mono output jacks to see if it was working. It worked great. So I had confidence to wire the switch, that's where I lost it. The first time I wired it up with a mono output jack to a diagram in Brain Wampler's book on building guitar effects. No go. So I wired it like the diagram Aron drew for the 3PDT switch with a stereo input jack. No go again.  Here are some pics. I can't figure out how to import them into this post, so they are on line.

http://s137.photobucket.com/albums/q232/jcwillow777/Boost/

Once I get this going, I would like to do another one for a friend, but I really like just using mono input jacks, cause I only want to use a 9VCD jack. That's what I plan on using in the one I did today, as soon as it is working. Any incite would be great. How do I insert a picture? I hit the insert icon, but I have no idea about how to insert the Picture. I have no insert picture option on my browser.

Thanks again in advance for you help.



Barcode80

Re: NPN Boost - Problem wiring 3PDT switch
« Reply #1 on: February 06, 2007, 08:02:08 PM »
we need symptoms. do you get sound when bypassed? does it work but not sound right?

to insert an image you have to get an online photo storage account (www.photobucket.com is a good free one) and you insert the link from there into the post. You can't directly insert images into your message any other way.

jcwillow777

Re: NPN Boost - Problem wiring 3PDT switch
« Reply #2 on: February 06, 2007, 08:55:40 PM »
I didn't try the pedal until now, I just assumed it didn't work because I hooked up a battery and the LED didn't come on so I assumed it didnt' work. The bypass works and the pedal works, but not very much boost. LED doesn't light up and there is a scratchy noise on the low end of the pot. I didn't have a 5K so I used a 10K instead. Before I hooked up the switch the pedal had quite a bit of boost and a little distortion at the top end, nothing like that now. I'm going to post this and then try to post the pictures in the following post. I just tried to but I got a message saying I ran out of time and nothing was posted.

jcwillow777

Re: NPN Boost - Problem wiring 3PDT switch
« Reply #3 on: February 06, 2007, 08:57:34 PM »
Trying to post pictures again.





Thanks again

jcwillow777

Re: NPN Boost - Problem wiring 3PDT switch
« Reply #4 on: February 06, 2007, 09:08:49 PM »
I forgot to mention, the pot does affect the volume. It doesn't turn totally of, but close. After playing with the pot, it have to say is it scratchy for most of the way.  I guess I'll just forget trying to put the pics in the post, I guess I'm just to dense to figure it out.

Barcode80

Re: NPN Boost - Problem wiring 3PDT switch
« Reply #5 on: February 06, 2007, 11:27:12 PM »
1) if you solder a 10k resistor in parallel with the pot you will make it a 5k

2) it sounds like you have something grounding now. since this didn't happen until you added the switch, i would check the lugs on the switch and make sure a glob of solder isn't bridging them. this might cause your 9v lug for your LED to short against the output wire of the pot that is soldered to the switch. i think this actually would be a likely cause of all the symptoms you list.

try removing the switch again and ensure the circuit still functions without it like before.

aron

Re: NPN Boost - Problem wiring 3PDT switch
« Reply #6 on: February 07, 2007, 02:33:36 PM »
Your switch looks like it is wired correctly to me:

http://i137.photobucket.com/albums/q232/jcwillow777/Boost/Boost2.jpg


jcwillow777

It's alive - I was making it too hard!!!
« Reply #7 on: February 07, 2007, 09:54:57 PM »
The pedal lives!! I guess it was just too easy and obvious. I have five pedals on my bench that I have put together and none of them work, so I just assumed I srewed something up in putting it together. I checked the battery and it was only 7.67V. I put in a new battery and voila - it worked and sounded great. The LED still wasn't working, so I decided to pull it out and check it and sure enought it was burnt. So I replaced it. The LED works and the pedal sound great!! Thanks for posting the project Aron. I think I'm gonna make another one, but I still wanna experiment with some different NPN transistors first. I am a happy camper!!! Tomorrow night I will drill out a case and mount it and add a 9VDC jack.

Thanks again Aron.