No boost in first LPB-1 build

[Filip]

I have just finished boxing up my very first pedal build. I decided to go for the EHX LPB-1.

Prior to boxing the effect up I test it and it worked as expected. But after boxing it up it does not boost anymore.

When I hit the switch the LED lights up and when I turn the volume pot down the volume goes down and when I turn it up it goes up, but never beyond the initial volume of the amp.

Since this is my first build I am not really sure what causes the problem and where to look so I appreciate all the help I can get.

Thank you!

Edit: I realized I forgot to post the schematics I used, here they are.

[GibsonGM]

Hi Filip, welcome, and congratulations on your first build!  The LPB is a fun one, and you learn a lot from it if you study the schematic.   The Vero layouts aren't as informative, but that's ok for right now.   

This happens often - it works, then it doesn't when you jam it in the enclosure!   First thing to do is to see if any wires are shorting out to the metal case.  Poking around with a pencil is a good way to do this.   Make sure the volume pot isn't shorting out, either.   The LED or its resistor can sometimes touch things they should not.  Sometimes a wire seems properly soldered, but has a "cold joint" (bad solder joint), and moving the wire makes it work/not work, which means you have to re-solder the joint.   Check that your jacks and their wires are ok....

If none of that works, you might have to remove the board from the box again and see if that helps.   If it does help, you KNOW something is touching the enclosure (grounding out) or a wire is loose/badly soldered, and making intermittent connection. 

If NOTHING works, you may have accidentally shorted the transistor.   So, if you can't fix it by wiggling and moving things, read this:  http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

With the board out of the enclosure, you'd need to measure the voltages at the transistor for us.  Take it 1 step at a time and you will make it work again

A neat thing to put together is an AUDIO PROBE, which you can use to 'listen' to transistors and things, to trace where something might be malfunctioning. Read about that here:  http://www.diystompboxes.com/pedals/debug.html

[canman]

I just had a similar problem with a phaser I built...worked out of the box, but quit working in the box!  In my case, the pot somehow went bad on me.  I doubt that's your problem here.

I agree with the above comment, pull it out of the box and test it again.  I know Gibson mentioned things possibly shorting out...make sure that the solder side of your board isn't touching the metal case or the back of the pot (if the pot doesn't have a dust seal).

You'll get it working soon, no doubt!

[antonis]

Prior to boxing the effect up I test it and it worked as expected.
.......................................................................................
When I hit the switch the LED lights up and when I turn the volume pot down the volume goes down and when I turn it up it goes up, but never beyond the initial volume of the amp.

It doesn't make sense...

(if you haven't tested prior to boxing I would say that you have interchanged C & E - something like a Buffer with a Volume control..)

[Filip]

Today I continued debugging the pedal, after a good hour of checking that nothing was touching the enclosure and that everything was grounded an so on I decided to rip the board out and just redo it. It was such a simple circuit and I could use a bit more practicing with the soldering iron, so it seemed like a good idea. I redid it with a slightly different layout, put it back in the box, fired it up and...nothing. No sound at all. I ripped it out once again just to realize a cap was a bit loose. I soldered it back in place, put the board back in the box, fired it up once again and...there was sound! And a great boosted sound as well!  

Thank you all for your help, I feel very welcomed and I am already planing my next build!

And keep an eye out in the picture thread, this box will be there as soon as I have put the right knob on it!

(And I still really need to build one of those audio probes!)

[Kipper4]

Well done Filip an welcome to the forum.
I love it when  plan comes together.

[GibsonGM]

All we need, often, is just some encouragement and patience!  Good job! 

[canman]

Nice!!

I had to rebuild a few circuits, it's a right of passage