Breadboard Annoyance

[Faber]

Okay, so I've been breadboarding SIMPLE NPN boosts (LPB2) on my breadboard for the past two days and I'm about to throw the thing across the room.  I've tried the search, and I'm still stumped.

I have the power and ground supplies bussed up like everyone suggests.
I've checked my connections many many times.
When I plug the battery in, it sounds exactly the same as when the battery isn't plugged in.
If I switch the transistor's orientation to the wrong way, it sounds exactly the same.
When I take the transistor out, it sounds exactly the same.
Even better, I've already built the pedal, and it works great.

Like I said, I'm a little annoyed with the whole thing, and I've already tried sleeping on it.

Any ideas?
Thanks!

[ianmgull]

I've never been able to get a project to work on a breadbord. 

[ayayay!]

Breadboards, I have found, require me to really "feel" each and every pin to be fully seated, and having my eyeball up to the board helps too.  I'll agree that you have to be gentle when moving the breadboard or putting in new components so as not to disturb the other ones, but yes they do work and yes they are a great tool. 

I've built the LBP2 on my breadboard, and even as simple as that circuit is I didn't get it right the first try, but I did on the second.   

[DougH]

Your DVM is your friend here. Check that everything you 'think' is connected is actually connected. Verify the resistors are actually the values you think they are. Check the transistor and caps. And finally, make sure everything is getting 9v that is supposed to.

[CGDARK]

The breadboard is the best tool for the DIYer. First you have to know how is the layout of your breadboard (not all boards are equal). Second you have to study the schematic in order to know what connect to what (use the data sheets for pinouts) and third try at first to use as much space as needed so you can see clearly what is happening then as you progress you can save space and test bigger projects. I remember when I was a newbie when I breadboarded the Craig Anderton phaser from EPFM in a single RS breadboard. It looked like a laberinth but it worked the first time the rest is history.

Good luck,

CG

[slacker]

How have you connected the signal to and from the breadboard?
You need to make sure the signal ground, from both the input and output jacks is connected to the breadboard or power supply ground otherwise you can get exactly the problem you're having.

[frank_p]

It's easy to make "wrong" connection on a breadboard.  You think you have plugged your component at the right place, but it's only one row over or under where it should be. 

Like Doug said, use your multimeter and the audio-test-probe.  I think that a breadboard is a good place to learn how to debug because:
1- Simple things might often go wrong ,
2- It's easier to use your ampmeter to see if the OK currents goes through your components.  Unplug, test, replug (at the right place).

Get some clips of a sort to put on you probes (alligator, hook, etc) to keep you DVM on places you want them to stay while playing with you connections.
It's not the best practice, but at first it helps and after a while you'll not need it anymore.

[DougH]

Remember- what you have on the breadboard is just another circuit. The same debugging principles (as outlined here in the stickies) for perf, pcb, etc apply.

[Thomas.R]

if you work in the middle of the breadboard don't forget that the power rails are not connected  in the middle with certain breadboards.
my solution when something doesn't work after a quick troubleshoot, start over the whole thing.

thomas

[Faber]

Thanks, guys!

Brilliant!

[jefe]

if you work in the middle of the breadboard don't forget that the power rails are not connected  in the middle with certain breadboards.

I had this very problem recently - I didn't realize that the power rail was split into 2 sections on my breadboard, so only about half my circuit (big muff pi) was getting power. I finally figured it out when I started poking around with my multimeter... "let's see, I'm getting 9 V here, and here, uh, why no power here, or here... ah ha!" One small jumper fixed the problem.

[Faber]

It was the jacks not being connected well.   

Thanks again!

[Jered]

  Stick with it. Once it becomes easy its the best DIY tool for FX. How else can you try three or four different circuits in an hour or two. Remember they do wear out. When I was using mine on a daily basis, I would have to replace it every 3-6 months.
  Jered

[ConanB]

I find the breadboard is a great tool for trying out an FX before I solder it all up. Only issue I have is noise; I always seem to end up with alot of noise and pots are very grainy, but when soldered up in a box the grainy pots are fixed but I do have slight noise still (my bad soldering and wire dress no doubt).

I did just buy a new small breadboard I was planning on using for tone control testing but ended up moving my breadboarded NPN Boost from my larger board to the small one and now it wont work, even after double checking connections. Need to check a bit more, but it is a different brand of board so I'm hoping it doesnt have any issues.

[Derringer]

if you work in the middle of the breadboard don't forget that the power rails are not connected  in the middle with certain breadboards.
my solution when something doesn't work after a quick troubleshoot, start over the whole thing.

thomas

I just learned this one the hard way

I had one breadboard that was/is occupied, ordered another from a different make and was frustratingly surprised to find that the rails were not internally connected!

This is where a continuity checker comes in handy.

[juse]

I find the breadboard is a great tool for trying out an FX before I solder it all up. Only issue I have is noise; I always seem to end up with alot of noise and pots are very grainy, but when soldered up in a box the grainy pots are fixed but I do have slight noise still (my bad soldering and wire dress no doubt).

Breadboards are notorious for stray capacitance issues as well. Just the way they are made alters values and introduces noise. Certain circuits don't like the breadboard because of this. But, that being said, breadboarding is still one of my favorite things to do.

Half the time when one of my breadboard circuits doesn't fire up, it is because of something simple, like a missing ground connection somewhere or a skipped row. It's easy to do & many times one little thing wrong keeps the whole thing from working. But, tracing with schematic in hand almost always works.

[ConanB]

Half the time when one of my breadboard circuits doesn't fire up, it is because of something simple, like a missing ground connection somewhere or a skipped row. It's easy to do & many times one little thing wrong keeps the whole thing from working. But, tracing with schematic in hand almost always works.

Been over the schematic a few times and it looks right, but it only just occured to me this new smaller breadboard doesn't have coloured stripes easily displaying where the power rails start and end, so maybe thats the case with this small board; the power rails are seperated after each 5th hole? The board is only about 30 holes long and 14 wide.

[juse]

Been over the schematic a few times and it looks right, but it only just occured to me this new smaller breadboard doesn't have coloured stripes easily displaying where the power rails start and end, so maybe thats the case with this small board; the power rails are seperated after each 5th hole? The board is only about 30 holes long and 14 wide.

Could be... have you tried beeping it with a DMM to see if the pwr/gnd rails go the length of the board? May be jumper time.

[nebucanazza]

I check my jumpers for the power rails from time to time...I had a bad experience where one of them got loose and left  half the circuit without power. But now I am quick to use the DMM to check whether basic  +9V and ground connections are working. Another technique I usually employ for debugging is - Connect your guitar, take the hot wire of your output jack and start checking the output right from the beginning of the circuit. Within minutes you will find the problematic component/connection( plus it's fun to hear what each stage is doing to your signal )

You could also label your +9V and Ground with a pen and use the same convention all the time. I have even marked 'DSG' at 4-5 spots for JFET circuits.

I tried an IC circuit on the breadboard for the first time recently but it just won't power up while directly plugging the IC or using a socket(9V and ground were correctly supplied to proper pins). This is odd as I have done many IC on breadboard circuits in college. I finally gave up and soldered the circuit directly.

[R.G.]

Breadboards wear out from repeated insertions and removals of leads.

Breadboards should be stored *upside down* or in a drawer where dust setting on them does not get into the holes.