LPB-1 with Mid Boost Filter - need help

[vicfiveleven]

Hi,

Built this http://guitar-fx-layouts.42897.x6.nabble.com/Utility-LPB-1-with-Mid-Boost-Filter-td10587.html#a46901.

Just found out that there's very low output and you'd have to crank the amp volume to hear a signal.  After running an audio probe it has signal when entering the 390k but when out to 9th row there's no sound.  Could that be a busted part?

Also, I looked at the data sheet for 2n5133 and saw that they have the same pinout for 2n5189 w/c is a good replacement for 5133 as what I've read.  Is it okay to use it and plug in the same orientation? I noticed that 5133/5089 pins 1 2 3 are E B C though.

Here are some pictures of the build:





Thanks in advance for the help.

[Marbles]

Hi!

Yes, you should turnaround your transistor, the pinout is reversed form the orientation on the layout. You can always safely do that I think with your silicon transistors. A lot of Devi Ever circuits do that. Just put the transistor in the other way and you have another cool sputtery fuzz ;)

Could you also tell me what values you used to come up with 11M? If you used 5m and 6m for example, I think they should be wired in series instead of parallel.

Your 9th row is ground. So it's correct you don't have any signal there.

[vicfiveleven]

I wired in parallel two 22M to get 11M.

[vicfiveleven]

How is the signal traced here by the way?  Should I trace it like this:

input > .1uF > 430k > 10k > collector pin > .1uF > 15nF > 11M > Tone 3

Sorry for being such a noob.  This is my 6th pedal build and the 2nd that didn't work right away. :(  I know, not all builds work right away the first time. But this is so small and looked like all parts and wires were soldered correctly.  Don't know where to look except using an audio probe and I'm not that good at trouble shooting yet.

But thank you for clarifying regarding the transistor orientation.  Just need help tracing the signal now.

[Marbles]

Oh, I'm a total noob when it's about reading schematics and tracing a signal, sorry. I do it by letting other people also check the top and bottom of my builds haha. And by doing it lots you will make lots of mistake. Every new thing that causes it not to work will be saved in your brain somewhere, and will be something you check next time.

One thing I would advise though, to keep it simple, is use the parts mentioned in the layout. It could be a money thing, but then again, a resistor or cap is cheap as chips and no need to put in parallel or series. It's another connection that can fail and could be harder to spot cause it's a bit messier.


From what I gather the flipping of the transistor didn't work? It normally is a possible cause for a signal not to come through fully. Or a solderbridge, but I can't see the bottom of your vero. Also the top placements is hard to see, but I'm sure you went over that multiple times.


This is probably not all true, but from what I think to know:

Your signal comes in from input. Goes through the first cap. The resistors 43k and 430k set the voltage for the transistor, they don't pass signal. So your input goes from the input through the .1uf cap to the base of the transistor. You could say that your signal then goes from Collector through .1uf, through 15nf to your tone 1, to tone2, to volume and then output.


Ish… Like I said, I'm not that good at following it. But that's roughly how you could follow it on the vero.

I think ;)

[vicfiveleven]

Yeah.  I totally get the point about putting parts in series or parallel.  It's another point that could potentially fail.  But I had no choice.  Those are rare values for my stock parts here and ordering online from my country is either too expensive or will take weeks to arrive. Sucks. But I'll keep that idea in mind. Thanks.

I tried the transistor both ways and yes, it didn't work.  Seems that the 4th row (collector) has no signal.  Even with the transistor plugged in the other way that row doesn't have any signal.  hmmmm I'll try and score it with razor blade again when I get home.

Thanks.

[vicfiveleven]

Hey, I did score all the lines with razor to no effect. Now I’m trying get the voltages of each trans pins. I don’t know if I’m doing it right but what I did was clip the black probe to ground and the red I used on each pin. On the dmm I selected 20 under DC volt. Am I doing it right? This is what I got:

E 0.41
B 0.83
C 9.16

Please tell me if I’m doing it wrong or not. If not, how to get voltages the right way. If I did it right, are the voltages normal?

Thanks.

[aelling]

Did you install the 430K resistor from base to +9v? I can't see it in the pictures.

EDIT: I think I know what the problem is, this is a LBP-1 with a Big Muff tonestack after it, the BM tonestack will create a volume loss unless you put a gain stage recovery after it. That's also what rocket88 mentions. You can do this by making another LPB-1 and have this effect going into it.

[vicfiveleven]

Yup it's there. The .1uF is covering it. But the volume loss is too much. I'd have to crank the amp to full just to hear a faint signal.  This was supposed to be going in a 1590BB enclosure with another distortion circuit I made or if I change my mind, I'll just put it in a 1590A enclosure so I can move it around my pedal boards.  Am doing this wrong?

What can you say about those voltages?  Cause if I can't have this running maybe I'll just make another one using just the stock LPB1 layout that I found I think posted by IVIark.  But the tone control on this caught my attention.

Thanks.

[vicfiveleven]

Nevermind, I just boxed the other lpb-1 layout with just the volume pot. With luck it worked right away.  I used 2N5089 and it sounded better for me.  Thanks for all the help guys. :)