News:

Forum may be experiencing issues.

Main Menu

Slambox V4 help?

Started by Giantsinbloom, April 22, 2013, 06:12:19 AM

Previous topic - Next topic

Giantsinbloom

Hello all!

Okay, so this isn't technically my first build. I attempted a sabretooth about 2 years ago and many of you were amazingly helpful with that. Then gradschool hit giving me no time for anything and I couldn't get all the kinks worked out.

I finally am getting back into it, and pulled out an old slambox PCB I had for my first build. I really practiced my soldering this time around and I think everything looks "okay" but I unfortunately have some issues. Sorry ahead of time about ONLY green and black wiring... used what I had.

Thanks ahead of time for any help!

Project Name: Slambox V4 ( I followed this wiring diagram for the stomp box harness. http://www.madbeanpedals.com/tutorials/downloads/StandardWiring_MBP.pdf)

General description of the problem: I get no dry signal when the effect is not engaged, just silence. Then when the effect is engaged it is a very loud buzzing. Rotating the pot, changes the level and intensity of the buzzing.

Steps that you have taken to try to resolve the issue: Double checked my wiring against the schematic and the madbean diagram previously linked. Checked for soldering bridges. Re-soldered some weak joints.

Substitutions: I substitued R1 and R2 with a 2M2 as suggested in the directions to achieve a bit darker sound.

Here are some pictures which I hope will help











P.S. When i read "rock it before you box it... I thought this meant dont put it in an enclosure prior to testing which has led to this spidery looking chaos... yeah... ha!

Haberdasher

sounds like there could be a grounding problem.

try grounding the sleeve of your input jack (this is normally grounded up against the metal enclosure, but no enclosure- no ground :) ).  you can just run a wire from the sleeve of the output jack across to it if that's the easiest thing to do

if you are going to be building more stuff it will probably be worth your while to build a test rig for the rocking before boxing bit
Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS

Giantsinbloom

Quote from: Haberdasher on April 22, 2013, 12:58:40 PM
sounds like there could be a grounding problem.

try grounding the sleeve of your input jack (this is normally grounded up against the metal enclosure, but no enclosure- no ground :) ).  you can just run a wire from the sleeve of the output jack across to it if that's the easiest thing to do

if you are going to be building more stuff it will probably be worth your while to build a test rig for the rocking before boxing bit

This morning I went ahead and threw it in my enclosure prior to heading to work. I tried it out and now I have buzzing when the circuit is not engaged and engaged. The only difference is that when the circuit is engaged, the buzzing is slightly more subdued. Does this mean that one of my ground wires is maybe improperly routed?



Also I ordered all the parts for a test kit last night after realizing my mistake. Pretty excited to be able to throw that one together!

Thanks.

Haberdasher

you know what?  I can't tell for sure but it looks like the ground wire coming off the bottom left lug of your stomp switch is hooked up to your input jack tip instead of its sleeve.
I think you need to switch around those wires on the input jack and you may be good to go
Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS

Giantsinbloom

Quote from: Haberdasher on April 22, 2013, 02:43:30 PM
you know what?  I can't tell for sure but it looks like the ground wire coming off the bottom left lug of your stomp switch is hooked up to your input jack tip instead of its sleeve.
I think you need to switch around those wires on the input jack and you may be good to go

Looking back through my photos you are absolutely correct. I need to flip those around when i get home.

Man and I had run through the wiring like 10 times. Thanks for the extra pair of eyes!

I will report how things go when i get home, now I just have to get through work...

Giantsinbloom

It Works!

Again thanks for your help :)


Haberdasher

Looking for a discontinued madbean board?  Check out my THREAD

FABBED PCB's FOR SALE:
Now carrying Matched JFETS