New DIY pedal doesn't work

Started by MilkymcMilkMilk, December 31, 2012, 01:07:45 PM

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MilkymcMilkMilk

I was referred to this website for some help.
I did my best to follow the debugging when it doesn't work thread to put this post together.

I built a devi ever Ruby clone using  this verified layout.  
http://tagboardeffects.blogspot.com/2012/06/devi-ever-ruby.html
I used this offboard wiring diagram  http://tagboardeffects.blogspot.com/2012/02/offboard-wiring.html
Only thing I did different than either of those diagrams was
add a ground wire on the veroboard right next to the one in the
diagram to connect to volume lug 1.

With the pedal bypassed my bass sounds fine.
With the pedal engaged the led comes on but no sound comes through.
I didn't include a battery connection and I don't have clips for
my volt meter.

Looking at that wiring diagram, what points would I test with
my meter?

Oh one thing I was curious about, the only spot I don't have a wire is on the ring of
the input jack, it's open.  would removing the extra ground wire I put on the veroboard to
go to volume lug 1 and hook lug 1 up to the ring on the input make any difference?

I am extremely new to this hobby, however I was able to successfully complete
a 1 knob fuzz pedal that has a battery connection, no power supply and no led.
So after that working out pretty well I thought i'd be able to do this pretty basic 2 knob jobby.
But i'm new to electronics and unfortunately have no real troubleshooting skills yet.
a few pics
http://i159.photobucket.com/albums/t122/Johnz24/DSC01709.jpg
http://i159.photobucket.com/albums/t122/Johnz24/DSC01706.jpg
http://i159.photobucket.com/albums/t122/Johnz24/DSC01707.jpg

Happy New Year!


rollo greb

check the wiring of the 3pdt. I can't tell from the photo if there is a jumper from the input jack wire to the other side of the 3pdt.

Also, check the bottom left of the underside of the board in the pic, there may be a solder bridge there?

Also, the underside of the board isn't touching the enclosure is it? (Sorry  ;D)

The ring of the jack shouldn't affect anything, with a mono cord plugged in it is just a ground point.

LucifersTrip

Quote from: MilkymcMilkMilk on December 31, 2012, 01:07:45 PM

Looking at that wiring diagram, what points would I test with
my meter?


the 3 lugs of each transistor

always think outside the box

garcho

try google-ing 'how to use a multimeter'. here's a quick rundown. It's really important to learn how to use one, but as rollo greb mentioned, the chances are high it will be wiring/soldering mistakes. You can use 'continuity mode' on your multimeter to check for soldering errors.
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Jdansti

Quote from: rollo greb on December 31, 2012, 01:43:01 PM
check the wiring of the 3pdt. I can't tell from the photo if there is a jumper from the input jack wire to the other side of the 3pdt.


It didn't look right to me either, but he's using this configuration. And it should work.  :)

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R.G. Keene: EXPECT there to be errors, and defeat them...

JOHNO

It looks to me that the collectors are going to grounded instead of the emitters..Try flipping the transistors around the other way.

MilkymcMilkMilk

there is a resistor lead from the input of the switch to the front middle, #4 lug I believe.
I may have cleared a solder bridge, it was close, hard to tell for sure, but I took a razor
blade to it and it's defintely not touching now.

There is one spot on the board that has a solder over a hole that has no component and joining
2 other neighboring solder points with components.  That shouldn't make any difference, should it?

Using my meter both transistors have the same read outs.

I triple checked that the wires on the switch are wired where they should be.

But obviously something isn't right.
But without more knowledge of what points to test with my meter I doubt this is going to work.


Jdansti

> It could make a difference. Are the two components that are joined by solder supposed to be connected based on the schematic?  If not, you need to disconnect them by removing the excess solder.
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R.G. Keene: EXPECT there to be errors, and defeat them...

MilkymcMilkMilk

I'm considering doing this build from scratch.
But I'd have to use the same pots, but I'm not sure they're still good.
Is there a way to test to determine if a pot is bad or not?
other than using a different one?

Jdansti

Sure. After you desolder the pots, place your meter (set to resistance (ohms)) across the outer two lugs. The reading should be approximately the resistance rating for that pot, for example,~10k.   If that looks good, move one of the leads to the center lug and slowly rotate the shaft. You should see the reading vary from approximately the full value of the pot to near zero.

If both tests look good, then you're ok.
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R.G. Keene: EXPECT there to be errors, and defeat them...

alparent

Before starting over......
I've you tried your build without the LED and Switch.
Just put your input jack on the input, the output on the output. Conect power directly and try it.
Most of the time the issue is with wirering the external stuff.

garcho

QuoteI'm considering doing this build from scratch.
But I'd have to use the same pots, but I'm not sure they're still good.

It's possible to ruin pots, but it's hard, or at least harder than ruining CMOS chips or something. If you have an ohmmeter check it like John mentioned. If you don't, just assume they're fine.

Again, hopefully this isn't too insulting, but make sure the bottom of your board isn't touching the enclosure. Do you have electrician's tape or something to cover the traces? Don't be offended, just asking because in the pic it looks like it's right against the enclosure.

Something really easy to build that can be a big help with this is an 'audio probe'. It sounds more exotic than it is. Solder a wire long to the tip of an instrument jack, and another to the ring. Plug that jack into your testing amp. Ground the ring to your board (any spot connected to common or ground will work, so long as all grounds - jacks, enclosure, ground trace on your vero - are connected!) and use the wire attached to the tip as the probe. Follow the audio path on the schematic with the probe and listen. For instance touch the base of Q1 with the probe, strum your guitar. Hear anything? if yes, then you know you've wired your input jack to the circuit correctly. Next, touch the collector of Q1. Hear anything? Is it louder/more distorted? If yes, then Q1 is working, at least good enough to check for problems elsewhere. Then try probing the base first (should sound like Q1's collector, but adjustable through the 1st pot), then the collector of Q2. If the collector of Q2 sounds like a fuzz pedal, then assume the circuit is working and you've fouled up the output jack wiring somewhere. If you don't hear anything at one of those test points, you know that the problem is around that area, and focus your attention on those components. Make sense?
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"...and weird on top!"