dod 250 dragonfly vero build problems

freak scene · May 15, 2006, 10:46:31 PM

i got this all together and it didnt work so i mucked around with it, and it still didnt work, so i set it aside for 2 months, then tonight i picked it up and mucked around a bit more and it still didnt work...

so i snapped some pics in hopes that i could get som help before i scratch the whole thing.

hope its not too sloppy...

thanks in advance.

markm · May 15, 2006, 10:48:47 PM

I can't help you with getting it running but, I think you should persue it further as this is a
really good sounding OD circuit.
Actually, It's MY favorite!!

freak scene · May 15, 2006, 11:00:53 PM

thanks! so far i have built the lpb and npn rangemaster off of his vero with no problem (they sound fantastic!), i figured this would be a good next step. i really want to get it working.

freak scene · May 15, 2006, 11:12:08 PM

i guess i should mention whats wrong haha. it works fine bypassed, but when engaged it has no sound until everything is turned up all the way and then ver little and very blatty.

markm · May 15, 2006, 11:28:29 PM

Maybe check the connections and/or resistor values to the 741.
Possibly a biasing issue?

rosssurf · May 15, 2006, 11:40:52 PM

Mark, I am on my second build. I did the Vero "Flatline" and then the Boss OD-1 with mods. Still troubleshooting the OD. There is too much bass. My limited experience tells me that there is a cross connection somewhere. Perhaps Tiny piece of copper strip or solder running over to the next row. Also be sure to check that the copper stripping in complet and has continuity where it should. I have a handy pair of , what my girlfrien calls "mad scientist goggles" This is a visor type thing that hasflip down binocular magnifying glasses. It also has one extra lens that flips down to get in real close. Hold your board with the copper strips facing you and a bright light directly behind it. Look real close for any tiny places wher the solder spilled over.
I hope this helps!
Ross T
crushingday.com

rosssurf · May 15, 2006, 11:46:09 PM

oh! also I use a razor blade and run it down between the copper strips to make sure there is no cross contacts. and an old totth brush to make sure I get any loose parts out.

MartyMart · May 16, 2006, 04:03:22 AM

Yup, there's a few places on the back of your board that look very "suspicious"

May well be a couple of tiny solder/copper bridges stopping it from working.
Using a little bit less solder wil help, I just had the exact same problem on Joe Gagans
"Decade" circuit, I had two "miniscule" bridges, which were throwing off the bias, and
I've made about 120 veroboard builds !!

Run a tiny Jewellers screw driver between all the strips ( a knife is bound to cut you! ) and
use a magnifying glass to make sure every copper "cut" is true etc.
You'll get it working, I use a copper "suede brush" also, to remove all the "gunk" from the
back of the board.

MM.

oldrocker · May 18, 2006, 12:12:43 AM

I must've been reading your mind I just built a DOD today. I built it the night before on a bread board to test and mod components before I perf'd it. Amazingly I only had one problem I missed soldering pin 4 to ground on the 741 IC. Anyway I didn't use the bypass switch or the L.E.D.s. just a switch that cuts battery power. I built mine from the Tonepad site which has a parts list for a MXR Distortion also.
Double check the setup around R2, R3, R4 and C1 since this is likely where you would make a mistake. The rest is pretty straight forward.

markm · May 18, 2006, 12:13:57 AM

It's a great sounding circuit isn't it?!!

freak scene · May 18, 2006, 08:01:00 AM

havent got it working yet, i ran between the traces with a jewelers screwdriver to scrape off any bridges, still nothing, then i re touched all of the solder joints, still nothing.

Toney · May 18, 2006, 08:06:14 AM

Have you checked the schem?

Do you know for sure the layout is verified.

It may well be worth your while to carefully run through it...

wampcat1 · May 18, 2006, 09:01:30 AM

Quote from: freak scene on May 18, 2006, 08:01:00 AM
havent got it working yet, i ran between the traces with a jewelers screwdriver to scrape off any bridges, still nothing, then i re touched all of the solder joints, still nothing.

Ditto on toney's advice, also - have you used an audio probe on it yet? That would be a quick and easy way to find out where the problem is.

bw

freak scene · May 18, 2006, 09:17:36 AM

Quote from: wampcat1 on May 18, 2006, 09:01:30 AM
Quote from: freak scene on May 18, 2006, 08:01:00 AM
havent got it working yet, i ran between the traces with a jewelers screwdriver to scrape off any bridges, still nothing, then i re touched all of the solder joints, still nothing.

Ditto on toney's advice, also - have you used an audio probe on it yet? That would be a quick and easy way to find out where the problem is.

bw

havent dug out the probe yet, i have kinda been working on this in 30 minute intervals haha. i have been working 12 hour days at my job for a while, so after i get home, eat, and shower, thats about all the time i have before i need to go to sleep. hopefully i will have the weekend off so i can fully get into this and figure out what is going on.

oldrocker · May 20, 2006, 10:29:14 AM

I've built 6 distortion stomps in the last few weeks. (Too much time on my hands.) The DOD 250 was my latest build and I really like it. It's not a drastic overdriven distortion but more usable then some other fuzz boxes I've built. My other projects were fun to play around with but more for heavy rock and metal than blues or rock. I think it would be worth getting it to work because you may find that you'll use this effect more than you know. I know I will.
My lastest stomp builds: Smash Drive(Big Daddy), Mockman, Big Muff, Muff Fuzz, Fuzz Face, and the Green Ringer(although I'm still debugging this one.)

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dod 250 dragonfly vero build problems