so, i broke a new dod pedal tonite...oops...but i found a cool mod... ;)

[pinkjimiphoton]

hi guys,

was out earlier buying parts (what else) and stopped at a pawn shop, lookin' around...found a really cool old silvertone lapsteel, almost jumped on it...150 bux i didn't have.

anyways, as always, i asked if they had effects...

and they had one...a dod fx69b grunge.

don't close the window yet, tho.   it gets better.

i ask 'em what they want for it, they say what will ya give me?

so i, of course, being  ever cheap, say 5 bucks.

he says eight. i say sold. i mean, for 8 bucks, ANY pedal is worth it.

so i bring it home, expecting it to suck heinously.

but believe it or not, it sounded pretty good. so i figured, after chilling with fine folks like you, to molest it badly and see if i could take it from ok to  HOLY SHEET.

i actually had some success.  here's a schematic...no idea if it's right. i don't know much at this point, still a newb.



so i did a search around for mods, and found this:

http://www.thestompbox.net/forum/showthread.php?8121-Pedal-Hacker-s-Grunge-Pedal-DIY-Upgrade

this was the suggestions made:

"Pedal Hacker's Grunge Pedal DIY Upgrade

    I finished it and it sounds amazing, way better than the OD-2 kit!! 2 resistors, 2 caps, and an LED diode! What a difference a few little components can make!! Here are the basic instructions if anyone is interested:

    DOD GRUNGE MOD

        REMOVE C19. YOU DON'T NEED TO REPLACE IT WITH ANOTHER COMPONENT OR ADD A JUMPER.
            THIS ADDS MIDS AND GIVES A FULLER TONE.
        CHANGE R16 TO A 1K RESISTOR. THIS LETS THE PEDAL CLEAN UP WHEN THE GAIN IS TURNED DOWN.
        CHANGE R19 TO A 22K RESISTOR.
            THIS MAKES THE DISTORTION A BIT RICHER WHEN CRANKED.
        NOW CHANGE C24 TO A .0047CAPACITOR. THIS MAKES THE 'HIGH' KNOB AS MORE LIKE A HIGH KNOB SHOULD.
            THIS CAP IS POLYSTYRENE, WHICH IS THE 'HOLY GRAIL' OF FILM CAPACITORS. EXTRA CARE SHOULD BE TAKEN WHEN SOLDERING AS THESE ARE MORE HEAT SENSITIVE THAN OTHERS.
        CHANGE D2 TO THE SMALL YELLOW LED.
            THIS GIVES A MORE COMPLEX, ENHANCED DISTORTION.
        DON'T CHANGE C6, EVEN THOUGH IT'S MARKED IN THE PIC."

of course, here's the pic:



i did some of the stuff,...changed r 16 to 800 ohm (it was handy) and had an instant difference in the response of the pedal.

also changed r 19 to a 24k resistor (i bought a huge grab bag of resistors earlier, and that was close enough to 22k for rocknroll)

took out c 19. it really DID help the sound of the pedal.

but what i did differently was remove d2 completely. get it the f*** outta there!! was like turning the suck knob way down.

so then i took out d3 (just below d2 in the pic) and replaced it ultimately with a ge 1n34a.

that did it. pedal sounded a bit nasally (which i like) and cleaned up pretty well with my strat's volume knob. not completely, but enough to play a relatively cleanish rocknroll rhythm.

huge difference...i mean i couldn't believe it.

but wait. i got creative. here's where stuff started to get strange.

i read all over the place about how peeps hate the 4558 chips in these things. they were actually marked something else, but i didn't bother writing it down.

i had read about stacking chips, and had an NTE889M  "dual low power jfet opamp", so i tried stuffing it on top of the '58s on the board.
there's 3 of them, the left and right ones (looking at the component side of the board) didn't do a whole lot, but the one in the middle was hip.

i mean REAL hip...it's subtle, but seemed to add in noticeable headroom and sparkle (which, with my luck, probably has nothing to do with it being placed there.),

so i soldered that puppy's 8 legs to it's arachnid brethren on the board, and fired it up.

i was like..."yeah!!". it sounds like it probably should have in the first place now, to my ear, much better, louder and with more overdrive and slightly less unusable distortion.

(you can turn the guitar off even with everything pegged, and the pedal won't feedback by itself like it did. )

but...i screwed something up. oooooopsies....

now, even tho the switch bypasses the effect, the bloody led won't go out.

i tried un-doing the mods i did, but to no avail...and am stumped. i mean, i can LIVE with it being messed up and always being on, but i'd really like to fix it if anyone has any ideas as to what the heck i did.

so ...long story short...

found a cool mod for a pos pedal.

and broke it at the same time.

can somebody send me a clue as to what to look for, or what i did, or how to fix it?

thanks in advance!!

jimi

[SISKO]

Nice story you have there 

Does the pedal bypass?

http://hammer.ampage.org/files/dodswitch.gif
Here is the general Dod style switching. If the bypass is working fine, then i would look the circuit surrounding the led. Specially  the 2n5087 (q1) on the bypass schematic. Keep in mind that the bypass schematic, the one you posted and the actual pedal circuit may differ in some components/values/connections.

[runmikeyrun]

I saw a used mint condition DOD Death Metal pedal at GC last night for $9.  I know they're horrible, but I almost bought it, thinking there MUST be some way to mod it to make it sound decent.  I passed.

[pinkjimiphoton]

hi sisko, yah, it bypasses fine, it's just the bleepin' led won't go out!! it KINDA dims...just barely..

[white paw]

are you using a battery or an adapter? i have a DOD supra distortion and it does the same thing when i use a battery, but not with an adapter

[pinkjimiphoton]

mine does it with adaptor or battery...i think one of the resistors i changed may have screwed up the bias on one of the jfets or something.

weird!!

i don't care, the pedal sounds great now..very nasal and brown...makes even my strat sound like my 66 firebird, which is about the brownest sounding gibson i've ever encountered.

[thetragichero]

this is a very old thread, but it came up when I was trying to figure out why I couldn't get the led to turn off with the footswitch even though the effect would go into bypass mode (note, as previously mentioned, the led stays on while battery powered regardless)
I changed the fet (q2) and bjt  (q6) related to the led switching circuit but still no dice

turns out I was overzealous about replacing electro caps in the signal path. had initially replaced c14 with a film cap and that turned out to be the issue. put the original electro cap back in and she works now

sorry again for the thread necromancy, but hopefully this helps someone else

[pinkjimiphoton]

haha, welcome, chris!

and necromancy beats necrophilia in spades

there's a joke in there somewhere, i reckon

thanks for bumping this, good to know there was a solution. i gave up on this thing years ago and dumped it.

but for the right price, i'd nab one again. for all the malignant regards it gets, you can get some great sounds out of this circuit
if ya spend a little time with it, and NOT with the pots dimed.

thanks for the heads up! peace!

[thetragichero]

this thing actually sounds pretty good now!
I added a Cornish buffer for poops and giggles threw a small pledge of perf to connect the extra components)

now I have the similar (but much crappier sounding) fx66 flashback fuzz to deal with. ugh so terrible stock

[pinkjimiphoton]

ugh. good luck. them are so horrible, tho i owned one for years, i could never bring myself to plug it in but ONE time.....





go make it do something good!!!