#1
So i bought a "broken" Ibanez AD9 analog delay pedal at a garage sale for 5 bucks with the intention of using the enclosure for a fuzz i built. when i got it home turns out it works fine off of battery (SCORE!!! was me response to that) but off ac adapter i get nothing.

this is what i know:

the jack itself is fine, but has very little voltage across it.. i belive about .8v not sure what that's supposed to be but i assume 9v

also the battery doesn't work when an ac adapter is plugged in, confirming the fact that the jack is not the issue

the diode that i believe goes to the battery clip gets incredibly hot when the pedal is plugged in, but i tried replacing it with an identical one and get the same result, so that's not the problem.

it seems like something is getting shorted out... but all the solder joints look fine. anyone have any more ideas of what the problem could be?

also. I have a 9v ac adapter that i soldered a 9v battery clip too. i ran a small portable amp i built off of it (crackerbox amp from make magazine... well worth the 5 bucks). is there any reason not to just hook that up to the pedal battery clip?

thanks for any info!
#3
nahh i checked the adapter it actually came with my old korg ax10g (rip ) and wouldnt backwards polarity destroy the pedal? Ill try to get some pics of it soon

http://www.analogman.com/graphics/AD9Circuits-copy.jpg

thats the only image i could find of the circuit board and its not really that helpful.. but the hot diode is the one on the top left

Ill try to get pics up when i have the chance
#4
We need pics of YOUR board. I know which diode you mean. It's the 1N400x, right? It's for polarity protection. If the polarity is ass-backwards, it'll heat up that diode until it pops.

Try reversing the polarity anyway. A short exposure won't hurt anything, since that diode still does its job.
#5
So you are right. I reversed the polarity by adding a 9v batt clip to the dc jack in reverese and it lit up and i jammed on it for a lil bit.

now I guess my question becomes why is this? and is this normal? Ibanezs website just lists a 9v adapter for this thing with no mention of reverse polarity. how do i know that pedals are reverse or not? Im assuming that it was manufactured like this and so now i have to go get a reverse polarity plug?
#6
the jack is supposed to be center pin negative. if the adapter that you are using is center pin positive (most are) then that could be it. if its the correct polarity, then the jack is wired backwards. check if its wired like this. it may be that something got wired wrong in yours, so just fixing a couple wires could do the trick.
#7
Quote by jof1029
the jack is supposed to be center pin negative. if the adapter that you are using is center pin positive (most are) then that could be it. if its the correct polarity, then the jack is wired backwards. check if its wired like this. it may be that something got wired wrong in yours, so just fixing a couple wires could do the trick.

Yeah, and Protip (to TS): Most pedals are center-negative.
#8
ok, is there a way to tell if a pedal is center negative or positive without plugging stuff in and seeing if it lights up.. that seems like a poor method.

also... doesnt it seem kinda dangerouse to have 9v adapters with different polarities for the same type of plug? like... if i get a negative polarity plug and whoops my brother needs to borrow a 9v adapter for his whatever... wouldnt that damage some stuff?
#10
not true on the polarity checking. when i was a younger man i had an old palm that i tried to build a battery pack for which i ended up wiring it backwards and frying the thing.

but it seems silly to me to have some devices wired 1 way and some another using the same plug. for the majority of devices that are built to be idiot proof their are a bunch that will fry if u plug in the wrong adapter.

I guess the reason im soo unwilling to accept the simplicity of this solution is i bought this pedal under the impression it was broken, but in fact it works 100%. the guy i bought it from was definitely not an amateur when it came to guitar equipment and i just don't see him making a mistake like that. although the battery that it came with was dead... soo he made a lovely 80 dollar mistake.
Last edited by somekid413 at Mar 23, 2009,
#12
Quote by somekid413
ok, is there a way to tell if a pedal is center negative or positive without plugging stuff in and seeing if it lights up.. that seems like a poor method.

on my ad-9 (and most of my other pedals) it notates somewhere on the pedal that it is center pin negative. in the ad-9's case, its on the bottom of the pedal. on boss pedals, its on a sticker next to the power jack.

also most power supplies notate on it somewhere the polarity, voltage and current. always good to check first, and its great that the guy who sold it to you didnt