Power supplies that kill pedals?

[Primus]

Hey all. I got a new DD-5 and after about 1 day of use with my dunlop DC-brick, it stopped working. The output produces faint output and the panning almost as faint. When I called to get service, they tried to get me to admit to using a non-boss power supply, which I would not admit to because I can't afford a dead digital delay and this is still under warranty. So the question is, did the power supply kill my pedal?

Also, a tangential question about the spyder I am building... It has 12 big transformers in it. Is there a better way to shield them than just metal stud covering style enclosure?

[Peter Snowberg]

Measure the voltage coming out of the supply and see what you get. If it's too far over 9V you may have blown a cap.

[Primus]

Thanks, Peter. I think i will do that to protect my other pedals and take this one in for a repair

[Connoisseur of Distortion]

10v caps in a commercial pedal?

sounds like a crime.

[toneman]

try puting a 9V batt in it & see if it still works or not.
U need a *regulated* 9V pwr supply.
Lots!  of examples on the web...
in fact, i think GEO has an article(?)
WallWarts are usually *un* regulated.
So, in all probability, since most commercial stompboxes are polarity protected with a diode,
U overvoltaged the pedal with the unregulated wallwart.
*Might* B a cap(?)
But, with a DigitalDelay, U have logic elements, not just analog.
So.........good luck....

[Paul Perry (Frostwave)]

Digital memory chips are very sensitive to overvoltage. You can even lose them thru momentary spikes.

[R.G.]

The replies on this thread are good. Unregulated supplies can tip over low voltage caps, and some commercial effects do use 16 and the occasional 10Vdc cap.

But there is another threat.

Never, ever use a 9Vac power supply without figuring out a foolproof way to keep from plugging it into another pedal. There are a very few commercial pedals which have their own 9Vac adapter. These have the same plug configuration as the normal 9Vdc plugs, but they put out AC.

This appears to be very damaging to pedals nominally protected by a reverse biased diode. The power supply puts enough current through the diode to burn it out, either open or shorted. If it shorts, it usually burns the diode in half and may char the PCB. If it opens, the power supply typically kills any ICs in the effect.

And it's an easy mistake to make.

[aron]

Good one R.G. We were at a gig and the guitar player was asking for a 9V wall wart. I asked him what the polarity was and he didn't know. I said he would chance it and pug a wall wart into it because he was desperate. In any case, luckily it couldn't work because the pedal had a larger than normal center tip so it couldn't fit. Once we had light and could really look at it, it was a 9V AC input!

[Alex C]

My Whammy IV is powered by 9VAC, and I made sure to wrap the adapter plug in red electrical tape to remind me (red like the Whammy).

I did the same (with yellow tape) with the 18V supply for my Neovibe (thanks again for that one, R.G.).