Wrong wall wart...what have I done?

[mrdobolina]

Hey Guys,
I plugged my Devi SM into the wrong wall wart this weekend and now I only get a constant hum. It's a DIY so I *thought* maybe something had come lose, etc.

I ended up breaking it down to the basics...removed the 3DPT, LED, and even the pots at one point to simplify and remove variables. Still getting the same hum.

The Volume POT works on the humming...not much else.

Did I fry something? If so what commonly gets blasted in this scenario?

Thanks all!

Dobo

[Mark Hammer]

Did I fry something? If so what commonly gets blasted in this scenario?

That's going to depend on what you have/had between the supply and the semiconductors on the board.

[R.G.]

A lot depends on two things. First, does this pedal have any internal reverse polarity protection? And second, was the wall wart you actually plugged by some chance a 9VAC source?

If the pedal has no reverse polarity protection, or if the wall wart you plugged into it has an AC output, it is possible that some parts survived, but also possible that as much as every semiconductor and polarized cap in the box is fried. There is no way to tell without more information.

Mark posted while I was typing. He's right.

[mrdobolina]

I'm kind of a newb...so it has whatever came with the Devi Soda Meiser kit....which I"m pretty sure is nothing.

So no protection and the wall wart had the polarity reversed. I'll start checking the components with a meter and see how bad it is.

Thanks Guys

Dobo

[StereoKills]

IIRC Devi's pedals never have polarity protection and don't usually have electro caps either. You'll probably have to replace the MPSA18's and 2N907A.

[oldschoolanalog]

IIRC Devi's pedals never have polarity protection...

Can anybody verify this?

[Scruffie]

IIRC Devi's pedals never have polarity protection...

Can anybody verify this?

Verified, here's her PCB, no Diode marked on the Silk Screen http://www.etsy.com/listing/41807111/pcb-and-components-torns-peaker-aenima Plus i've seen them, no Polarity Protection diode and I can't remember seeing any Electrolytics either.

[StereoKills]

IIRC Devi's pedals never have polarity protection...

Can anybody verify this?

None of the schematics she has released on her forum ever have them included......
Very bare bones designs, but creative too!

Soda Meiser Schem...
http://forum.deviever.com/viewtopic.php?f=40&t=4191

[mrdobolina]

Thanks Guys...I have a mouser order queued up I'll throw some extras on 

appreciate the quick feedback.

Dobo

[Paul Marossy]

IIRC Devi's pedals never have polarity protection and don't usually have electro caps either.

That's not good. You have to idiot-proof things as much as possible when you are selling things to the general public. You are bound to see every thing imaginable happen when it comes to what people try to plug into a DC jack.

[StereoKills]

That's not good. You have to idiot-proof things as much as possible when you are selling things to the general public. You are bound to see every thing imaginable happen when it comes to what people try to plug into a DC jack.

For less than a nickel more it would seem like a no brainer......