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DIY Stompboxes => Building your own stompbox => Topic started by: Lobsang on January 03, 2004, 06:18:25 PM

Title: Sudden death
Post by: Lobsang on January 03, 2004, 06:18:25 PM
Hi evryone!
I had a little problem today. Not so long ago I wrote here asking if I could feed several pedals using a high- current wall wart. I received some answers which concurred that the high current should not harm anything, but I shouldnt exceed the voltage.
I got a 12v- 5A transformer and built a rectifier section since. I measured the output and read 17v. I thought that this would be tamed with a proper load, so I hooked two pedals to see what happened. One of them died, a Boss Overdrive to be exact. The switch is permanently "on", being a FET + flip flop electronic section I bet the culprits are the 2SK30 FETs but I havent pop it open yet. It sure smells burnt from the inside! The other pedals I tried were my own creations and they took the 17v like nothing. I think this kind of switch does not take such an over voltage, my units are all true- bypassed... what you think? As for the power supply, what can I do to bring down this beast? Remember its 5A, not a tiny little cell phone wall wart. Can I use a regulator?... Any help will be much appreciated, thank in advance.
Title: Sudden death
Post by: Joep on January 03, 2004, 06:27:52 PM
Drawing a few miliamperes from a 12V-5A transformer will not take the voltage down......

You should use a regulator the get the voltage down, like and 7809 or a LM317 adjusted to 9V.

Are you sure you didn't reversed the polarity on your pedals, most of the pedals should take 17v although they are not designed for it.....
Title: Sudden death
Post by: smoguzbenjamin on January 04, 2004, 05:43:07 AM
The Boss pedals use 10v caps. That's probably what you burned in there ;)

Never ever put more than 9V on a Boss. ;)
Title: Sudden death
Post by: Travis on January 04, 2004, 06:45:22 AM
Because once you let all the smoke out, it'll never work again.
Title: Sudden death
Post by: smoguzbenjamin on January 04, 2004, 07:59:53 AM
Yup, electronics run on blue smoke :mrgreen: lol