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Burnt Out Pedals?

jkn09
October 14th, 2009, 01:13 AM
Is it possible to burn out a pedal by trying to power it with too powerful of a power supply? I sold some pedals to a buddy of mine (Dano BLT and DOD Flashback Fuzz fwiw) and he only had one power supply, but it was waay to powerful. Something like 27v. Anyway, he's new to all this stuff, and I told him I'd never done anything like that, but I'd like to get an answer (and possibly how to fix it if anyone knows) for him. He really had no clue what he was doing. Anyway, now they won't turn on. Any thoughts?

Thanks!

Ben Harmless
October 14th, 2009, 04:23 PM
Yep.

Most pedals work on magic smoke. Once you let the smoke out, they don't work anymore.

27v will let the smoke out of most pedals I know. I'm sure there's some that would survive, but modern electronic design probably dictates that those pedals are built with the lowest rated components available...

The BLT (great pedal, BTW) is toast, and will be much easier to replace than repair. The DOD, I dunno, but my gut says the same thing.

11 Gauge
October 14th, 2009, 04:43 PM
The only scenario that I can see where they might be okay is if the polarity of the power source was DC and was reversed, in which case the protection diode and a few surrounding components would have fried, possibly.

But if the polarity was correct, 27VDC will kill both of those pedals. Some semiconductors can handle 24VDC or higher, but for many the upper limit is 18VDC. And some are less. It's also very common for electrolytic caps to be rated at 25VDC or less. Film and ceramic type caps are usually good up to around 50VDC or so.

And if the power source was not DC but AC, the pedals would have fried at just about any voltage.

Before going any further, can you give the exact specifics on the power supply used? Was it DC or AC? Was it center pin negative or center pin positive?

Montana_Dawg
October 15th, 2009, 02:24 PM
The only scenario that I can see where they might be okay is if the polarity of the power source was DC and was reversed, in which case the protection diode and a few surrounding components would have fried, possibly.

But if the polarity was correct, 27VDC will kill both of those pedals. Some semiconductors can handle 24VDC or higher, but for many the upper limit is 18VDC. And some are less. It's also very common for electrolytic caps to be rated at 25VDC or less. Film and ceramic type caps are usually good up to around 50VDC or so.

And if the power source was not DC but AC, the pedals would have fried at just about any voltage.

Before going any further, can you give the exact specifics on the power supply used? Was it DC or AC? Was it center pin negative or center pin positive?

+1. Also, check to see if there is a series resistor on the power supply input. Some pedal makers put it in their designs. At 27VDC input, it would fry most of the resistors I have seen.

marshman
October 15th, 2009, 05:18 PM
The shells are probably worth more to DIYers to put their home-rolls in than the repair headache...probably.

jkn09
October 18th, 2009, 04:57 AM
The shells are probably worth more to DIYers to put their home-rolls in than the repair headache...probably.

Yeah I'm probably just going to end up doing that. He's just getting started playing guitar, so I'll prob just build a basic fuzzbox for him.

Thanks everyone for the help