Can An FX Box Get Fried Like This?

Jon Light · From: Saugerties, NY

I'm trying to figure what is possible, what is plausible, what is likely, what is just not likely.

I had a stomp box plugged in to a wall wart 9VDC (with correct amperage specs for the unit). It worked fine before, it worked fine during this rehearsal session.
Then ... it did not work. At the end of this same session I found that a Class D power amp driving some side-fill PA speakers was also dead.
I was not aware of any power glitches but a surge over the lines is certainly not uncommon here in the woods.

Question:

Can a voltage glitch/spike/surge run thru an ac/dc converter such as a 1SPOT and wipe out a digital stompbox?

--AND--

Can this happen and leave the 1SPOT undamaged, working just fine? That's what's throwing me -- can something at the end get fried but leave the power supply intact?

Had to send the unit (Fishman Aura, out of warranty) to get repaired.
Coincidences do happen and I'll accept that, if the answer to the above question is 'nope...no way---that 1SPOT would definitely be toast if the stompbox got zapped'.

Benjamin Davidson · Posted 1 Nov 2020 6:51 am

Short answer, yes its likely a surge wiped the pedal and left the 1Spot intact. Its likely that weakest component was in the digital pedal woukd fail before the power supply. The company most likely will replace whatever PCB the failue was on, and my experiance it would be ome of the small IC or DSP chips.

How it would leave the 1spot functional you may ask? Power supplies can pass alot more current than your digital pedal will draw. The 1spot will pass 1700ma based on published ratings, 120vac input and 9vdc out. There is a number of ways a voltage spike will pass through the 1spot, spike DC voltage and leave the 1spot fully functional. A quick spike will find the weakest component, which seldom is the tranformer and rectifier curcuits of the 1spot and is usually a small surface mount resistor or capacitor on a PCB or aforementioned IC or DSP chip within the pedal itself.
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Jon Light · From: Saugerties, NY

That's a great answer, Benjamin. Thank you for that. Gives me a much better understanding.
Fishman replaced a board at their flat rate $50 bench charge. It is what it is.
I wonder if a cheap sacrificial surge suppressor/power strip would have shielded the unit. Most of my stuff goes into strips. For no good reason, this did not. Worth looking into.

George Biner · From: Los Angeles, CA

I can't find schematics for a 1 spot, but that big 1700 mA output current rating might even add to your problems -- when the 1 spot gets hit with a surge, like a drunk getting hit with a two by four, it probably will not be able to control its output during that brief time, so the output you get will likely go all over the place, backed up by a boatload of available current, crushing your puny stompbox, which has little or no protection against. I'd be curious to see what on the stompbox burned up. Obviously, investing in a top notch surge suppressor is probably a good idea where you live.
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Bill A. Moore · From: Silver City, New Mexico, USA

Voltage fluctuations have weird results. Years ago I hired my PA system to a local band at a club our band had played dozens of times. Almost the end of the last set, the stage lights got bright, and then went off, as well as the guitar player's SS amp. When I got the system home, I realized one of the channels was out on the Carvin monitor amp. All other amps, and equipment in the rack were fine. The guitar's amp was dead, but the rhythm player and bass player were fine. The owner told me later that the cooler motor had shorted, and caused a voltage spike. He too lost some electrical equipment.

Jack Stoner · From: Kansas City, MO

I've used a (good qualit8y) surge protector for my equipment for years. Let the surge protector do its job and sacrifice itself instead of equipment. After a known power surge many surge protectors will still "work" but the surge protection is gone. For that reason I replace my surge protector once a year - cheap insurance.

I've been using the Furman SS6B EMI/RFI/Surge strips with the 15ft power cord for the last 7 or 8 years. Watch sites as some put them on sale periodically. American Musical is one.
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Jon Light · From: Saugerties, NY

Really good info in all these posts. And thanks, Jack, for saying what I already knew but tend to forget, about how a surge suppressor can be spent without showing any signs. I wish they would just trip (or even die) and let you know. I do believe that some investment is in order. Be cheap, pay the price.

Jon Light · From: Saugerties, NY

Larry Dering · From: Missouri, USA

Jon, one of brick power supplies would likely be your best bet. I know lots of guys who use them for that very reason. It's a shame we have to resort to other safety measures to protect our gear.

Jon Light · From: Saugerties, NY

Adding to this ---
I realized this morning that oh wait -- the wall wart was hooked up to a rack-mount Furman M-8x2 Power Conditioner. The one that has a little green LED in the front that says "Protection OK". So that means that whatever happened, it made it past the surge protection of the Furman, right? Well, some time reading product descriptions tells me that this is misleading, to say the least. As far as I can tell, whatever 'protection' you think you are getting out this, surge protection is not part of the deal. I feel like I've been suckered (although I vaguely remember reading this very fact a long time ago, here on the forum, I think?).
And I feel like I assumed exactly what they hoped I would assume, being relatively non-techie and not knowing the right questions to ask.
I wish the SS6B wasn't a Furman. I'd rather do business with someone else. But they seem to own this category. Oh well.

Jon Light · From: Saugerties, NY

Jack Stoner · From: Kansas City, MO

The "Protection OK" may just mean you have the third wire AC Power ground. Or like I mentioned it has already taken a surge hit and no longer surge protecting even though the lite says OK.

You have to get into the high dollar commercial units for better system status indicators. When I was still working as a LAN/WAN Network Manager the government agency I worked for used $250 (and that was a bulk discounted price) power strips for our computers and servers. Pricey but they did the job and the company backed the product.
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Jon Light · From: Saugerties, NY

I just ordered a 2-pack of SS-6B's from AMS (a few dollars cheaper than Sweetwater). I noticed that in addition to this model, Sweetwater has a similar Furman that, if I am reading it right, is not sacrificial. It shuts down in event of a surge. $18 more. It was tempting, possibly a better value in the long run. But it was not 100% clear to me that it would serve the exact same purpose.....same protection via a different, non-destructive circuit? I could have inquired here but I didn't want to keep asking questions, on & on.....

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