Guitar Surgery

Inventor · Posted: Sat May 02, 2009 6:02 pm Post subject:

Oskar,

Oh, lol, well that was not very spectacularly intelligent of them! This is small signal stuff, with a leetle bittty transformer that has a mu-metal case and cost $55 plus shipping (DJ paid for them as usual on this project). Not some big honking AC transformer thingie! It will fit snugly into my Squire's cavity once I get off my butt and put it in there! lol, good story though...

Les

seraph · Posted: Sun May 03, 2009 1:08 am Post subject:

Oskar · Joined: Jul 29, 2004 Posts: 1751 Location: Norway

Inventor · Posted: Sun May 03, 2009 3:41 am Post subject:

That is hilarious, the mind-numbing stupidity of some people! How did he think that sound would come out of the thing, from the guitar body? One imagines the angels watching over him as he crafted his strange little cable. Could they keep a straight face? Were they worried for him? Gives new meaning to the band AC/DC, lol!

Oskar · Joined: Jul 29, 2004 Posts: 1751 Location: Norway

Inventor · Posted: Sun May 03, 2009 3:48 am Post subject:

blue hell · Posted: Sun May 03, 2009 3:54 am Post subject:

Inventor · Posted: Sun May 03, 2009 4:00 am Post subject:

Agreed. In that case may I suggest that we split the thread at the anectdote and move it to schmooze? Might be fun...

Oskar · Joined: Jul 29, 2004 Posts: 1751 Location: Norway

No can do, I'm the bumbling moderator of the S'n'T sub-forum, along with Andy, who is really a BobTheDog, and I won't - or can't! Cool

Anyway, the story belongs in here, as a cautionary tale of how NOT to modify guitars, especially electric ones.

seraph · Posted: Sun May 03, 2009 4:13 am Post subject:

I heard of someone trying to connect a microphone to the mains hoping to get his/her voice amplified. where the signal was supposed to come out remains a mistery Shocked

Inventor · Posted: Sun May 03, 2009 4:16 am Post subject:

To tell you the truth, I'm a bit worried by this story. There is a safety concern with my and DJ's geetar invention, which is that the strings have an electrical connection to the jack plate. So if such an idiot were to do that with our invention, it would not just be the pickups that got electrified but the metal strings themselves! Far more dangerous.

Similarly, if an amp were to fail in such a way that juice from the mains got pumped back into the geetar, well the same thing would happen. I think we need some kind of protection device like a really low current fuse or shunt clamp or something to prevent this potential danger.

So yes, the story does have relevance to the topic... What to do, what to do?

seraph · Posted: Sun May 03, 2009 4:27 am Post subject:

I can see the titles of the newspapers:
"Teen electrocuted by his geetar - Inventor and DJ wanted!"

Rolling Eyes

Inventor · Posted: Sun May 03, 2009 4:39 am Post subject:

Antimon · Posted: Sun May 03, 2009 4:47 am Post subject:

Inventor · Posted: Sun May 03, 2009 9:02 am Post subject:

Oh, no problem Stefan, this has turned out to be an important safety discussion about real things that happen to real people. What do you think, maybe something as simple as a shunt voltage clamp? No, that would short-circuit the mains. Perhaps a specially designed circuit that presents an open circuit when the voiltage gets above a few volts? I dunno yet...

blue hell · Posted: Sun May 03, 2009 9:36 am Post subject:

I thought you used an output transforemer Les? It would probably just explode and that would be it ;-)

Inventor · Posted: Sun May 03, 2009 6:14 pm Post subject:

That's true Jan. In the current design the transformer is grounded on both sides but that can be changed to accomplish isolation. Trouble is, then the bridge wouldn't be grounded. I think we need one of those surge protector thingies, whatever they're called, one with a low voltage threshold.

BobTheDog · Posted: Sun May 03, 2009 11:07 pm Post subject:

Or a big sticker saying "Don't connect to the mains you numpty"

Uncle Krunkus · Posted: Mon May 04, 2009 3:23 am Post subject:

DrJustice · Posted: Mon May 04, 2009 3:34 pm Post subject:

I think the bridge, and thus the strings, are normally connected to ground in most guitars, and AFAIK there aren't any safety devices....

DJ
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Inventor · Posted: Mon May 04, 2009 3:54 pm Post subject:

Oh yeah, good thinking DJ! We're good to go then.