Crazy Repairs #1 – SCRATCHIES!

Having done musical instrument repair for several decades, you’d think I’d seen everything. But once in a while . . .

“I’m not sure what’s going on,” she began, handing me an old archtop guitar. “There’s something wrong with the pickup. It’s . . . ‘scratchy’.”

“Scratchy?”

Yeah, scratchy. I start playing it and then I hear scratchy sounds coming out of my amp. Real loud.”

I looked the instrument over. It was an old, full-bodied traditional archtop jazz guitar with a floating pickup attached to the pickguard with a single volume control. The output jack exited out the bottom of the pickguard. It was a very clean, simple installation, Not much to go wrong.

“How long has it been doing this?”

“Since the middle of November.”

I wrote up a work order and promised to take a look. Back in the shop I checked the guitar and electronics carefully, then plugged it in to test.

No ‘scratchies’.

The wiring was sound, the volume control was clean and quiet, the output jack was solid. After running out of things to check I called her up.

“I couldn’t find anything wrong. Maybe you have a problem with your cord or amplifier.”

“Well, I tried a different cord and it still did it.”

She picked it up the next day. The day after that she called me back.

“Scratchies! It’s scratchin’ to beat the band! I even tried another amp! Can’t you hear it?”

I didn’t know what to think. I asked her to bring in everything – the guitar, the amp and all her cords to check.

I connected everything and fired it up.

Nothing.

The amp was clean and quiet. The cord was flawless. The guitar refused to cooperate. Finally, I gave up and called her once again.

“This one’s got me stumped. Tell you what – come in tomorrow and we’ll hook everything up and you can show me what you’re hearing.”

The next day she came in. I hooked her system, and she sat down and began to play. After she strummed a few chords, a big loud electrical popping began pouring out of the amp.

“You see?  Scratchies! Scratchies! They’re driving me crazy! Can’t you do something?” she pleaded.

I watched her play. She was strumming chords big band style – strum, strum, strum, with big bold down strokes.

Then it hit me.

“I know where the scratchies are coming from.”

“You do?”

The guitar had an old celluloid pickguard, and she was wearing a long sleeve sweater.

“It’s static electricity,” I said. “The sleeve of your sweater is rubbing across the pickguard, building up a static charge. Since the electricity has nowhere to go it keeps building and building, making the pickup crackle when the strings vibrate. It probably only happens during the winter months when the air is dry, which is why you didn’t notice it until now.”

She seemed relieved that nothing was actually broke. I suggested that rather than replacing anything we apply a clear mylar sheet over the pickguard to make it less likely build up static. After I sent her happily on her way, I took a break and treated myself to nice warm latte.

© 2014 Leo Bidne

2 Comments

  1. clipper

    Classic fix mr. wizard……

    Reply
  2. Bob Lawrence-Markarian

    McGuyver would be proud!

    Reply

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