Sho-Bud Pickup Hum

Keith Banning · Post by **Keith Banning** » 13 Apr 2009 2:25 pm

Hi All,

After having my LDG in storage for a few years, I pulled it out and it is humming somethin AWFUL. It's almost unplayable. Any suggestions, check wiring etc? New pickup? Will I miss the tone?

Thanks,
Keith

Keith Banning · Post by **Keith Banning** » 13 Apr 2009 2:54 pm

Oh, and its most definitely 60cycle hum. I've tried turning off the lights, moving it etc. No joy.

Keith

Tom Quinn · Post by **Tom Quinn** » 13 Apr 2009 3:18 pm

You have an open ground or a coil short somewhere. It's an easy fix if you have a good guitar repairman around.

James Morehead · Post by **James Morehead** » 13 Apr 2009 4:12 pm

Check your wiring and solder joints for issues, especially proper ground.

Keith Banning · Post by **Keith Banning** » 13 Apr 2009 5:30 pm

OK, I have the pickup out of the guitar. It has this rather hokey looking grounding scheme of wrapping a bare portion of the ground wire (blk) around a screw on on of the changer string retainers so that when the screw is tightened, the wire presses against the metal spring retaining angle metal and the wood of the guitar. Seems like that could be a dubious ground in the long run (35 yr old LDG).

With the guitar pickup out of the guitar, I still get the same hum when I hook it up to the amp or a mic-pre instrument input. Is it possible for these pickups to go bad? I'm not sure, but I think its original and an old single coil. See attached photo please.

Sonny Priddy · Post by **Sonny Priddy** » 13 Apr 2009 5:43 pm

Some one on The forum Had Sho-Bud Pickups For Sale. And Jerry Wallace Can Re Wind It For You. he Dose a great Job. SONNY.

James Morehead · Post by **James Morehead** » 13 Apr 2009 6:08 pm

That "hokey looking" way is the right way to ground your changer so that you do cancel hum when you touch your strings to play. Make sure you do not have corrosion or paint under that spring holder when you put it back together. I like to also run the ground wire under a changer screw, on the way to the jack.

Jerry Wallace is THE man to rewind shobud pickups, and is quite reasonable, too. Wonderful workmanship!! You would be pleased, and you could keep your original in your guitar, too.

jerrywallace@plateautel.net

Keith Banning · Post by **Keith Banning** » 13 Apr 2009 6:52 pm

James Morehead wrote:That "hokey looking" way is the right way to ground your changer so that you do cancel hum when you touch your strings to play. Make sure you do not have corrosion or paint under that spring holder when you put it back together. I like to also run the ground wire under a changer screw, on the way to the jack.

I see! I "technically" would prefer a more positive ground than a piece of metal jammed up against some wood (like a tap screw terminal or something)....but, that's not even my problem and it's worked for a LOT OF guitars in the past! It's the pickup, not the in guitar grounding scheme.

Thanks James. I have a call in to Jerry.

If you were me and you love the sho-bud tone, would you have this one re-wound or maybe look at a TrueTone (Jerry's model)?

Thanks,
Keith

James Morehead · Post by **James Morehead** » 13 Apr 2009 7:06 pm

Keith, Rewind your original to 17,500, and you will haveyour shobud tone. Same with a new Truetone, go 17,500. It will keep a smile on your face.

Keith Banning · Post by **Keith Banning** » 13 Apr 2009 8:11 pm

Thanks James. Mine is currently measuring 16,870 ohms on my Fluke meter. Does the impedence (or resistance?) change over time and degrade?

James Morehead · Post by **James Morehead** » 13 Apr 2009 8:17 pm

The impedance will become compromised eventually, as the insulation on the wire deteriorates with age, resulting in eventual faiure. MHO, for what it's worth.

Bill Fall · Post by **Bill Fall** » 14 Apr 2009 5:52 am

FWIW, the LDG's pickup looks to be the same as those used in the Super Pro. I had Jerry Wallace at TrueTone rewind both from my Super Pro to their original specs, and they came off sounding much too brittle, trebly & screechy. Jerry went through four rewind iterations, increasing the count each time till he ended up with 20K+ on both. That finally produced beautifully bright (but not excessively sharp) highs, and warm, lush midranges for both necks, with rich, almost teeth-chattering bass notes on C6th. I don't know if perhaps different wire gauges or variation in the tightness of windings may account for the difference, but I'd be hesitant to specify less than 20K, if you send the LDG pickup to Jerry for rewinding. Jerry's definitely the man to go to, however.

James Morehead · Post by **James Morehead** » 14 Apr 2009 6:37 am

Yes it's true, everyone hears something different, and each guitar is different, like Bill brings out. Listen to Miss Leslie's album "Between the Whiskey and the Wine" and you will hear what 17,500 in a '73 LDG sounds like. Of course Ricky Davis's hands on that beautiful LDG. That may be a good way for you to sample the tone.

Bill Fall · Post by **Bill Fall** » 14 Apr 2009 8:00 am

Actually, what I meant, James, is that rewinding the pickups with same number of wraps as they originally had, totally altered the sound to something not at all like their original tone. In the end it took a lot more windings to recover, and then surpass, that original color & sound.

James Morehead · Post by **James Morehead** » 14 Apr 2009 8:08 am

There's a difference in the modern wire vs. the old wire of yesteryear, which means counting wraps is pretty much a moot point. It's about measuring impedance. We have our 'bud pickups rewound to 17,500 and coiltap at 11,500 with great results. This is what Ricky uses, and I follow suite pretty much. I have been playing with coiltaps at 7,500 to 9,000 for kicks and grins, and i can capture a great early '60's sound. Again, if it sounds good to you, then it IS good.

Richard Damron · Post by **Richard Damron** » 14 Apr 2009 10:45 am

The term "impedance" has been used erroneously several times in this thread. It is the vector sum of capacitive reactance, inductive reactance and resistance and is frequency dependent thus not measurable with garden variety VOM's and VTVM's. All that you are measuring is the resistance of the coil of wire. That resistance is directly proportional to the wire diameter - ohms per foot - and the number of turns on the coil - the length.

Don't mean to be an egghead 'bout this but felt the need to clarify the use of the terms.

Brint Hannay · Post by **Brint Hannay** » 14 Apr 2009 11:14 am

James Morehead wrote:That "hokey looking" way is the right way to ground your changer so that you do cancel hum when you touch your strings to play. Make sure you do not have corrosion or paint under that spring holder when you put it back together. I like to also run the ground wire under a changer screw, on the way to the jack.

Seems as though running both pickup wires direct to the jack, and adding a wire from the jack ground lug to a changer screw would accomplish the same function, with a more certain changer ground connection than the spring retainer route.

Ricky Davis · Post by **Ricky Davis** » 14 Apr 2009 5:50 pm

Of course you have to have raise springs; at least one; attached to that bracket....ha.
When these old shobud pickups start going microphonic; that also illuminates the inharent single coil hum.
I would say since you have a reading that low..that it cerainly is loosening up inside(going microphonic)...and needs to be rewound.
Now; the rewinding is diff....because Jerry using a much higher quality wire than Shobud used back in the day.
If you have the sloted fingers; those are the later model shobud finger tops(same as superpro) and it's a inferior metal(along with other things on the superpro) and needs to be rewound heavier than the earlier finger which were aluminum.
Me and Jerry have gone though all different ohmage to find the sweetspot...and the alunminum top fingers(the ones with the pin you hook the string on); sound best with 17,000-17,500. The later model fingers with slots; need about 18,000-19,000...and those being the lighter side to heavier side(brighter to warmer); but I wouldn't go under or over either.
The Truetone designed for the shobud is the superior single coil pickup...and you just put one of those in wound to 17,500 for the aluminum or 18,500 for the sloted.....and you're in tone heaven.
The original shobud pickups were wound on the heavy side; because of the old type thinner wire they used to wind.....they usually always read; between 18,000 and 20,000 ....yes that inconsistant...and this was from the Pro II on...>the professionals were a whole nother bird.
Hope that helps.
Ricky

James Morehead · Post by **James Morehead** » 15 Apr 2009 6:24 am

Brint Hannay wrote:
Seems as though running both pickup wires direct to the jack, and adding a wire from the jack ground lug to a changer screw would accomplish the same function, with a more certain changer ground connection than the spring retainer route.

That may work as well. Then again, maybe not as well.
How complete the changer is grounded is what I'd be concerned with. If you touch your strings and you hear a hum, then you are not grounded well enough. So the final results are what is really important, right?