Tuesday, June 23, 2015

Teisco Gold Foil repair

fixing a vintage Gold Foil pickup

I bought this '60s made in Japan Gold Foil on eBay "as-is" with the intent to repair it.  It had no output and showed no resistance on the meter so I took the cover off by removing the phillips head screws on top.  

Next I removed the magnets which are simply held in place by their own magnetism on either side of the coil.  They were installed with South polarity facing up.  As I was inspecting the coil, I removed some tape and noticed the tiny 44 gauge coil wire had become detached from the white lead wire.  I resoldered and checked the resistance, it was now showing 5.3K.  

This might seem like a low resistance for a single coil, but don't be fooled!  The low resistance makes these nice and clear while the powerful magnets and the squatty coil make it sound full and fat.  I have repaired another Teisco Gold Foil that was around 6.3K and I have seen DeArmond pickups showing upwards of 10K, so there is quite a variance in specs of what is called a "Gold Foil".  I based my own Humbucker-size Gold Foil pickups on vintage pickups I see come into the shop.

When dealing with classic pickups like this, it is always better to use the original coil if possible for the most authentic tone.  The most common cause of dead pickups I see is sweat or moisture corroding the coils.  Usually there is no other way to repair a corroded coil than to rewind it, which I will do with vintage-spec wire to the appropriate number of turns.  Rewinds usually cost about $50 per coil. 

With this pickup I will probably wax pot it so that it will be less microphonic and install in a Telecaster.  Here is a quick video I made of the pickup in my tester guitar:

Monday, June 15, 2015

The Nashville workshop!

As some of you know, my girlfriend and I moved from San Francisco, CA to Nashville, TN in May 2015 to be closer to a vibrant music scene and to start a new life in The South.  The move was so exciting as we took a two week road trip across the country.  You don't get many chances to pick up and move to a new place so we took advantage of the opportunity.  Becca started a blog called the Bay To River Rambler and you can see her photos and writings here.

We found a place in East Nashville with a standalone garage that I converted into a workshop and now I have more space than I know what to do with!  I built myself a 2x8 workbench and got a drill press and now I am up and running.  The pickup winder is all tuned up and I'm cranking out pickups again, ready to get your guitar tone in tip-top shape.

Things to look forward to in July:

Gold Foil release July 4th I'll be releasing a brand new pickup based on the originals from the '60s.  I designed mine to be on the more affordable side compared to vintage or reissue pickups by other manufacturers and still embody that twangy, low-fi character.  They will fit in a standard humbucker rout and start at $90 each.

Summer NAMM in Nashville July 9th, 10th, 11th  I'll be there walking around, checking out the exhibits, and meeting as many people as possible.  I won't have a booth this year, but I'll be staking it out for future years.  Check out https://www.namm.org/summer/2015 for more info on how you can go.

Wednesday, March 25, 2015

Balancing output with a humbucker

Using a simple resistor to match a single coil with a humbucker

It's a classic combination: a humbucker in the neck and a single coil in the bridge, but it can be a real challenge to keep that single coil from sounding too thin in comparison.  The problem arises for three reasons:

  1. humbuckers are naturally warmer and louder than single coils
  2. at the neck the string vibrates farther than at the bridge causing more bass and volume
  3. humbucker-equipped guitars usually come with 500K pots
The third reason is the one I'll be talking about first.  Typically humbuckers sound better with 500K pots and single coils sound better with 250K pots.  This is because single coils sound better with a little bit of the highs bled off to the ground, and humbuckers (being naturally dark) sound better wide open.  This Telecaster Custom (shown above) came with four 500K pots, one each for neck volume, neck tone, bridge volume and bridge tone.  This sounds fine for the humbucker but to give the bridge pickup a little more warmth we are going to use a resistor.  If you follow this link you'll find a wiring diagram for the American Telecaster HS.  Scroll down to the second page and you'll see two pots, a switch and a resistor leading from the hot lead of the bridge pickup to ground.  Scroll down to the third page and you'll see that these are 500K pots and a 270K resistor.  I didn't have a 270K resistor, so for the Telecaster Custom we are going to use a 220K in series with a 39K resistor to give us 259K.

I then covered the resistors with shrink tubing to prevent a short and soldered it between the ground and the first lug on the volume control where the hot lead for the bridge connects.  You can also see a high-pass filter soldered between the first and second lug of the volume control consisting of a .001 uF capacitor and a 150K resistor wired in parallel.

This gives you a more uniform blend of highs and lows when you turn down the volume control.  This trick works great on bridge and neck pickups and I use it on all of my guitars.

The final thing to do is adjust your pickup height.  You want your bridge pickup to be reasonably close to the strings without touching them.  Depress the first and sixth string at the last fret and raise the pickup until it is very close.  If the pickup sounds harsh and metallic then back off a touch.  The neck pickup should be adjusted all the way down to the pickguard and then raised until the volume of the two pickups is equal.