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Thanks for the comments guys. Scott, yeah I considered the potential head heavy issue when I chose to go with the SG for him. The basswood body and maple neck changes the balance a bit from a 'real' SG, so it is something I'm quite mindful of... is it weird to be weighing hardware on kitchen scales when you're doing a mock build?
I like your attention to detail and the trouble you take to correct small niggles.
With two Gibs on the go you must be pretty busy.
I'm keen to see more of your excellent work on this project.
Considering doing a flamed cap SG myself next year (long wait?)
Time to re-drill the bridge and tailpiece post holes. Using a 7/16" Brad Point bit for a nice tight fit, and I spent some time checking the specs of both the bridge and tailpiece so that I was certain of:
1) What the respective spacing should be.
2) How deep the bushing holes needed to be drilled (it differs between the two).
I carefully marked out the new holes and then sat the hardware in place to double-check that everything was correct.
http://www.pitbullguitars.com/wp-con...y_plugs_04.jpg
Next, I very carefully drilled the holes to the required depth (in stages), first the tailpiece and then resetting for the different depth for the bridge. Then, I made sure that the tailpiece ground wire hole was re-opened and clear.
http://www.pitbullguitars.com/wp-con...y_plugs_05.jpg
Finally, I sat the tips of the bushings in the newly drilled holes to check that everything was aligned… looks good to me. Time to start sanding the body.
http://www.pitbullguitars.com/wp-con...y_plugs_06.jpg
Hi Scott, I love reading your build diaries. It's already been said, but your attention to detail is amazing.
Your "builder" skills put my "assembly" skills to shame. Where I settle for "character" you settle for nothing less than perfection.
Keep it up mate, and you might even convert me into a "builder"
Cheers mate,
rob
Beautiful attention to detail. Looks like this is going to go well!...
Well, the pickguards for the two ST-1's, Blondie and Brownie, are now wired up, so it's time to give this build some electrical attention too. I always planned on using the stock PBG humbuckers that came with this kit, but I've been thinking lately it would be nice to have a coil split option as well. As the guitar is for my nephew, having a coil split would make it more versatile and allow him to experiment with both humbucker and single coil sounds. So, rather than buy new pickups just for coil splitting, I thought I would have a go at 'fixing' the perfectly good stock pickups.
The challenge: Convert the stock 2-conductor, mystery magnet, PBG humbuckers into 4-conductor plus shield, Alnico powered, tone monsters.
Challenge accepted!
A quick check of the stock pickups showed the bridge as 11.12K and the neck 10.68K. It will be interesting to see what they end up as after surgery. Using a magnetic compass showed that the screw coil of the bridge pup is a south magnet, with the slug coil being north (north on the compass points to a south magnetic pole). Same process for the neck pickup showed its slug coil as the south pole and the screw coil as the north. This is important for replacing the magnets, and if you want to run split coils across pickups as hum-cancelling pairs.
Warning: Do not try this unless you are willing to potentially ruin a perfectly good set of pickups!
The surgery begins…
First step, remove the pickup rings.
http://www.pitbullguitars.com/wp-con...surgery_01.jpg
Next is a slightly tricky part, removing the chrome covers. These are soldered at two points to the base plate, and you have three choices: break the solder and risk kinking the cover, saw/cut the join which can get metal filings in the pickup, or de-solder/melt the solder enough to lever the cover away. The latter option is difficult as you need a very powerful, ideally temperature controlled, soldering iron, as you need to quickly heat up the solder point, separate the join and then remove the heat before it starts heating up the whole pickup. If your iron isn't powerful enough you'll have to sit it on the join for ages, which will heat soak the entire pickup and start melting the wax and possibly other bits… this would be bad. I used a combined method of quickly heating the solder while gently prying the cover's side away from the baseplate. Leave the mound of solder on each side as you'll need it re-attach the cover.
http://www.pitbullguitars.com/wp-con...surgery_02.jpg
Once the covers are off the bobbins are exposed and you have access to the stock wiring connections… I'm going to cheat and use these to attach the new 4 conductor wires, as trying to connect directly to the ultra-fine copper coil windings is just inviting disaster. The coil windings are unbelievably fine and often quite brittle so, inevitably, you will break some of the wires while trying to connect to them, and if you break a coil start wire… it's game-over (you can't unspool more to reconnect it). So, I'm taking the easier and safer route and using the connections that are already there, as explained below:
http://www.pitbullguitars.com/wp-con...surgery_03.jpg
Bridge: 2-conductor wire (yellow) still in-place.
1. Shield/bare wire connection to Bridge South Start (the shield wire is connected to both south start and the baseplate at point 5).
2. Black link wire connection to Bridge South End (the black wire links the end points of each coil).
3. White (hot) connection to Bridge North Start.
4. Black link wire connection to Bridge North End (the black wire links the end points of each coil).
5. Shield wire connection to Bridge baseplate (provides the electrical shielding link to the baseplate and chrome covers for hum reduction).
Neck: 2-conductor wire (red) has been cut at the end of the outer covering, and the black link wire cut at its mid-point. The wires must be carefully cut so that you have enough wire available to solder connections to later.
6. Shield/bare wire connection to Neck South Start (the shield wire is connected to both south start and the baseplate at point 8).
7. Black link wire connection to Neck South End (the black wire links the end points of each coil).
8. Shield wire connection to Neck baseplate (provides the electrical shielding link to the baseplate and chrome covers for hum reduction).
9. White (hot) connection to Neck North Start.
10. Black link wire connection to Neck North End (the black wire links the end points of each coil).
Clear as mud? Basically, the south start becomes your ground, the north start becomes your hot, and the south and north coil ends are linked to produce the hum-cancelling effect.
Once you have access to the (short) cut wires connected to each coil's start and end, you need to very carefully strip the ends of the covered wires. It's probably best to use a sharp knife for this as you can't afford to pull on these wires at all, as you may detach them from the coil winding or worse break one of the fine coil wires. Also, de-solder and remove the clipped shield wire from the baseplate (it may be easier to do this once the baseplate is removed in the next step)..
http://www.pitbullguitars.com/wp-con...surgery_04.jpg
Replacing the magnets on these pickups is complicated somewhat by the fact the manufacturer seems to use glue as well as wax potting, so there's a messy mix of wax and gummy glue holding the magnets in place. So, to get them out it's easiest to remove the baseplate from the coils via the four phillips-head screws on the underside.
http://www.pitbullguitars.com/wp-con...surgery_05.jpg
Then, it's a matter of carefully prying, levering, and separating the glue to get the magnet out (you can see the stringy, gummy glue residue below).
http://www.pitbullguitars.com/wp-con...surgery_06.jpg
Once you have the old magnets out it's time for the shiny new ones to go in. In this case I'm using an Alnico 2 for the bridge pickup and Alnico 5 for the neck. Again, you need to use a magnetic compass to work out which pole is which (compass north points to a south magnetic pole) and ensure the new magnet goes in matching the orientation of the old one. As I determined at the start, the bridge screw coil is a south pole and the neck screw coil is a north pole.
http://www.pitbullguitars.com/wp-con...surgery_08.jpg
Poles checked and re-checked, and shiny new Alnico magnet set in position.
http://www.pitbullguitars.com/wp-con...surgery_09.jpg
Out of interest, I weighed the old magnets and the new Alnico's. The old ones weighed 11g, while the new Alnico's weighed 19g… quite a difference.
Time for the big moment. Work out how long you want you pickup leads to be, neck is usually longer, and then strip the covering and tips of the individual wires. Feed the new lead through the baseplate and then solder the bare shield wire to the baseplate at the same point as the old one. Helping hands/clips and small vice etc really helps at this point, as you need to keep the lead steady on the baseplate and positioned very close to the coils (I found it best not to re-attach the coils to the baseplate just yet). However, if the glue holding the two coils/bobbins together has become separated then it would be best to re-attach the coils to the baseplate once you've soldered the shield wire before proceeding further (see last paragraph of this post). Once you have a stable set-up… very, very, very carefully solder your 4 conductors to the coil wire stubs. And, I do mean carefully, any pulling on the coil connections could detach/break the wires.
I decided to use the standard Seymour Duncan colour-coding: Green = South Start (ground), Red = South End, White = North End, Black = North Start (hot).
http://www.pitbullguitars.com/wp-con...surgery_10.jpg
At this point it's a good idea to use a multimeter to test your connections, make sure your lead's coil pairs (green and red, white and black) work, and that nothing is shorted. Once you're satisfied, cap the connections with some heatshrink tubing so there is no possibility of shorts.
http://www.pitbullguitars.com/wp-con...surgery_11.jpg
I carefully re-attached the coils to the baseplate using the four screws, making sure the magnets were evenly positioned and that the pickup lead was sitting in the right spot. Be careful tightening the four screws as over-tightening them will tend to flare the coils apart and outwards. I then tucked the new connections between and around each side of the coils and used a couple of tight winds of fabric pickup tape to secure everything. Ready for the cover to go back on!
http://www.pitbullguitars.com/wp-con...surgery_12.jpg
Re-attaching the covers is similar to removing them, but harder. You have to get the solder points hot enough for the solder to flow and make a solid join (more difficult than breaking to joints) and again remove the heat before everything else melts. I ended up using two soldering irons, one on the cover's side edge and the other on the baseplate, to get the joint attached as quickly and solidly as I could.
Covers re-attached, rings on, 4-conductor Humbuckers with Alnico magnets.
http://www.pitbullguitars.com/wp-con...surgery_13.jpg
Once they were finished I did some quick tests… with interesting results. The change of magnet has produced a slight change in resistance, making them marginally hotter, which means the original magnets were a touch weaker than I expected. I guess the extra set of joins to connect the 4 conductors could also maybe nudge the values a little.
Bridge:
Original value (old magnet) = 11.12K
New value (Alnico 2 magnet) = 11.57K
Neck:
Original value (old magnet) = 10.68K
New value (Alnico 5 magnet) = 11.24K
I also did a quick back to back test using my one string test board, comparing the 'new' humbuckers with another stock set of pups. From what I can tell, the 'new' sounded thicker but with more clarity and better defined highs. But, I'm just guessing until they're actually plugged into an axe. I also tested the pickups split, which gave a nice single coil sound, and then tried linking the Bridge south (green and red) with Neck north (white and black), and got the expected hum-cancelling which is a good sign.
I haven't re-potted the pickups, as pretty much all of the original wax is still in place, but I won't really know if it's enough until they're played at volume. Also, I've noticed on a couple of sets of these stock humbuckers that the screws on the screw coils don't always actually screw for adjustment… it seems more like just wax and the magnets are holding them in position. I may need to take some remedial action on this eventually, just see how it goes.
For now, I'm really pleased with the result: a set of PBG 4 conductor Alnico powered humbuckers ready for my nephew's SG