Monday, June 9, 2008

Wiring the pickguard

In my last post I explained the process of spraying the color on. After that I spent the three days spraying three coats of clear lacquer per day, finishing the clear coats on May 27th. The guys on the ReRanch guitar refinishing forum suggest letting it wait 3 days per coat before the final wet-sanding and polishing,and counting the four coats of sanding sealer thats 13 coats or 39 days -- July 5th to be exact. It turns out that I'm out of town on vacation for the two weeks at the end of June so the long wait shouldn't be all that hard -- especially since I've got other things to keep me busy, like wiring the pick guard.

I abandoned my original plan to do stock Strat wiring in favor of the Strat Lover's Strat with tone switching from the Guitar Nuts website. This circuit provides all of the standard Strat switching options and adds the ability to put the bridge pickup in series with whatever other pickups are selected via the 5-way switch, and to put the neck pickup out of phase with the others. The bridge-in-series is activated by pulling out the volume pot, the neck pickup phase is reversed by pulling out the "neck" tone pot. With the tone switching feature the active tone control follows the bridge-in-series on/off switch. In other words, with the bridge-in-series switch off, the "neck" tone control is active. When the bridge-in-series switch is on, the "middle" tone control becomes active.

Here's the schematic for the Strat Lover's Strat (click to enlarge)

I think of the bridge-in-series switch as a rhythm/lead switch. Put the 5-way in neck/middle position for rhythm and adjust the tone using the "neck" tone control. Pull out the bridge-on-switch for lead and adjust the "middle" tone control.

This is probably one of the more complicated wiring setups for a Strat, requiring the use of two push-pull pots for the volume and neck tone controls. The push-pull pots provide the normal control operation for volume or tone and also have separate leads that are switched by pulling the knob out (and pushing it back in). Back in early May I purchased two of these pots and the third tone pot -- all 250K Ohms -- from Stewart MacDonald. The 250K pots are recommended by Seymour Duncan to match the Vintage for Strat pickups, and replace the 500K pots I originally purchased from Carvin.

Step 1 was to add aditional shielding foil to the underside of the pickguard, and mount the pickups, switch and pots.

I think the contrast of the black pickup covers will go well with the dark grain filler in the wood and the ebony fretboard. I've got black knobs to go with the black pickup covers too.

I stared at the circuit diagram for quite some time, comparing it to other diagrams, until I was pretty sure that I knew how it worked. To reduce the amount of thinking required while soldering, I re-drew the diagram to better represent the actual physical layout of the switch and controls.

Each set of six push-pull switch leads are stacked up over the three leads for the pot so space is tight, but I had the foresight to solder everything from "bottom up" to avoid having to use the soldering iron underneath something else that I had already soldered.

I haven't use a soldering iron in over 20 years, but after a few hours I was done. Its not very clean & tidy but I've double checked it with the multimeter and it appears to be wired correctly and working.

I expect it to be early July before I post again. All that remains to do is the final wet sanding and polishing of the body, assembly and setup. I can hardly wait!