Very nice write up..

You.. pickup switch... issues much? ?

I am not going to vehemently badmouth Cor-Tek switches. This one, if original (very likely), has been running for more than 23 years. One might expect bit of fluff or slightly worn contacts. I did not plan to open it up to document the contacts' condition for you all. Might as well consider that, but I was planning on replacing it anyway, even if I did not suspect it. The problem might very well be a dodgy earth joint, a dry joint on that volume pot is very likely. The wires came off easily, in a bunch, when I de-soldered everything. Speaking of which:

De-soldered, I measure:

Neck Pickup DC Resistance 3.75 KOhm.
Middle Pickup DC Resistance 3.62 KOhm, reverse polarity, reverse wound.
Bridge Pickup DC Resistance 3.75 KOhm.

Volume pot: 450 KOhm Linear.
Tone 1: 260 KOhm Log. (not original, "recently" replaced)
Tone 2: 220 KOhm Linear.

Wiring to Tone "2" was not according to diagrams, input and output wires swopped around. Being a Linear pot, probably did not matter. No idea if the volume and tone "2" pots are original.

As for the pickup construction, it might be just what I need for fuller, sweeter tone, in terms of wider magnetic field lines. Considering the low DC Resistance, and the weak magnetic field above the pickups, as well as how low I dropped them, the guitar should have been "dead". I suspect that's the reason for the 450K volume pot. I may be taking a stupid bet with a 250K volume pot?

Sad collection of discarded spares, good for future projects. Sorting out the Cor-Tek (PCB says “94”?) terminals is easy if you start with a wired example, and know where it is supposed to lead.

Pushing the polepieces proved to be no problem. The way I see it, these pickups would be assembled on a plastic bobbin with polepiece sleeves, the windings go on first, underpaid worker picks the correct length poles to press into the bobbin holes, clamp the bottoms flat on the special jig, thereby ensuring stagger is within “spec”, apply glue, apply the bar magnets. I do not see them clamping the magnets for 24 hours, so the glue has to be a very quick-cure magic stuff. I do note that there is scope for a “shorter” bobbin, allowing the coils to be fatter/wider, which would help to attain the tone I am chasing here. Would also enhance the field strength above the bobbin. I pushed the poles to “modulated” stagger. Connected to a multimeter on AC, swiping some steel item over the pickup, many milliVolts appear. I am positive that the coils are still good. I worry about the different contact lengths the poles have with the bar magnets, and need to measure that effect. The other problem, 3-D, is the field line topology, surely the higher pole will have a “wider” field along the string? There has to be an easy way to measure the output of each pole at the relevant string height. I can check it with a multimeter, plucking each string, once assembled again. Requiring disassembly to adjust. And in any case, do we want equal string response anyway? What we hear and what seems “ideal” is not related. Altogether a nice science project here. Now this is exactly where OCD masochistic tendencies rear their ugly heads. Stay tuned.

“Modulated” stagger, closer to what experiments with my guitars indicated I might like. Yes, corrosion. I guess the poles were nickle plated, but years of sweaty gigs took its toll. You should see the scratches on the pick guard between the strings near the middle pickup…

Pushing the poles, though easy, was not a five-minute job. And they are not equal across pickups. But, they were not. Imperfections are what make our favourite guitar tones, no? If OCD is required, one could build a jig with the relevant stagger, and press once to get reaaaallly close, after which, of course, OCD will require hours of miniscule adjustments. I am not there, yet. See it this way, three pickups, three tone profiles, why not modify each to an unique stagger to get exactly the sound you want from each? So many things to do, so few guitars to experiment with…

Coming soon: Pics of slab-sawn hot-rolled steel trem-block-to-be. Now that takes time. I do not have a suitable chunk of Brass I am willing to sacrifice, to cut to shape. I am considering Phosphor-Bronze saddles too. But that requires lots of holes, tapping, shaping. Worth it, I guess. Low friction, good wear properties, high strength, good elasticity, high density, corrosion resistant. Why use brass for nuts at all, if better materials exist? The "tone", no doubt.

A simple, qualitative pole piece tester: A piece of guitar string used as a spring balance. This is by no means rigorous, I would need to build a rather solid test jig, but this gives a rough indication that the poles do have similar strengths – certainly no large differences between the lowest and highest poles.

Setting a piece of string like this to vibrate, one can clearly see the damping effect of the pickup. The vibration starts to dampen when the string is still far from the poles. I am sure there will be a demonstration somewhere on YouTube. From what I see, “normal” pickup heights will have a large effect on string vibration. No free lunch.

As promised, the steel trem-block-to-be. Maybe putting this aside in a dark place will encourage it to auto-convert to the item I need? No. Some work ahead.

I also added a 0.17 mm Aluminium plate to the bottom of the pickguard.

“Some work” (Ha ha, that’s good!) later. New, full size steel trem block, 280 grams. (The magic weight on the internet?). Compared to wimpy lightweight original. It better make a difference.

Some enhancements: O-ring trem arm friction thing on top, adjustable, spring-loaded trem arm tensioning things on bottom, easily accessible. I do not use the arm, never had an opportunity, with years of fixed bridges, but I must look towards the future. The friction enhancements do work, slightly. Longer spring required, and one can play with O-ring size to enhance friction, if the arm is to be part of the guitar, not screwed in and out all the time. On the “Floyd Rose” I sommer merely lightly touch the Floyd with my palm if I feel a need to alter the pitch. Not with a Strat. I made up a shorty trem arm too, no use having an arm that extends to the neck.

Ah, yes, note the suitably “distressed” dings and machining marks on the new block. I am certain final finish has no influence on tone, but seeing as brand new “distressed” and “aged” guitars (and parts) are so sought after, maybe it does have an effect? Better to be safe. I should post a picture of the donor block, my dad used it as an anvil for many years. So, in effect, one could call this a “custom, cold hammered steel” trem block. I shall leave it as is, no paint, and I do not have access to nickel or tin plating (yet…). I live in a semi-arid region, I do not expect corrosion to be much of a problem, but if required, I can artificially corrode it (rust browning, heat blueing) to add a tough layer of oxide protection. Ah, what the heck, it will do that itself with time.

With that little thing out of the way, time to work on the electrics some more, and see what I feel like about new saddles (might purely be dependent on screw threads), and then, those tuners. Will see how I can “improve” them as well. After this piece of steel work, I feel like Superman.

All-in-all, I do not understand why aftermarket trem blocks are so expensive. Especially those Calla-something guys. Now, making a tuner, compared with …

Superman left the premises, in a hurry, looking at his watch, frowning, when I started wiring. The new pots had no flat washer under the fixing nut. The old pots had three thin washers that fit, too big for the old metric pots, just right for the CTS pots.

First wire attached to the switch, I thought, “I did not check whether the switch will clear the bottom of the body?” Measures out fine, if I do not run wires over the switch. No need to chisel away wood.

Shielding the cavities are not on my agenda, the inside of the body is quite rough, with several sharp-edged steps. Too much sanding, smoothing, re-painting (?), and then, the issue of hoping the foil will stay stuck to the body. I am not convinced. Guitar was pretty quiet enough for my purposes.

HSH style cutouts. Handy for future owner “upgrades”.

Wet paint scraped during assembly? Easy chisel work.

The new rats’ nest, uhm, wiring. The space available for the twisted pair neck leads below the middle pickup will limit how far I can lower the middle pickup. I tried to re-route the wires to make it look neater, not all bundled into a mess and squashed between the pots and body. Not a lot of space here, maybe that “swimming pool” style cut-out makes sense.

I am doing the “Mod Garage” Tone Split Mod, with bridge on the bottom pot (0.022 microFarad), and neck and middle on the top pot (0.022 microFarad). Capacitor choice is merely a “hope for the best” initial choice. Unfortunately, even if “split”, the most used quack position will have both pots and capacitors? How do I measure this? Kinman-style treble bleed, 120 K resistor, 0.001 microFarad capacitor, sleeved to avoid shorts. Also a first guess, to see how it works. Using a “star” ground scheme, star being two brass fittings under the volume pot.

“Easy remove” option for the output wire, so as not having to unsolder wires every time I feel the silly need to remove the pickguard to modify something. The guitar had a single core shielded conductor, with the shield mesh doing the grounding job. I cannot see using this “twin flex” lead to the plug as a much worse option, will have to do until I find a shielded twin-core replacement. I had to drill the output lead hole in the body to 6 mm. Good news is that the body seems to be solid wood, not ply. To avoid de-soldering the string/claw ground wire when removing the pickguard, it will also be screwed down, not soldered. On the bench, signal is present at all the relevant switch positions from all the relevant pickups.

New, low-milage, as yet unworn tuners. Very similar design to the originals, different factory stamp, butterbean knobs. Fits the original holes. No rattles in unlubricated state, so they should work slightly better than the old, well worn items. A medium term solution to a long term problem.

The new set’s covers looks much like the originals, but they are not the same. The panelbeater job, well, it arrived here with the dome bashed in, I merely tried to bash it out again. No way to “restore” it to original looks.

Naked paddle, with old bushing. The bush is rather short, the new set has slightly longer bushes of equally loose fit around the tuner shaft. To be replaced with these phosphor-bronze bushes, closer fit, less rattle.

“New” tuners and bushes, fitted.

Maybe I should do something about those faded string trees? Might as well.

New screws too. Old set of tuners now awaits some permanent solution “refurbishment”, but I think the gears are worn too much to expect close fits.

And new phosphor-bronze string tees. Not finished yet, but I needed to re-string first, to see where the strings run. Slots and polishing to follow.

Guitar is back together, I still wanted to do a brass trem spring claw, but that can be done at a later stage. Saddles, well, these are still in a good condition, but a set of “decent” saddles will be appreciated. I was worried about the effect all the new components will have on the guitar’s character, being used to what it was. I am glad to report that it is still the same lekker playing guitar, but much more useful. The tone pots work, well. The volume pot, with the treble bleed, works better than before. The treble bleed does not become overly harsh at lower volumes, and the interaction between the volume and tone pots is good. Nice to be able to tone the bridge down a bit.

I fitted Ernie Ball Super Slinky’s, worried that the lighter gauge will be insufficient, but it is good (Previous set was D’Addario XL 10 -46). By the time I need to replace strings again, I should have a good idea of any work or alterations to be done to component values. For now, a powerful, lekker and useful guitar with new tonal possibilities to explore. It is wonderful through the 5F1 copy. All my work shifted the guitar towards the sound I had in mind, I am relieved.

Thanks to all the people who made this possible - suppliers of guitar, tuners, pots, 5F1 kit, spares, speaker, etc.

Next one?

modulator Thanks to all the people who made this possible - suppliers of guitar, tuners, pots, 5F1 kit, spares, speaker, etc.

Next one?

Enjoyed this thread! Thanks, looking forward to your next refurb/restore ?

modulator
well done.. Its soo Nice when you achieve what you set out to do..
We Now need a Sound clip, and an Over-all Ogle Picture,
I have been following this with eagerness, been and Interesting and enlighting read