curtisa

I'm willing to bet that's the difference. The neck pickup wires are longer and unshielded, and will pick up more noise than the bridge and middle pups, which have less exposed lead length. The route that the wires take may have an effect on the degree of noise pickup too. If this is finally the cause of your noise problems I can think of a few things you can do (in order of effectiveness): 1. Desolder the existing pickup leads and throw them away. Replace with a piece of shielded hookup wire - shield conductor replaces black wire, centre conductor replaces white wire. 2. Tightly twist the existing black/white wires from the neck pickup. You'll probably have to remove the pickup from the guitar to do it effectively. You may want to consider doing this to the other two pickups as well. 3. Live with a little more noise from one pickup

I'd expect most switches to make a bit of electrical (*crackle*) and mechanical noise (*thunk*, picked up by the pups) as it is moved. I note that the leads from the Klein pickups are not shielded and are just two plain wires. Are the leads on your P90s shielded cables or separate wires? Worth checking. The photo on the Klein website makes it look like the black wires from each pickup are meant to be soldered to ground, rather than white/yellow. Does the neck/middle combo have that typical Stratty "quack" (think Hendrix "Little Wing" or Dire Straits "Sultans of Swing"). An incorrectly phased neck pickup relative to the middle will sound quite odd when combined together and lose it's hum cancelling ability too.

Sorry, can you clarify - did you use the wire to touch the mounting screws of the pickup or the pole pieces?

Wow. That's a curly one. I've never heard of lowering pickups to reduce buzz?? That implies that the proximity of the pickups to something is the problem (the strings?). OK, here's something different to try - take a piece of wire and attach it to your output jack sleeve (ie, ground), use the other end of the wire to dab on to the magnetic pole pieces of the neck pickup, and check if the noise changes when the poles are grounded via the wire. Edit: just in case I'm misunderstanding you - all guitars will buzz slightly until you touch an earthed part of them (eg, strings), it's just more apparent on single coils.

IME the StewMac shielding paint isn't all that great when applied to timber, but every little bit helps. I typically see readings of 200-300 ohms when measuring between the sleeve of the output jack and any point on the control cavity where I've applied the paint - definitely not a dead short as it should be. More coats of paint help. Applying the paint to smoother surfaces helps. Not using the paint and utilising other forms of shielding such as copper or aluminium foil tape helps Even so, the fact that the buzz is affecting only one pickup out of three suggests that the overall shielding is probably not the issue. Your suggestion of systematically breaking down the circuit is a good one, even if it is labour intensive.

As Bob suggests, it's not necessarily the fix but it's an easy one to try out. You don't even need to solder it if you just want to quickly try it out, just twist some wire around the switch earth terminal and dab it to the nearest ground in the guitar and see if the buzz changes.

The ground tab on switches is only provided as a means of earthing the metal (non-switching) parts of the switch in situations where the mounting method is not electrically conductive. Us lucky guitarists are one of the few situations where wiring a dedicated earth to the switch can be necessary. It's possible that the Seymour Duncan wiring diagram is assuming that there is a layer of conductive shielding tape under the pickguard that would be earthed via the pot cases. Fitting the switch to the scratchplate then earths the switch frame via the conductive tape and there is no need to provide a separate earth. Then again, the diagram may also be assuming that your switch simply has no earthing lug. Then again, there isn't an awful lot of metal to touch in a strat 5-way switch when it's installed, so the designer may be lazy and is not bothering to earth the switch frame. The joys of guitar wiring diagrams... Does your guitar have any cavity shielding? If so, is the cavity shielding conductive to ground in all locations? Extremely unlikely, but perhaps the switch itself is providing just enough additional shielding to the neck pickup wiring so that when you touch the unearthed switch the buzz is reduced via the conductivity of your body. Another thing to look at is that there is a tone control hanging off the neck pickup. Poor soldering or faulty components here may account for excessive noise on that one pickup too.

Slightly left-of-field possibility, assuming the circuit works exactly as intended and no grounding errors are found: Is it possible that your bridge pickup is wound hotter than your neck pickup (to compensate for the volume difference between positioning the pickups at different points along the strings), and you've accidentally installed the neck pickup in the bridge position? The pickup with more turns will have a hotter output, but also pick up any stray noise more effectively, hence the neck pickup being slightly noiser than the others if they've been swapped.

With the pot full up or full down there will be continuity between the centre lug and one outer lug (the schematic symbol for a potentiometer helps visualise how the wiper, or centre lug, behaves when moved to the extremes). One of the outer pot lugs will be connected to ground, as will the sleeve terminal on your output jack, and the pot case (if you've made a ground "blob" on the case itself). If the pot were wound all the way to zero when you made your measurement you will see continuity between the output jack sleeve and tip. It is unlikely that there is a dead short in the pot to the case with the volume full up, as any such fault (assuming the case is grounded and the rest of the circuit is OK) would result in total loss of signal output. A true diagnosis of a pot failure is difficult to do with the rest of the circuit still in place - your best bet is to unsolder and remove it from the guitar and test it on the bench.

That's a pretty good suggestion actually, and is an area of the PG.com site that appears to be lacking somewhat. At a basic level guitar wiring should be really simple to understand, but there's still a lot of misinformation and voodoo floating around clouding the issue. I'd be willing to contribute an entry-level tutorial on such a topic if the project warranted it (although not wanting to step on yer toes, Prostheta!)

Good idea on the new tutorial, Prostheta. Some brain ideas/brain farts in your genereal direction: Perhaps it would be good to define what the limits of the build will be a little more clearly. The body is obviously pre-finished and in good condition, and the brief is to put together a guitar from spare parts. I guess most beginners would start building guitars in this way (it's certainly how I got into it) - buy a pre-finished body, a fistfull of parts and slap them together. In keeping with the "buy parts and assemble" ethos of this tutorial, would it be better to avoid the more advanced techniques such as refinishing, bridge conversion and neck construction, and limit yourself to sourcing premade components, fitting a bridge to the route it was intended for, fitting a premade neck and checking for alignment, doing a fret dress and setup etc? You could always include some more detailed steps in the tutorial such as how to plug and re-drill the trem post screws if the bridge doesn't exactly align with the original screw holes, or how to tweak the neck pocket if the neck heel is a slightly different shape. If you were to make this more of an intermediate tutorial (maybe the reader has a couple of partscaster builds under their belt by this stage?) you could perhaps include a section on building a standard neck from scratch, stripping the body and refinishing, blocking the trem and fitting a hardtail, rerouting the neck pickup for a humbucker etc. Probably a bit more high-level than you were intending, but a lot of such a tutorial could easily be used to update much of the main projectguitar website. IMHO the PG.com site has been looking a bit tired for a while now, especially in comparison to the forum and maybe this tutorial could be the impetus for giving the main site a spring clean. I've noticed that while it appears a lot of dead links have been pruned in recent months, there are still a number of external pages that are lost, or links to forum threads sans photos. Maybe now is a good time for a number of build/modification tutorials 2013-stylee and associated website pick-me-up? Brain ideas concluded

Sorry, I realise now I've misread your last comment about getting the "solder to stick to the top" as "sticking to the tip", assuming you meant you were having trouble getting the iron to heat properly in the first place.

Solder not taking to the tip of the iron either means the iron isn't getting hot enough, or (more likely) the tip is so worn and dirty that it can't be tinned anymore. Iron tips are designed to wear and be replaced, might be due to fit a new one. A clean tip will help the transfer of heat to the pot shell via the layer of solder that is applied to the tip, and establish a good solder joint. Check also that you're not using a tip that is too small or the wrong shape to allow such large solder joints to be made. This may be telling you how to suck eggs, in which case I apologise in advance, but the correct method of soldering two surfaces together is to use the iron to heat up the area to be soldered, applying the solder to the area and letting the heated surface melt the solder. Using the iron to transfer a heated "blob" of solder to the target surfaces is asking for dry, weak joints. The technique should work for everything, whether it be an 8-pin chip on a circuit board or fitting elbow joints to copper water pipes. Setting up a grounding point on the pot shell will also be easier if you do first thing before it's even fitted to the guitar. Once you have the solder "pad" on the back of the pot shell done, every successive remelting of it for the attaching of wires will be easier. I find that it's easier to make the ground point on the pot in the side of the shell, rather than smack in the middle - less area to heat up makes it easier to establish a clean joint. The ring lugs that Prostheta posted a picture of is the only dedicated method I know of for attaching a wire to a pot or switch body, and probably more fiddly than it's worth. The iron I use is a basic 25W plug-and-go, fixed temperature unit. Provided the surface of the pot shell if prepped correctly I can solder a wire to it using this iron in about 10 seconds. The only thing it struggles with is the grounding wire that attaches to a trem spring claw, in which case I switch to a butane iron (the only thing I currently have that gets/stays hot enough). A Weller soldering station should have more than enough grunt to see you through just about anything you can throw at it.

Prostheta beat me to it. Wot he said!

If you can make the hum completely disappear by touching the cable at the jack socket, I'm willing to bet that your ground wire to the bridge is open-circuit. If you have a multimeter (even a cheapie from the hardware store) check continuity from the ground lug of the jack socket to your strings (should be 0 ohms if the ground wire is intact). Other things to check are correct wiring at the jack socket (are the signal and ground lugs reversed?) or a break in the ground connection to the pots or pickups.

Sorry if I came across a bit standoff-ish, certainly wasn't intended. I guess some of us are trying to understand exactly how playable you want it to be, ie a fully working instrument, a device that will offer some degree of playable interaction with the user, or something that is only used for its visual impact. I wish you good luck with your project, and am still interested to see the finished product!

The bridge you use has no bearing on the fret spacing. If this instrument is all about the looks rather than the playability I'd suggest that it only needs to be built in such a way that it could convince a casual observer that it is guitar-art. Use the Stewart Macdonald fret position calculator posted earlier and enter "25.5" for the scale length, "21" for the number of frets and set the "instrument" field to "Electric Guitar". Install your frets and bridge on the instrument as close as practicable to figures given in the table generated by the calculator. Leave about 8mm past the end of the 21st fret to allow for fretboard overhang. There's no need to get too carried away with accuracy to three decimal places on an instrument that can't be tuned or amplified. In keeping with the "looks" aspect of this build I'd install electric guitar strings, even if you can't tune them properly. Just get enough tension on them to pull them taut and not have any sag along the length of the neck.

All the parts are there to secure both ends of the strings. The nut has an integral anchoring system to hold the strings in place, while at the uh..."ammo clip" end of the guitar the tuners form part of the bridge assembly to secure and tension the strings to pitch. Yep - you're thinking of the Floyd Rose Speedloader.

How about a headless bridge setup? If cost is an issue there are several sellers on Ebay that offer headless assemblies for under a hundred bucks. The string nut/clamp could hide under the barrel block at the top of the neck. You may have to recess behind the bridge to allow access to the tuning thumbscrews.

Your EL34s are cathode biased - there is no dedicated negative bias supply other than what is generated across the cathode resistors. Subbing in your PPIMV pot in place of the 220k grid resistors will be fine. I'd also recommend grid stopper resistors in series with the EL34 grids, around 4-5k (may be suggested in your datasheet?). The schematic in the 5th post down the following link is a good starting point. Ignore the 1M resistors in parallel with the PPIMV pot, just sub in your 250k dual pot and grid stoppers in place of the 8.2k resistors. http://ampgarage.com/forum/viewtopic.php?p=24181&sid=4b78ef45476054b9051dcb2bce745763

This recent conversation got me curious enough to try out a trapezoidal neck profile. I took the neck off my old Buster-caster and hit it with the scraper for 30 minutes or so to give it a flattened back about 3/4" wide up the middle of the neck, and angled sides starting at around 45 degrees at the nut and tapering off to maybe 30 degrees or so at the heel. The results are interesting. It definitely feels odd initially, but you do get used to it fairly quickly. Hooking the thumb over the bass side of the neck is actually more comfortable than you'd think to look at it. Certain note runs across strings tended to put the pad of my thumb on the edge of one of the trapezoid corners, which was a little bit like having a pebble in your shoe. Maybe this is where skewing the trapezoid along the length of the neck would be more useful? For all I know it could be poor lefthand technique on my part though. Playing up on the higher frets was definitely easier, particularly on the bass strings where the fingers are reaching across the full width of the fretboard. The trapezoid edge on the treble side of the neck had no benefit to me. I never position my thumb on that side, and the rest of my left hand makes very little contact with that surface while playing, so flattening it off was redundant.

Maybe the OP needs to clarify a little. My understanding was that it is an LP-style guitar with a bridge humbucker, and two singlecoils in a humbucker route in the neck position, and that the switching was different enough from a standard LP to make it unfeasible with a standard 3-way toggle, ie [bridge humbucker] - [bridge humbucker + neck inner single] - [neck outer single]. I actually agree with you though - the Black Beauty switch you suggested is the best alternative provided it's easy to get a hold of. If the LP "look" is an issue then my suggestion of the rotary switch may be discounted by the OP based on appearance or practicality. My other suggestion makes it possible to use a standard 3-way at the expense of losing the automatic swap of the two single coils when changing between the middle and neck positions.

Don't think it can be done with a standard LP-style 3 way switch, and to my knowledge the switch used in the Black Beauty is as rare as hens teeth. Could be done using a 3 position/2 wafer rotary switch, but they're not the most user-friendly in a situation where you need to quickly move from one pickup selection to another. With two single coils side-by-side in the neck position the tonal difference between the two may not be enough to warrant the pickup combinations you've listed. What about using a splitable active humbucker in the neck position, like the EMG 81TW, and leave one coil permanently disabled (or even switchable on a push-pull pot)? Then you could have [bridge] - [bridge/neck single]-[neck single] on a standard 3-way switch.

Yup. Google "PPIMV" or "post phase inverter master volume". The only drawback I can see is that any active controls you have in the negative feedback loop (eg, presence, resonance or variable negative feedback controls) will become less effective as the PPMIV is decreased towards zero.

So, is it time to start warming up the soldering iron?