custom cut Black Tusq bass nut

 ive used this artificial bone material before for my acoustic guitar bridge saddle & nut, & my electric guitar nut, but i still forgot how labor intensive it actually is. its also more nerve wracking the closer you are to finishing, 1 mistake, like cutting the slots too deep or making the bottom lopsided, & its ruined!

i always start by cutting it to width with a hair to spare (the general rule for all the steps involved).

ive used a razor blade & coping blade before, but this time i used a dremel with a diamond wheel.

a nice wood block is the essential work station, & i used 220 + 150 grit sandpaper, just dry, the Tusq is literally a solid block of lubricant so no wetting is necessary.

after cleaning up the rough cut, its time to measure the original nut. there was nothing wrong with my height, so i just copied it 1:1, though i always round the shoulder, as opposed to the sharp angle on the factory nuts.

just a pencil works great to mark the Tusq. there is some mind fuckery to be wary of: you cant just trace the thing, since the front & back are different, so overlaying them really is only useful for width & slot spacing. 

i started by marking the highest edge & sanding that flat, then marking the opposite lowest side & sanding at an angle to meet that.

after getting the top plane roughed in, i start the string slots with a sharp file. then comes the necessary tedium, using the actual gauge strings to cut the actual slots. i use old cutoffs to avoid bending or marring new strings.

i find the easiest way is to lay the string flat & hold the Tusq. i cut my slots until about 1/4 or 1/5 of the given string is left protruding from the top plane, that is to say, the slot will contain a little over half the string thickness.

once the slots are roughed in, refinement can begin. even though you cant compare the nut as a whole very easily, you can compare each individual slot.

i measured the height of the original nut, from fretboard to the top of each string (since the strings are too low to see any measurement on the ruler underneath the string). then i did a handful of test fittings with the new nut, comparing the string height, making absolutely sure i didnt overdo it.

after that, its all about patience & finesse. i decided to leave the new nut about 1mm tall, to leave room for breaking in/tuning several times. once you find that the slots are as deep as you are comfortable with, if its still too tall, you can sand the bottom, keeping it flat on the sandpaper on the wood block.

i used just a tiny smear of original titebond woodglue in the corner of the fretboard/neck to tack the nut in place, keeping it easy to knock loose if necessary but secure for string changes.

next, im gonna take care of the bass wiring.

Custom Treble Bleed Circuit & Harness upgrade

 the knobs on my guitar have annoyed me for a long time, i just never felt like they gave me a decent sweep or the sound got too muddy to use.

i finally decided to pull the trigger & upgrade all the internals all at once, since id have to pull the entire harness to do any 1 thing anyway.

the plan was to do:

1. jack upgrade to Puretone gold.

2. harness upgrade to braided jacket.

3. pot upgrade to new a500k pots (& relocate the position to have both vol pots up top oriented to match the pup positions).

4. new .033 orange drop tone caps.

5. custom treble bleed circuit on vol pots.

6. add copper tape faraday cage for both pups.

alot of my materials/items arrived staggered timewise, & i just couldnt wait to do the jack, so i ended up doing that first. since i couldnt find a gold mono jack, i used a stereo jack wired for mono.

i eventually replaced the masking tape with a bit of bobbin tape.

from what i read, it was recommended to remove the harness from the f hole, but i ended up doing it through the pup hole since i was planning to remove that anyway.

i used floss to keep the old pots labeled, then later to pull the new ones into place.

the generic chinese version of the overpriced stewmac jack removal tool proved to be absolutely indispensable. it also came in handy later to maneuver the pot nearest the jack back into its home, by just tipping it vertical from its side to allow easy pulling with the floss.

the original selector case held a shared ground for ALL THE WIRES. the bridge & neck pups as well as the jack wire jacket all tied together to the ground pin. theres contradictory confusing info on the internet about this & google ai was totally fucking me up because it kept referencing Gibson or SeymourDuncan wiring which apparently uses a dedicated bus ground with non jacketed pushback hot leads. Ibanez uses integrated copper jacket grounds. the new wire i bought used the same style so i copied the grounding & verified every case was ground to itself, eachother, the bridge, the tailpiece, the strings, & the jack.

ill also mention here that i found a metal tab embeded in a support beam inside the body directly adjacent to the selector switch hole. i could not find any mention of this anywhere online. it was bent like it had either been sandwiched by the swith or pressed against it. it didnt test to have any continuity with any other part of the guitar. i read about some guitars being sprayed on the inner faces with conductive paint & google ai guessed that the tab could be meant to ground the paint to the switch, but if there was actually paint, i inagine the tab would be pointless if the switch is making contact with the inner face when installed anyway. just out of superstition, i oriented the small tab to be pressed against the side of the swith when installed to give it ground contact...just in case.

turns out the original tone caps already were .033, doh! also, they were nice neat 100v versions, as opposed to the 400v monsters i was forced to buy because orange drops werent available in 100v.

before i bought the braided jacket wire, i hadnt looked close enough to realize that my factory wiring was copper braided under the plastic jacket, this new wire had tinned braided jacket with no protective insulation jacket, so i had to taco fold it all into bobbin tape. 

i wanted to redo the lengths & routing anyway, to get rid of excess & meet the new custom pot positions.

i originally ordered the wrong tone caps by accident (.00033 instead of .033) but it turns out they came in handy for my treble circuit. in order to get a unique .00066 value, i doubled up on the .00033 caps in parallel on each tone pot. 

i experimented with a 300k resistor in parallel but found that putting the 300k in series in FRONT of the parallel caps on the hot lug of the vol pot gave me a way smoother sweep.

i also fucked up buying full size pots instead of minipots (i hadnt realized my factory pots were mini because i didnt remove them until it was time to start). they turned out to be barely passable size wise so i just used them. at least the 9.5mm height & 3/8" width was correct for the holes.

my crude wiring diagram, first draft but its correct, just meant for personal use but sharing for posterity.

these are the knob positions i switched. i had also been using a dumb reverse phase magnet setup for a while, which i just reversed to stock again. for the record, it goes slugs facing eachother, north/positive toward the slugs.

for the faraday cage (to avoid having those nickel covers on the pups, i used 1 layer .5" bobbin tape, 1 layer of conductive adhesive copper tape over that, & BEFORE THE COPPER TAPE CAN TOUCH ITSELF TO CREATE A LOOP, interrupt that copper wrap with the start of the 2nd bobbin tape wrap, which then covers the entire layer of copper after adding a little tag of extra copper to wrap down over the edge to ground to the pup baseplate.

i actually had to buy a new multimeter because apparently the 2 multimeters i already own were garbage & only measured resistances up to 2k, even though 1 of them cost over $200 new. the new multimeter i got was $15 & had manual settings for up to 200mk! technology can be awesome sometimes.

i tested my pup resistances when isolated, then used that data to verify my pot wiring, then my selector switch signal on the lugs then through the jack using a cable plugged in with clips on the sleeve & tip.

at middle position i read 5.5k, neck position gave me 8.1k, & bridge position gave me 17.3k. basically a success.

overall, it was sort of a nightmare working without an access panel. its an incredibly fucking stupid design, but i just didnt have the energy to do an access panel mod right now, even though the possible procedures were whirling around my head the entire time. 

i quit while i was ahead & put some new strings on & fixed my intonation to wrap it all up. im pretty happy with the sweep result, & the relatively intact quieter signal that results at low volumes.

next i have to make a custom tusq nut for my bass guitar, then do some rewiring on the ratnest in that one.