C18Q1. Jazz Box Tart-Up

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  • NomadNomad Frets: 549

    Decided to make a start on the nut while I think about the electrics.

    The slot in the guitar is recessed at the headstock side...


    Fortunately, this 5mm bone blank is a perfect fit...


    After making an approximate mark for the length it's to be cut to, a pencil that's been sliced down the middle is run along the frets to give an indication of where the bottoms of the slots are likely to be...


    The pencil is then shimmed and a second mark made above the first...


    ...to create a guide line for the initial shaping...

    Filing to the upper line won't define the final height of the nut - it will be cut down more once the fret slots are cut. On the left, at the 6th E, it'll come down a little, and probably quite a bit more the other end, with something approximating a curved, tapered path between the two. The final height depends on the slot depths, and it's better to creep up on the sizing than to try and second-guess things. Same with the overall length - cut with some to spare, and then fettle bit by bit until it's a good fit.

    Here's the nut after cutting and filing to the initial shape...

    And after a bit of sanding to get a feel for where the curves are going to be...

    Note that there's a radius at the ends, following the curved back profile, but the radius stops short of the headstock to avoid having the back edge of the nut curving in at the recess - want it to be flush there, but for the exposed edges to have some roundover.



    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • NomadNomad Frets: 549

    I decided to do the truss rod cover, which wasn't mentioned I the opening post, but was always intended to be replaced.

    The original is this plastic affair...

    ...which has a slide-out hatch thingy...

    The hatch thing is quite a good idea, but it feels flimsy and isn't really in keeping with what the old jazz box look.

    So I took an offcut of ebony headstock veneer and drew round the original cover with a white pencil...

    ...and cut out the shape using a jewellers saw...


    I then put the two covers together, marked through the holes with the pencil and then made dimples with an awl...

    1mm diameter pilot holes were drilled using the Archimedean drill above, which were then enlarged to 2.2mm using a hand drill...


    When I went to check on the guitar that the hole positions were okay, I found that the cover was being offset by the nut, so I added a little chamfer to the straight edge...


    The hole positions were now fine...


    To finish off, I rounded over the outer edge, gave it a lick of linseed oil, followed by some home-brew wax polish and a buff...


    And here it is on the guitar...


    Compared to the earlier shot from this angle, where the cover is pretty matt, the oil and polish has brought it up with a nice sheen that matches that on the headstock



    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • RabsRabs Frets: 2602
    tFB Trader

    Great job..  And that truss rod cover totally fits the whole look..

    Ive never seen a trussrod cover with a hatch like that... I do like that idea quite a lot but it would have to fit well and not add any unwanted vibration...

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  • NomadNomad Frets: 549
    I don't think it had any vibration issues, but it just felt that it was one wrong finger movement from breaking.

    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • paulnb57paulnb57 Frets: 3044
    Its amazing how the little details make such a difference......looking great!
    Stranger from another planet welcome to our hole - Just strap on your guitar and we'll play some rock 'n' roll

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  • NomadNomad Frets: 549
    edited January 2018

    I knew there was a reason for dithering on the electrics, even though it didn't occur to me immediately. Another thing that has to be done is to seat the bridge, which needs a bit of space in the vicinity of the volume control - much easier to do if there is no volume control to get in the way.

    Seating the bridge is done to get a good contact with the top of the guitar, particularly in the areas directly under the posts. If there were gaps under the posts, there would be flex in the little arch shapes, which would effectively work like springs when the strings vibrate. What we want is a good compression contact under the posts to get good coupling to the top of the body, and it should be the body that vibrates in sympathy with the strings. Since the body will have its particular resonances, some string frequencies will be damped and some emphasised (and no doubt with some commensurate effect on the pickups, since they're mounted to the same vibrating plate). The hope is that the result of this is a so-called woody tone.

    Here's the bottom part of the new bridge in the approximate position...

    (The camera is off-centre, here, not the bridge.)

    Not too bad on the right, but a huge gap on the left. Boing, boing.

    I actually had two goes at this. Yesterday, after I had done the sanding, I found that there were still fairly large gaps, although they had moved towards the inner edges (so only touching the body at the outer ends). I realised that it was due to how I was holding it - I didn't want to press on the middle because it's pretty thin, so I was sort of using the two posts as handles while also trying to apply light to moderate pressure. Whatever I was doing, I was still getting flex during the sanding, so I added a stiffener before starting the second attempt today...

    It's a bit of beech with holes drilled in it to match the posts, with the adjuster wheels used to hold it down firmly. This felt much better - no flex.

    Here's the setup...

    Mask off the nearby openings and put an additional bit of tape under the area where the sandpaper goes in case there are any gritty bits at the edges that might scratch the finish. It's then a case of holding down the sandpaper (the fingers stretch outwards to keep some tension in it to pull it flush across the surface) and working the bridge back and forth with the other hand. I kept the motion pretty short - no more than about +/-15mm either side of centre. This was to give it a decent chance of ending up with a profile that's a good match to this particular part of the curved top - the more the bridge deviates from its ideal position, the bigger the risk of moving onto a different part of what is an irregular curve and sanding a different profile into the underside.

    The next three shots show the sanding at various stages...

    Here, the outer ends are being sanded first - the lighter brown bits towards the inner ends of the two bearing surfaces are sanding dust. Remember that this is the second attempt - here, I'm removing the high spots I created in the first attempt.

    Coming along...

    Note the numbers written on the underside in white pencil. These are to aid orientation by indicating which side is 1st E and which is 6th E. Don't want to reverse the ends in case the curve of the body isn't symmetrical. Also, note that the dust patches don't extend much beyond the ends of the bridge - short strokes.

    And done...

    This is 80 grit paper, cut from a roll bought at Machine Mart. I quite like it - cuts well and is very durable.

    After the shaping, the underside is brought to a smooth finish with finer grits...

    The numbers have been reinstated so they're nice and clear - they'll be needed when the bridge is installed. The edges were also given a light sand because they end up quite sharp after the sanding, which could mar the finish.

    And another shot of it on the body afterwards...

    Still some slight gaps, but far, far less than what it was like at the start (and after my first attempt without the beech stiffener). When I tried putting a little pressure on the posts, these closed up, while the ends lifted slightly. I'm happy that there will be good coupling between the bridge and the top.

    Not much more to do ,now. Still got the electrics, but I've now ordered some bits which include some Switchcraft jack sockets, so they won't go in until that stuff arrives. I think I won't do the series/parallel idea - not keen on finding that it adds too much noise once it's all installed. I will have another look at my numbers for the capacitance values - I'm leaning towards two 22nF caps at the moment.

    I'll put some initial slots in the nut to set their positions, and I'll have a look at the profile of the top of the replacement bridge compared to the radius of the fingerboard. Once those are done and the electrics are in, I can fit the hardware and do the final setup.

    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • JalapenoJalapeno Frets: 6378
    Looking chuffing awesome so far !  Get a Rosewood "Jazz" bridge
    Imagine something sharp and witty here ......

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  • TTonyTTony Frets: 27345
    I'm not sure that "Jazz box tart up" with a bit of T-Cut quite reflects the scope of this work
    ;)

    Love the thinking and the attention to detail.  I'm guessing that lots of little improvements is going to add up to one hugely different - and better - guitar.
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  • NomadNomad Frets: 549
    edited January 2018
    Jalapeno said:
    Looking chuffing awesome so far !  Get a Rosewood "Jazz" bridge

    I already have an ebony one (which was bought ages ago). I recently read that it's traditional to use the same material as the fingerboard, but I didn't know that at the time. I'll use the ebony one and see how it goes.


    TTony said:
    I'm not sure that "Jazz box tart up" with a bit of T-Cut quite reflects the scope of this work

    I suspect my tart-ups tend to be a bit more involved than the term might imply (my recent workshop tart-up was certainly involved).


    TTony said:
    Love the thinking and the attention to detail.  I'm guessing that lots of little improvements is going to add up to one hugely different - and better - guitar.

    Yes, that's what I'm hoping for. The Ibanez Artcore range seem to have a good reputation for jazz guitars at the budget end of things, and from what I can tell, the AF55, the cheapest one, is basically the same guitar in terms of wood and construction as the more expensive offerings. They just went cheapo with the finish and, in particular, the pickups (the rest all have what look like better pickups). I assume they all have the same pots and other bits. In terms of looks, I like the style of the AF55 more than the others - basic, old, and non-blingy. When I was shopping for a jazz box, I looked at Thomann's Harley Benton offerings, and wasn't so keen - similar price to the AF55, but too much bling, so I went with the Ibanez (after having a play in GuitarGuitar and liking the neck profile) on the basis that it could be worked up to something better. In the end, it will have cost about the same as one of the dearer Artcores, but will have the look I prefer, and arguably have some further improvements over those as well (mainly pickups, bridge and nut).




    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • NomadNomad Frets: 549

    Next up was the curvature of the bridge. Since I plan to fit an all-wood bridge, the only adjustment available will be the overall height at each end along with a bit of scope for tweaking with nut slot files. The bridge radius needs to be chosen such that it works with the radius of the fingerboard - a wrong choice here could result in string heights over the frets that are inconsistent, resulting in some strings being too high and/or some strings being too low.

    A bit of reading suggested that there is some debate on the ideal radius for a bridge - some say it should be the same as the fingerboard, and others say it should be much flatter. In terms of geometry, an ideal setup would have a compound radius board with the nut and bridge radii chosen to give the desired string heights across the board at all frets. Quite possibly, this would mean that the profile formed by the strings would fit onto a cone that's had its top cut off at the nut. This would result in a given radius at the nut and a flatter radius at the bridge. Assuming a suitable compound radius on the board, all of the intermediate radii under the strings would then follow the radius at each fret in such a way as to give the desired heights.

    This doesn't really apply with a constant radius fingerboard - you either have too flat a radius at the nut, or too curved a radius at the top fret, which means that the string heights, both across and along the fingerboard, are something of a compromise. How much of a compromise is hard for me to say because I haven't tried to model the geometry, but I do have other guitars with constant radius boards, and they seem to be playable enough. That would seem to imply that it's not that critical, really, unless you want an incredibly low action.

    So, in choosing a radius for the bridge, I reasoned that the best plan is to make a shape that will allow me to tweak the final string heights with the minimum of fuss using nut slotting files. Since I'm not sure whether the ideal bridge radius for least compromise is smaller or larger than the fingerboard radius, I decided to make it the same as the fingerboard, and that is 10" (in spite of what it says on the Ibanez web site, which is 12"). This means that, if the bridge radius needs to be flatter, I cut deeper slots in the middle, and if it needs to be more curved, the deeper slots are at the outer ends.

    Here's the top of the new bridge next to a 10" radius gauge...

    A noticeable difference - big gap in the middle.

    After some more checking, it looks like the bridge is cut to a 14" radius...

    I then had to decide how to work the shape. My first thought was to just run a file along it longitudinally to make the new radius, but the posts in the lower part of the bridge go into blind holes in the top part. After some measuring, it was apparent that extending the 10" radius all the way to the ends would result in breaking through to the tops of the blind holes, which I didn't want. So, I decided to work across the bridge in the saddle area, bringing the outer saddles down while leaving the material beyond these intact.

    Here's the bridge after doing this...

    A good match to the 10" radius. I didn't use the gauge while doing the filing because it's too long to fit into the length that was being taken down - I made a little card template and used that instead. The filing was a surprisingly delicate operation - light pressure and only 3 or 4 strokes each time before checking with the template. I used a good quality medium cut flat file for this (ie, one that files without buggering about). The very first strokes were taken very gently to check whether there was any splintering of the ebony at the trailing edge, but it was all okay - working it with the file was fine.

    After it reached a profile I was happy with, I judiciously pared the little steps at the ends away with a small chisel and tidied them up a bit with a round file. After that, they were sanded a bit, and then both parts of the bridge were sanded a bit more, partly to take off the factory glossy finish (which was already gone from the saddle area on the top), and to round over the various edges a little. That came up quite matt, so a lick of boiled linseed oil was applied to get some sheen back.

    Here's the result...

    That looks pretty good to me. There may be some more of this filing malarkey later once the slots have been cut during the final setup. It depends on how deep the slots end up when getting the string heights done - if the saddle heights look a bit off compared to the slots, I might want to rework the profile to tidy things up.

    There's another couple of reasons for taking this approach. One is that it lowers the minimum bridge height a bit. I've already had this bridge on the guitar, and I found that the 1st E side was virtually right down. Since I'm hoping that the fret job will result in a slightly lower action, I need some scope for adjustment here. (This is also helped by the seating of the bridge, which will have taken some material away from the underside). The other reason is that it's better to do this now rather than after the final setup. If I had buggered it up today, I wouldn't have wasted time doing the setup; and, having already done some work on the material, I've now had some practice and have a better feel for what it takes to remove a certain amount if I want to rework the saddle heights after the slotting - less chance of buggering it up if I want to do some more shaping after the setup.

    That's the preparation of the bridge done. I still have the initial slots to do in the nut. A bag of bits arrived today, including some Switchcraft jack sockets, so the electrics can be started.

    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • TTonyTTony Frets: 27345
    Detailed work, detailed explanations, and detailed pics too.

    And thanks for taking the time to share it all.


    I'm starting to think that I should pay far more attention to detail in my own challenge builds!
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  • NomadNomad Frets: 549
    edited January 2018

    The devil's in the details, Tony.

    I try to always think through each stage before I start - consider ways to do something, do some research if I'm not sure, and aim to have as clear a plan in my head as I can manage.


    Anyway, the electrics are now done. The first thing to do was to enlarge the holes for the pots, which was done using a tapered reamer...

    The tape around the cutting part is a depth marker - once that reaches the top of the guitar, the top of the hole is large enough for the CTS pots. The holes were made vertical using a round file (lightish pressure, and short, fast strokes to minimise the chance of tear-out on the other side, and constantly moving the file around the hole to keep the shape even, while avoiding cutting into the edge of the hole at the top).

    Then it was time for some soldering. The components were fitted into a bit of cardboard with holes at the same spacing as on the guitar...


    The wiring between the components is done...

    Some bits were done with the component removed and either held in a vice with rubber jaws, or just balanced on the bench - things like the caps, bits of tinned copper wire going between pot lugs and casings. The main reason for using the cardboard was to ensure that the wires that go between the bits are definitely long enough.

    And the pickups are connected...

    During this phase, I was testing regularly - fitted the caps to the switch, and measured them with an LC meter (I got it wrong the first time and had to take them off and do it again - series and parallel are arse for tit with caps, which I already knew, and I still buggered it up). Tested again when I wired the blower switch in at the volume control, and kept on testing at each stage. Much better to spend a couple of minutes verifying the work than to do it all in one go, find out that something's wrong, and have a more complex circuit to troubleshoot and - perhaps more importantly - have a lot more crap to desolder and resolder to put things right.

    Once the pickups were connected, testing included plugging into an amp and tapping the pole pieces with a screwdriver to make sure there were appropriate noises, and that all of the controls did what they were supposed to. In this case, that included two tone control settings and the blower.

    In the end, I opted for capacitor values that give me 7nF in normal mode, and 17nF with the tone control push/pull raised. The values were achieved by having a 10nF and 22nF in series for 7nF, and adding another 10nF in parallel with both of those for 17nF. With the tone control turned right down, I could hear the effect of the cap settings when tapping the pole pieces. Whether all this results in a resonant peak around the upper notes remains to be seen.

    With the wiring done, I then prepared the body for getting the stuff fitted. I used plastic air tubing for aquariums...

    Each piece is fed through to give a suitable length, then cut and knotted at the outer end. Note that they're all taped to body. This isn't to stop them slipping back in, but to keep them out of each other's way. They're done one at a time - once knotted, they're drawn through so that there's a little bit of tension, and then taped down. By doing this, each tube is held up out of the way of the subsequent tubes, and that means that the routing of the tubes inside doesn't result in any dodgy overlaps, tangles, etc. If you don't have the routing nice and separate, things will get in a mess when you try to draw the components and wiring loom through. Each tube is labelled to ensure there is no confusion.

    The bit of blue tape near the pickup opening is holding the earth wire in place. This is the only bit of soldering that will be done at the guitar (the neck pickup goes down through the hole for the bridge pickup, and then up through its own hole).

    The tubes are then attached to the components after fitting any shakeproof washers...

    The tube for the jack socket passes through the socket and has a second knot tied in it on the inner side. The rest are attached using tape while taking care to avoid the threads. I used fair amount of tape on each join - wrap a few overlapping turns on the tube first, then over the pot/switch, and back up over the tube. Pull the tape taut for every wrap, to the extent that it's stretching. This will make a much stronger bond between the adhesive and the tube/part, and the subsequent layers of tape. There should be no looseness between the tube and the shaft of the thing it's taped to.

    I was somewhat dreading this bit...

    ...but it actually worked pretty well. Once the components were in their holes, I undid the knots and slid nuts and washers down the tubes and got them loosely onto the threads so that everything was held in place. Then... test again just in case something is amiss with the wiring. It was okay, so I tightened each carefully with a spanner, undid the tape and removed the tubes.

    The neck pickup was then jiggled through to its own hole, and both were screwed down...

    ...and everything was tested again.

    The pickup switch was back to front. Bollocks! I checked the metal toggle to see where the black mark was that I had put on before threading everything through (black on the side of the switch that goes towards the bridge pickup). It looked like it had become rotated during the threading - the black mark was on the neck side (towards the volume control). I slackened it off a little (just enough to give it some freedom to move), worked out which way it wanted to rotate more easily, turned it, and tightened it back up...

    ...and tested everything again. All okay this time.

    Those pickups and pickup rings look a hell of a lot better.

    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • paulnb57paulnb57 Frets: 3044
    Great write up Nomad, I rewired my Epi 335 but used normal multi core wire, what a bugger of a job that was! Using the wire with the  braided outer makes so much sense!  Thanks for sharing all the detail...
    Stranger from another planet welcome to our hole - Just strap on your guitar and we'll play some rock 'n' roll

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  • NomadNomad Frets: 549

    Cheers, Paul. Yep, the braided stuff means the hookup wires are screened, which makes a difference with a hollow body like this.

    I put the guitar back together today. For now, I used the original nut so that I could get an idea of how the string spacing looks at the bridge, and a general feel of the action. I've only done a little bit of setup so far - intonation, overall bridge height and pickup height. Currently, the action is pretty similar to how it was before, but with a notable lack of fret buzz in certain areas (especially high up). I didn't need to adjust the truss rod when I strung it back up, but I'll see how it looks when its had time to settle - I suspect the relief is more than it needs to be, but is masked somewhat by the action still being high at the nut.

    The final embellishments compared to the original were changing the toggle bitty to a cream one, and fitting two of the knobs that were originally fitted to my Vintage Lemon Drop - gold top hats with 'Volume' and 'Tone' on the tops (these were binned immediately when I got the Lemon Drop, and replaced with speed knobs).

    So, a more detailed setup is still to be done, but I'll leave that for a bit while I get used to the changed guitar. For now, here are some pretty pictures.

    First, a comparison of what I started with, and what I have now.

    Before...

    After...

    In cosmetic terms, it's surprising how much difference a bunch of quite small changes can make. It's really just pickups, bridge, plastics and a polish, but it now looks like a proper 50s era non-blingy jazz box rather than the wayward conception that Ibanez had come up with. Overall cost, including buying the guitar (new), works out to just about £400, which is about in the middle of the Artcore range, and I suspect these pickups are probably better than what they come with.

    Some detail shots...

    The shape of the top is a bit odd at the neck pickup - it's quite concave, which means the pickup ring has the wrong shape at the edge, but I can live with that. The neck pickup ring is also fitted back to front - fitting it the conventional way would have resulted in the pickup being very tilted. With the taller side of the ring towards the neck, the pickup is nice and parallel to the strings. The bridge pickup is installed normally, and is fine. Don't see much light catching the body here, but I noticed that the tailpiece is reflected in the satin finish.



    A clearer shot of the bridge here. The strings are just resting where they landed when I strung it up.



    Leaving the looped string ends on for now until the setup is done. The strings are 11-gauge D'Addario Chromes (flat wounds).

    I've been playing it through my Laney Cub 10, plugged straight in, and my initial impression of the tone is that it's sweet and mellow, especially on the neck pickup. Fairly similar with both on, but with a bit more clarity. The bridge pickup on its own is quite middly, but doesn't get harsh. Still messing with tone control settings. I'm quite surprised at how much range there is with the 7nF - on the neck, there seems to be a sweet spot at around 2.5 to 3. Switching to 17nF takes it into Wes Montgomery muffletastic territory. It has a completely different voice to any of my other guitars, and I have to say, it sounds way better than it did before.


    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • TTonyTTony Frets: 27345
    If you finish jobs this quickly, you'll have time for another couple of dozen before the end of Q1.
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  • SargeSarge Frets: 2370
    A really good informative read with good pics and details, thanks for sharing with us.

    The guitar looks great.... but that gap under the neck pickup ring is enough to bring on a bout of ocd in me ;) 
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  • NomadNomad Frets: 549
    edited January 2018
    TTony said:
    If you finish jobs this quickly, you'll have time for another couple of dozen before the end of Q1.

    Aye, but it took me three years to start it...


    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • NomadNomad Frets: 549
    Sarge said:
    A really good informative read with good pics and details, thanks for sharing with us.

    The guitar looks great.... but that gap under the neck pickup ring is enough to bring on a bout of ocd in me ;) 

    Well, nothing is ever perfect, but I know what you mean. There's always the option to work it a bit later, or maybe get a taller one with a view to getting it down to a suitable height after the shaping (partly why I didn't tough the one I had).

    Nomad
    Nobody loves me but my mother... and she could be jivin' too...

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  • Jez6345789Jez6345789 Frets: 1756
    It’s been a real good detailed read and should inspire us all to take the time to tweek our lesser guitars to get the best from them. 

    I do do think it looks way better and if you are getting the sound then win win
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