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Prostheta

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Posts posted by Prostheta

  1. Not really, aside from a minor value change in one position. In the 80s circuit, the varitone is active all of the time and the switch controls active to the backup passive mode. In the 70s bass, the varitone can brought out of circuit using the switch, in which case a small value capacitor and resistor are left in circuit to keep the filter bleeding off RF frequencies.

    Just look at how redundant that varitone is! Unfortunately there's not much simplification that I can do with the retrofit preamps. 22MOhm resistors aren't a common value, so it laying eight of them around there is silly talk.

    Aria Pro II SB-1000 70s (v1).jpg

    Aria Pro II SB-1000 80s (v2).jpg

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  2. In principle that sounds fine, however it seems like a very large operation to create a small amount of angle. Off the top of my head, you could calculate this angle using right angle triangle trig by the opposite being 1mm and the adjacent the length of the fingerboard. So that's what, tan(angle)=opposite/adjacent? It won't be a lot, as it's roughly 1/4 of the height loft of that mm loss over the length of the board. Drop the fingerboard at the nut 1mm and you gain 0,25mm at the bridge assuming that the fingerboard is 3/4 the length of the scale. The trig gets you closer to the real answer, but this approximation shows it won't produce the results you need.

    edit: 1/3rd of the height loft, hence 0,33mm and not 0,25mm....oops

  3. The Taylor approach is not a full-width neck pocket, but a recess that exists solely to accommodate the first couple of mm of the neck. That solves the external shoulder-to-body seam problem with neck angles. Having a full-width tenon would require additional mass on the internal neck block to maintain stability. There's a lot of tradeoffs and bad paths to follow, which is exactly why I admire the smart industrialists like Bob Taylor and Paul Reed Smith. They aren't afraid to introduce strong new concepts and manufacturing ideas directly into the market that is dominated by traditional thought. I digress.

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  4. The shims under the fingerboard extension are pretty much a given. My thought was how the neck join is going to be configured. Tilting the neck back requires material to be cut from the shoulder and the plane copied to the tenon if it meets the back of the mortise. I'm sure it's going to be simple work that requires patience more than anything. Oh, and an ultra sharp chisel. Nobody expects an ultra sharp chisel. And fanatical devotion to the pope.

    Fasteners are a relatively modern invention, at least in terms of metal with threads. If these engineering products were available during the period that defined most of the techniques and configurations that are revered today, they would have been utilised or experimented with. That quickly goes down the path of the circular modern/traditional argument though. I prefer a palette that draws from everything as a reasoned selection of personal choices, with at least a good understanding of both extremes.

    I wish I had time this morning to dig out that Taylor vid on how their necks work in terms of shims, recessing and bolts. I doubt that @ADFinlayson needs that polluting his thread though. Back to work....

  5. Looking good. All by the numbers and showing attention to exactly where it's required.

    I suppose that there a number of ways to reconfiguring this to create sufficient loft over the body for the correct action. My mind always goes to the industrialists like Taylor rather than the traditional methods. I like the idea of a neck that retains the look of a traditional instrument but incorporates the ability to adjust and refine geometry. I don't know if you want to go this route, or even can by this stage, but that's where my thoughts lead.

    Without me going back through the last eight pages, is this intended to be a glued-in or bolted-on neck? Both are valid, however I think the former would feel less satisfying to most should shims in the mortise become necessary (likely I would think). I have grown to like bolted constructions for the tension within the joint, as sonically they do seem to "add" more detail, or at least result in a construction that is characterful in sound as opposed to not. At the very least, there will need to be a shim under the fingerboard to backfill the gap created by introducing this elevation.

  6. The varitone is a stack of RC values that are used by the preamp to form an active LPF with a reasonable mid bump before the cutoff, hence why it changes the "character" of the sound differently to a passive LPF like the tone knob. I've played around with the idea of making an alternative varitone that is continuously variable as opposed to a selection of six RC values, partly because of the control but mostly because the rotary and fourteen components fabricobbled around it was just another example of Aria Pro II being slightly mad in the head. I didn't go too far down that rabbithole.

    The "tonal pocket" you mention is why the SB-1000 is a recognised and desirable instrument....the weird neck taper, comparatively-larged cross section of the neck profile, Jacaranda fingerboard and neck laminations of quality wood that doesn't really come around any more combine to make it what it is. The 5th-7th positions have a very distinctive midrange which was common to the sister models such as the SB-700, etc. They were the same dimensionally, but different in terms of electronics and hardware configuration. That "honk" is what makes them stand out in pop recordings of the time....they sit differently in the mix to say, a Thunderbird or a P-bass. Maybe a bit more into J territory?

    The polepieces in the MB-1E were all steel slugs of slightly differing lengths to match the string radius. They were built using two rotation mating ABS bobbins that look similar to a J pickup, but with evenly-spaced pole positions so generally a great big ceramic humbucker. Later pickups like the MB-II and MB-III used the same configuration, but half-loaded the bobbins with poles or rod magnets in a P-bass pattern.

    Fret clatter is definitely underrated. I don't think Entwistle, Lee or Harris would have the same punch without it.

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  7. Looking forward to some CNC time in the near future. In the meantime, I went full-on and adapted the 24-fret Invaders model back to the original 22-fret SSH.

    65.jpg

     

    Aside from a few differences here and there, plus a couple of fixes and omissions....this is on the money. I modelled the tremolo using measurements taken from a modern production Schaller Lockmeister which is an OFR without the name or the price tag. Drawn up provisionally for Fishman.

    3f74974b-ff13-4674-9418-9a430fa9ad88 (1).jpg

  8. I'm specialising in desktop product design for manufacturing via CNC, so a guitar is familiar ground for me and is applicable to my degree work in that respect. Rendering is a valid form of product visualisation, whether for testing the aesthetics of materials and colourways, examining surfacing in how it reflects light as gradual or aggressive contours, etc. Similarly, I used a €15k structured light 3D scanner to examine a few tops as a way to discuss appropriate derivation of geometric data.

    Of course, I do want a guitar. We all want many many more guitars....I hope?

    I didn't mention this at any point, however the entire model is valid internally also. Not quite to the soldering and wiring loom level, but in terms of graduated surfaces inside the cavity to place pots and switches the appropriate distance from the external surface. I don't aim low.

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  9. The two Mirages are still needing to be painted, which is all dependent on catching a booth at the right time. Otherwise, I did all the design work on the carved top Mirage, which I learnt last week was a production model and maybe not so much of a prototype. Nonetheless, I've never found another one like it ever beyond mine and the one that was photographed for the catalogue, which isn't mine.

    gallery1.jpg

     

    Näyttökuva 2023-08-06 143635.png

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  10. Measure the height of the strings over the body at the pickup (A), measure the height of your pickup (B). Select a distance of how close you want the strings to be to your pickup (C).

    A-B-C

    If the string height is 20mm, your pickup height is 40mm and you want a 2mm gap, that's -20mm.

  11. I'd never discourage re-use of things that still have usable lifetimes! Burrs are better for shell and stone than for wood since they abrade and chip rather than shear and cut, however down at the sizes of 0,5mm - 1,0mm (1/64" - 1/32") this is far less of an issue. 1/16" (3,175mm) is getting to the point where burrs burn and cause ruts rather than evacuate material efficiently, but if it works it works. Those smaller sizes never work in Dremels anyway as they tend to have silly amounts of runout that make a 1,0mm bit increase in cut by something like 50%. Even if the bit survives, it's cutting using far less than its actual cutting surface. I wanted to upgrade my pantograph's Dremel with a spindle, but by this point I might as well be making an inlaying CNC 😕

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  12. "Notes to self" are a fundamentally important trick if anything! The problem I always have is that ideas live in my mind, but the biggest challenge isn't about coming up with them or refining them, it's about realising them....being able to write down your thoughts and ideas, or vocalise them to another person even if they don't need to collaborate is a productive step. That might be me, not sure. I don't know how other people's minds work 😉

  13. I've seen that myself in "B" grade boards. Ebony with what look like water marks from drips. It doesn't come out and is a "feature" of the wood. I dislike the throwaround term "B" grade since that means something very specific in wood grading, much like how AA/AAAAA etc. are meaningless compared to proper grades within the wood industry. They're perhaps accepted as a shorthand of sort, but cut directly across the sense of grading terms. I digress.

    Veijo is actually very much missed by the Aria Pro II community as he became (more accurately, fell into being) the primary source for repro MB-type pickups. Much the same as myself and the preamp circuit upgrades I make for these basses and guitars. We sent each other a fair amount of business either by direct reference or by virtue of co-existing in the same tight market. It can often get to the point where these market demands run away with themselves beyond capacity to provide, which I believe happened with Veijo. Probably not even the most profitable business to be working in either, given the expensive of tooling and labour!

    Veijo made the pickup for my 5-string Aria Pro II-based bass:

    ....also in the post immediately above that one, you can see flecking as I was discussing in Ebony. That polishes up nicely though.

  14. I take it that is Veijo Rautia?

    Ebony with striping to it like that has a unique property in that when polished like glass, the not-black areas gain a glassy 3D depth. It's a good opportunity to treat it differently to jet black Ebony, or worse, dye it black. Many years ago I made a 7-string neck with an "Indian" Ebony fingerboard that had marginal brown striping, and that polished up like an Ebony version of Tiger Eye. Very amazing.

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  15. I can't say either way, however for my own purposes I am idly considering which direction to hunt for any sort of Maple top. I can see properties of the original's that indicate what sort of cut it was from and maybe guide myself that way. It isn't too important. I do want to avoid those silly high grade PRS-type tops that are so tight they have no real character to them. That's why a birdeye with a bit of wild curl introduced would be great. This is getting a little ahead of myself as well, because what is available at the time will be available at that time. I don't imagine starting this project physically until at least next year, and I know that money is terribly tight because of my time out of work to study. Things are nice in theory, but you can only stare into your navel for so long.

  16. Look at images of flamed violin backs and you don't tend to see cathedral grain lines, leading me to think that quartersawn is preferable. I have no idea to be fair, since hollow bodies just haven't come into my area of work. It would make sense though. My ESP showed a lot of that, so it was probably a nice riftsawn/flatsawn piece. Beyond the cosmetics, I don't have a real preference if I had to choose. That being said, if a nice curlyish birdseye set became available during a period when I actually could afford it, maybe.

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  17. I don't have a hell of a lot to update on, however whilst I am waiting to find the most opportune time to paint the two bodies, I'm progressing the carved top Mirage as the basis of a manufacturable product desktop study. That is, 3D modelling, manufacturing schematic production, the 3D scanning and all of that other degree stuff. I'm also touching on fault-tolerant CNC pneumatic workholding jigs, but enough about me 🙂

    Näyttökuva 2023-05-18 103632.jpg

     

    There are still a few bugs to work out, plus a number of design changes to fulfil. One being that the neck is to be 22 fret rather than 24, plus the bridge and pickup locations moving because of this. The lower cutaway nicks the location of the pickup ring, which obviously wasn't a problem in the original HSS version.

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  18. Grinding off the barbs is a good idea. The zero fret will always be under string tension, and it can always be seated with a little wood glue. Enough that heat will allow it to be removed when needs be. Using a SS fret for the zero is a good idea also. I use a larger size than the rest of the frets and bring it down after levelling.

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