Experimental Prototype bass... I hope

[mhoss32]

@Si600 haha thank you! Its the garage actually, temporary workspace while the workshop i usually use is still closed

@TwoTimesBass each pickup will go to a different output, with independent preamp controls for each itll be a 4 or 5 pin mini XLR, switchcraft do mini xlr jacks that are very similar in size to a standard 6.35mm so it should still look and feel pretty normal 

[TwoTimesBass]

24 minutes ago, mhoss32 said:

@TwoTimesBass each pickup will go to a different output, with independent preamp controls for each itll be a 4 or 5 pin mini XLR, switchcraft do mini xlr jacks that are very similar in size to a standard 6.35mm so it should still look and feel pretty normal 

Thanks mhoss, that makes sense, gives you some great options for the matching pedal! Those mini XLR's are pretty good, i've used them on a couple of (non-guitar/bass) projects in the past and they stand up well. Lemo also make some great, if a bit pricey, mini multipin connectors.

[Simon.]

Wow! You don't do things by half, @mhoss32

This is the gift which just keeps giving. 

[MoonBassAlpha]

23 hours ago, TwoTimesBass said:

Thanks mhoss, that makes sense, gives you some great options for the matching pedal! Those mini XLR's are pretty good, i've used them on a couple of (non-guitar/bass) projects in the past and they stand up well. Lemo also make some great, if a bit pricey, mini multipin connectors.

Lemo connectors are indeed things of beauty. They're so well made and finished. 

[itu]

On 03/02/2021 at 23:33, TwoTimesBass said:

Lemo also make some great, if a bit pricey, mini multipin connectors.

Lemo and Fischer are quality, but also the most expensive connectors in the market. The smallest are a PIA to fix, if they ever get hurt - and they do in active use, like outside broadcasting.

[mhoss32]

I shall take a look at both, thanks for the tip!

The marquetery beam is now planed down ready for the truss rod slot to be built on it, so a few gratuitous beauty shots are in order of the flattened side before it gets covered up:

the next step i loosely tape the carbon rods around the double action truss rod, so that it will fit snugly, and get the positioning right on the neck:

The carbon rods will run the whole length of the neck, over the body transition and up into the headstock a short way. this way theres no weak points along the neck where stress could build.

The rods are then epoxied in place, with a 6mm wide strip of cabon between them. they're slightly narrower than tyhe beam, as i changed the design slightly to use the new woods, but i will re- veneer both sides so that its all perfectly flush before building up the rest of the neck blank. these things are stiff... like really stiff. as you can see the rods have 8mm holes down the middle, and i bought additional 8mm rods to go inside if i felt it wasnt rigid enough, but i now think thats not going to be a problem very pleased

The first 8 coild for the pickups are done now, so i started building one up!

Each pair is wired together in series (the little red wire) and then wired onto the PCB. ive removed all the standoffs and screws to give myself some more space.

Then the next pair...

and before you know it:

all 8 coils, nicely wired together. i tested the switch and the DCR values are all as expected

Next i start glueing the bobbin mounts in place. these are what will determine the height of each vertical pair, controlled by turning the black hex screw. this is done with a very small amount of CA glue, so little that i can easily take them apart with a sharp scalpel if needed. the magnets sit perfectly flush with the top of the bobbin mounts, giving nice consistent heights across all the coils.

and heres one all together! nice and neat, and it looks like itll fit perfectly into the cover. ill save that treat for my next upload though

here you can see how it all works. the vertical pairs are mounted over a brass standoff, and pushed up by a spring and some foam mounted beneath the coils. as the screw is tightened, each assembly can move up and down independently. the 4 holes in the pickup cover leave these screws exposed, so you just bolt the pickup in place and move the coils within the pickups to set the volume

 

 

 

 

[Si600]

I'm all moist.

[Richard R]

1 hour ago, Si600 said:

I'm all moist.

Almost what?

[Hellzero]

Wow ! 

[BassTool]

10 hours ago, Hellzero said:

Wow ! 

What he said 😲

Amazing! 👌🏼

[roman_sub]

Absolutely amazing. Subscribed

[mhoss32]

Big update today!

First off, i started to cut out the Malee Burl scales into the branches that will be inlayed into the fretboard:

The knife scales themselves were about 10mm thick, so idivided them down the middle so i could get both of the branches out of juat 1 scale. waste not, want not. this kind of cutting looks complex, but its pretty easy with some patience and a sharp coping saw

I have another branch to cut, then i'll inlay these to the fretboard, and then inlay the leaves over the top. at least thats the plan!

as with my last bass, this bass is going to have a Bigsby modified for a bass. this worked pretty well last time around just by drilling a new string bar with 4 holes in it and stringing it up as usual, but it did present a couple of problems:

1. the angle that the strings had to wrap around the string bar was a bit too tight for bass strings

2. a normal bigsby tension bar (on a b50 or b5) is probably a bit too low for big thick bass strings, making it a nighmare to string up without damaging the finish of the bass

so i decided that this time id try a new approach. firstly, the whole colour theme for the pickups and hardware is a nice mix of black and gold, so i started off buying a matte black bigsby 500 clone and immideately binning most of it

first i decided to tackle the string bar, which last time around i turned from a 10mm piece of brass round stock on a lathe, and then drilled 4 holes through for the strings. this time started much the same way, with 10mm brass round stock, but this time i used a dremel to drill 4 smaller holes only halfway through.

I then used a tap to thread the holes, so they would accept an M2 steel threaded standoff. I tested this with a few sets of bass strings, and the ball end of the strings fits very snugly around this post. this means that the angle of the string wrapping around the bar isnt quite as harsh as last time, and these threaded posts are much stronger than the small split posts on normal guitar vibratos.

The Brass polishes up really nicely just using some fine sanding sponges and some brasso applied with it mounted in the drill. i will later use a diamond file to cut the groove needed for the clip to hold it in place. ive tried this on a test piece and it works remarkably well. you can see in the second picture the snug fit of the string ball end around the steel standoff

The tension bar was a little more complex. i added some threaded rivet nuts to shrink the tension bar holes from 9mm down to a threaded m4 brass rod. this was so that i could use some of these brass thumb nuts as tring rollers. this gives me a few advantages, a less steep angle to the bridge, less friction as the bigsby i used, and finely adjustable string spacing to ensure the strings run dead straight from the string bar to the bridge. ill also get a little gold sticker printed up with my logo for the small indentation where the bigsby logo would normally go. the balance between black and gold is about right, and i think if i mount it with some nice gold scres, itll look pretty classy

Over in Pickup land, things are coming along swimmingly even if i do say so myself!

The 3 pickup wires (Hot cold and Voltage for the LEDs) are soldered on, and the 4 LED's are in place. these are 3mm box LEDs, in bright blue, which fir perfectly into the 4 small square holes on the pickup cover i showed earlier.

you can see that there are small round cutaways in between the bobbin mounts. the pickup covers have 3 more brass standoffs mounted to them, that then slot down through these holes and line up with 3 more holes in the PCB, which i can then secure with screws. this means that the PCB and cover all all ridgidly attached together, but allow the colis to move freely up and down inside:

 

on the right hand picture you can see the 4 larger standoffs that the coils are screwd onto pointing up, and the 3 smaller ones that connect the cover to the base inbetween

and ta da! one bass pickup assembled and ready for a test. the 4 screws im using at the moment are black, but when it all goes together i will use gold screws for both these and the 3 mounting screws around the edge. taking a bit more inspiration from wal there!

as a quick test i hooked up one of the preamps to the pickup, with 2 9 volts wired in series to provide 18v. i had to switch out one resistor as the voltage was a bit too low for these LED's (the preamps will be powered by 24v phantom power in the finished article) and it worked just as expected!

I had a little frosted plastic window cut to fit in the small recess to diffuse the LED light a bit but this is how the display looks:

Those are "P", "reverse P", "J" for Jazz and "H" for humbucking. this lets me see with just a glance down what mode both pickups are in, without having to have bright LED's shining out the front of the bass, result!

and back down in the garage, ive cut the two rosewood neck/body beams and got them glued up to each side of the marquetry beam and truss rod channel:

you can see in the background of these some of the laser cut templates for the neck and body, looking forward to the next parts of this build!

and heres the whole assembly glued up and ready for the next steps. if youve noticed the big hole in the left hand piece, dont worry. i measured beforehand and that will be past the edge of the neck. gived you an idea of just how much of the bulk of this neck will be carbon fibre. ill rout the body end down so that its flat and ready to accept the top of the body before i cut and glue the wings in place, but im going to leave the headstock end untouched for the time being. this will let me shape the neck to its final profile whilst still keeping the option to add more stiffness by adding additional cabon rods down the 8mm channels i showed in the last post. im looking forward to getting the body together and seeing it start to look a bit like a bass!

 

[Pea Turgh]

Bloody hell!  That’s a lot to take in!!  Awesome work.

[AndyTravis]

Genuinely genius level stuff

[Richard R]

This is fabulous and utterly mind-boggling!  Are you keeping a log of the hours spent on it?

[mhoss32]

Thanks guys!! @Richard R, im keeping track of some things and not others. Woodwork, pickup winding, soldering i am yes, so that i know roughly how long it might take me next time round. But drawing up plans and simulating circuits and things not so much. Im hoping that once those bits are done once i wont have to do them again!

[Andyjr1515]

This does have to be one of the most innovatively exciting threads to date.... 

 

[mhoss32]

@Andyjr1515 Just following your example Andy! i've been lurking in the build diaries thread since before i knew one end of a hammer from the other

[Daz39]

You mean each end of a hammer does different things?!

[Hellzero]

I think I'll call you Mad Professor for now on @mhoss32 ! This project is a pure to delight to follow and you have really great ideas. Can't wait for the next episode. Fantastic craftsmanship !

[Simon.]

Just.... you know... just... wow.

So many great things about this build, it's difficult to pick out any one.

👍

[Jabba_the_gut]

Fascinating project! Completely different to anything else.

[BassTool]

Gumph 😳

This is just another level 🤩

Incredible stuff, all of it, truly amazing work👌🏼

 😲😲

[mhoss32]

im trying a new technique that was suggested to me for marking the fretboard for inlaying the branches. holding the branch down and using a spray paint to mark the area to be cut away:

im pretty pleasantly surprised by how well this seems to work, very easy to mark the edges with a scalpel and chisel, and then just work up to the line.

once id got the 2 branches cut out and the areas for the inalys chiseled away, i set them in place with some CA glue and flooded around the edges:

This is the lower of the 2 branches, and you can see the colour contrast with the macassar ebony fretboard. should look really nice with the leaves in place over the top

Meanwhile, im getting ready to cut out the 2 top pieces with some laser cut templates:

these have been made to leave a perfect 2mm gap down the S shaped join in the body, so once these top pieces are cut and trimmed, i can run 3 layers of veneer (white, black, white) down the middle. this should give an effect similar to the rendering on page 1, and should look pretty cool with the flamed redwood top. im not sure this approach would look quite so good with a burl top or something like claro walnut, but with flamed wood with a grain running one direction and the chatoyance running perpendicular, i think itll be a nice effect. in the future if i make any more of these with those woods ill just to a straight bookmatch.

I also cut the laminated beam that will make up the body wings into the 2 pieces i need. this also lets me line up the laser cut template with the top to make sure the carbon fibre extends down the the right distance

all looks good to me, so time to cut the wings out. again, i am missing a bandsaw bigtime here, but patience can normally replace industrial equipment:

here you can mostly see the pattern that will be visible at the top and bottom of the body wings. the innermost piece of walnut doesnt extend all the way to the end, however, as it only needs to match up where the wings meet the central beam

I also put together another little helpful gadget for this build:

its a test prototype for the preamp, that allows me to test lots of different component values without de-soldering. the 8 dip switches let me test 3 different values for the top and bottom of the frequency sweep and the top and bottom of the resonant peaks without endlessly swapping out resistors. its a bit too big for installation inside a bass in reality, but its a useful tool in understanding how these things sound. im just using it plugged into one of my other basses at the moment. the single pot controls the frequency sweep, and the push/pull function selects between high and low resonance. im hoping that once ive got this all buttoned down, i can get another version of this made smaller for retrofit into another of my bass guitars.

 

 

[binky_bass]

If this turns out to be a Wishbass I will be very upset...