mhoss32

I love this sort of project, lots of changes like these add up to a massive difference in the end. Respect!

@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

Thats a good bit of information, @Hellzero, ive never tried one of their preamps, ill have to look into it. some very interesting stuff on the PDF for the bassXX preamp though The next stage in the marquetry work for the back of the neck is to finish off the pattern at both ends, and extend the beam so that it runs the length of the body and the headstock. first off, i cut another strip from the walnut/purple veneer that will extend the central stripe. the idea is to have this exend all the way down the back of the body and the headstock as well: i also cut strips from another fretbaord blank to exend the rosewood parts. i then cut two more triangles from the oak/maple rope laminate so that it looks like it wraps around at either end: then, using a hardwood board as a backstop, its all clamped and glued together then, once both ends are extended this way (the body extension is longer than the headstock, for obvious reasons), i planed each side flat and glued a strip of the light veneer down either side: and finally, carefully remove the excess with a sharp chisel Very pleased on how this has turned out. im looking forward to planing one side dead flat and glueing the Carbon rods in place as this will ensure everything stays flat and straight. this may look pretty but it isnt stiff ive carried on winding my pickup bobbins in the meantime, and started to do the first bits of work on the pickup PCB's as well: this is the 4 position switch for the pickup in place. the pickups are going to be fairly large, but i wouldve struggled to save much more room than i did. These Brass standoffs are then attached the the PCB base with some black nuts. these are M3 standoffs, and the 4 Hex bolts screwed into them will be used to adjust the coil heights for each string (this is what the 4 holes in the top of the pickup cover are for) the plan later on is to replace these with some shiny gold screws, but for now these black ones will work just fine. so far everything lines up nicely as expected The leaf inlays arrived in good condition, and im really pleased with them. they should look lovely in a macassar ebony board. ive decided that i want to add something else to these however, to really make the fretboard stand out. the plan is to inlay 2 tree branches cut from a brown Malee knife scale blank to add some additional detail and contrast to the fretbaord. doing this on the dining room table, the little one wanted to come and do drawing too, so a pleasant evening spent all round! the next step is to cut the branches from the burl and then inlay these into the fretboard, and then move onto the shell laminates. im also shortly going to cut the two rosewood beams for the neck as well, and hopefully finish one set of coils so i can get one of the pickups wired up to make sure everything fits... busy busy busy

Thats an interesting point, ive never been one for fully discreet solutions but as you say thats mainly due to size. you can also buy fully discreet transistor based "discreet" DIP-8 package opamps, although they are eye-wateringly expensive, and their power draw is similarly huge. if i remember correctly, Orange sells discreet replacement opamp chips for their amps, would be interesting to see how much different something like that would make. maybe in the future i will experiment with a design that can fit those kinds of solutions inside a control cavity, but that would almost certainly have to be phantom power only.

Glad to hear it @bloke_zero always nice to meet some fellow electro-nerds The Opamps are really an interesting point when it comes to this kind of thing. obvously the main factor in choosing them for most manufacturers is how long they can last on a single 9v, but take a look around online and you will find that the tried and tested TL062 and LM358 that are often used are a bit behind the times. annoyingly, the best of the best of opamps available right now are surface mount only, as opposed to socketed, but maybe ill try and get a board made up with them in the future

There will be two outputs, one balanced stereo and one mono. The preamps will run independent paths through an MN balance pot and a stereo volume pot, with a switch to choose between the mono or balanced stereo output. the switch then acts as a mute switch when flipped the other way

Yes, thats the plan Simon! to be honest i dont know how well it'll carve or how it'll look as a rounded neck profile... but thats all part of the experiment! i am not looking forward to attacking it with a bunch of sharp tools mind... that will be a nerve wracking day! Don't worry Richard, I will be sure to make it to every one i can, if this is going to become a semi-business of mine i need all thr feedback from experienced players i can get! Im glad it isnt JUST me interested in the nerdery, its very satisfying when you get things to work the way you intended! with regards to the pickups, the answer is eventually most likely yes. half of the point of this bass is to see what people like but also work out any kinks, and some kinks you can't really work out on paper. you need to wind the pickups and hear them and wire the preamps and try lots of different configurations... so im hoping that a MKII version of both the pickups and the preamps can be made available after this is all finished. I already have a couple of things id change slightly, including the coil height (they didnt really need to be that tall) and maybe re do them with 1/4 inch magnets for greater output but similar DC resistance. with the preamps this is actually the third circuit i simulated, the first was a copy of wal's current control layout; 2 frequency sweeps with pick attack and resonance, and the second was similar to an alembic with 3 mode preamp: Low pass/High pass/Band pass, so id be interested in actually building those to see if anyone had any interest as well!

Hahaha I'd never noticed that before, damn you now thats all i can see now I look at it too 😂 Preamps are now all soldered up!! all box caps in place, tested for the right inputs and outputs, all seems to be working as expected thus far. lots of tests to happen now to muck about with component values and make some final decisions about the filter profiles. this first setup is the widest frequency sweep, from around 100hz at the bottom up to 6.8khz at the top. if i find that either end sounds wrong or wouldn't be useful, i can just change a few resistors/caps and try again. at this stage im thinking i may have them tuned differently from eachother, with the bridge pickup having a much wider sweep to allow for more top end. The Opamps ive got in here are LME49720's, which are some seriosuly good Hi Fi opamps. these are the kind i have in my headphone preamp on my desk, and they sound phenomenal. Much faster slew rate and much lower distortion than those normally used in onboard preamps, but that comes with the downside of much, much higher power draw. not many preamp makers give exact details on the predicted battery life or power draw of their preamps, but Noll for example quotes typical draw of 1.5mA, which is pretty good. a typical 9v battery would hold about 600mAh of charge, meaning about a 400hr battery life. compare that to these beasts the LME49720s have a draw of about 5mA per channel, each. and theres 7 channels being used by the preamp. and theres 2 preamps. oh dear that means about 70mA of power draw at maximum...which, Maths fans, means battery life on a single 9v of less than 10 hours. not exactly great so lets talk solutions. as mentioned before, the plan is to have a phantom power input, running at 24V that will power the preamps most of the time. Sorted!! but... what about the one in a hundred time when i want to just plug and play without the phantom power? Ta Da! this is a Battery protection and charging board that takes 3 18650 sized Lithium ion batteries, the kind you might get in powerful torches. the plan is to mount this in the other side of the bass, and have the same 24v power input to the preamps run to this as well. this will: 1) charge the batteries in place whenever the bass is plugged in 2) protect the batteries from under voltage and over voltage, and ensure the power is cut once they are fully charged (very important for lithium cells) 3) allow me to carry additional batteries and swap them out if needed 4) run the preamps at a reduced 12v when a normal jack is plugged into the bass. 18650 cells have some serious capacity. a 9v battery- about 600mAh. these bad boys - about 3500mAh. and thats at 12V, not 9. meaning that i can get 50 hours of play time with the hi fi opamps on a full charge, not too shabby! Again, if youre only here for the sexy wood stuff, i must apologise for the electrical nerdery. i assure you there are dullards like me who really find this stuff interesting! but, here you go: the fairly nerve wracking process of slicing that 50mm block in half on the mitre saw. clamped carefully and then sawn slowly. measure 9 times, cut once! but the patient left surgery in good shape! well... sugery number one. this now needs to be repeated... twice... on even thinner pieces. admit it. own up. who was watching up to this point thinking this was all going to go horribly wrong? I certainly was, and im sure glad it didnt. there are a fair few hours invested in this up till this point! then its just a process of glueing them end to end with some CA Glue, and glueing the little extra triangles in place in the remaining gaps, letting it all set up nicely, and then planing down one face nice and flat 😁 honestly, im pretty chuffed with this. im very much ooking forward into turning it into a proper neck blank and getting moving on the body of the bass properly. by my measurement its about half an inch longer than i was aiming for, but thats fine and should run perfectly from the headstock to the body. roll on the next experiment!

Thanks so much guys... please do not uncross those appendages haha the next step in the marquetry laminations is to add the namibian rosewood triangles i cut earlier to fill in the gaps. at this stage the pattern is 7 repetitions long, and much the same as the rope pieces these triangles are cut and sanded one at a time to ensure they fit as closely as possible. at this stage the edges dont have to be 100% perfect, as they will be planed flat and a veneer strip will run either side of the pattern, but the closer the better as it will require less faffing later on: ("T" stands for top, the number tells me which fits in which gap and the arrow tells me which edge should lie closest to flush) i found it easier to line them up this way, and although they arent perfect, once theyre cut flush it should all look pretty tidy: with one edge cut off you can see that for the most part the gaps aren't too bad. this piece is still pretty much bang on 50mm deep, so the plan is to cut it into 4 slices and lay them end to end, filling in the missing triangles as i go. colour wise im very happy, the contrast between the different woods is good, but its not over the top. all in this experiment is going pretty well! meanwhile in pickup land... the magnet of each bobbin is wrapped in masking tape, which is then sealed with another bead of liquid CA glue at the top and bottom. these are then ready for winding. my home-made winder has a maximum speed of 1000RPM, which on a normal pickup bobbin would probably be uncomfortably fast and produce a LOT of vibrations. with these individual bobbins though, it seems like 900ish RPM is just fine... if a little noisy. process wise it couldn't be simpler. tie the 42AWG copper wire 5 or so times round the eyelet marked "S" (for start), stick the bobbin to the winder with some double sided tape, check the winding direction (clockwise for north up, and counter-clockwise for south up) and let rip! 900RPM, with 10000 winds per coil... means about 11 minutes of winding per coil. then just cut the wire, tie it off at the eyelet marked "F" (for finish) and voila: one bobbin, nice and tidy! one down and 15 more to go... this should keep me busy for a couple of evenings. i used a soldering iron to melt off some of the insulation around the eyelets and tested the DC reesistance. one coil is pretty much 1.6k ohms. a little less than expected but that means a bit over 6k for each single coil mode. should be about right when matched up to the preamps, and give a nice natural sound. one thing a lot of multi coil pickup makers do (i am told) is use a heavier (41AWG) wire, which gives the pickups more upper mid-treble clarity (or so i am told), so that will definately be an experiment for MKII even more excitingly... check these out!! pickup covers! boy am i happy with these. they are printed out of a high strength nylon, which is then Vibro-Polished for a smooth finish. the website describes the freshly printed finish as similar to an extra strong mint, and the vibro polished finish as similar to a soft mint, and theyre about right. nice and smooth and a very consistent colour. and these things are hard as nails. the thin strips that divide the coils are 1mm thick, and they are noticeably stronger than injection moulded plastic. you can see in the picture on the left the switch tips in place. these lie flush eith the top of the pickup for a cleaner look (they wont actually be right up against the end of the slot like in these photos), and should allow the pickup modes to be switched easily whilst staying well out of the way. the plan is to colour in the little MH logo gold, and have gold mounting screws and 4 gold coil height screws in the middle as well, which i think will look great Also, the pots are now soldered onto the preamp: the Blue one is the frequency sweep, and the green one is the resonance. you can probably see the green one is actually a push-push clicky swtich as well, which will allow for a higher (16+DB) boost at the resnonant frequency when in 4th order mode. the reason for this is that the height of the resonant peak naturally changes when the preamp is switched from 2nd to 4th order mode, and this switch will allow the user to choose whether they should be even at the bottom of the resonant sweep, or at the top. not always totally useful, i know, but certainly useful in a prototype to work out the correct component values, and keep variables the same when testing for different sounds. This is the second one underway as well. i ran short on a couple of resistor values so had to buy some more, which were green (hence the different resistor colours), but still 1% metal foil. the one resistor between the two IC sockets is a bloody tight squeeze. just the box capacitors to go on, and then i can mount one in a pedal to test with a couple of different basses which i am really looking forward to!

Haha i am going to feel like ive led everyone up the garden path if this all goes wrong! All fingers and toes crossed please

As it turns out, the whole thing seems like its a hell of a lot easier the second time around. chalk that up to a combination of experience, the oak panels being a lot cleaner cutting than the obeche ones, and doing things in a different order. Firstly glueing up the laminates again with the oak in the centre. i also used a bleached maple veneer for the outside instead of the Koto, for the same reason. a tighter grain means less splintering and cleaner cuts: I think i actually prefer this colour combination to the yellower woods, it just seems a little more subdued. these are then cut up into the cross pieces and the little triangles needed for the rope pattern: and once we have them and check them for fit with the walnut and purple veneer core... i then start to glue them together. this is kind of a slow process. these are all cut by hand and are 50mm deep, so no two are 100% identical. this means carefully matchingand sanding 10ths of a mm off if bits dont line up perfectly. they're glued up with some high viscosity CA glue, which doesnt soak into the grain the upper middle triangle here is a good example, i had to bring it down by a tiny bit to get it to fit better but slowly but surely, with lots of measuring and lots of waiting for glue to set... here we are, 5 repetitions in. by my measurements, 7 repetitions of this and ill have a pattern that runs from the bottom of the headstock pretty perfectly to where the neck meets the body. the triangles will be made from some namibian rosewood fretboard blanks that are exactly the right thickness back in pickup land, im starting to assemble the bobbins. First, take a 5mm alnico 5 rod magnet, mark the north pole with a mark and then add a bead of CA glue around the bottom: then set it into one of the bobbin pieces, like so: i then use one of the bobbin holders as a spacer to ensure a perfect 1mm proudness to the magnet at the top, with only a drop of ca glue this time: and once the top is held in place with the drop of glue, i can remove it and carefully run a bead of glue around the seam using a cocktail stick: This is where it really helps to have CA glue of varying viscositites, the gel glue holds its shape and wont drip down when glueing the first piece, and liquid glue will wick into any tiny gap when glueing the second. and finally, a bit of a preamp update. the pots im using for this are Bourns 10% tolerance mini pots, which are approximately 10mm in diameter. this means that i can use components up to 10mm tall (10mm proud of the PCB) without taking up unobstructed space in the control cavity. as the opamps i want to use are high end, hi-fi opamps, i want the other components to be similarly appropriate for high audio fidelity. im therefore using 63vDC Nichicon fine gold electrolytic caps for the power circuit and decoupling cap, and some 10% tolerance box caps for those in the signal path: you can see ive also added the 4 IC sockets for the Opamps, and pins at either end for the power inputs, signal inputs and outputs and ground connections. the 3 pins in the middle are to connect the 2nd/4th order mode switch. i then start to add the resistors, which for this im using 1% metal film, 1W resistors. i chose these as they were the highest wattage i could fit on the board and in the 10mm vertical space: theres a lot of these to solder, and then another board to do for the other preamp before i run a test to finally decide on component values next step... winding some coils!

That's the plan!

Hellzero, that is absolutely correct! as the carbon fibre laminations in the centre of the neck are providing the majority of the stiffness and stability, the long "beam" that runs down the back of the neck can be mostly decorative. the plan is to use a series of pieces laminated together, along with the rosewood triangles cut on the mitre saw to create a marquetry pattern that runs the entire length of the neck from headstock to body. I spent a few hours planning it out in large scale, using the known thicknesses of the various pieces of veneer that i have available to me: what im aiming for is a central band, made from black walnut and a purple dyed constructional veneer, with a 5 band "rope" pattern criss crossing it up the neck something like this: the first stage in this process was laminating up several pieces for a test, and then cutting enough for a couple of repetitions of the pattern: This was the first stack of laminates I tried for the rope: the centre is Obeche, and the laminates are Koto (very similar colour to the obeche) and a black dyed veneer. it quickly became apparent, however, that although this combination was fine for the purposes of a test, these lightweight woods have a grain that is far too coarse for this kind of detailed marquetry. the small triangles that need to be cut simply splintered and disintegrated at the fine edges, so the material choice will have to be re-thought for the final piece. but once id cut the test pieces and glued them up with some CA glue, the effect doesnt look bad: Im pretty confident that with some minor adjustments to the measurements and to the materials, i can make up a beam for the back of the neck with a very similar repeating pattern. i found some 5mm oak panels at a model makers, and some tighter grained maple veneer to amke the "rope" pieces out of, which should hold together much better than the Obeche and Koto. the only issue is the oak is slightly thicker, and so the rosewood triangles will have to be re cut slightly larger, and the walnut/purple stripe will have to have an additional layer of cherry veneer added to either side to make sure the pattern continues to line up: the plan at this stage is to create a block with 6 or 7 repetitions of the pattern about 50-60mm thick, which i can then cut and lay end to end to create a single long beam with 24-28 repetitions around 10-12mm thick. ill then extend this at either end with some more rosewood and the purple/walnut/cherry pattern so that it extends all the way through the body and headstock. by my count, if you divided this neck into every single individual piece this would count as a ~660 piece laminate neck! might not be a world record but id say still pretty good! Meanwhile here are some pictures of teh PCB's for the electronics/pickups, fresh from the manufacturer: The small squares on the left are the Bobbin top/bottom pieces, which are 1mm thick. these are still really stiff and the manufactureer quotes less than 0.1mm tolerance so the holes in the middle should be bang on the 5mm needed for the magnets to fit snugly. another advantage of having these manufactured by the PCB manufacturer is the small "start" and "finish" eyelets for the copper wire are also pre drilled and have solder pads, making the whole business of making the bobbins a fair bit simpler. the third benefit of this approach is that these being pcb board have a full layer of copper top and bottom, meaning that if i finish each coil by wrapping the coil in layers of insulation and copper tape, they will be surrounded top, bottom and sides in copper shielding, to reduce EMI noise. The bobbin mount is at the bottom. when i put the bobbins togetehr, the magnets will sit proud of the top of the squares by 1mm, and then this will be connected together using the 1mm thick bobbin mount. this will mean the magnets will be flush with the top of the whole assembly, and the thickness of the pickup cover is only 1.5mm. this should mean the distance from the strings shouldnt be an issue. The big PCB is the pickup, obviously. the holes on the left hand side are to accomodate the slide switch: the holes on the right are where the LED's will be soldered, and the holes in the middle are where the coil pairs will be connected. at the top left you can also see three additional solder points; which are for the Hot, cold and an LED voltage in from the preamp PCB. the Preamp pcb will have seperate power circuits for the external power and battery power, so that the LED's dont draw battery power if the bass is running on them. Finally in the bottom left is the PCB for the preamp. this one im extremely pleased with. the final measurements were 90 x 34 mm, with both of the potentiometers (filter frequency and resonance) mounted directly to the board, and the toggle switch to change between filter orders will be connected by a wire. the spacing of the pots is 50mm, so i should be able to have the controls on the bass nicely spaced out (bearing in mind that there will be two of these boards: one for each pickup) next time round ill be putting some of the bobbins together and getting ready for winding, and also going through some of the component choices for the preamp

Thank you all for the information, love reading through informative stuff like this! Its a good Point regarding whether the truss rod is needed andy, but the plan is to use 10mm square carbon fibre rods with an 8mm hole down the centre, which by my calculation should be stiffer than a normal hardwood neck, but not completely immobile. this way i can add some releif with the truss rod if needed, and if the neck isn't stiff enough i can add additional carbon down the centre hole (either an 8mm carbon tube or 8mm carbon round rod): with that said Hellzero, lets talk pickups. this is a reeeeally big experiemnt, but the plan is to build 2 multi coil pickups (8 individual coils, in two rows of four), with anico 5 magnets and 10,000 rounds of 42AWG wire per coil. the overall idea is to build pickups with the clarity of multi coils, but with a wide range of adjustment built in, both in terms of coil configuration (similar to Sims super quads) and adjustable coil height per string. let me explain The first part of this is the bobbins for the pickups: The bobbin itself will be made from a single 19mm x5mm alnico 5 rod magnet, with 2 fibreglass pieces making up the top and bottom (part 1 in the picture above). these are going to be 1mm fibreglass pcb with two eyelets to soldre that start and finish of the coil to. these will be wired in pairs next to eachother: and will then be attached to one another vertically using the bobbin mount (another 1mm thick fibreglass piece) with a 3.5mm hole in its centre. this hole is to accomodate a screw and a spring will be mounted under each bobbin mount, that will allow for each string pair to have their height individually adjusted, in much the same way you could with steel polepieces and a ceramic or neodymium magnet. this is probably just me over-engineering things but alnico magnets have always sounded more natural to my ear. this whole assembly of 4 pairs mounted together and wired together in series-pairs will then be mounted to a PCB baseplate, and a 3d printed pickup cover: the 4 holes on the top are where the screws that will adjust the height of the bobbin mounts will be (these will be standard m3 hex bolts), and they will screw into brass standoffs mounted to the pcb baseplate. you might also notice that these are quite wide, and that there are 4 holes on the left hand side, and a slot on the right hand side. This is to accomodate the switching mechanism for the coils. The Sims way requires an additional hole to be drilled in the bass for the 4Pdt switch that selects the coil configuration, and the pikcup mode is displayed via a 3 colour LED on the front of the pickup. my way is somewhat different. there will be a slide switch mounted into the pickup itself to change the configuration, and a small display on the upper edge of the pickup (somewhat similar to gibson's pickup ring tuner for guitars). there will be a single box LED in each of the 4 square holes, which will correspond to a letter cut in the upper edge of the pickup this allows me to: >have no extra hole for a toggle switch >have 4 different coil configurations instead of just 3 >have the configuration displayed with an illuminated letter instead of just a colour: This is what theupper edge of the pickup will look like (the red areas or the recesses for the screws) the modes are (left to right): 1) P pickup (pair 1 and pair 4) 2) Reverse P pickup (pair 2 and pair 3) 3) J pickup (pair 1 and pair 2) 4) Humbucker (all 4 pairs) Pairs 1 and 3 will be North up and Clockwise wound, and pairs 2 and 4 will be south up and counter clockwise wound, meaning that all 4 configurations will be hum cancelling Ive got my PCB's off with the manufacturer, and the pickup cover is off with the 3d printers: and ive got some more pieces for my nutty experiment cut up: Can you tell what it is yet?

While that discussion conmtinues in the background, let's talk about the neck through construction The idea here is to integrate carbon fibre rods into the lamination of the neck woods, to allow for greater stiffness, a simpler construction and a reduction in the wastage of materials. here is a rough sketch of the neck cross section and the proposed way of building up the blank that will run the length of the bass: The principle here is that the two 10mm carbon fibre square rods and the 1mm carbon fibre strip will be epoxied together to create a U channel around a normal double action truss rod, running the length of the neck. this will be laminated to the side pieces and an additional strip down the back that will run the full length of the bass to create a blank with a central core of carbon and wood around the three sides. Ive seen a very similar principal to this employed by another Luthier local to me in the construction of acoustic guitar necks, with excellent results. Excellent in terms of stiffness and stability, yes, but in additon the stiffness provided by the carbon fibre and the hardwood pieces (in this case Namibian rosewood) will mean that the 9mm strip that runs down the rear of the neck can be made with decorative laminations... at least that is the theory. the whole blank is only going to be around 20mm thick, and so additional pieces will be added to make up the bulk of the rear of the body, and the headstock will have additional pieces laminated front and back. so to keep you patient wood people happy heres some lumber porn: This is the Namibian rosewood that will make up the rear of the body, as well as the 2 main laminates along the sides of the neck And here are the 2 pieces of flamed redwood that will become the top of the bass. the figure on these is insane. and especially along the upper horn the flame should look absolutely awesome. and meanwhile... without giving too mcuh away, ive been working on my lunatic idea for experiment number 6, so stay tuned for what could be a spectacular failure or success

haha i love posting on this forum, ask and you shall receive!! BigRedX, Thats a good point, i hadn't really considered, obviously with the EQ02 i use there is no blend between the pickups, but i do find myself just setting and forgetting once i have the tone the way i want. do you find the controls on the EQ01 to be too sensitive? or is it useful to have such a wide range of frequency sweep? In terms of pickups blending im juggling a few ideas. obviously with both stereo and mono outputs the blend control would be slightly different from a normal setup. at the moment im thinking about either an 11 or 23 position rotary switch with resistors to turn it into an MN taper pot. this should allow for very careful matching of the different switch positions to different outputs from each of the pickups HellZero, thats very helpful. i do have a bass with an East Preamp, which also quotes 18db Boost and Cut, and your'e right its probably the last used of all of the knobs. The wal Pickups are certainly part of their particular "magic" tone. Multi coils have a very distinctive sound to them, and the filter controls work brilliantly in wal basses as they are specifically matched to those pickups placed in thheir exact positions. Im not surprised to hear you say the alembic approach is the most natural sounding, that has always been the main focus of their pickups and their electronics, and the ones ive heard are so clear and clean its really surprising. out of curiosity what control layout were you ujsing? ive seen alembics with 3 way switches for Q control and ones with a seperate Pot.

That is a very good point, Zero, i will have to give these a good range of testing to make certain that there isnt some crazy overboost too low in the frequency ranges. the Aguilar OBP-3 claims +-18Db at 40Hz centre frequency, it would be interesting to hear from some owners of that preamp to see how they feel the Bass boost sounds cranked all the way. With regards to the steeper slope colouring the sound, you're spot on. the 12db/octave slope is fairly unobtrusive to the sound, and i think that probably if you had both preamps onboard switched to their 4th order slopes it could end up sounding pretty unnatural, but the hope is that with the ability to switch between them there will be situations where dropping certain frequencies from one pickup is desireable while allowing the other one to handle wider frequency ranges. excellent to get your feedback though, im sure that there are loads of people who prefer the filter-controlled approach to tone shaping, and others who prefer the more traditional boost/cut. Just like SpondonBassed said, too many options can be overwhelming, especially if it isnt clear how they actually translate into tone!

Okie dokie, lets talk Filters (if youre only here for the pretty pictures of woodwork, don't worry this part wont be on the test) The idea for the controls on this bass are as follows; each pickup will have its own preamp, which will have controls somewhat similar to alembic's filter preamps. that means that each pickup will have its own Low pass filter, with adjustable cutoff frequency, and adjustable resonant peak. the layout for each pickups will be like this: This will be achieved with 2 potentiometers, 1 which controls the frequency sweep such as this: as the control is turned, the cutoff frequency decreases and more and more of the treble and Mid frequencies are filtered out, leaving only the low end. you can see from the graph above there is a 12 decibel "peak" at the cutoff point. this is often referred to as the 'Q' or Quality factor, and can also be varied. The second potentiometer will control the 'Q' factor or resonant peak such as this: These controls should allow for a very wide range of tones, especially with one filter for each pickup. the exact range of both the frequency sweep (from maximum to minimum frequency cutoff) and the range of the resonance control are yet to be decided. once i have a test board made i will try a number of different vlaues to decide which sounds best. it may be that i use different values for the bridge and neck pickups to achieve a greater range of adjustability. My thinking at the moment is that i will try 3 different frequency ranges: Low - 250Hz through to High - 3.8kHz (from the research i can find online this is similar to the range sweep of Wal's current electronics) Low - 300Hz through to High -4.8khz (again, from my research this is similar in range to that of alembic's filters, although it also seems this varies from one set of electronics to another in alembic's case) Low - 100Hz throught to High -6.8khz (this is a far wider range of a sweep, but may be useful with one filter per pickup as it allows the resonant peak control to boost high treble frequencis on one pickup. this is close but not quite as wide a range as ACG's EQ01 and 02 i believe. i have an ACG EQ02 in one of my Buzzards, and i absolutely love it, but the sensitivity of the frequency sweep control takes some practice to get right) I want to balance a wide range of tones with the frequency controls not being too sensitive, as its important to have a control setup that allows people to easily recreate sounds accurately without too much effort For the Resonant peak control, ive decided to go with a potentiometer rather than a switch. again this is based on my own experience with the EQ02, being able to sweep the resonance from low to high i find that at least half of the time i have the control not at either extreme. from what ive read and from videos ive watched, both ACG and Wal filter preamps have a resonant peak adjustment from 0-10db at the cutoff point. (thats the peak you can see being adjusted in the second graph), and Alembics (take this with a pinch of salt because ive heard a lot of different answers for this from different people) have an adjustable peak up to 15db again, i think i will test with a number of values, allowing for a peak of 10, 12, 15 or 18Db (18db being the highest boost commonly available on preamps from aguilar, bartolini etc) and then we come to the "experiment" part of this design. Im confident i can get a compact circuit to achieve all of the above, but i also want to try something different. as far as i'm aware, all of the aforementioned filters are what is referred to as "2nd order" filters, which have approximately 12db of rolloff per octave (this is the steepness of the rolloff at the filter frequency). it is possible, however to create Higher order filters with a steeper rolloff. a 4th order filter for example would have a rolloff of 24db per octave: In terms of tone, this control would not necessarily be particularly useful if it were applied to both pickups at the same time, but with individual filters per pickup, this would allow the neck pickup to have more of the midrange harmonics filtered out at the bottom end of the frequency sweep, giving a cleaner bass tone, and at the upper end of the frequency sweep, this would allow for the resonant peak to attenuate high treble frequencies whilst filtering out unwanted high frequency noise more effectively. Thats the theory anyway... it remains to be seen if this works the same way in practice This plot shows the frequency sweep with the filter in both modes, the red traces are in 2nd order mode, and the blue traces are in 4th order mode with the resonance control set to a max peak of 12db. as i said before, this is an experiment, but im excited to see what this sounds like in practice. I will cover the preamp in a bit more detail once its been put together and ive decided on component values. Meanwhile the strips of Cherry are all glued up around the Padauk, and the layers of the wlanut are next

Thanks Andy! I figured i can do it just as well as if i had a workshop but faster, but its good to get confirmation from someone as skilled as you! I remember reading the psilos build log at the time and drooling the whole way through, absolutely gorgeous build Hellzero, that Ibanez is a cracking looking thing, ive seen them before but never realised the jack was positioned that way, and ive never seen a deviser before andy, but that looks amazingly comfy too. Basses where ergonomics are the number one focus always have a certain elegance to them i think. That socket position is a clever idea, i shall see if i can make it work! Excellent to get some proper useful feedback from you guys on stuff like this i just dont play long or often enough (or own enough basses) to get a full picture of how details like that can make a big deal to how easy a bass is to live with long term.

Thats really interesting... I have a bass with that jack socket position as well! One of my buzzards has it and youre right its certainly one of the best ways... Im surprised it isnt more common as just as TheGreek says, on Ritters basses they are mounted on the rear cavity cover. The problem may be space related however, with the preamps and switches in this bass i will have to see how much space is available on the back, and how deep the control cavity is. Its a really good point though, as i said its never been something ive thought about too much, given your experiences what would you say are the bad, good, better of jack socket placement? Would be really interesting to get the opinions of some more experienced bassists than me!

Ah, thats interesting, i thought the lower horn was big enough to give a comfortable curve over the knee, which way do you think it will slip? im less concerned about access to the upper frets, the thin horizontal line on the neck is the 26th fret position, so the 24th is actually above where the lower horn meets up with the body. And also an intersting point regarding the jack socket position, i hadn't planned that aspect yet. ive never thought of jack socket positioning to be a big deal ergonomically, where is the ideal spot do you think? not one ive thought out fully yet, but it will need to be as this will have two output sockets, one for mono and one for stereo with phantom power. Here are a few pics of the first stage of laminating: the centre is Padauk, and the first strips on are a constructional 2.5mm Cherrywood veneer. I ran a bead of liquid CA glue along the edge join to make sure there was no splintering or chipping out as the edge was planed flat. The plan is to laminate 3 edges of the padauk with cherry, and then repeat the process with a layer of 2.5mm black walnut The idea is to create laminations that give good contrast along the carved edges, but also when looking at the upper and lowe edges of the bass, similar to this: In the first picture above, you can see in the background a mitre saw and a big collection of cut pieces and CA Glue, these relate to experiment number 6, which is well under way! Im also in the process of drawing up the neck inlays: the falling maple leaves will be made from abalone and Gold Mother of pearl, which im hoping will create some good contrast with the macassar ebony fretboard. Ive sent this drawing off to Bruce Wei, the guy who normally does the inlays i do, hes a great guy to work with and always produces amazing stuff, even from drawings as rough as mine! Next post ill run through some of the pickup design/some of my initial work on the preamp as well, so stay tuned!

"Boredom is the mother of invention" I have been bored. very very bored. So i started thinking about the next Bass build, and thinking turned to planning and planning turned into scheming. Ive had a couple of bass playing friends reach out to me and ask in the past if id ever build a bass for them, and ive always said no. essentially i just never felt qualified to build something to a standard that i would want to charge someone for it, and ive always liked my bass builds to be suitably "home made", plus i never have enough free time to get it finished in a reasonable timescale. Plus, the workshop id normally use to do all of the work, with all the big power tools (Bandsaw, Router table, Table saw etc) has been closed all the way through lockdown, which makes the whole thing even more of a pain. but this is where i came up with an idea. i decided that what i'd do, is take the time and build a prototype, a pattern bass if you will, in order to try out all of the ideas ive had, get the design correct, work out any kinks and complications, and if anyone likes it and it turns out good, then i can use it to show people what theyd be paying for. And if i can do it in a garage on a workbench with fairly basic power tools, ill feel confident in being able to repeat the feat once the proper workshop is back open. Im certainly never going to go full time luthier, but id love to be able to do this as a hobby where i can recover the costs! So.... The design. This is one i spent most of the first lockdown (in march) planning and thinking about. i had a few basic parameters that i wanted to stick to: 1.Not crazy over the top - my last bass turned out great, and i love it, but its design is a pretty aquired taste. this one needs to be a little more universal in its appeal 2. Lighweight - whatever happens i dont want a bass i make to stay hung on a wall for all its life because it breaks its owner's back every time he/she plays it. this means making sure the aesthetic design is fairly compact, but also that the material choices and construction are considered from day one 3. comfortable - this kind of ties into the lightweight aspect, this needs to be comfortable to play standing up and sitting down, with easy to use controls and fairly normal dimensions. i dont want it to have crazy narrow string spacing or a mile long scale length 4. Unique. this is my big focus for this project. i want this to be something special. ive got a few ideas for it, that i will share as we go through the build and see what people think. in the end this is what this prototype is for, to see which experiments work and which don't! With those in mind, heres a quick rundown of the specs (although these are subject to change depending on the aforementioned experiments) Neck through construction - (experiment number one, the neck through blank will have carbon fibre laminated directly into it to save material, reduce weight and improve stability) 33" scale length, 26 frets Body - laminated from walnut, maple, Padauk with a curly redwood top (experiment number two, as opposed to a book match top, this will have a "swan matched top", i will explain below) slotted headstock - similar to Bolin Steinberger bass macassar ebony fretboard with tree/leaf inlays tune-o-matic style bridge with custom graphite saddles - paired with customised bigsby with bass guitar string and tension bar electrics: 2 Multi coil custom pickups (experiment number three) - similar in construction to sims super quads (switchable coil combinations) but with 8 individual coils (a la Wal pickups). there are reasons for this which i will explain in due course stereo filter based preamps (experiment number four) - active filters with variable frequency, resonance and independent mono and stereo outputs (these have a few interesting qualities whih again, i will explain in due course) internal, replaceable lithium ion battery pack, and integrated 24V phantom power connection and accompanying pedal (experiment number five) that will allow for extremely high power draw, hi fidelity op amps to be used in the preamps Im taking some interesting inspiration for the body design, little bit of CT, little bit of Wal, little bit of some of ther other boutique scroll basses out there: The flamed redwood will be divided along the S-shaped curve, and have a sandwich of veneers in between them. the white areas in the upper horn and left hand side will leave the wood below (black walnut) to show through. this is to show off the lines of the bass, but the cutaway on the left will act almost like a thumb rest just at the upper edge of the pickups. this is obviously a pretty rough representation, as the edges will be carved and rounded to expose the various coloured laminates underneath. this build isnt going to be happening in real time, ive been sitting on this for a while so that i could get some of the more time consuming and boring bits out of the way first, so im hoping that updates will be fairly regular moving forward. im super excited, and have at least 3 full notebooks of sketches and drawings and notes and diagrams for all of my crazy hair-brained ideas! and on a final note, there will be experiment number 6... which is i think the most ambitious and least likely to work of all of them... but i will play that one fairly close to the chest. for now ill say this: if it works the back of this bass is going to be more impressive to look at than the front Look forward to sharing this one with you guys!

Very VERY cool, what a head turner

I love that logo, eye catching but not brash Ive Just got the logo for my upcoming build(s): again, not quite as clever as yours but nice and simple

Awesome collection of woods, the Zebrano really adds a lot. really looking forward to seeing this develop!