mhoss32

@Kinkh Thats some ace work on the schematic, A really useful piece of work for anyone looking into this. @funkle, as you mentioned, the way i went about the "pick attack" feature is very similar. On the filter board (right) there are 4 output pins on the right hand side: 1. OUT (the filtered signal) 2. GND ( ground) 3. VB (biased voltage to pass to the volume board) 4. P/T (a clean passthrough signal from the pickup) These then feed into the volume board (on the right). when the volume pot is pushed in, the filtered signal is passed straight to the pot, so it acts as a normal volume control. when it is pulled out, it blends the filtered signal with a second signal, which is the P/T signal that is then Low pass filtered and boosted. the level of each of these 2 signals and the overall boost can be changed using the 3 trimpots on the board. the picture above is actually an older prototype, the newer version only has 2 red mini switches on the volume board. these can be changed to change the frequency of the peak for the pick attack mode: OFF - OFF - 1.5kHz (sharp peak) ON - OFF - 2.2kHz (sharp peak) OFF - ON - 2.1kHz (shallower peak) ON - ON - 3.5kHz (sharp peak) From your simulations in LTspice, it looks like the Wal boost in attack mode is much broader than the one in mine, but centre looks around 3.5Khz I got some great feedback from both @Andyjr1515and @benh, who have prototypes, so im still working on these. In terms of layout though, separating out the boards does provide some extra flexibility in terms of setup. using a single volume board, you can run the P/T pin (for the pick attack) from either the bridge pickup or the neck pickup, or have a switch to switch between them! The idea behind these was to make the system as customisable as possible, so the user can have a very simple setup similar to a wal (push pull for resonance on the frequency pots, and push pull pick attack on the volume), or add in additional controls if they want more tweakability like on ACG's preamps. below is a normal installation: (note the "jumpers" on the pins at the bottom corners of the board") One feature that can be useful for example is having additional settings for the resonance (such as ACG/Alembic filters). when the jumper is in place, the push pull is simply Low/High. but the jumper can easily be replaced by a 2 position switch, 3 position switch or pot for variable resonance: There are also pins / jumpers to change filter modes but that's even more complicated. sorry for the low quality JPEGS here btw, these are snips from my first draft at the instructions for these preamp boards. Id say that based on the plots you put up, it wouldnt be too difficult to simply much about with frequency values on these boards to replicate those plots very closely, although as you say im not certain whether some of the character comes from the somewhat outdated component choices. If @Kinkhdoes go ahead and build an exact copy of that schematic, ill certainly send one of mine over with matched frequencies to compare! Honestly the work of people on this forum never ceases to amaze me!! amazing work and can't wait to see the build progress!

No problem, always happy to know people enjoy this stuff as much as i do! I will PM you regarding sending you one over, i will have to check i have the right OP-amps in my parts at the moment but if not they can be easily sourced. The ACG is extremely clean sounding, i know exactly what you mean. im not entirely sure of the reason for that, partly i suspect it may well be down to the complexity of the signal path but im not sure. having not tried the lusithand preamp im not sure how they would compare, in mike's brilliant video on the last page you can hear a good range of the sounds. it can certainly get very gritty towards the middle of the sweep with the resonance turned up. It's worth mentioning that in the latest version of the preamp, the volume board can be configured as a normal volume, or as a "les paul style" volume, where the control layout would be Vol / Vol / Tone / Tone, in my first experiment i did it this way and had each of the volume controls handling a diffferent "pick attack" - the neck pickup with a treble boost (like the wal) and the bridge pickup with a mid boost about 1.4KHZ - food for thought.

@funkle I'd agree, the narrow band boost (Pick attack) is a very useful feature. the one sound generally lacking from these filter based preamps is a "mid scoop", which the pick attack effectively remedies in terms of frequency sweep not going below 150-200hz, (I mis read my own doc- these preamps do go down to 150), so early on i whipped up this little bit of kit: This was my test bed, which let me test frequency ranges down to 50hz all the way up to 7khz by switching all the dip switches in different combinations. the thing to remember is when we're talking about sweeping down and removing frequencies above the cutoff frequency. with the resonance turned down and the frequency backed all the way off to 200hz (or just below) you are actually starting to pull the Mids out a fair bit, leaving you with some low-mids and all of the bass. to my ear, sweeping down below this started to reduce the overall volume a little too much and left a very boomy bass sound with very little in the way of harmonics. I will admit however, it's totally a matter of personal preference, and with the addition of a pick attack going down to (and even below) 100hz would allow for a more pronounced mid-scooped sound. totally a matter of what kind of sounds you find useful. as i mentioned before, the upper and lower limits of the multi filter can be modified fairly easily (2 components to change) @MoonBassAlpha i did look into doing an SMT version, with some through hole components, but i never actually got the PCB's made up. i may well look into it once i get back into this, i did my best to keep the whole thing extremely compact, but its very tightly packed components on both sides of those boards.

Sorry for the late reply all, been away recently! @Rich many thanks rich, Think thats probably my favourite part as well! @funkle, I've been following your thread with a lot of interest in the end for this bass i settled on 2 different ranges, one for each pickup being slightly different the neck pickup was a sweep of 200 - 3.8khz i believe, and the bridge pickup was 200 - 4.5khz. The Preamps that @benh and @Andyjr1515 have tested for me have are slightly different: The board on the left is the filter board and the 2 res switches allow the user to change the frequency sweep: Switches on - 200hz - 3.7khz Switches off - 200hz - 5.0Khz and the spread of these 2 settings can further be tweaked by swapping out some resistors on the back. the push pull pot switches from high resonance to low resonance mode the second board is a normal volume control with a push pull switch that turns on a "pick attack" (very similar to Wal's pick attack mode), for which the frequency can be changed using the 4 red switches at the bottom. I had to pause a lot of my work on these, my original plan was to batch produce and sell them but my recent house move has take un a lot of my time. i wanted to make a preamp that could be super simple, but could easily be made way more complicated if thats what the user wanted (the ability to add resonance switches, resonance pots, and even filter mode switches can be added by swapping out a couple of little jumpers on the board, no soldering!). if people are interested i will post all the info on these in the thread

I may well enter, still have a few ideas cooking. I'll be interested to see if anything sub-6 strings makes the top 5 in either category

Loving this topic, really interesting stuff! In regards to the Preamps, I fumbled about with some filter preamps in my last build : They can be a bit tricky, but while i was doing the research i found that there were some fairly big differences between different manufacturer's filters: One other thing that the Wal filters have (aside from the relative simplicity of having a single frequency sweep and a simple hi/lo resonance from the push pull pots) is the "pick attack" That is a real challenge to get right. Ive got a couple of prototypes for a preamp with this feature out there, @Andyjr1515 & @benh were kind enough to give me some good feedback on the design so im still working on some improvements as you said above, multi coils are extremely time intensive to build, hence the expense! Really looking forward to seeing this come together!!

Not sure if i'm missing something along this journey... but if im not mistaken older Wal basses used to just use a Volume with a click switch at 0 So you wind down the volume to 0, then the switch disconnects the battery. might be worth looking into but not sure how easy it is to get hold of them in Audio Tapers Other option is to get a push pull knob and link the battery connection to that. My last custom bass had the battery pack wired up that way, and its a doddle to re-wire. no need for more holes or anything

Good Lord! Stunning stuff

Bloody hell... Thats a marvellous bit of work it really is. I shall pour a g&t, find a comfy chair and enjoy re-reading the thread! Congrats, a real achievement. You should be damn well proud

"more clamps is best clamps" -me, 2021

@Jabba_the_gut many thanks! Im looking forward to it too @Si600 thats a good question. For one thing im now certain i can reduce the footprint and improve the overall design. The coils need to be shorter and need more coils, and most likely i could move up to a 41 AWG wind for extra treble response if you were going to use them with filter preamps. Once i've had a go at a rework i'll be in touch! A 5er right away would be a bit overpriced IMHO, as it would mean a fresh design and reprint of the base pcb, but after a redesign it wouldn't be too tough i would think.

+1 for the EVO gold. both of my last 2 builds ive used it and im a huge fan.

@Andyjr1515 Thats High praise coming from you andy!! as i say, im extremely greatful for all the positive comments and encouragement @itu im glad you found it useful! i think one thing to bear in mind is that a lot of the veneers etc went to waste during the making of this bass, so in reality if i made another the overall cost of materieals would be slightly less. id hopefully be able to get 2 basses out of all those veneers second time around with a bit more knowledge... and i hope id be able to reduce the timescale on it now that ive done it all once and as i mentioned earlier in the thread, i wouldnt want to attempt inlays this complicated on someone elses bass until id had a bit more practice! Unfortunately for prospective buyers (but very fortunately for me) i've just managed to) buy myself a house, so a lot of my DIY time allocation will be going on plastering and laying laminate floors! then again if any enterprising builders in the north west fancy trading some hours for a bass then feel free to drop me a PM @binky_bass... what type of wotsits we talking here? normal or giant?

@Daz39, ive got a few ideas brewing as i mentioned earlier in the thread, a lot of the material choices for this bass were made with the consideration of "if this experiment goes to s***, how much is this going to cost me?" and so most of the wood choices were relatively inexpensive... as such id love to have another stab using some more expensive wood options in the future, and ive got a few changes id make to the pickups and preamps next time round as well. @binky_bass, certainly not too prying, im happy to share if it helps others! The wood costs were broadly as follows: Body wood - Padauk - approx £22 Body veneer laminations + extra veneers for the neck: approx £80 (these are expensive partly because they are thick constructional veneers, and partly because they cost a lot to ship) neck laminations (veneers /oak boards / rosewood) - approx £50 Namibian rosewood block for the neck through - approx £45 other various veneers etc approx £30 macassar ebony fretboard - £40 inlays - approx £100 Flamed redwood top (imported from US, bit of a difficult one to quantify as it came with a couple others) - approx $80 for the top approx $70 for the shipping plus import tax... probably total about £100 for the rest of the parts: Bigsby b500 clone (a good one) - £35 brass parts for customisation - approx £10 Tune - o matic bridge - £21 TUSQ graphite blocks - £12 Sperzel locking machine heads - £91 assorted extra hardware (inserts, straplocks etc) - approx £30 for the electronics: 3D printed pickup covers + switches - £33 truss rod - £16 carbon fibre in the neck - £32 PCBs for pickups, bobbins, preamps - approx £50 spool of 41AWG wire - £26 electrical components (resistors, caps, pots, knobs etc) - approx £40 bits for power supply + custom cable - approx £30 there were many other assorted costs for sanpaper, fresh router bits+jigsaw blades etc, and stuff i already had like the finishing products which i can't total up here. (if id had a swear jar in the garage id be broke) so based on that math, total would be somewhere around £850-900 ish. which is frustratingly expensive really, ive built some nice basses before for less than half of that, but there just arent many cheaper ways to do some of the stuff on this one. as for time, thats a difficult one to say. i think with all of the reworks of various things id hazard a guess around 240 hours, but maybe more than that. hope that is helpful to anyone wondering like i was saying, id like to do the next one with some fancier woods/veneers... just seen this fretboard blank for sale... that sort of gets the cogs turning

Thanks again so much guys! There's been so many kind comments throughout this thread and i so glad everyone has enjoyed it! I just hope it lived up to the expectations Daz, thanks! The sliders on the pickups switch the pickup coil configurations between 4 modes: 1. p bass 2. Reverse P 3. Jazz bass 4. Humbucking The other controls are: Push pull master volume, switching between stereo output with outboard power and mono output with battery power Balance knob Then each pickup has: Frequency sweep low pass filter 2 position switch between 2nd order (12db/octave rolloff) and 4th order (24db/octave rolloff) Resonance control from 1db peak up to 10db peak, with a push switch in 4th order mode up to 15db