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Post by JohnH on Dec 5, 2023 16:13:19 GMT -5
I'd add that, if instead, a normal battery supply was allowed, this effect would probably be fairly easy to replicate DIY.
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Post by JohnH on Dec 5, 2023 6:47:37 GMT -5
Interesting gadget!
I'm thinking it's a thing that switches suddenly between the pickups (the 'rather square' response), backwards and forwards at a given adjustable frequency, rather than as a smooth wave, like an old tremolo.
But using the two pickups does seem nice, and that makes sense as an on-board device, the only place if can easily be to get easy connection to two pickups.
Guitar circuits don't reslly need to drive much power, so they can be low current if so designed. A super-capacitor could hold enough charge for quite a while. It notes how it's charged by plugging in a battery for a few seconds. Seems a neat idea and saves having to access batteries inside.
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Post by JohnH on Nov 15, 2023 16:11:42 GMT -5
Hey JohnH , this was in my youtube feed: Does the 'mystery' treble bleed look familiar? Yes indeed, and you saw it all here first! Meanwhile, 13 years earlier, here is the 'Mystery' TB: See page 3 of this thread. I will also note that before this thread, the standard recipe on the internet for the Parallel TB had a 1nF with 220k. 220k causes some thinning out as to roll down, and 150k proved to be better. The one he called Parish looks to be one of the Fender 'Tonesaver' recipes. It's a good video, no surprises though.
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Post by JohnH on Oct 10, 2023 15:33:01 GMT -5
Hi erwan, welcome to GN2! I'm glad you found your answers. If you try this, please let us know what you think of it!
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Post by JohnH on Oct 3, 2023 16:46:05 GMT -5
Explanation below..... Ok so I reckon the key to this is the fact that the rungs are tilted alternately. Were it not for this, with horizontal rungs, the ladders would fall at equal rate because then, there would be no forces transmitted up the wires as a rung impacts the table.
But, with skewed rungs, when one hits at one side it imparts an impulsive force to that rung that causes it to rotate about its mid point. And the other end tries to rotate down. in doing so it sends a tension shock up the cable, giving extra downw;uard impulse to rungs above. This happens alternately left and right, and after several have hit, the effect has imparted enough extra impulsive 'tugs' on the still falling rungs that they have fallen noticeably faster and further
If you'd like to experience this effect personally, take a baseball bat or a cricket bat and strike a fast ball, or a tree, not at the 'sweet spot' but at the very tip of the bat. But not too hard or you may break your wrist!
(No spoilers or hints were viewed, but thanks to my maths teacher Mr Fisher, who explained the physics to me in high school about 45 years ago)
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Post by JohnH on Oct 2, 2023 15:23:19 GMT -5
Hi frets, on the few that I built, I found the same as you, in that the shielding helps, in most cases.
The clearest example that I had was on a fairly nutzy Strat build, I had the guitar plugged in and amp running as I closed the pickguard down over the cavity. This was an Ibanez Roadstar II , with 3x single-coils, where the jack was on the pickguard. So the PG had foil glued behind it, all the pots were grounded and in contact with the foil, all grounded to the jack as so to the amp . In that state, before closing it up, there was expected single-coil hum at 50hz (our mains frequency), plus mains-related buzz due to fluoro lights, computers etc nearby.
My cavity shielding was also foil, but not directly grounded. It was to get its grounding by contact of overlapping edges when the PG was screwed down,
So as the completed PG was offered over the guitar and lowered into position, there was hum & buzz, hum & buzz, then a crackle at contact and then much reduced buzz, with a little hum.
So I reckon good shielding helps with the more annoying buzz component of mains-related interference. Fender seems to agree, and my 2010 Am Special Strat came with foil on the PG and a conductive paint cavity shielding, with its own grounded lug.
I think there's not much gets induced just into the top of the pickups, but that that there is can be reduced by following our mantra of not hanging from hot.
What also helps a lot with the buzz part while playing, is grounding the strings via the bridge, hence grounding the player. All guitars seem to have less noise when the player is fretting at least one string.
But there's one case where I reckon shielding is not needed, and that's on a classically-wired LP or similar. With these, all wire runs are within grounded, braided screens, pickup base-plates and covers are grounded too. Even an old-style capacitor, of the rolled-up foil kind, can have the outer foil on the ground side so protecting it. There's only a few very short solder connections that aren't covered by this arrangement. But all that grounded braiding around wires must add quite a few pF's of capacitance, and that may be part of the classic LP tone.
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Post by JohnH on Sept 23, 2023 23:04:56 GMT -5
Thanks for trying it, and maybe it'll work!. I guess the idea is a lot easier on a full-size simple single pot where the track lifts right out
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Post by JohnH on Sept 23, 2023 21:07:24 GMT -5
For a real Hewlett Packard, of the type whose grandfather helped land the Space Shuttle, and which every engineering student of the 1970's and 1980's lusted after and is still using today (unless they couldn't afford one and bought a Casio instead) it HAS to be RPN (Reverse Polish Notation) or else it denies their HP heritage. In RPN mode, the input for our puzzle would be, if working left to right with the intent to respect PEJMDAS:
8 Enter 2 Enter 2 Enter + x ÷
answer is 1
Or if one wants strict PEMDAS:
8 Enter 2 ÷ 2 Enter 2 + x
answer is 16
If anyone wants to remember these magnificent old engineering work-horses, many of them have been lovingly recreated as Android apps, mostly for free or for a few $, on Google Play
And I agree about the lady in the video. As smart and beautiful as she is, our favourite Aussie will always be Gumbo.
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Post by JohnH on Sept 23, 2023 16:07:11 GMT -5
We seem to be getting rather distracted by the small issue of solving the fundamental basis of human mathematics, which is merely the foundation of all science and engineering, when we should really be getting on with the more important work of rewiring the worlds guitars?
Thinking about just one day as an engineer, Im likely to be interpreting, writing and communicating maths in multiple different ways eg:
1. Quick numbers in a calculator or calculator app, which if its of good quality post about 2000AD, will display a full line and then follow PEMDAS to evaluate it, but if its older, or simpler (including the latest basic calc app built into Windows), will do each operation as you enter it, with a different result
2. I might revert to my favourite HP calculator, with RPN notation, which sorts out priorities in a much more compact and logical way. Great if you learnt to be used to it years ago, plus the BUTTONS feel REALLY nice!
3. Checking or setting up a spreadsheet, in which we use ^, * and / etc, plus more ( ) brackets than you can poke a stick at, just to be sure
4. Handwriting a calculation on a pad. And this leads to another source of conundrum: If you represent division using a / symbol, then PEMDAS tells us how to apply it. But if you instead morph the division into a horizontal line with calc above and calc below, does the transition from '/' symbol to horizontal line then give the division a higher priority? I would say yes-maybe! A similar issue occurs in writing slides for an engineering lecture, except its easier to read than my 2023 handwriting.
5. Working out numbers in my head, which is probably a place that such numbers should stay
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Post by JohnH on Sept 23, 2023 3:05:53 GMT -5
The 1M idea was to be in addition to the track scraping. So scrape one half of the track length to increase resistance, and also scrape a full disconnect at 0, and then also wire the 1M.
This should offer zero resistance = full bass at 10, 200k at mid turn (250 x 1000/(250+1000) =200), rising to say 700k (or what ever can be achieved) at just before 0, then 1M at 0
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Post by JohnH on Sept 23, 2023 1:10:13 GMT -5
If its used, the 1M resistor would be across the same two lugs that the cap uses. One pot lug is not involved in bass cut.
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Post by JohnH on Sept 22, 2023 14:44:15 GMT -5
Another avenue, not yet explored but easy to try:
Take a standard linear 500k pot, open it up and remove the track and do some careful scraping at the edges of one half of the track to 'stretch' the resistance. I know this works in principle and I've done this to take low-specced log pots that measure at around 400k and get them up to 500k. But can this idea go further?
I reckon you could maybe add a couple of hundred k by working on a linear 500k pot. The trick will be to keep the centre of the track consistent and do the scraping at the edges. Also, to pre-figure which half of the track length to work on so it tends toward being the anti-log pot that you need.
Could end the process with a full no-load cut across the track that will be at 0 on the knob, for max bass cut. Then, when wired up, could put say a 1M resistor across the resulting contraption so its net 1M at 0? This will also smooth out the response and make the 10 to 5 range a slightly smoother 200k instead of 250k
This is speculative, but the starting point is a $10 pot so not much to lose. What I don't know is how much scaping is feasible but still maintain the reliability of the pot.
A nice aspect of this pot-brain surgery is that it can be extremely precise. You can have a meter clipped to each end of the track, measuring the track resistance in real time and you can watch the k's increase scape by scrape!
What could be done with a 250k linear pot?
(let me know if this is interesting but unclear and then I'll sketch something)
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Post by JohnH on Sept 21, 2023 16:54:03 GMT -5
hi ignerint, a warm welcome to GN2. I'm sure we can figure something out with a switch.
Working on this will be wonderful way to remember your Dad. My father was also a maker of things, and I think of him every time I build something.
As for the details, the basic approach is very simple from pickup to toggle to bass and treble cut. Then a switch with two poles is needed to select which of two volume pots receives the pickup signal, and also to select it to go to the output and cut out the unwanted pot. (diagram needed)
But, I'd suggest to consider two pots of the same value, probably 500k, unless you have a reason not to. And the switch can either be a srperate mini-toggle, or a push-pull switch mounted on one of the pots. All simple standard parts in each case. The choice can come down to depth and space in tbe guitar.
If you'd like to, we'd be happy to see a picture of the guitar!
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Post by JohnH on Sept 19, 2023 14:54:12 GMT -5
Id agree with you, the answer should be 1 (but the PEMDAS version =16?)
But I suppose in real life, there are very few cases where this comes up with simple numbers. The implicit multiplication isn't a feature of normal life using only numerals and can get confusing. While 2(2+2) has a clear meaning, and 2(4) does also though its quirky looking, its not the same as saying 2(4) =24 (!). Or if we start using the '.' symbol as a multiplication, we could get 2 x 4 = 2.4 (!). Europeans get around that to some extent, by using a comma ',' instead of a decimal point.
So I think in practice, we have to drop out of using the implicit notation once its down to a specific numerical calculation rather than a line of algebra.
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Post by JohnH on Sept 18, 2023 21:21:47 GMT -5
What seems to happen as you reduce the bass-cut cap is that you still get about the same max low cut, but it starts to eat more into the mids too. Probably best to try some values, but here are plots with a 500k pot at max cut, with 2.2(solid blue), 1.5(green) and 1.0nF (red) cap. There are also 1.8nF and 1.2nF values in between. But no implications at max bass = 10. The great thing about all these bass cut circuits is that no matter what values they have, they all completely bypass themselves at 10.
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Post by JohnH on Sept 18, 2023 20:25:51 GMT -5
I reckon the best way to use a linear pot for bass cut, would be a 500k one, as you suggest. Ive tried thinking before about adding resistors, but cant wrangle anything better by doing this. This 500k B pot will give a reasonable spread, but not quite as much max bass cut as a 1M. Here' s a plot Its a Texas Special with 250k volume, and a no-load treble pot. Dashed blue is no bass cut, the lowest green curve is max bass cut with 500k and 2.2nF. The red one was to try to find where you get about half the effect, and its shown at 25% of the turn. So youd get no bass cut at 10, half the cut at 7.5 and all the cut at 0. Not too bad? For comparison, a C1M pot would get to that same setting by turning down from 10 to about 5 or 6, and would have a bit more total cut at 0, compared to max cut on the 500k B
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Post by JohnH on Sept 18, 2023 17:59:10 GMT -5
Sure, I think the TBX mod by Phostenix is just a clever way of wiring the pot, but doesn't need a mod to pot itself, if you already have a TBX pot.
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Post by JohnH on Sept 18, 2023 16:44:18 GMT -5
PTB circuits are great because both the bass and the treble side can be set to max and have no extra effect. In fact the treble on a PTB can be no-load, if you want the option of a bit more instead of less.
TBX's have their own quirky-ness (see our tone control discussions) but Phostenix' re-imagining of it as a combined treble/bass control is very clever.
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Post by JohnH on Sept 18, 2023 16:40:06 GMT -5
Maybe it might have some tones that could be liked, but it looks that it will always be taking some tone away and so that the natural sparkle of a simple standard wiring is diminished. So if you want to try it, maybe do a reversable lash-up version to test it. Then if you like what it does, I'd suggest that the pot could have a push-pull switch so it's completely bypassed unless you pull the knob.
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Post by JohnH on Sept 14, 2023 3:54:30 GMT -5
Here's one, just based on minor wrangling of the main switch, no added tricks. It provides what IMO are the five most useful sounds that an HH can make, being each separate humbucker, B and N combos of humbuckers or singles, and a neck single coil. It puts the usual selections Bridge Hb, both Hbs, Neck Hb into positions 1, 2 and 3, and then does Bn + Ns, and Ns at positions 4 and 5. So I'd get the Bridge humbucker and neck single, where I'd want them for quick switch-swiping between them, plus a bonus Tele-like quack sound. The three usual HH sounds are available and overall there are four humcancelling settings. Some shunting and hanging is involved though, just for the two coil-cut options.
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Post by JohnH on Sept 13, 2023 16:01:27 GMT -5
For me, after trying quite a few HH and HSS schemes, I keep circling back to my favourite for what I use on my LP. Personally, I much prefer a full or partly bypassed coil cut on an HB, rather than parallel wired HB, despite humcancelling issues. It's edgier and a nicer contrast to the full HB. I'm hamfisted with quick switch changes so I want my best settings at each end of the switch. I usually want to swipe quickly from a neck single to a full bridge humbucker. My build would use two tone pots, one for each pickup, wired using three lugs to do single at 10, Hb at 9 and then Hb with tone rolled off below that. I've had this on my LP for 15 years and I never want to change it! The neck goes to a full coil cut, the bridge version is via a cap to keep a bit more weight. Volume can be one or two knobs, to suit either a Strat or LP layout. But then, the switch is only three position, so it's a Tele switch rather than a Strat switch, or a toggle. So I'm disqualified unless I can make it more complicated! (an LP version of the above is in the schematics guitarnuts2.proboards.com/thread/3167/simple-les-paul-mod-parts )
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Post by JohnH on Sept 12, 2023 16:43:15 GMT -5
Yogi's will be hard to beat! But I might work one out to do what I would seek on an HH.
Do you want to set any rules about other parts? like pots or added switches?
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Post by JohnH on Aug 26, 2023 15:50:15 GMT -5
That seems very good, I traced it through successfully But obviously, I had to find something! And its a red wire crossing a black wire near the top left switch pole, and a pink crossing a red near the lower right switch pole, without the neat little white gaps!
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Post by JohnH on Aug 24, 2023 8:21:26 GMT -5
I don't see N x M on that mark up. Did you see my suggestion in the post before reTrEaDs?
Keeping thd tones that you want unchanged and also having borh the series options that you want may be getting outside of the range of these simple parts.
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Post by JohnH on Aug 24, 2023 3:54:27 GMT -5
It's a clever idea, swapping the second blender to a tone control.
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Post by JohnH on Aug 23, 2023 8:17:48 GMT -5
I think the most practical combination of the two schemes would be reTrEaD's zerobux, and add S2 from mine. S2 simply swaps the hot dnds of M and Bsouth with each other. So they swap places in all positions where they occur. This will give you N to NxM blending, N+Bs, Bs, Bridge parallel. Really all tbe good tones eith blending just in position 5 and the autosplit at 2
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Post by JohnH on Aug 21, 2023 19:54:35 GMT -5
Oh great! thanks for postng!
f you look at my avatar, thats the Strat that I dd this too. I have a sub-miniature toggle between the pots, and thats the extra switch. I usually leave it un-moved, so ts as you have wired it. But, when its flicked, you get another interesting selection of different sounds n about the same relationship to each other. Its like the same guitar but swapping to a different set of pickups.
I like reTrEaD's scheme too
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Post by JohnH on Aug 20, 2023 16:43:24 GMT -5
reTrEaD's looks fine too, with a couple of comments:
Diagram shows the switch poles being those furthest apart, on the diagram the most left and the most right. Many other diagrams (such as mine) show the left bank of switch lugs shifted up half a space. Still the same order. Switches differ so beware of a mix up while wiring!
reTrEaD's cuts out blending in all settings except N x B, while mine keeps blending active in 2 and 4, giving two extra tones. These are still quacky, being parallel mixes with M, but a little thicker than usual. You may prefer the simpler operation of not having these tones though, so then you just set your blender for position 5
With all these schemes, need to be very careful to figure out what wires go to which coil, and the N S order of the coils on the guitar. My diagrams show how these are on my Fender HSS, which is also very explicit since you can see on the back of the pickup where each wire goes. But most pickups need interpretation and checking. No matter what, for an in-phase hum-canceling combo, you need a north and a south coil. You can identify relative polarity with a compass.
For the tone, I think a no-load 250k tone pot and a 250k volume is a great combo for HSS.
Good luck with wiring!
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Post by JohnH on Aug 19, 2023 20:12:46 GMT -5
Id suggest to look at the SSM2 scheme linked above, and then if you don't want the extra switch (S2), just hard-wire it without that switch with wires connected in the 'S2 down' setting. It has a Master tone.
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Post by JohnH on Aug 19, 2023 18:54:06 GMT -5
reTrEaD can comment on the zerobux scheme, But I have something that's close to what you might seek: guitarnuts2.proboards.com/thread/6873/strat-ssm2-hss-sounds-dpdtParticularly, its HSS (my favorite Strat arrangement), and it blends a bridge coil in series with the neck (I agree, its the best!) Im linking SSM2, which has one extra switch, but in the first line, is a link back to a simpler SSM which has the best of the sounds and might do you. It doesn't directly do auto spit at position 2, instead, the bender works there too, to go from B single + M, to B humbucker + M. So you get the options These were about the last Strat scheme I worked out, there's nothing else I want in a Strat and I've had SSM2 as a daily player for about 10 years.
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