Just bought some posh new pickups for one of my Yamaha Pacifica and was recommended to upgrade the pots,wires, capacitors and switches at the same time to get the most from them. How much of an effect does this have on the quality of sound? The original ones in the guitar are cheap and flimsy plastic and very thin wires etc. The new parts weren't expensive but do they really make a noticeable difference?

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"Ignorance more frequently begets confidence than does knowledge" Charles Darwin.

Any time you put a pot between a guitar pickup and the amp you are altering the tone. To what extent varies depending on the pot Ideally you want one that is completely out of the way when it's flat out I've found the pots mostly OK. Ish. But I've often replaced because of going with coil taps so a push / pull pot goes in.

With the capacitors, there are big sonic differences to be made with the SIZE of the capacitor.... Many tone circuits mean that the cap is 'in circuit' even when the tone control is on 10 so the cap can make a difference, let alone when you roll it back..... There are an awful lot of folks out there selling stupidly expensive bumblebee caps to put in Gibsons but quite where the snake oil vs reality boundry is I couldn't say.... I've tended to stick with decent quality 'orange drops' or the 'greens' which come in at about 20p each

I tend to rewire all of my Far East guitars - every one I've ever had has been superb in every respect bar the wiring which has been utter pants The wires that are there tend to be way too long, too thin (not sure this makes a sonic difference but they just LOOK flimsy and I don't like it!) and jammed in the body cavity as best they can - they are left long for ease of assembly but anything long floating around is going to pick up noise. Also I've found it very typical for the bridge (and therefore the strings) to not be properly grounded such as you get a vast reduction in noise levels when you touch the strings. This drives me potty. On every one, I've had resistances of 5 ohms or worse to ground from the bridge. Sorting this out is a good start.

IMO, it's worth looking up tips on 'screening your guitar' which essentially involves coating the body cavities with turkey foil. Especially for single coil guitars, the benefits of doing this can be huge and it costs you pennies and a bit of your time. If it's a Gibson style guitar and tunnelled as opposed to Fender-ish openness then I've used screened wire to go up to the pickup switch. Every little helps

The various capacitor dielectrics, the insulating material betwween the "plates" does influence the sound in that certain materials produce more measurable distortion than others.

However such distortions are only measurable at noise levels of -90dBu and lower and are thus really only the preserve of top end hi fi and professional mixers etc.

I am of the opinion that the inherently mediocre noise and distortion levels of even the best guitar electronics makes all claims about special caps and Rs so much snake oil and wire is just bloody wire! Hi fi or no hi fi.

"It is only rock and roll" was never more true.

Dave.

And what is your opinion as to the merrits of turkey foil and its improvements in noise level? Cos I love it

Quote Gary_W:

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And what is your opinion as to the merrits of turkey foil and its improvements in noise level? Cos I love it

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Chuk foil is fine! Does the job. I am told you can buy adhesive backed 30mm copper tape (plumbers) but I have searched DIY stores hereabouts in the past in vain.

Thin tinplate is also good since you can mould it to the cavity and solder it to form a rigid, drop in can. Some lager cans I am told are plated steel not ally. Good to find as you would get a double pleasure whammy, low noise guitar and inebriation!

Don't forget the back of the scratchplate.

Dave.

and don't forget in a typical passive guitar ct. the capacitors are only decoupling, not coupling. This means they just short certain frequencies to earth, they are not in the actual signal path. Only the volume pot is in the signal chain.

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Only the volume pot is in the signal chain

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Eh?!?? If it's sucking frequencies out of the overall sound, it's by definition "in the signal chain". Whether electrons have to physically pass through the component on their way to the end-jack is irrelevant.

Quote grab:

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Quote:

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Only the volume pot is in the signal chain

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Eh?!?? If it's sucking frequencies out of the overall sound, it's by definition "in the signal chain". Whether electrons have to physically pass through the component on their way to the end-jack is irrelevant.

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Agreed - the cap is providing an easier path for some frequencies, and which frequencies / how easy it is depends on the value of the cap and the tone pot setting / value

If anyone doubts the difference wiring harness CAN have, just solder the pickup directly to your output jack without any pots, caps or switches in the way.... I fiddled recently due to the learning curve that was 'vintage gibson wiring vs modern gibson wiring' and discovering that, done 'wrong', you get a pretty muddy old mess. And that's all because of caps that 'aren't in the signal chain'

Quote fletcher:

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and don't forget in a typical passive guitar ct. the capacitors are only decoupling, not coupling. This means they just short certain frequencies to earth, they are not in the actual signal path. Only the volume pot is in the signal chain.

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Err? Sorry Fletch' no, the capacitor in a basic "top chop" tone circuit is effectivley a load and thus any nonlinearity it exhibits will cause distortion but as I say, such artifacts are well below the noise floor of even the best guitar rig. Indeed the first triode the signal hits will produce more distortion than the worse capacitor, and we won't even TALK about pentodes!

Dave.

Edited by ef37a (15/02/12 03:23 PM)

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I am told you can buy adhesive backed 30mm copper tape (plumbers) but I have searched DIY stores hereabouts in the past in vain.

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Hey, Dave, how are you? My power brake is still going strong you'll be delighted to hear! You can get sticky copper foil on ebay. In fact I bought some for another build but never got round to fitting it. Maybe I'll do it on this one as I've invested in the pickups and snake-oil wires! Here's the link:
Copper foil on ebay

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"Ignorance more frequently begets confidence than does knowledge" Charles Darwin.

Hi H.L.

Not that clever at the mo THB but musn't whinge! Glad to know the hot box is still cooking.

Dave.

fair enough, but still I would have thought the quality of de-coupling caps matters far less than the quality for coupling caps.

I bow to your greater knowledge Dave.

There is a clear, but subtle, distinction between 'Quality', a measure of how well made something is, and 'the qualities of', which is about the electrical characteristics of a component.

The first is essentially, how many days/weeks/months/years will it be until I am likely to need to replace this part.

The second is, how if at all will this part change the sound of my instrument. In my experience, things like the type of capacitor are less than insignificant. A 50 year old Gibson or Fender with a bumblebee or oil filled cap may well sound different than a modern Gibson or Fender, but 99.99% of that difference is due to the woods ageing 50 years and countless other things. The type of cap is insignificant in the big picture. And, more to the point, in a modern instrument the difference between two pieces of wood cut from the same tree is going to make a bigger difference than switching from a ceramic disc cap to an Sprague Orange Drop, a NOS bumblebee or a re-issue oil can.

Where the electrical qualities of a part can make a real difference is in the taper of a log pot. That decides how effective and usable your volume and tone controls are.

However, to go back to Hugh's original post. I DO recommend upgrading pots and switches when replacing pick-ups on budget and even mid-range guitars. The reasoning is simple... Good Quality pots and switches are likely to last a LOT longer in normal use. No point in replacing your pick-ups this year and next year having to go in with the soldering iron again to replace a cheap pot or switch that's failing. Do the job once and forget it. And I habitually rewire with new cable rather than reuse what's in there already. It costs pennies.

Andy

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When the going gets weird, the Weird turn Pro.

Quote Gary_W:

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If anyone doubts the difference wiring harness CAN have, just solder the pickup directly to your output jack without any pots, caps or switches in the way....

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That makes a substantial difference, but not for the reason you might think Gary.

Guitar pick-ups are remarkably complex for what is essentially a coil of wire in a magnetic field. So both players and manufacturers have developed a short hand for talking about them that hides a lot of important details.

I am sure you've seen those nice frequency response curves on manufacturer's sites that 'help' give you an idea how the pick-up sounds. But not only are they largely meaningless, they hide a multitude of sins.

Technically, pick-ups don't have a frequency response curve, they have transfer characteristics. A pick-up is an AC generator with inductance, capacitance, and resistance. The net effect of all those components is that it 'looks' like it has a high pass filter giving the bass roll off, and a high pass filter with a resonant peak before rolling off the high frequencies. And you can show that on a graph and it looks very like a frequency response curve.

HOWEVER, and you will notice that it is a big however, that response curve isn't fixed. Every component you add between the pick-up and the first buffer (usually the amp input or first buffered effects pedal) changes the capacitance, inductance and resistance of the circuit. And that in turn changes the sound the pick-up makes. And I have to be very clear about this, those components are doing two things simultaneously. They are modifying the AC output from the pick-up and they are also changing the sound (or transfer characteristics/frequency response) of the pick-up itself.

One way to test this would be to fit a unity gain buffer pre-amp in a guitar with a single pick-up. Then put tone and volume controls after the buffer in a switchable bypass circuit. With tone and volume on full you will hear far less difference when you bypass them than you heard when you wired the pick-ups straight to the output jack. You were right to hear a difference but your conclusions are incomplete.

Andy

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When the going gets weird, the Weird turn Pro.

What ef37a says. Guitar electronics are universally piss-poor. It doesn't make a jot of difference what components you use, any foibles will be inaudible beneath the sea of noise and distortion typical of a normal guitar rig. If guitarists and their techs cared, and knew enough to do anything about it, almost every aspect of guitar technology would be totally different. As it is, we have a hidebound market where anything invented after 1967 is treated as at best an amusing novelty and at worst as an economic threat.

Quote fletcher:

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fair enough, but still I would have thought the quality of de-coupling caps matters far less than the quality for coupling caps.

I bow to your greater knowledge Dave.

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Sorry Fletcher mate but again no! The cap is not a "decoupler" in the sense that a 22mfd hung on a valve HT rail is (tho' there are those odd birds that say that even these are technically "in the audio path" My view about that is pretty much.... Bollx!).
As I say the tone cap is a load, part of a frequency dependant potential divider. Consider, if you replaced the cap with a very nonlinear device such as a diode? You would certainly expect that to distort the signal?

But I say again. Capacitors DO vary in their "fidelity" but the distortions are at least an order below the noise floors that most of us mortals enjoy, about the limit of 16bit operation.

Re coupling caps. So long as their reactance is low at audio frequencies, i.e. very little signal voltage is developed across them, even electrolytics are audibly "perfect".

Dave.

Quote uphillbothways:

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What ef37a says. Guitar electronics are universally piss-poor. It doesn't make a jot of difference what components you use, any foibles will be inaudible beneath the sea of noise and distortion typical of a normal guitar rig. If guitarists and their techs cared, and knew enough to do anything about it, almost every aspect of guitar technology would be totally different. As it is, we have a hidebound market where anything invented after 1967 is treated as at best an amusing novelty and at worst as an economic threat.

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Absolutely! The technology now exists at lowish cost to build very low noise guitar amps, and you can buy them. In principle it was always so, circuit techniquies such as cascode front ends and multiple low impedance circuits, DC heating,could have been producing audiophile amps (in terms of noise)for decades but the cost would have been prohibitive and in any case so long as the electric guitar resembled an anntena,open to everything from 50Hz to infra red there was little incentive!

Dave.

No need to say sorry Dave, I'm here to learn! Yes I was thinking more of the type of caps used in amps, tv's etc. to remove unwanted frequencies. My electronics gets rustier every year! My jazz playing is improving though.....

Thanks for your time.

Another lovely post, Zen.

The discovery a couple of years back as to the difference that a decent quality guitar lead made vs a reasonable quality lead was a bit of a revelation.... Both had effectively zero DC resistance but I'm guessing the fact that it interacts with the pickup and changes the transfer characteristic is where the money's at here? All I know is that with my little valve amp a whole bunch of the lovely ringy harmonics are either 'there' or 'almost there' depending if I plug in my posh lead vs the one that cost a fiver. Both are DC resistance-wise good and are the same length....

The wiring harness in the guitar making a difference..... I was a believer as of a month ago. I bought a Burny Les Paul (a little cracker for £400) and immediately decided to put new pickups in it. I bought a set of Irongears (great pickups for the cash IMO) and also went for his 'Mr Page' wiring kit http://www.axetec.co.uk/kit%20lpkit02%20mr%20page%2004%20watermarked.gif


so as I had the benefits of coil taps, out of phase sounds and 'everything on' in one guitar

Following the diagram above made the guitar completely useless if you dared to roll the volume back on the guitar - you had an absolute wall of mud.

This wiring diagram is one of several 'gibson' style diagrams and it 'cures' the issue whereby if you use the middle position and roll one volume control off completely you have zero output. This certainly fixes that - roll off one to zero and it still works with this diagram.

Unfortunately, it cures this (IMO non-issue) at the expense of robbing all of your high end when you don't run the volume controls flat out.

I swapped it for the rather more usable version where the pickup goes to the input of the pot, NOT the wiper. Fixed. Tone was back as it should be and the little quirk of 'turn one volume to zero and all the output dies' came back I like it like this but I guess that is a different strokes thing. But, unless you never roll back volume or like it as woofy as Barking dogs home I'm hard pressed to know who would like it like that

So what is your take on the relative costs of different pickups? The Axetecs cost me about £60 for the pair They are designed over here, then machine-wound using 42 gauge wire in China (IIRC). At the other end of the scale, you get hand-wound pickups over here that will set you back 4-5 times the price..... Does scatter winding actually make a difference or is that somewhere where the snake oil / pricing bridge gets well and truly crossed???

And, as far as 'advances in the last few years' go. I have a pair of far-east built G+L's with the MFD pickups in them which are a little bit different to the standard classic designs. I must say they are stunning and I would never consider swapping them! Very 'hifi' is the best term I can use - pardon the terrible attempt at talking about a sound! I absolutely love them as does my amp, so that'll do for me

Edited by Gary_W (16/02/12 10:21 AM)

Quote fletcher:

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No need to say sorry Dave, I'm here to learn! Yes I was thinking more of the type of caps used in amps, tv's etc. to remove unwanted frequencies. My electronics gets rustier every year! My jazz playing is improving though.....

Thanks for your time.

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Ok! Well one does not like to be seen to be putting people right all the time!

And time Fletcher my friend, I have ooodles of.

Dave.

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If guitarists and their techs cared, and knew enough to do anything about it, almost every aspect of guitar technology would be totally different

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Can you give us some examples of what you mean? Cheers

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"Ignorance more frequently begets confidence than does knowledge" Charles Darwin.

Thanks Gary,

Pick-ups are an interesting subject

Lots of old wives tales, misinformation, misunderstanding, and only a handful of people in the world who have any in depth understanding of how they work. I for one certainly don't have that deep understanding but I am pretty good with the broad principles.

In some ways there's very little difference between budget chinese pick-ups, big brand pick-ups, and expensive boutique models. They can all give you pick-ups that broadly sound the same. The differences aren't night and day, and are generally pretty subtle, but they are there, even if you need a nice responsive amp to hear the benefits.

Scatter winding is certainly not snake oil. A large part of the sound of a pick-up is the capacitance, inductance, and resistance of the coil. But as well as having those overall characteristics, each turn of the coil has a capacitance, inductance, and resistance relative to every other turn. The overall values are the sum total of all the internal values. The internal values vary according to the relative positions of the two coils. On a machine wound coil there is a very even distribution of these internal relationships. But with scatter winding there is an uneven distribution. For a typical coil of 6000 turns that's roughly 2.684 x 10^20065 internal pair relationships. So, there is a material difference. The hard part is finding a nice way to show how that contributes to the sound!! The closest I can get is that for every note on every string of the guitar, and all of it's harmonics, there is a part of a scatter wound coil that is optimised to reproduce it.

Scatter winding is interesting for another reason, it helps address this...

Quote uphillbothways:

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If guitarists and their techs cared, and knew enough to do anything about it, almost every aspect of guitar technology would be totally different. As it is, we have a hidebound market where anything invented after 1967 is treated as at best an amusing novelty and at worst as an economic threat.

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Scatter winding came about as a result of a small number of obsessive people like the late David White who were convinced that hand wound 1950's pick-ups sounded better than the modern machine wound equivalents. They went to great lengths carefully dismantling old, broken, pick-ups to try and understand what made them different, they did a lot of research, tracked down former employees of Fender and Gibson to pick their brains.

There is a fundamental problem with the view that "almost every aspect of guitar technology (could) be totally different". It is a classic example of not seeing the Forest for the trees.

It is very easy to break down the guitar and amp chain into individual parts, components and systems. And once you've done that it is very easy to re-engineer those parts to do their job better. Better pick-up technology, electronics that work properly, better materials, better engineered trems, the list goes on.

But it's not that simple. Whether we like it or not the electric guitar evolved between the 1920's and late 1950's and it coincided with the growth of recording and broadcasting. The most dominant popular music until the early 1980's was driven by the electric guitar. Whole generations have grown up listening to that sound, it is ubiquitous. On the TV, on the radio, still on most chart records, whole generations have grown up with it.

That handful of classic guitars (tele, strat, les paul, gretch, 335) aren't just classics. They are THE DEFINITION of the electric guitar. And that's the problem with 'improvements', the benefits are real, but the downside is that they subtly take the sound of the instrument away from what listeners and players expect. And in that sense guitarists are no different from violin players, they want a classic Cremona instrument, if they can't have that they want a good 19th Century one, and if they can't afford that they want a modern instrument made by a maker who builds in that tradition. It's not that the violin can't be improved, but it can't stray too far from what was established by Stradivari and his contemporaries.

Andy

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When the going gets weird, the Weird turn Pro.

Too right Andy!

One perfect example to me of "wrong being so right" is the classic 4x12 speaker cab.

No matter how much it costs the constuction from a purely "hi fi" enclosure point of view is just crap. The timber is not dense enough, should be 50mm MDF at least. The panels are unstiffened and undamped, the front baffle is so "full of holes" that structurally it is hardly there at all! The things should be at least a foot deeper.

Then the speakers are wired in SERIES parallel (yes, there were a few 8R bass cabs that used special 32 R drivers). But this is the sound we know and love.

I do however commend any progress on making guitars and amps quieter, especially now that we are "on top of them" with home recording. I do not think hum and hiss add anything to the "art"?

Dave.

Quote zenguitar:

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There is a fundamental problem with the view that "almost every aspect of guitar technology (could) be totally different". It is a classic example of not seeing the Forest for the trees.

It is very easy to break down the guitar and amp chain into individual parts, components and systems. And once you've done that it is very easy to re-engineer those parts to do their job better. Better pick-up technology, electronics that work properly, better materials, better engineered trems, the list goes on.

But it's not that simple. Whether we like it or not the electric guitar evolved between the 1920's and late 1950's and it coincided with the growth of recording and broadcasting.

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I have to disagree. There are all sorts of really big improvements to be made that don't deviate from the traditional sound and feel we expect.

The strongest example I can give is this - why are there no amps on the market with variable-impedance inputs? We all know that impedance matching is of vital importance to a guitar's tone, for reasons you've laid out quite eloquently - a guitar, amp and cable form a complex tuned circuit. We know that the necessary circuitry is quite inexpensive relative to the cost of a quality guitar amp. There are scores of mic preamps on the market with variable impedance, from cheap ART units up to boutique exotica.

The only reasonable explanation is that most buyers don't know any better and that most manufacturers are quite happy spending bugger-all on R&D. The only manufacturers I can think of who seem to give a toss are Line 6 and Roland, but they're hamstrung by the conservatism of the market. Line 6's DT-series amps provide "true valve tone" with enormous versatility; Roland's VG-series shows what might be possible if there were even a handful of guitarists thinking creatively. Both have sold a fraction of the units they deserve to.

Variable OUTPUT impedance?

I can think of several including those from my old "stable" (they called it "resonance").

If you mean variable INPUT Z then no problem, just stick a 2.2meg pot in place of the first grid leak with say 100k slugging the bottom.

Dave.

@ Andy - many thanks for the thoughts on the scatter winding... Very interesting.

Following on from your thoughts, can we reasonably say that there is no difference at all between the Axetecs I fitted and (say) Seymour Duncans (which are also machine wound)? Provided, of course, that they have the same basic pole design and the same number of turns / output level?

If I understand your ethos of 'scatter winding means that some bit of the pickup will sound great anywhere on the neck', can we extrapolate that to say that a machine wound pickup will have a few optimal notes where it excells and the rest will sound a tad flatter? Or am I taking the analogy too far here?

Speaking of scatter winding.... I just did a complete re-build on a Wah pedal - it was a US - built Vox 847 that I got from eBay for £35 or so. It sounded pants IMO

I stuck one of these in it http://dandyjob.com/product.php?id_product=15 which is a hand-wound inductor. I also had one of the circuit boards off him and stared again, so the wah is a vox on the outside only. Results are stunning, but I can't say how much of that is the scatter wound inductor vs the fact that I've 'Clyde' spec'd the thing and done so with metal film resistors to cheer the noise levels up.

Oh what a luverly topic we have here

If I can throw a little something into the mix... Did you know that in the early 1960s, the Spotniks were the first guitar band to use radio links direct from their guitars? Their lead player was a bit of an electronics wizz and would wow the crowd by coming off stage and moving amongst them while still playing.

No worries about changing cable capacitance, microphony or dodgy leads there

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It wasn't me!
(Well, actually, it probably was)

Quote Folderol:

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Oh what a luverly topic we have here

If I can throw a little something into the mix... Did you know that in the early 1960s, the Spotniks were the first guitar band to use radio links direct from their guitars? Their lead player was a bit of an electronics wizz and would wow the crowd by coming off stage and moving amongst them while still playing.

No worries about changing cable capacitance, microphony or dodgy leads there

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That's as maybe, but how many gigs ended early when a taxi turned up outside?

Quote Gary_W:

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Following on from your thoughts, can we reasonably say that there is no difference at all between the Axetecs I fitted and (say) Seymour Duncans (which are also machine wound)? Provided, of course, that they have the same basic pole design and the same number of turns / output level?

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No we can't, and that's not what I said. What I said was that they were generally the same, which is not the same thing as identical. And I also said that the differences were subtle but significant, and dependant on the amp/fx. You originally mentioned 42 gauge copper wire, for example. Not all 42 gauge copper wire is the same, and even if you discount variations from the insulation material you still have to take into account the thickness of the insulation which can have a significant effect on the final size of the coil and it's electrical characteristics.

For example, compare 20 Axetec PAF type humbuckers with 20 Seymour Duncan bridge Pearly Gates (which is just a very accurate copy of a specific PAF in one of Billy Gibbon's Les Pauls). All of the Axetecs will be within the range of a generic PAF, but very few will be the same. With the Pearly Gates they will all be very similar indeed. And that's where you pay the premium for Seymour Duncan, the materials they select and the Quality Control that those materials go through (and the QA for the build process) means that you get a consistent and repeatable pick-up.

And to confuse matters further, the distinction between machine wound and scatter wound is pretty blurred. Some people use scatter winding to mean hand feeding the wire, others use it to mean an automated process consistently replicating the hand wound process. When I visited David White's workshop nearly 20 years ago I watched him working. He had an Atari ST controlling a bank of 4 motors turning the pick-up bobbins. The wire feeds for all 4 bobbins were linked together, he would wind one pick-up totally by hand and the other three wire feeds would follow his movements and wind exact copies. Now it is perfectly possible to record the movements of the wire feed and repeat them on a sophisticated winding machine.

Quote:

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If I understand your ethos of 'scatter winding means that some bit of the pickup will sound great anywhere on the neck', can we extrapolate that to say that a machine wound pickup will have a few optimal notes where it excells and the rest will sound a tad flatter? Or am I taking the analogy too far here?

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Again, that's not what I was suggesting or implying, it's the wrong analogy. A better analogy would be with Studio Monitors. A good studio monitor should represent all frequencies honestly, but a great monitor allows you to hear everything with greater clarity and definition. A machine wound pick-up won't have a few optimal notes, all the frequencies will be there but there will be a degree of smearing them together. The scatter wound pick-up has a little more depth and clarity in the sense that you can focus into the detail of the individual notes within a chord.

But the reason it can get confusing is that we really are talking about subtle differences here. In the real world you have to factor in the quality of your amp and your gain settings too. And to put it in context, switching from light gauge strings to mediums will make a far bigger difference to your sound than switching between such similar pick-ups.

And to take things back to the original subject of this thread... EVERYTHING about a guitar and FX/amp/speaker chain affects the sound to a greater or lesser extent. What matters in the real world is how significantly or not changing ANY of those things affects your sound in the context of how you play, what equipment you use, and what settings you use. For most people most of the time, the differences are insignificant. Guitars and guitar rigs are all about trade offs. For half of the music I like to make these things matter a lot, for the other half you can't tell the difference because of the distortion pedals, amp distortion, reverb, delays and god knows what else I slap on it.

Andy

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When the going gets weird, the Weird turn Pro.

Quote uphillbothways:

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I have to disagree. There are all sorts of really big improvements to be made that don't deviate from the traditional sound and feel we expect.

The strongest example I can give is this - why are there no amps on the market with variable-impedance inputs? We all know that impedance matching is of vital importance to a guitar's tone, for reasons you've laid out quite eloquently - a guitar, amp and cable form a complex tuned circuit.

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I don't think I once mentioned impedance matching. And I don't think we all know that impedance matching is of vital importance. I'll be perfectly clear about this, my principle knowledge is about the guitar itself and I am not great on amps. Dave, Will, and Folderol, among others, are far better qualified that I am when it comes to amps.

But I would like to know exactly what you mean by impedance matching so I can think it through. For example, a typical humbucker has a resistance of 7k to 10k, a hot humbucker from 10k to 16k. A typical valve amp has an input impedance of 500k to 1Meg. Are you suggesting that the input of the amp be matched to the pick-up around 10K, be a variable between (say) 500k and 2Meg, or a mixture of both (variable between 4k and 18k)?

Andy

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When the going gets weird, the Weird turn Pro.

Re coil winding:
Are pickups defined by number of turns or total wire length in the bobbin?

I ask because a totally "robot" winder is going to give a far, far more consistant winding tension, probably tighter as well. This means a coil of a specific turns number will be more compact, higher interwinding capacitance.

The "input/output" whichever Z question I shall wait on clarification as yourself Andy!
I would like it noted that different brands of AI's differ in input Z quite considerably. My trawl through some specs' a while ago gave figures ranging from 100k to 2meg* and yet in 6 years of reading AI reviews in SoS and other (lesser of course!) mags, not one writer commented upon the change of sound which must have obtained from his day to day amp! (guitar amps are almost all 1meg). I draw two possible conclusion. 1) Input Z has little effect so long as it is >100kish.
2)All reviewers are mutton past 3kHz!

*The A&H ZED 10 has 10meg inputs and is thus well suited to passive acoustic pups.

Dave.

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Oh what a luverly topic we have here

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Thankyou! Agreed!

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"Ignorance more frequently begets confidence than does knowledge" Charles Darwin.

Quote:

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why are there no amps on the market with variable-impedance inputs?

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Forgive my ignorance, but doesn't a buffer circuit help with this, ie the sort of thing you get in a good Roland pedal? I have a Craig Anderton book about electronics projects for guitarists and he recommends building a separate buffer unit to put in your signal chain to sort out the big losses in tone?

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"Ignorance more frequently begets confidence than does knowledge" Charles Darwin.

Quote Huge Longjohns:

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Quote:

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why are there no amps on the market with variable-impedance inputs?

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Forgive my ignorance, but doesn't a buffer circuit help with this, ie the sort of thing you get in a good Roland pedal? I have a Craig Anderton book about electronics projects for guitarists and he recommends building a separate buffer unit to put in your signal chain to sort out the big losses in tone?

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It sure would. A tin containing a TL072 and a PP3 (better 2) clipped to the strap and connected by less than a mtr of low cap' cable would make ALL the cable arguments redundant.

You want advanced guitar technology? How about some early 20th century stuff? Make said buffer a low Z balanced out and give guitar amps a balanced input!

'Twould cost peanuts.
Dave

@ Andy - thanks for the clarification

The amp I'm using does seem to love passing on all of the lovely little ringing harmonics which is why (for my ears, gear and tastes) the cables made such a big difference.

As to the Axetec and SD thing. It's odd. I've had a couple of sets of Axetecs now and in both cases I've prefered them to the Duncans I've had in other guitars.... I've got a Godin LGX-SA and I absolutely love the way it plays. Through modelling gear the SD's sound great. Through my Matamp, the Godin sounds fab until you put on one of the other guitars.... the Axetecs on a £400 burny put in a better performance to my ears in terms of the 'chimey, ringy stuff' than the Godin does which is a real shame..... They're both big old slabs of mahogany, both have the same brand of 10's on them, both have machine wound pickups that are broadly similar in the resonant peaks / DC resistance (which I take on board are only a rough guide due to the wiring harness, cable, other stuff etc).

If I am now reading you correctly, the chances of a scatter wound pickup being more harmonically rich in the way I'm describing (when paired with the right amp, gain settings etc of course) is greater than for the machine wound SD's that are in it. Whilst I seem to have misread one or two things so far, would that one be a fair comment?

Bad people here. Now causing me to look at £175 Bulldog sets and £200 Bareknuckle sets for a Godin

On the input impedence front, my (probably poor) understanding was that amps have a high input impedance and that is what a guitar likes..... The reason some pedals wreck your tone is that some have a much lower input impedance hence all your top end goes....

I make a lot of my own pedals (designs from the net, I'm not good enough at it to design my own). To go with my home brew, I'm fortunate enough to have a Carl Martin Quattro fx pedal (it's an all analogue thing with comp, distortion, tremelo and delay). This has a 1meg input impedence and a completely transparent buffer - I've tried to be able to tell the difference with this in circuit and 'bypassed' vs no being there and I can't..... Anyway, it has a buffered FX loop in the pedal as well so it's the perfect place for homebrew effects..... It takes care of all the loveliness that is impedence matching and keeps the guitar signal absoulete pristine. Well, until I jam it through a Fuzz Factory clone which kills all attempts at being subtle

Quote ef37a:

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Re coil winding:
Are pickups defined by number of turns or total wire length in the bobbin?

I ask because a totally "robot" winder is going to give a far, far more consistant winding tension, probably tighter as well. This means a coil of a specific turns number will be more compact, higher interwinding capacitance.

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Yep, you've got it Dave. A whole bunch of variables there. For a fixed number of turns, the actual length of wire will vary according to the winding tension. For a fixed length of wire, the number of turns will vary according to the winding tension. The resistance is largely a function of the wire length, the inductance is largely a function of the number of turns. Capacitance is a function of both. I know it's not quite as simple as that, but it gives us a handle on things. Most pick-ups have their DC resistance listed (easier to measure ), but most pick-up winders suggest that the most important measure is the Inductance.

The best electrical definition of a pick-up I have seen is this; An AC generator connected to an LCR network.

Quote Gary_W:

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If I am now reading you correctly, the chances of a scatter wound pickup being more harmonically rich in the way I'm describing (when paired with the right amp, gain settings etc of course) is greater than for the machine wound SD's that are in it. Whilst I seem to have misread one or two things so far, would that one be a fair comment?

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Yes, I would say that's fair. Maybe add 'focused and detailed' to the mix. But before you are tempted to spend more money, remember we are talking about subtle differences here. And trust your experience with budget pick-ups too. You will have noticed that while I am happy to say that there are genuine differences between budget, big brand and boutique pick-ups... I've never said that any is better than any other. All that matters is what works best in a particular guitar for a particular player.

The great thing about luthiery and guitar teching is that there are rarely right or wrong answers. In the final analysis all that matters is whether you have an instrument you like, or not.

Andy

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When the going gets weird, the Weird turn Pro.

One experiment I've wanted to try for years (but never had the time, money or facilities for) was wavewound individual string pickups - decades before anyone coined the term hexaphonic. For those that don't know, wavewinding is what they do on balls of string, and not only can a wavewound coil hold itself together without a former, but it has an incredibly low self capacitance. This is why the winding style is extensively used in RF coils.

The reason for the low capacitance is that there is a lot of air in the winding as it criss-crosses. This is also the only downside I know of. Such windings are far more bulky than layered or even scatter (we used to call them bunched) windings.

A related idea I had (which is probably totally impractical), was to do away with magnets altogether and have the coils as part of HF oscillator circuits. The movement of the strings would then frequency modulate the oscillators, and the strings themselves would not be subject to damping.

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It wasn't me!
(Well, actually, it probably was)

That sounds very interesting folderol. I actually saw a very brief clip of a ball of string being wound on TV a day or so ago, can't remember what it was on though. And anyone who's held a ball of string will recognise just how much structural integrity it has. Might be worth doing some more research. You certainly have got me thinking about it.

Andy

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When the going gets weird, the Weird turn Pro.

The strings will still be damped. The magnets don't generally make a huge difference to damping, compared to the physical string-and-body setup. If they did, a string's sustain would vary greatly depending on the load connected (amp or DI box). In fact the voltage produced drops significantly depending on the load (due to the pickup's impedance) but the string is not majorly affected. To test this, vary the load (variable resistor across the guitar jack) as you play the guitar without an amp. You need a very small load to make a difference - a typical amp input impedance won't make much odds.

Re your inductors driving the strings though, that's what an Ebow does. There have been various experiments on this over the years, but none really took off. Although as Zen says, we define the electric guitar sound as what we already know, so significant variations face a massive traditionalist hill to climb!

Silly thought, but you could build an electric guitar without pickups in the traditional sense.

Replace the pickup with a powerful rare earth magnet, then take the output from between the machine heads and the bridge. Probably via a ribbon mic transformer or such to get the impedance up to a halfways sane level.

The strings themselves would form a single turn 'winding'....

Now even with a transformer in there the output impedance would be more then a little on the low side, so think mic preamp rather then guitar amp input stage, but it might be interesting.

Actually, if I was trying it I would probably put a multi channel preamp right in the cavity, maybe something common base or such to handle the very low source impedance.

Lots of places to go if you are not looking for a traditional electric guitar sound.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!