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Post by blademaster2 on Jun 5, 2020 9:53:57 GMT -5
As I understood their statement, the authors noted that there was an initial transient from the stimulus (like a guitar pick creates) and after that had decayed then they observed that the remaining generated pickup signal waveform, now with fewer transients and easier to observe, differed from the measured string movement as a result of non-linearities in the pickup response.
The following are my thoughts, and not explicitly stated in the paper nor defendable with any measurements I have made: Assuming that the observed non-linearities are a property of the pickup response that is also present (but harder to observe visually) during the attack transient created by plucking the string, then it seems to me a reasonable inference that this generates harmonics (as any non-linearity would) during the transient, too. This would, to me, account for some of the tone of the pickup and could well be different between pickup designs and magnet materials used.
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Post by blademaster2 on Jun 4, 2020 22:45:07 GMT -5
No - in fact I have not myself shown anything, and I am not making any claim to defend. The point is that harmonics are much smaller in amplitude than the fundamental (this is something I *have* seen myself) and that is where the difference between a guitar and, say, a trumpet exist if playing the same note. So if a difference is observable in time domain as the authors indicated then I would expect the difference in tone to be audible. In fact given the characteristics of sound waves that I have seen on oscilloscopes I would expect to hear differences in tone to be audible even if they were not easily visible on the oscilloscope. Are you actually asserting that an observable effect of non-linearity in a time domain plot is not likely to be audible in the tone? As I said, I would expect just the opposite. I don't understand why you discount magnitudes in this conjecture, asserting that any change, no matter how small, must be audible. Suppose two pickup makers offer AlNiCo 5 Strat pickups, one with more turns than another, the inductance is different, but that's covered in the RLC distinction that we're discounting from the discussion, what other source of variation exists between these two pickups that you think might impact amplitude with respect to time? I do not discount magnitudes - the RLC response is clearly highly influential. I am only suggesting that other effects are being ignored if bode plots are the only analysis and comparison method.
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Post by blademaster2 on Jun 4, 2020 22:40:54 GMT -5
This is the basis of my question originally, and finding that paper seems to answer it - there *has* been work done in this area, but evidently not within this forum. Interestingly the authors used a Seymour Duncan single coil pickup for their experiment, which was what I used in my aforementioned home experiment with body woods. I can assert that I am not alone in saying that pickups respond non-linearly, and unless the cause of this non-linearity is identical for all pickup designs, which I highly doubt, then it is quite reasonable to expect different pickup designs to introduce harmonics in slightly different ways and therefore to sound different. I am prepared to accept the possibility that these differences are subtle. I don't mean navel gazing in a bad way, I ponder it often, but being perfectly honest, I think on my part, and others part, it's motivated by a wish for their to be a difference, and not the likelihood of their being a difference. I don't know the specifics of their experiment, but there is a known reason that the harmonics dacay more quickly than the fundamental; the rigidity of the guitar string. The higher harmonics are physically more narrow than the lower ones. The string is effectively more stiff from the perspective of those narrow harmonics. Some of the energy gets transferred to the lower harmonics, and some is lost as heat. Maybe their experiment is talking about something else, I don't know. Lots of things make a difference, but not everything can be heard. For every ten observed difference, on average, only one of them is genuinely audible. The threshold of human hearing is about 1dB difference in quiet conditions, 2dB in normal conditions, and higher in the midst of cacophony. What makes this sort of investigation difficult, such as determining the significance of pickup microphony, is not discovering whether it happens at all, but discovering if it's audible. That's what makes the wood inquiry so unlikely, being familiar with what sorts of changes result in what sorts of amplitude changes, and realizing that the odds of wood type affecting >1dB changes somewhere along the functional frequency range, all else being equal, is very low. I, too, have pondered it a lot. Years ago when I built my first guitar I assumed that the wood made zero difference in the tone. It was only when I experienced surprises (I will not go into them) that I became convinced the other way. I was certainly not the victim of confirmation bias. My more recent experiment, much more controlled, again convinced me of a difference due to the wood but it also showed me that this is rather subtle compared to, say, the location/shape/amplitude of the response peak (however from the plots you have generated I observe that once the pickup is loaded by the cable capacitance these differences in peaks become far less pronounced). Despite being convinced of the subtle influence of body wood on tone, as I have become over the intervening years, I have no skin in this game. Same goes for pickups and the existence or nonexistence of audible non-linearity on tone. This will never be my career, and I am simply looking for answers to better understand our instrument. To my ears the timbre of the attack varies for different pickup designs, and it sounds more complex to me than a simple frequency response difference. PIM might explain it but I cannot prove this. On the other hand it may well be shown that the amplitude response of pickups over frequency ends up remaining the only characterization worth pursuing in this forum, however I would suggest folks track down that paper to see the specifics of their experiment (it was a reasonably controlled lab experiment involving two types of stimulus with metal moving in front of the test pickup). The fact that the authors observe (in time domain) and even mathematically model non-linearities of the pickup response tells me that it is worth looking into it further, if only to be complete in the analysis and modeling of pickups.
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Post by blademaster2 on Jun 4, 2020 22:21:21 GMT -5
it is quite reasonable to expect different pickup designs to introduce harmonics in slightly different ways and therefore to sound different. I am prepared to accept the possibility that these differences are subtle. You have not shown that the non-linearity has any significant effect on the sound. Seems premature to suppose that there might be differences between pickups. No - in fact I have not myself shown anything, and I am not making any claim to defend. The point is that harmonics are much smaller in amplitude than the fundamental (this is something I *have* seen myself) and that is where the difference between a guitar and, say, a trumpet exist if playing the same note. So if a difference is observable in time domain as the authors indicated then I would expect the difference in tone to be audible. In fact given the characteristics of sound waves that I have seen on oscilloscopes I would expect to hear differences in tone to be audible even if they were not easily visible on the oscilloscope. Are you actually asserting that an observable effect of non-linearity in a time domain plot is not likely to be audible in the tone? As I said, I would expect just the opposite.
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Post by blademaster2 on Jun 4, 2020 18:59:19 GMT -5
Hello again,
I will ignore the "naval gazing" comment, but I will note that I have myself heard differences (albeit subtle ones) when experimenting with different body woods in the most controlled manner I could achieve. No one can convince me that I could not hear a difference, and I have no agenda here.
I found and read the following paper:
NON-LINEAR IDENTIFICATION OF AN ELECTRIC GUITAR PICKUP, by Antonin Novak et al, published in Proceedings of the 19th International Conference on Digital Audio Effects (DAFx-16), Brno, Czech Republic, September 5–9, 2016. In the paper some experiments and measurements were made that showed, through simulation that matched experimental results, that the identification of pickup non-linearities was reasonably well modeled using a simple Hammerstein representation. This model uses a non-linear element followed by a linear filter element.
In this paper, the authors state that:
" ...the magneto-electric conversion done by the pickup is modeled using static non-linearity followed by a simple derivative. The static non-linearity represents the non-linear relation between the string displacement and the magnetic flux which can be evaluated using computer simulations and implemented as an exponential or N-th order polynomial ."
Regarding their experiment, the results of which the paper shows matched their Hammerstein representation model rather well, the authors noted the following:
"As expected, the string displacement is distorted just after the excitation. It becomes less and less distorted as the harmonics of higher orders fade with time. The output signal of the pickup exhibits the same kind of behavior with time. One can notice that the output voltage is more distorted due to pickup non-linearities. The displacement signal measured with the vibrometer is then used as the input of estimated parametric Hammerstein model of the pickup and both measured and synthesized pickup outputs are compared on the same graph .... The difference between estimated and experimental signals is plotted .... showing that the model succeeds in describing the non linear behavior of the pickup when used in realistic conditions."
This is the basis of my question originally, and finding that paper seems to answer it - there *has* been work done in this area, but evidently not within this forum. Interestingly the authors used a Seymour Duncan single coil pickup for their experiment, which was what I used in my aforementioned home experiment with body woods.
I can assert that I am not alone in saying that pickups respond non-linearly, and unless the cause of this non-linearity is identical for all pickup designs, which I highly doubt, then it is quite reasonable to expect different pickup designs to introduce harmonics in slightly different ways and therefore to sound different. I am prepared to accept the possibility that these differences are subtle.
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Post by blademaster2 on Jun 4, 2020 16:38:28 GMT -5
Okay, I guess I will never obtain consensus from the forum on any non-linearity becoming influential in the tone of a pickup.
So if the wood makes zero difference (a statement that I do not personally believe), and pickups are such simple gadgets that they essentially only exhibit the frequency response characteristics of a theoretical RLC circuit loaded by a guitar pot and capacitive cable, then any of the differences between all solidbody guitars should be able to be synthesized by adjusting the parameters of an active filter. But unless a magnetization curve can be produced and to show on it where the permanent magnet strength of the pickup sits, and the excursions in the emanating field from that magnet due to string vibration from that highly-biased point in the curve can be shown to be locally very linear in the generation of the electrical signal, I will have difficulty accepting all of that.
Personally, with all of the guitars I own and have played it does not feel nor sound as simple as that to my senses.
I can, however, accept that with the myriad of factors in a guitar, from wood and body construction to scale and strings and pickups, nothing alone can be claimed to dominate the resulting tone. No instrumentation or simulation will be convincing to me (I could not tell the difference between a celtic harp compared to a guitar if I were to look only at waveforms and spectral measurements).
So, to summarize, I understand that there *have* been experiments performed to detect the production of harmonics due to PIM from pickups and that they indicated that the pickup response is essentially perfectly linear - at least as far as the instrumentation can show. Is that correct?
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Post by blademaster2 on Jun 4, 2020 8:37:55 GMT -5
Understood.
So if the low end is flat and invariant between pickups, then we conclude that any guitarist who mentions low end response of a particular pickup is only able to hear a different in the mounting stiffness of the pickup into the guitar and nothing about the pickup design itself. I can accept that.
If the peak is only a theoretical RLC resonant peak, then again there are not many differences between pickups except for the amplitude of this peak and its width, which is influenced by the coil wire resistance (damping, as you said). The magnet material and how much of it is present has an effect on eddy currents, and that effects the peak amplitude through damping - but nothing else ... or is that wrong, and if so what other response would be affected?
The roll-off will always be the 40 db/decade of a theoretical RLC circuit.
That means that only difference, and the only figure of merit (if I can call it that) of any pickup, is the amplitude and shape of the peak. We all ignore the effect of the body and mounting in these characterizations (and I will not spark another tonewood debate here, especially since the pickups are tested on the benchtop).
So why are there so many pickups on the market, and so many perceived differences between them?
To me there still seem to be other factors coming into play. If you look at hysteresis plots of magnetic materials there are few regions where it looks even somewhat linear but I would expect any small non-linearity will introduce harmonics that may not be easily detected on a time domain or frequency domain plot. They would be there, but I disagree that we should be able to see this distortion on a time domain plot. Similarly a frequency domain plot (bode plot) only looks at amplitude response to pure swept sinusoidal input and ignores distortion and other harmonics. Human hearing detects attributes in a waveform that human eyes looking at instrument displays cannot. I am not referring to saturation/desaturation of the magnet material, which I agree likely requires a much stronger field waveform than we see in a guitar, however being permanent magnets means that the magnet material has already been driven pretty far up this magnetization curve and remains there, where it is certainly not a linear portion of the curve.
Perhaps your suggestion of introducing a signal of a very pure sinusoid on the exciter coil and looking at the spectral response of the pickup at that one frequency, other frequencies could be seen due to any non-linearities. This would also, I expect, be different depending on the amplitude of the exciter coil input so it would need multiple amplitudes for each frequency tested. If this showed nothing visible on the analyzer it does not convince me that harmonics produced by the material are not audible - non-linearities are producing harmonics whether or not we can easily see it in instrumentation.
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Post by blademaster2 on Jun 3, 2020 21:26:45 GMT -5
Hello,
I have been impressed by the rigor of the testing and characterization that many of you have performed on pickups. As I understand it these have dealt exclusively with the frequency response, usually looking for a pronounced peak response before rolling off, and I infer from the various posts that the higher the peak the better (or more desirable) the pickup is in many people's view.
Has anyone been performing any testing on the linearity of the response over frequency as a function of stimulus amplitude?
Peak response to a sinusoidal stimulus is one very interesting and important attribute, but the tonal response of a pickup must be at least somewhat influenced by the amplitude/magnetization linearity (more likely the non-linearity, given the metals used for pickup magnets) and hysteresis. These non-linear effects would introduce additional harmonics. Many guitarists will mention the bass and mid response of pickups, and whether pickups are warm or edgy (and I am sure I am missing a large number of the descriptors in this sentence). I expect that these characteristics are strongly influenced by pickup response linearity (probably over frequency if it varies, but I do not know that off-hand), and the resulting tonal characteristics will clearly be a factor of how strong the player picks the string and of the pickup height.
Hysteresis might be harder to test for a continuous-wave vibration source using the method I have seen being used here, but non-linearity and the resulting introduction of harmonics seems plausible especially where the stimulus coil is 'air-core' and therefore linear at the input.
Just a thought ....
P.S. If this has been done extensively and I missed it ... please accept my apologies (and please also show me where this is located)
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Post by blademaster2 on May 30, 2020 22:24:29 GMT -5
Looking terrific. Nice luster on the finish, too.
Looking forward to seeing the completed item.
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Post by blademaster2 on May 23, 2020 10:49:36 GMT -5
Because doing it right would cost more money. Not a lot more, but when you're building lots of guitars, it adds up. Just for example, let's say, between the US-built PRS guitars and the imports, they produce 50K guitars per year (I have no idea if that's a realistic number for PRS or not, just by way of example). Let's say that the extra labor to apply a second coat of shielding paint, and the extra paint, plus the ground wire and labor to wire it, cost $2 US per guitar. That's an extra 100 grand to the bottom line every year . . . In fairness to PRS, they are not alone in doing this, lots of other mfrs do the same. Looks good to the eye so you think it's shielded, but does nothing. Fender puts a useless piece of foil on the backs of Strat pickguards, for example; it doesn't even cover the whole underside much less connect to anything. many thanks! I cannot speak for Strats without taking a look, but I have a guitar that does the same with the foil under the pickguard. The collar of the potentiometers at the base of the threads is metal and electrically/structurally connected to the casing, so when the grounded potentiometers press against it with the compression of the nut and washer it forms a pretty reasonable connection. It is not a full Faraday cage but I am of the understanding that it does reduce noise from EM fields that are incident from many angles. I am curious now about PRS and what they do for their shielding, since it seems pointless to paint on anything internally if it does nothing at all. However I have no PRS available to me to investigate.
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Post by blademaster2 on May 23, 2020 5:10:21 GMT -5
Well that is not bad at all - still such a shame about the bust-through.
[Incidentally, your tiles are the exact same as my home had, so I gather your house was built in the 1950s?]
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Post by blademaster2 on May 22, 2020 7:14:54 GMT -5
Oh man! That has got to hurt after all of the careful work you did. I feel your pain.
Needless to say you are going to use an opaque finish, which I hope was your plan all along.
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Post by blademaster2 on May 18, 2020 6:40:43 GMT -5
also for the record i doubt you actually *want* all three pickups in parallel. will be SUPER quiet and thin compared to other combinations (if we're just using dcr as a baseline, three 7k pickups in parallel has a dcr of 2k33. i guess some guys like that but I'm not sure i would) welcome welcome welcome I have a guitar, a Strat copy with a label of Northern II, that has just that on one of its settings: all three pickups in parallel. It does sound thinner and has even more 'quack' than a Strat on switch positions 2 or 4 and I can imagine that some folks might like it for the same reasons. As expected it is a little quieter than other settings, but not a lot quieter and it is definitely usable. I like it myself as an option on occasions.
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Post by blademaster2 on May 12, 2020 17:57:47 GMT -5
I generally avoid washers that bite into the wood or cause high compressive force. When I tighten pots I usually press the pot from the back as I tighten the nut from the other side. Once it starts to grip the wood on the inside I usually have no trouble from then on.
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Post by blademaster2 on May 12, 2020 8:01:57 GMT -5
For the guitars that I built I *always* used to drill the hole slightly smaller than I wanted, and then do the sandpaper-on-a-dowel step. The dowel would be around 2/3 the size of the hole.
I would mostly sand in a circle by turning the dowel (or pencil or pen) and moving it in a circle at the same time, and make only small motions up and down. That way I would minimize the chance of splitting the wood (although I used fairly fine sandpaper for this). This gave me very smooth holes and a perfect fit for the controls to slip through. It is also a good idea to very slightly sand a curve into the wall of the holes so that the threads of the controls are less likely to catch on the wood and cause splitting either on installation or on removal.
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Post by blademaster2 on May 3, 2020 11:19:06 GMT -5
Hmm... last night after failing twice to solder to my sanded ground washer, I have the idea that maybe the solder doesn’t stick to my small wedge tip bc it is a gold/dark-yellow material. The solder easily sticks to my large silver-colored wedge tip. And the end of the small pointed tip is also gold/dark-yellow material. What it that goldish material? Am I right that solder doesn’t stick to that type of material? If so, why is that material on the end of tips packaged with a soldering tool? Guess I need to buy new tips? Also, twisting ground wire-ends together before soldering is a bad idea bc that prevents the wire’s contact with the solder point? <harder to heat up... Is it better to make many different solder connections near each other to make the star ground point? Serious questions; making sure I’m thinking correctly. I, too, am struggling this week with soldering to larger pieces of metal. Many irons cannot maintain the temperature to a melting point for the solder when there is a lot of metal to suck away the heat. If you cannot heat up the part fast enough to melt the solder where needed you end up keeping the tip on the work for too long and the heat then goes everywhere and might damage or melt other parts farther away. Your sanded washer might also need a lot of heat to solder properly. The tips also can degrade due to corrosion from the flux, and they are usually only good when they remain silver with solder on their ends. Once the surface corrodes and flakes off it is usually not possible to get good results. [For the connections to a stereo power amplifier I am rewiring right now, I actually resorted to making connections to a bus bar - the output signal node - by suspending the bus bar (14AWG solid wire) with a clamp, and having my son heat up the metal with a plumber's torch while I applied the solder using my 140W gun. It was awkward, but the fillets were beautiful when I was done. When I installed this into the more constrained heat sink assembly I could not use a torch because of electronic parts nearby, and one iron would not provide enough heat, so I used two irons at the same time and it did the job - barely.]
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Post by blademaster2 on May 3, 2020 10:59:08 GMT -5
You guys will be ashamed of me. I chickened our and went with Seymour Duncan’s. SH-6, a Staggered Quarter Pounder and a Pearly Gates Bridge. I love it. Put a phase switch on the Quarter Pounder. Thanks for all your help. I almost went with the Bensons but I had the SH-6,Quarter Pounder and Pearly Gates that I bought all used. I was looking through my parts and I figured what the heck, those three ought to make a nice combination. They do... I would say that whatever you like, and produces sounds that match your style, is the best choice for you. I avoid all of the guitar fashion and trends myself. Boutique or not, there are only a finite number of innovations and variations in a guitar pickup that can be made. I am very pleased with all of my SD pickups, and my Tone Rider pickups (despite being Chinese-factory made), and even my 1979 DiMarzio Dual Sound pickups. None are "boutique" brands. I remember when everyone was telling me to install a preamp, or get active pickups like EMGs, and replace all of the hardware on my guitar with brass. I did neither and never regretted it.
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Post by blademaster2 on Apr 30, 2020 17:12:02 GMT -5
I agree that the acoustic contribution compared to the magnetic contribution would be minimal - unless the amplifier gain in the room created a much louder acoustic signal that was then picked up microphonically.
Based on this, do you accept that Brian May's guitar as depicted in the movie Bohemian Rhapsody could be used as a microphone for Brian to talk back to the studio control room through it? I still have a hard time imagining that those Burns pickups, even the middle one that was not potted, could be so microphonic (but then why would Brian not have said that it was not accurate when they made the movie?)
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Post by blademaster2 on Apr 18, 2020 9:51:08 GMT -5
Hear Hear!
Now about those guitars, for which we all share our love ....
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Post by blademaster2 on Apr 16, 2020 20:47:59 GMT -5
I might be less qualified to comment on the others who test these things all the time, but I am still pretty pleased with the sound of the Seymour Duncan SSL-1 single coil pickups I have on two of my guitars. I also was impressed with the thin 'stratty' tone of the Tone Rider pickups that I have on another of my guitars (a strat copy).
For humbuckers, my experience is less broad but I remain pretty happy with the Seymour Duncan Black Winter pickups (and using them in split coil mode also) that I bought a few years ago. Having said that, all of the humbuckers I have ever tried seem to be a little dull and muddy compared to the single coils, so if there is another humbucker out there that is more crisp I am willing to try it. My first guitar used DiMarzio Dual Sound pups an they also sounded good to me.
So those are my 2 cents worth.
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Post by blademaster2 on Apr 15, 2020 17:00:16 GMT -5
Hmmm. That video is okay but a few items there would alarm me. You do not usually want the tip as hot as you can get, for reasons I already mentioned (but the wire he was soldering is not likely to be hurt). The iron tip he uses looks *filthy*.
I get my iron to heat up the part so that the solder melts onto the part just as he says, but first I tin the soldering iron tip with a small amount of solder so that its thermal connection to the part and therefore its ability to transfer heat to it is improved. You do not want to spend a long time heating things up because then the added heat travels everywhere and everything else starts to get hot, which is how damage can happen to the other parts farther away (i.e. like the volume control parts). Also, the solder will not flow "toward" the heat source, but rather it flows along the metal up or down with the heat and the flux like capillary action (which is why I also use separate flux in addition to the flux in the solder core). Good flux and cleanliness are key to getting a good joint as much as the heat is.
[BTW, I am not a soldering expert nor am I certified to the NASA standard, but I have done soldering that has passed NASA inspection and is currently orbiting the Earth.]
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Post by blademaster2 on Apr 15, 2020 15:54:51 GMT -5
There is a range of soldering temperatures used, but 900F seems on the high side (I had a PC board manufacturer express surprise when I set an iron to 800F, saying it should have been below that). It will indeed drop once the solder has started to accept heat from it to melt, but that seems still on the high side. It could be a function of the thickness and mass of the soldering iron tip, too, but you probably only get good temperature regulation in the temperature-controlled tips of more costly soldering stations and not the soldering pens that just dump power into a heater without a thermostat.
Having said all that, guitar parts are not as fragile and sensitive to heat shock as tiny ICs and chip-type capacitors and resistors so as long as the soldering is done quickly it might not be a concern.
There are other methods to maintain a clean tip besides the damp sponge, such as a bunch of curled metal like steel wool that scrapes off the flux, but a NASA-certified inspector with whom I worked was perfectly happy with the sponge (he insisted that the sponge be very clean and rinsed off before and after each use). His primary concern was cleanliness for the solder and the joints not becoming contaminated.
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Post by blademaster2 on Apr 15, 2020 13:22:22 GMT -5
Kidding aside, I knew kids in highschool who would chew on solder. I can only imagine how much they damaged their brains with lead poisoning.
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Post by blademaster2 on Apr 15, 2020 13:13:43 GMT -5
That does not sound normal. The solder itself would not be turning black, but the flux might be. A higher wattage iron usually provide more heat energy to maintain its temperature while more solder is being warmed up and taking away that heat, but not by going hotter. Higher wattage irons usually are larger with more metal at the tip and therefore more mass to store heat energy, and that way they maintain their temperature closer to the melting point as the solder takes away that heat.
When I solder I actually use flux as a separate thing in a squeeze bottle in addition to the flux in the solder core. Mildly activated rosin flux (RMA) is able to be left on the metal and will not be corrosive so you need not clean it (other types of flux might eventually eat away at the metal and should be cleaned off after soldering). Also - clean the soldering tip using a moistened sponge after every time it melts solder, and after you are done, so the flux will not remain there and oxidize or corrode the tip.
Digikey has wire-type, flux core solder. Personally, I would also choose Sn63Pb37 leaded solder rather than lead-free since it melts at lower temperature and is easier on the parts (just wash your hands after touching it to avoid lead contamination). I have purchase many brands, but Kester brand solder like their 24-6337-9756 seems reasonable and Digikey has it in stock and can ship to you.
Also, whatever you get make sure it is for electronics and not acid-core plumber's solder.
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Post by blademaster2 on Apr 8, 2020 16:56:50 GMT -5
Right, and for me, too as I was never coordinated enough to do that cool pick/swell effect that some do so well (like Van Halen's "Cathedral"). I usually have it on full volume, so I would probably be as well off with a linear as Audio if I was inclined to do that.
I think the mid point is SQRT(10), or just above 3 (slightly more than 3.16) on the log scale.
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Post by blademaster2 on Apr 8, 2020 10:27:18 GMT -5
Linear versus Audio taper will influence how fast the volume goes up as you turn the pot, but both will work well and give you 0% to 100%. It depends on your preferences. Audio taper was developed so that the perceived volume change would be even as you turn the dial. Guitarists might want something different, especially if they regularly use the volume knob for swelling notes after picking them because it might be preferred to have the volume swell more rapidly at the beginning of the turn than an audio taper will provide. The trade-off is that the finer adjustment capabilities for lowering volume settings is a lot more sensitive as you turn, and if it was that way on an audio system it might be annoying.
The actual full-scale resistance will have a tolerance on it, so your 514k pot sounds like a regular 500k pot and your particular one is off by being only slightly above that specified value.
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Post by blademaster2 on Mar 30, 2020 12:27:47 GMT -5
And there are countries that write backwards. That for me is the only real problem with the ascendency of the Chinese influence (not to mention the associated crippled keyboards). Ever see a southpaw trying not to drag his or her hand over wet ink? It's daft. Their choice of course but painful to watch. Of course there are better ways to accomplish anything, and if a southpaw gets together with a right-handed guitar lifestyle, he or she exponentially widens the choice of instruments and may well save a little too. Better? not necessarily for the individual, but bringing together both views, if a left-hander can be tipped over into travelling the other path from the get-go, it's proof of the "it doesn't matter- it's all down to dexterity" concept and dexterity is subsequently improved in the dormant "unnatural" hand at the same time. Lots more guitars to choose from. Win win. So no, I don't agree that imposes upon the neophyte by an elmer. The noob always retains the right of self determination. If'n you go to someone for advice and choose to ignore it, fill yer boots but don't expect that person to waste time on offering advice again down the line. Ever watch Steve Vai with the Heart Guitar? And like the piano, when did you last see a left handed fiddle player in an orchestra. PPE doesn't look too good in such an ensemble. If I could change anything about the Strat, it would be the Tele ;<D e&oe ...There are a number of examples of well-regarded guitarists who are left-handed but learned to play right-handed (and if *I* was well-regarded I would add my name to that list, however, .....): - Steve Morse: When I asked him about it once he said that his "picking is still weak" - and I almost laughed out loud, and told him that he is one of the best nonetheless. - Rik Emmett (from the Canadian band TRIUMPH): I asked him about being a lefty and he said that he started at first playing 'upside down' when very young but then his guitar teach suggested that at the beginner stage it is not much different either way, so he learned to play right hand guitars. He said that although picking was a challenge at first, he later found that his left-hand technique had an advantage compared to right handed players. - Joe Perry - Duane Allman - Gary Moore - Billy Corgan - Mark Knopfler
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Post by blademaster2 on Mar 23, 2020 14:53:08 GMT -5
Agreed. Grounding pattern importance arises over larger distances and/or where there is enough return current flowing through the 'ground' (which should have zero current) that the difference in the reference voltage from location to location causes a noticeable signal. The guitar cavity, and the current flowing, is small enough that either of them is probably okay, although in theory I expect a star ground connected only at the jack is the best configuration.
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Post by blademaster2 on Mar 17, 2020 16:20:32 GMT -5
I spent a while yesterday debugging my 1970-era AMPEG V4. It suddenly sounded very dull and lifeless on Channel 1, and I first suspected the preamplifier 12AX7 since Channel 2 was fine. Opening it up, swapping the preamp tubes between the two channels showed that it was not the tubes (although the two had noticeably different tone, which surprised me that I could hear a difference. One was more edgy and the other more clear and crisp but both sound good). I ended up opening it up and spraying cleaner into the controls, which seemed to correct the initial problem I had. The thing is so darned heavy, even doing that is a major undertaking, but it is worth the effort. (It is still in excellent condition). Someday I might need to do a full re-cap, which will be very involved ... I have the sister to that. A V4b. Same amp, minus the sensitivity switches and reverb, plus an 'ultra-low' switch. I love the tone controls but what were they thinking, using linear pots for the volume controls? Ugh. Stellar cleans but don't try to drive it into power amp distortion. Your ears will bleed before you ever get close. And yes, it's a beast at roughly 65 pounds. But it could be worse. I never owned an SVT but I did some repairs on one for a friend. 85 pounds. Oh my aching back! I have actually modified my AMPEG V4 to reduce the volume to around 1/20 of the signal level. These mods are completely reversible, but they permit me to turn it up and get a good edgy distortion from the preamplifier stage at around 7-8 without attracting the police. It is still pretty loud, but usable if I was in a jam session or a small club. Sadly, at home it is still only used at those levels when the wife is out for obvious reasons. When I first bought this amp I was a kid and wanted a Marshall-type crunch, which this amp is not going to give and I was disappointed. But now I appreciate its 'smokey warmth' and cleans (and I have since acquired a Marshall combo, a VOX AC15, and I plan to round it out with a Fender someday).
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Post by blademaster2 on Mar 3, 2020 15:52:19 GMT -5
All the best for a happy future together.
I expect your activity in guitar/amplifier related areas might decline for a bit. All good, of course.
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