The insulated laminates are to reduce power lose in the form of heat in the transformer core. The insulation prevents eddy current circulating between laminations. It doesn't matter if the outer edges of the lamination are shorted. This would not increase the power lose much because eddy current are local short path circular currents. Not conduction.
I'm no aerodynamics engineer either, but aerodynamic lift / downforce is proportional to the square of the velocity, so in general there is very little lift or downforce from automotive aerodynamic aids until speeds get far above legal limits on public roads.
Sadly, you can still manage to get enormous aerodynamic drag, simply by having a frontal cross-sectional area the size of a barn door. Which is more or less what the Jaguar i-Barn does.
To put some numbers to it, I read somewhere that the Jaguar i-Blob is limited to a top speed of 124 mph. Using the aerodynamic lift equation (f=1/2 rho Cl S v^2), a very efficient spoiler with an area of half a square meter and a lift coefficient of unity (1.0) would generate about 95 kg of downforce, the weight of a fat man.
That sounds good until you compare it with the ludicrous 2760kg curb weight of the i-Lump. (Not far shy of 6000 lbs if you prefer imperial units. Or just about the weight of TWO Volkswagen Beetles if you prefer a historical comparison.)
This means, at 124 mph, the downforce from our hypothetical very efficient nose spoiler is a paltry 3.5% of the weight of the i-Lard. At legal speeds (i.e. about half of 124 mph), downforce drops four-fold, so less than 1% of the i-Fatty's gross weight.
Incidentally, the i-Blubber reportedly has a frontal area of cross section of about 2.4 square metres - about five times the area of my hypothetical spoiler. Drag coefficient is a claimed 0.29. Put those numbers together, and aerodynamic drag at 124 mph would be about 132 kg.
At 124 mph, it would require about ninety-six horsepower to fight that much drag force.
(And we are not counting additional drag from the enormous tyres as they thunder over the overburdened asphalt.)
For reference, the Volkswagen XL1 - an experimental project vehicle which put drag coefficient above design fads - managed a drag coefficient of 0.19, and achieved greater than 300 miles per gallon. Many of today's production cars have drag coefficients in the range of 0.22 - 0.24. Not stellar, but still considerably better than the i-Piggys 0.29.
I would love to hear actual hard numbers from the aerodynamics engineers at Jaguar who measured and wind-tunnel tested the i-Juggernaut, but I'm sure they would prefer to maintain their silence and keep their jobs.
-Gnobuddy
What seems to have been overlooked is that an important reason for welding ONE corner of a transformer is for safety. If a transformer winding shorts to the core it doesn't matter which lamination it shorts to. With a welded corner EVERY lamination will be shorted to ground, reducing the electrocution hazard. Only one corner being welded is not going to affect the transformer that much.
I've worked for two transformer companies making laminated transformers and a power supply company making their own high frequency magnetics.
A top quality transformer will be vacuum varnished for improved reliability and reduced noise output. The varnish will usually cover any nicks in the wire's insulation.
The next step down is varnish dipped transformers. The varnish doesn't penetrate as well. I tend to think, why bother.
Cheap transformers are welded together instead of being bolted together. They are often not even varnished at all, making them less reliable and much noisier
Guitar amplifiers as a rule suck. Using only a woofer is inane. To make up for the lack of treble response from the woofer the signal must be equalized and additional output voltage used at higher frequencies. The causes the amplifier to clip prematurely from high frequency content while the average volume level is still low. Adding a midrange and tweeter allows full output of the amplifier before clipping occurs.
Back in the 70's I played guitar through an Altec Lansing 1208 Bass horn cabinet with a 511B mid/hi horn with an 808-8B mid/hi frequency compression driver. I used my own vacuum tube preamplifier with a squalid state power amplifier. The squalid state power amplifier was a mistake, but I was still young and stupid then. Overall I still had a tone that I much preferred over they typical guitar amp setup. The efficiency of my speaker cabinet was so great that I was never able to play at full volume with only a 100 W amplifier.
Scott Novak
I've worked for two transformer companies making laminated transformers and a power supply company making their own high frequency magnetics.
A top quality transformer will be vacuum varnished for improved reliability and reduced noise output. The varnish will usually cover any nicks in the wire's insulation.
The next step down is varnish dipped transformers. The varnish doesn't penetrate as well. I tend to think, why bother.
Cheap transformers are welded together instead of being bolted together. They are often not even varnished at all, making them less reliable and much noisier
Guitar amplifiers as a rule suck. Using only a woofer is inane. To make up for the lack of treble response from the woofer the signal must be equalized and additional output voltage used at higher frequencies. The causes the amplifier to clip prematurely from high frequency content while the average volume level is still low. Adding a midrange and tweeter allows full output of the amplifier before clipping occurs.
Back in the 70's I played guitar through an Altec Lansing 1208 Bass horn cabinet with a 511B mid/hi horn with an 808-8B mid/hi frequency compression driver. I used my own vacuum tube preamplifier with a squalid state power amplifier. The squalid state power amplifier was a mistake, but I was still young and stupid then. Overall I still had a tone that I much preferred over they typical guitar amp setup. The efficiency of my speaker cabinet was so great that I was never able to play at full volume with only a 100 W amplifier.
Scott Novak
Depends on the tone you want. Maybe this will apply to surf music, but if you go Rock'n Roll and overdrive the amplifier, additional squawkers and tweeters will make you sound harsh, shrill and nasty.
Best regards!
I was going to write something similar, but I think Mr. Novak is having fun yanking our chains.
The alternative is to believe that he has a completely unique personal preference for a guitar tone that will force virtually every other non-deaf human on earth to run away crying for mercy, fingers in ears.
-Gnobuddy
There is more than one way to distort a signal. Driving an amplifier's output stage into clipping is one of the least flexible methods.
How an amplifier responds when it's output section is driven into clipping varies considerably between amplifier designs. When a typical power amplifier using negative loop feedback is driven into clipping, it is no longer capable of electronically filtering out the power supply hum and you will have a substantial amount of 120 HZ or 100 HZ hum mixed into the signal (60hz and 50HZ line frequency respectively). FYI, an amplifier using negative loop feedback turns the amplifier into a constant voltage regulator. When the amplifier is driven into clipping it can no longer regulate. Other unpleasant anomalous behaviors can and do occur at clipping when negative loop feedback is used. Negative loop feedback is a Band-Aid fix at best and is fraught with problems. So just say NO!
If you do the clipping at line level and also do so in a balanced manner, not only will the harmonics be mostly even order, but you also have the ability to tonally shape the clipped signal. This also allows you to drive your amplifier to higher levels before the output stage clips.
In addition to the other problems that I've mentioned, using a woofer full range also causes the treble to be very beamy and not well dispersed.
My amplifier designs are fully balanced input to output. The power supply hum is properly filtered out under any amplifier condition and it is not affected by output clipping. My amplifier is not subject to grid blocking distortion when clipping and it mainly produces even order harmonics. It's simply not as harsh as a typical guitar amplifier when clipping.
If perhaps you still want to achieve distortion by driving the amplifier's output into clipping, you do have to option of tonally shaping the output. Using a woofer to tonally shape the amplifier's output is just one of the poorest and least flexible methods to use.
Scott Novak
"You take the blue pill, the story ends. You wake up in your bed and believe whatever you want to believe. You take the red pill, you stay in Wonderland, and I show you how deep the rabbit hole goes."
How an amplifier responds when it's output section is driven into clipping varies considerably between amplifier designs. When a typical power amplifier using negative loop feedback is driven into clipping, it is no longer capable of electronically filtering out the power supply hum and you will have a substantial amount of 120 HZ or 100 HZ hum mixed into the signal (60hz and 50HZ line frequency respectively). FYI, an amplifier using negative loop feedback turns the amplifier into a constant voltage regulator. When the amplifier is driven into clipping it can no longer regulate. Other unpleasant anomalous behaviors can and do occur at clipping when negative loop feedback is used. Negative loop feedback is a Band-Aid fix at best and is fraught with problems. So just say NO!
If you do the clipping at line level and also do so in a balanced manner, not only will the harmonics be mostly even order, but you also have the ability to tonally shape the clipped signal. This also allows you to drive your amplifier to higher levels before the output stage clips.
In addition to the other problems that I've mentioned, using a woofer full range also causes the treble to be very beamy and not well dispersed.
My amplifier designs are fully balanced input to output. The power supply hum is properly filtered out under any amplifier condition and it is not affected by output clipping. My amplifier is not subject to grid blocking distortion when clipping and it mainly produces even order harmonics. It's simply not as harsh as a typical guitar amplifier when clipping.
If perhaps you still want to achieve distortion by driving the amplifier's output into clipping, you do have to option of tonally shaping the output. Using a woofer to tonally shape the amplifier's output is just one of the poorest and least flexible methods to use.
Scott Novak
"You take the blue pill, the story ends. You wake up in your bed and believe whatever you want to believe. You take the red pill, you stay in Wonderland, and I show you how deep the rabbit hole goes."
Monkey see, Monkey Do!
The status quo usually sucks. This especially applies to the world of electric guitars and high impedance pickups, which are not only problematic because of their sensitivity to interwinding capacitance and cable capacitance, but also because of their poor design, as well as being wired in an unbalanced configuration instead of balanced. Les Paul was clearly on the right track. But he didn't go low enough in impedance.
The electric guitar world blindly fails to look at the root cause of their problems and instead relies upon Band-Aid fixes that don't really solve their problems.
I rarely accept the status quo as being rational or reasonable.
Scott Novak
"You take the blue pill, the story ends. You wake up in your bed and believe whatever you want to believe. You take the red pill, you stay in Wonderland, and I show you how deep the rabbit hole goes."
"Do you know much about rock guitar music?"
"No, but I know what I like."
Les Paul guitars, OK. Les Paul's trebly, ice-picky playing tone? Not so much.
Pretty difficult to argue with someone's opinion without it devolving, but I'll wade in, having played guitar 45 years, and having built a bunch of amps based on Trainwreck, Marshall, Hi-Watt, Komet, Fender and other vintage designs.
While it is true that many less than ideal circuit design, component choice, placement and other arcane approaches tend to dominate guitar amp design even today, two generations of fantastic guitar tone have been produced primarily on these arcane designs. Ultimately, the tone more people want to hear most, one could argue, is a true measure of success, though Mr. Novak may see it as irrational. Digital modeling amps are a great example of more recent technology being used to capture those vintage tones.
Best to you
As i said, Less Paul was on the right track, but he didn't go low enough in impedance.
The same mistakes repeated over and over again don't make them right. They just become the status quo.
Most of the designs you mention also use negative loop feedback. Many of the problems caused by negative loop feedback were well documented by Norman Crowhurst in the 1950's, but most people refuse to listen. And by that I also mean that most people have no idea of what the difference between negative loop feedback and no negative loop feedback sounds like. And even then, most people that have actually done listening tests have done so with severely flawed systems rending their testing a waste of time.
You might stand a chance of modeling a distorted tone, but good luck modeling a clean tone from an excellent vacuum tube amp.
The fact is that nearly all guitar players have NO idea what their electric guitar actually sounds like. What they know is the sound produced by a severely flawed pickup design amplified and further distorted and an equally flawed reproduction system.
Most guitarists have no idea how badly coaxial cable is mucking up their tone.
The fact is that most guitarists have no idea of what their are missing. As they say, ignorance is bliss.
If you start with a system that ACCURATELY reproduces the guitar you can always muck up the signal to recreate existing mucked up tones. But when you started with a mucked up system you cannot produce an accurate reproduction of the guitar's true tone.
Most guitar pickup and amplification systems can best be described as one or two trick ponies. NOT very flexible and by and large lacking.
Scott Novak
The same mistakes repeated over and over again don't make them right. They just become the status quo.
Most of the designs you mention also use negative loop feedback. Many of the problems caused by negative loop feedback were well documented by Norman Crowhurst in the 1950's, but most people refuse to listen. And by that I also mean that most people have no idea of what the difference between negative loop feedback and no negative loop feedback sounds like. And even then, most people that have actually done listening tests have done so with severely flawed systems rending their testing a waste of time.
You might stand a chance of modeling a distorted tone, but good luck modeling a clean tone from an excellent vacuum tube amp.
The fact is that nearly all guitar players have NO idea what their electric guitar actually sounds like. What they know is the sound produced by a severely flawed pickup design amplified and further distorted and an equally flawed reproduction system.
Most guitarists have no idea how badly coaxial cable is mucking up their tone.
The fact is that most guitarists have no idea of what their are missing. As they say, ignorance is bliss.
If you start with a system that ACCURATELY reproduces the guitar you can always muck up the signal to recreate existing mucked up tones. But when you started with a mucked up system you cannot produce an accurate reproduction of the guitar's true tone.
Most guitar pickup and amplification systems can best be described as one or two trick ponies. NOT very flexible and by and large lacking.
Scott Novak
Not yet. That will happen when I'm ready to start selling my amplifier and low impedance pickups.
Scott Novak
Please stop using the Quote button when you're next in line.
Did not realize this was a rule unless you are referring to wholesale quotes of an entire post rather than properly focused quotes. One problem is that you don't know if you are next in line by the time you finish your post.
Les Paul wasn't the last person to try low impedance pickups, and neither are you, by a long shot.
Starting small, I wound my own low-impedance pickups once in the 1980s; about 2k winding resistance, a quarter of the typical single-coil. They worked, but the guitar sounded more like an acoustic guitar than an electric guitar. Useful when you want a vaguely acoustic sound from your solid-body electric guitar, but by no means capable of making the sounds I want from my electric guitars.
Let's go to a bigger example. Commercially, low-impedance magnetic pickups are routinely used in thousands of acoustic-electric guitars (Taylors, for instance), where their wider bandwidth does a better job of capturing the sound of these types of guitars.
There's more. Epiphone Les Paul Ultra models include a low-impedance magnetic pickup (the Shadow Nanomag), designed to produce vaguely acoustic-guitar sounds for those moments when you need to play an acoustic song in the middle of your otherwise electric set.
We're not done yet: Fishman Fluence pickups use a printed-circuit "coil" that's extremely low impedance, I think only a few tens of ohms. Those coils sound horrid by themselves, so a major part of the pickup design is an onboard active preamp with heavy audio filtering to make the ultra-low-impedance coils sound more like the high-impedance pickups we all want to hear.
So there are tens of thousands of guitars currently available with low-impedance magnetic pickups, and there are numerous manufacturers making low impedance magnetic pickups today.
These low-impedance pickups have not replaced high-impedance electric guitar pickups, not because everyone is too stupid to see the light, but because the vast majority of guitarists don't like the way they sound.
That's certainly true. And there have been mistakes repeated over and over, such as not using screen resistors in some high-powered guitar amps.
But once again, you are far from being the first person to have spotted these mistakes - there are plenty of both commercial and DIY amp designs that don't make these mistakes, real and supposed.
Traditional Vox guitar amps don't use negative feedback. None of my own DIY valve guitar amps use negative feedback. Plenty of DIY designs out there on the 'Web use no negative feedback.
Just for fun, a couple of years ago I sat down with paper and pencil and worked out the exact equations for NFB around an amp with a specific nonlinear transfer function, the tanh() function, which is relatively analytically tractable, while being reasonably representative of amps with symmetrical non-linearity. Then I wrote some Python code to generate plots of the output of this virtual amp when driven to clipping, with and without various amounts of negative feedback. You can look at the plots and see how increasing amounts of NFB make the onset of clipping harder and more abrupt, which are not usually desirable characteristics in a guitar amp.
So, once again, it's not just you; plenty of smart people have figured out that NFB doesn't necessarily mix well with guitar amps, particularly ones that are routinely driven to clipping.
I agree that for many years, the majority of modeled amps have completely ignored the subtle non-linearities needed to represent clean tube tone, and focused instead on kazoo-noises to excite the target market (teenage boys.)
However, the currently available Boss Katana line does a pretty passable job of sounding "tubey" on the "Clean" channel. It's not 100%, but IMO has turned the corner from "Yuck!" to "Good enough!"
Nonsense. Plenty of us have plugged an electric guitar into a Hi-Fi amp and speaker system over the years, and heard the resulting sounds. Yes, plenty of us also knew to use a high input impedance buffer between guitar and RCA input jack.
Most of us who tried this experiment found the results sounded awful. Clean tones are thin and sterile, distortion is utterly horrific and actually painfully unpleasant.
So most of us who tried this quickly abandoned this approach. Not out of stupidity or ignorance, but because we didn't like the resulting sounds.
I have encountered *one* other person online who said he preferred this Hi-Fi approach to electric guitar sound. He also said he was a novice guitarist and had very limited playing ability (which probably means he strummed open chords with the ball of his thumb, a type of guitar playing where Hi-Fi sound doesn't sound awful.)
So there you go, you're not the only one on the planet. You have at least one other person in your camp!
Severely flawed if you think of it as a Hi-Fi amp gone bad, yes.
But not flawed at all if you want to generate the electric guitar sounds that guitarists and audiences alike have come to love over the past sixty or seventy years.
Nonsense. Many, many guitarists have experimented with guitar cables of various lengths, from 1 metre (~3 ft) to 10 metres (~30 ft), and then chosen the length they prefer based on the resulting sound. And many, many guitarists have experimented with building an active preamp either into the guitar itself, or within inches of the guitar output jack, buffering the cable from the guitar pickups.
I've done both of these things myself, and I decided that I preferred the sound of the raw pickups into about 5 metres of traditional coax cable.So that's what I use now.
The fact is that most guitarists hate the sort of sounds you seem to prefer. You are, of course, entitled to your personal preferences - but that doesn't mean everyone else is too stupid or too ignorant to see the superiority of your personal preferences.
Yes, in principle. In practice, it can take ridiculous amounts of circuit complexity, or impractical amounts of amplifier power. For example, a typical guitar speaker might have a 10 dB rise in frequency response from about 300 Hz to 3.5 kHz, immediately followed by a steep treble cut equivalent to a fourth-order low pass filter (see attached image.)
Replace that "mucked up" speaker with a speaker with a flat frequency response, and your amplifier now needs ten times as much output power to generate the 10 dB peak near 3.5 kHz. It also needs a fairly complex active filter to reproduce the 4th-order lowpass characteristic.
Certainly you can do this, but it's not hard to see the attraction of just letting the speaker do it for you.
You are right about poor treble dispersion from the large guitar speaker. Like you, I also looked into using a much smaller driver for frequencies between, say, 500 Hz and 5 kHz. This is easy to do if you want a relatively flat response (which, as described above, is bad for e-guitar.) But it's not easy to do when you want that slow rise in frequency response from 300 Hz to 3.5 kHz, which is a crucial part of making the guitar tone articulate, clear, and crisp.
Quite true, but most of us do not want to hear an accurate reproduction of an electric guitar's true tone, particularly a solid-body electric guitar!
The true tone of these instruments is awful, and I say this as a guitarist who's spent thirty years of my life in love with guitars, and thousands of hours working on becoming a better guitarist.
There is considerable truth to this, but I have yet to see an overwhelmingly better alternative.
Modeling amps give you many "tricks" instead of one or two, but they have traditionally sounded like fifty different kinds of kazoo in one box. Lots of choices, but all of them bad-sounding.
Some of the newest modeling amps and preamps (like the Atomic Amps Amplifire products) are quite considerably improved over their kazoo-like ancestors, but cost more than a better-sounding real valve guitar amp. And there is the Boss Katana 50, which has many tricks in one box and sounds better than a kazoo, but doesn't sound quite as good as a '65 Princeton Reverb doing its one-and-only trick. It doesn't sound as good as an Amplifire either, but, crucially, hits a sweet spot for sound quality, flexibility, and price-point.
-Gnobuddy
Attachments
Gnobuddy - you have captured and expressed my own thoughts and experiences perfectly. I just didn't have the energy or desire to do such a good job countering the hyperbole.
Amp and guitar design (like so many other things in life) is not a zero-sum game. If one person actually can build a more effective mousetrap, it doesn't mean all other mousetraps that came before were ineffective.
Proof of concept would do much to convince others, Mr. Novak. Please do let us know when you have examples we can all judge - after 45 years I'm still interested in good tone (until my ears give out).
Amp and guitar design (like so many other things in life) is not a zero-sum game. If one person actually can build a more effective mousetrap, it doesn't mean all other mousetraps that came before were ineffective.
Proof of concept would do much to convince others, Mr. Novak. Please do let us know when you have examples we can all judge - after 45 years I'm still interested in good tone (until my ears give out).
Mod hat off.
Members report this stuff as annoying, and as such, the Mods have to deal with it. I don't think the Mods need anymore work, this forum is huge. Let's make this easier for them, not harder.
Mod hat on.
Listen to what this guy ^ says.
Yes he was.
Take a chance. 99% of the time you will be next. It's easy to go back and grab what you need if you're wrong.
Members report this stuff as annoying, and as such, the Mods have to deal with it. I don't think the Mods need anymore work, this forum is huge. Let's make this easier for them, not harder.
Mod hat on.
Listen to what this guy ^ says.
Gnobuddy - I second / third/ fourth......I totally agree with your assessment!!!
I have found that my Katana 50 sounds really good for a solid state amp. Perfect, no...but the fact that I don't have to lug around a bunch of pedals just to go play at a friends house is great too!!!
My grandfather had a saying.
"If you think you invented it.....well your probably too late as someone else probably had that idea too....its really all about who did it the best."
I have found that my Katana 50 sounds really good for a solid state amp. Perfect, no...but the fact that I don't have to lug around a bunch of pedals just to go play at a friends house is great too!!!
My grandfather had a saying.
"If you think you invented it.....well your probably too late as someone else probably had that idea too....its really all about who did it the best."
Thanks, GTKaudio and IceFyre13th!
I've been badly burned by kazoo-sounding digital amp emulations several times in the past, and have stayed away from them for some six or seven years now, waiting for the technology to get better.
And IMO it finally has. I just got a Katana 50 myself. It sits by the couch, next to my beater Epiphone guitar, ready for practicing and noodling whenever possible.
IMO it makes an excellent practice amp. The sounds may not be perfect, but they're good enough to stimulate creativity and widen my list of playing techniques by allowing me to experiment with a variety of sounds and effects, all easily available at apartment-friendly SPL levels.
-Gnobuddy
I've been badly burned by kazoo-sounding digital amp emulations several times in the past, and have stayed away from them for some six or seven years now, waiting for the technology to get better.
And IMO it finally has. I just got a Katana 50 myself. It sits by the couch, next to my beater Epiphone guitar, ready for practicing and noodling whenever possible.
IMO it makes an excellent practice amp. The sounds may not be perfect, but they're good enough to stimulate creativity and widen my list of playing techniques by allowing me to experiment with a variety of sounds and effects, all easily available at apartment-friendly SPL levels.
-Gnobuddy
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