Insulating baseplates with tape : why I find it discussible, finally.

[freefrog]

Got to jump in with my non-coil-centric view of single coil (let's just settle on Strat for the sake of this discussion) and Gibson-style humbucker. The aperture and general shape of the magnetic fields are very different. Someone may have done this, but try winding a humbucker so the resonant frequency is the same as a Strat pickup...yeah, yeah, the inductance is different, the height of the peak is different...but get close. Now listen. Or go back to my much earlier suggestion...wind each to low/medium impedance...low enough so the resonant frequency is at 25 kHz or so. Now listen. These two pickups absolutely do NOT sound the same. So more than the coil shapes the signature tone of a magnetic pickup.

I'm just amazed that fewer folks have actually tried this. I don't think you can understand pickup tone until you do.

I'm just a tinkering hobbyist but since 2003, I test each pickup passing in my hands with a void coil exciting its resonant peak THEN with a track recorded direct to the board: singles notes then chords, whose frequencies are stacked by a frequency analyser.

Of course, the position of the PU and its aperture have a paramount importance in the result.

Now, when I stack an “electrical” resonance on the spectrum of the related recorded track, I always see how the resonant peak of the pickup interacts with its way to “read” the strings. :-)

I'll post an example later if possible.

Thx a lot for the trick about the shielding paint and thx to all of you for the thoughtful answers!

[ScottA]

I'm just a tinkering hobbyist but since 2003, I test each pickup passing in my hands with a void coil exciting its resonant peak THEN with a track recorded direct to the board: singles notes then chords, whose frequencies are stacked by a frequency analyser.

Of course, the position of the PU and its aperture have a paramount importance in the result.

Now, when I stack an “electrical” resonance on the spectrum of the related recorded track, I always see how the resonant peak of the pickup interacts with its way to “read” the strings. :-)

I'll post an example later if possible.

Thx a lot for the trick about the shielding paint and thx to all of you for the thoughtful answers!

I would love to see that example!

[freefrog]

I would love to see that example!

Well, Scott, you've gone MUCH beyond my flawed experiments in the videos about your Zexcoils, so I'm not sure that my drivel makes sense here... but you'll find below two screenshots. I've intentionally selected "prototypical" pickups whose dual RZ is "spectacular". PU1 was in mid pos, PU2 in bridge.

Of course, I keep in mind the comb filtering due to the place of the pickup and explained here: Pickup Response Demonstration Applet






Please, consider that changing these tracks and data in "readable" pics takes me more time than desired. Thx for your understanding...

[David Schwab]

Got to jump in with my non-coil-centric view of single coil (let's just settle on Strat for the sake of this discussion) and Gibson-style humbucker. The aperture and general shape of the magnetic fields are very different. Someone may have done this, but try winding a humbucker so the resonant frequency is the same as a Strat pickup...yeah, yeah, the inductance is different, the height of the peak is different...but get close. Now listen. Or go back to my much earlier suggestion...wind each to low/medium impedance...low enough so the resonant frequency is at 25 kHz or so. Now listen. These two pickups absolutely do NOT sound the same. So more than the coil shapes the signature tone of a magnetic pickup.

I agree with you here, but my point was that you can get one type of pickup to do a pretty convincing imitation of the other by changing the frequency of the resonant peak with a filter. It's not the same, but it's kind of like when people switch out one coil on a humbucker and accept that tone as sounding like a single coil. Technically it is, and it's brighter, but it doesn't sound like a Strat. But it's often close enough for the desired outcome.

So that's why I said the dominant difference is the resonant peak, but there's lots of other differences too.

I make some bass pickups that sound very much like a Rickenbacker 4001 bass, even though they are made nothing at all like Rick pickups, and are hum canceling.

[Rick Turner]

Well, you can also just use a tunable low pass filter on a low Z pickup (or medium Z) as we did with Alembics. And you know what? Superimposing a typical high Z response curve onto an essentially flat response pickup doesn't quite get you there. Yeah, it's useful, but I never did hear an Alembic guitar sound quite like a Strat or Les Paul. And that is some of the why I got into my low Z winds on classic cores experiment...in fact it's a lot of the "why". I want to know more about what's going on underneath the filter effects of the coil.

I am utterly amazed at how much resistance (pun intended) there seems to be here to this whole concept of learning the effects inherent in the 3 D dynamics of magnets, pole pieces, and coil size INDEPENDENT from coil LCR effects. Looks to me like a lot of winders with blinders on. There seem to be two main camps here: 1) Vintage recreationists who slave over copying the past down to the color of the rust, and 2) Low Z winders who completely abandon "traditional" magnet/coil physical relationships. I started in camp 2, but eventually wanted to know more about camp 1...I felt there was more going on than is typically discussed and obsessed over. It's traditionalists vs. new technologists with very little going on between. I think there's a lot to be learned in that middle ground.

[freefrog]

Well, you can also just use a tunable low pass filter on a low Z pickup (or medium Z) as we did with Alembics. And you know what? Superimposing a typical high Z response curve onto an essentially flat response pickup doesn't quite get you there. Yeah, it's useful, but I never did hear an Alembic guitar sound quite like a Strat or Les Paul. And that is some of the why I got into my low Z winds on classic cores experiment...in fact it's a lot of the "why". I want to know more about what's going on underneath the filter effects of the coil.

I've bought a Variax500 as soon as it has been released, 11 years ago. Its modeling is supposed to mix the character of a virtual electronics with the acoustic resonance of a virtual guitar took as a whole.
It's extremely interesting to see how, with the same virtual pickups and pots, spectrum and dynamics change according to the virtual "body" selected (and according to the fictive position of the virtual pickup in this virtual body, of course).
If only the sound of the piezo transducers wasn't so prominent in each virtual model! There's a parasitic resonance somewhere around 1khz, which makes the old Variax "hollow" sounding whatever is the "model" selected (reason why I've finally fitted mine with added rails pickups + series/parallel selectors)... It seems that the limits inherent to hardware are not so easy to overcome when it comes to mimic the tone of another instrument... :-/

FWIW (probably not more than 2 cents).

[Rick Turner]

I wouldn't be quite so quick to blame the piezo transducers. You're also hearing front end buffers, A/D converters, DSP algorithms, and D/A converters. The digital world brings with it a whole range of possible "issues". Also we're really in the infancy of digital music, and the Variax system is kind of early generation stuff. If you want to hear the latest, check out the Antares AutoTune guitar system; it's pretty amazing.

[David Schwab]

I never found most of the Variaxe electric guitar models to be very convincing. But the acoustic guitars sound very good. It is very cool technology though.

The guitarist in one of the bands i play in got a Fractal Audio Axe-FX II. So far he mostly gets it to sound like the Mesa amp he replaced with the AXE-FX lol

But still, why do you need a guitar to sound EXACTLY like a certain guitar? I see absolutely no reason to do that ever. Just get a tone you like.

Some people are real slaves to having a Strat sound exactly like a Strat, etc., while the more innovative guitarist will mod the guitars to get the tones they want, not the stock tones of the guitar.

[David King]

Not all guitarist are created equal. I thank the heavens for a decent sounding guitar + rig when the player has no ear or imagination for tone whatever.

[freefrog]

I wouldn't be quite so quick to blame the piezo transducers.

I don't blame them. I suspect them to be the main reason of a prominent hollow sounding mid bump because this sound is also there when I hear the Variax unprocessed (which is possible when the "Workbench" Line6 box is connected with the guitar). There's also users who have changed their piezo's and noticed an improvement. There's finally Line6 who explained why these piezo's could generate unwanted resonances in the first generation of Variax. The new ones are supposed to avoid this issue.

why do you need a guitar to sound EXACTLY like a certain guitar?

In the case that I explained above, the resonance is really annoying on a recorded track: it's just loud and ugly. Enough to strike the listener more than the notes themselves.

That's the problem IMHHHO with such groundbreaking products : they don't always cooperate with existing effects and amps. Hence tones which are sometimes not musically satisfying. For instance, I've stuggled with an innovative "prototype" of pickup whose high frequencies were unbearable in the Top boost channel of my Vox. It was simply impossible to dial out the unpleasant part of the sound. Such a pickup would be unusable for many guitarists.

[Rick Turner]

Piezo pickup resonances are usually way out of the audio range, but with them, it's location, location, location along with exactly how they are mounted. Without examining one of these, I suspect it's too closely coupled to a resonant part of the instrument, and the pickup is just transducing what is going on there. There is what the top of the pickup "sees", and then there's what the bottom of the pickup "sees" in pressure mode piezos.

I can count on one hand the engineers who I think actually know something about how piezos work and how to interface them successfully with guitars; it's a dark art, and one not particularly conducive to small shop experimentation. It's easier with piezo film than with piezo ceramics where you are up against pricey minimum orders to even experiment, but it's still too expensive for casual hobby makers of pickups. I got lucky having access to piezo ceramic blocks in a convenient size when I was doing R&D at Gibson Labs in the late 1980s.

[freefrog]

Piezo pickup resonances are usually way out of the audio range, but with them, it's location, location, location along with exactly how they are mounted. Without examining one of these, I suspect it's too closely coupled to a resonant part of the instrument, and the pickup is just transducing what is going on there. There is what the top of the pickup "sees", and then there's what the bottom of the pickup "sees" in pressure mode piezos.

I can count on one hand the engineers who I think actually know something about how piezos work and how to interface them successfully with guitars; it's a dark art, and one not particularly conducive to small shop experimentation. It's easier with piezo film than with piezo ceramics where you are up against pricey minimum orders to even experiment, but it's still too expensive for casual hobby makers of pickups. I got lucky having access to piezo ceramic blocks in a convenient size when I was doing R&D at Gibson Labs in the late 1980s.

Thx to allow me to learn new things!