Can someone please explain inductance to me in simple terms?

[cjenrick]

Re: Can someone please explain inductance to me in simple terms?

Look at cable TV. 1 Megahertz going down miles of coax. Sure, there are repeaters, but the frequency in that cable is 100 times that of your high notes on the guitar. If capacitance was simply lumped into the equation, then the losses would be so high that nothing would come out the other end. In other words, the coax is like a tuned circuit. You remember Guitar Slim or Buddy Guy with their 100 ft cables? How much signal did they lose? how much hi end?

What about the first trans-Atlantic telephone cable? They wrapped mu metal around the cable wire to give it more inductance, otherwise the signal loss would be to great to run the cable.

 

[PicoRiveraTele]

Re: Can someone please explain inductance to me in simple terms?

Look at cable TV. 1 Megahertz going down miles of coax. Sure, there are repeaters, but the frequency in that cable is 100 times that of your high notes on the guitar. If capacitance was simply lumped into the equation, then the losses would be so high that nothing would come out the other end. In other words, the coax is like a tuned circuit. You remember Guitar Slim or Buddy Guy with their 100 ft cables? How much signal did they lose? how much hi end?

What about the first trans-Atlantic telephone cable? They wrapped mu metal around the cable wire to give it more inductance, otherwise the signal loss would be to great to run the cable.

It's a solid established fact that the guitar cable's capacitance resonates with the pickup's inductance. I'm not too familiar with telephone line issues, but the reason capacitance is such a big factor in a guitar cable is because it's a high impedance circuit. If the pickups were low impedance, cable C wouldn't be an issue, but then again they wouldn't sound the same, either.

An analogy I like: the high impedance pickup is like a tall mountain to climb, so the currents sees this cable capacitance and decides it's the easier route to take to get to the other side. If the impedance of the pickup were low, the current can pass across the pickup easily enough, so the cable capacitance would be (almost) ignored.

 

[cjenrick]

Re: Can someone please explain inductance to me in simple terms?

You know, you are absolutely right! me bad.

if pickups had a Z of 75 ohms, you could drive miles of cable, this might be one of the reasons Les Paul invented the recording LP.

here is a graph showing that indeed, at frequencies close to that of the rez freq of pickups, the Z of coax drops and will degrade signal.

there are some cable shoot outs on youtube, hard to hear a difference but that is probably due to lousy audio quality,

so a good case of foot in mouth disease form me, sorry about that, :15:

 

[Dave Locher]

Re: Can someone please explain inductance to me in simple terms?

Cjenrick, I "liked" your post because it is so rare to see anyone admit they are mistaken OR apologize! This is the internet - the typical response is to keep flogging the dead horse and then resort to personal insults...

 

[cjenrick]

Re: Can someone please explain inductance to me in simple terms?

ill tell ya, the more i learn, the less i know, wtf? :dunce:

 

[freefrog]

Re: Can someone please explain inductance to me in simple terms?

ill tell ya, the more i learn, the less i know, wtf? :dunce:

Same thing here (especially with guitar transducers, as I said somewhere above) ! )

It's probably the case for most (if not all) human beings and it's not a problem, since it gives us occasions to discuss and to share things.

BTW, about the tonal effect of cable with passive PU's, I like this demo: https://www.youtube.com/watch?v=u2sjeVQpS94



Regarding cable emulation, the question remains to know why the PRS Sweet switch mimics 100ft of cable with a delay line, which is the equivalent of 10 small inductors in series + 11 small caps to ground after/before these inductors.

A possible answer would be that PRS opted for snobery while a simple capacitive load would have done the job.

It's not my choice since, IME, the Sweet switch gives a more natural tone than a crude 4,7nF capacitor to ground... )

 

[PicoRiveraTele]

Re: Can someone please explain inductance to me in simple terms?

there are some cable shoot outs on youtube, hard to hear a difference but that is probably due to lousy audio quality,

Guitar cables? Like they plug them in an listen? The sad thing is they probably spent two hours making that video when two hours of reading could have led them to realize such a test is misguided. This survey you posted here https://forum.seymourduncan.com/sho...simple-terms&p=4198322&viewfull=1#post4198322 is pF over "metre", and distills in data form all the difference you could hope to hear.

 

[Discharged]

Re: Can someone please explain inductance to me in simple terms?

they probably spent two hours making that video when two hours of reading could have led them to realize such a test is misguided.

How is it "misguided"..?

/Peter

 

[PicoRiveraTele]

Re: Can someone please explain inductance to me in simple terms?

How is it "misguided"..?

/Peter

It's like trying to figure out how much something weighs by lifting it and guessing how heavy it is, rather than just setting the thing on a scale and getting an exact number.

 

[Discharged]

Re: Can someone please explain inductance to me in simple terms?

It's like trying to figure out how much something weighs by lifting it and guessing how heavy it is, rather than just setting the thing on a scale and getting an exact number.

The video shows the highs are affected running a guitar through different cable lenghts. something I find extremely useful.

How does your analogy work with the given paradigm shown in the video? Or you were talking about something else? Sorry if I seem dense, but I just don't get it.

/Peter