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Double P, reverse double P or both?


baa

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2 hours ago, baa said:

Seems that I might have to do some trial and error...🤔

In the original guitar humbucker the coils were wired back to back (either series or parallel) and the magnets in each bar reversed otherwise the string signal from each half would cancel out. The signal from each half are  virtually identical, but in a neck and bridge mix the signals are different so the situation is slightly different.

 

 

Humbuck.jpg

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16 minutes ago, bloke_zero said:

Awesome! Looks HEAVY (in concept I mean not weight). Will you be exhaustively documenting your findings with high quality audio?! Pretty please? 🤞

Unfortunately my computer burned, so I have no recording possibility. 😢

It will only be my subjective opinion.

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On 07/11/2021 at 23:50, pfretrock said:

It seems that Leo thought the magnet polarities did not affect the humbucking. But clearly the magnet poles were different in each half in Fig 2 and 5.. This is a happy accident. Everyone copied his assembly.

 

From the Patent:

 

"Although the voltage induced in coils 41 and 44 due to vibration of an associated string 16 are additive, the violtage induced in such coils due to the effect of an extraneous field , such as that produced by a power line, are in a bucking relationship. This is because the coils 41 and 44 are reverse wound relative to each other, and the magnet polarities are not important in regard to extraneous fields"

 

Indeed, hum is caused by an electromagnetic field not a magnetic one.

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On 07/11/2021 at 23:50, pfretrock said:

It seems that Leo thought the magnet polarities did not affect the humbucking. But clearly the magnet poles were different in each half in Fig 2 and 5.. This is a happy accident. Everyone copied his assembly.

 

From the Patent:

 

"Although the voltage induced in coils 41 and 44 due to vibration of an associated string 16 are additive, the violtage induced in such coils due to the effect of an extraneous field , such as that produced by a power line, are in a bucking relationship. This is because the coils 41 and 44 are reverse wound relative to each other, and the magnet polarities are not important in regard to extraneous fields"

 

Indeed, hum is caused by an electric field not a magnetic one.

Edited by Stub Mandrel
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Got the bass back yesterday and compared it with an original.

Only a fast comparison through an Amplug Bass. But there was a difference, more well defined somehow.

But that can be differences in strings, serup and such, so i'm going to find a way to record so I can compare the different placements in the same bass.

 

20211114_202523.jpg

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On 12/11/2021 at 11:46, bloke_zero said:

Awesome! Looks HEAVY (in concept I mean not weight). Will you be exhaustively documenting your findings with high quality audio?! Pretty please? 🤞

I managed some quick and dirty recordings in an old laptop  with audacity.

 

I shifted the pickups without even loosening the strings, so everything else is identical.

https://www.dropbox.com/sh/69pd1n90qvn6pkf/AADdZlEzP_DghSFko7gPjjX0a?dl=0

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On 19/11/2021 at 21:34, baa said:

I managed some quick and dirty recordings in an old laptop  with audacity.

 

I shifted the pickups without even loosening the strings, so everything else is identical.

https://www.dropbox.com/sh/69pd1n90qvn6pkf/AADdZlEzP_DghSFko7gPjjX0a?dl=0

Wow - thanks! Really striking how much difference there is between the configurations. I'll be back - with notes! 

Right away the difference between the two neck positions is huge - I'm assuming they were all recorded at the same volume?

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3 hours ago, bloke_zero said:

Wow - thanks! Really striking how much difference there is between the configurations. I'll be back - with notes! 

Right away the difference between the two neck positions is huge - I'm assuming they were all recorded at the same volume?

You assume right 🙂

And i was careful to keep the height of the pickups the same in all positions.

I played every take with the same attack (as best i could).


 

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I really appreciate the opinions I get here. 😀

I've been playing VP-710B since the early 80's and i'm a bit stuck in my ways.

So I was concerned that was too biased.

But I feel that it was the right thing to do, even though my other five will stay original.

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Just to re cap on pfretrock's wiring diagrams - how have you wired these two pairs of pups ?  could you draw this out for us (me) just want to check back over what i did on my five string pictured above. My pups do have reversed poles on each pair, so a north and a south on each set, but as i later changed from vol, tone vol, tone to installing a pup balance pot So this is now Vol, balance and tone, tone. Could someone just reasure me to how this should be wired and i'll go check and draw mine out.

I just wondered but i guess if wrong it would either be a dead short or hum. I was thinking of changing this back to my original pot layout but I always find i prefer any bass with two pups to have them both on full anyway 😄 the two controls interacted and each tone also affects output of the overall sound.

 

Cheers  

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1 hour ago, deepbass5 said:

Just to re cap on pfretrock's wiring diagrams - how have you wired these two pairs of pups ?  could you draw this out for us (me) just want to check back over what i did on my five string pictured above. My pups do have reversed poles on each pair, so a north and a south on each set, but as i later changed from vol, tone vol, tone to installing a pup balance pot So this is now Vol, balance and tone, tone. Could someone just reasure me to how this should be wired and i'll go check and draw mine out.

I just wondered but i guess if wrong it would either be a dead short or hum. I was thinking of changing this back to my original pot layout but I always find i prefer any bass with two pups to have them both on full anyway 😄 the two controls interacted and each tone also affects output of the overall sound.

 

Cheers  

I can't help you, sorry.

BBQV did all the routing and soldering. And he soldered everything back as it was from the beginning. And when I shifted the pickup-positions i just moved them sideways with the leads still attached.

So its basically the same design as in a Les Paul.

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On 12/11/2021 at 19:33, Stub Mandrel said:

 

Indeed, hum is caused by an electric field not a magnetic one.

 

Are we talking about 'mains' related hum here - '50Hz' noise + harmonics (100Hz is often the largest component due to rectification) ?

Adjust frequencies for '60 Hz' territories of course !

That interference is primarily magnetic field related (H-field). It's always an electromagnetic field but the relative contributions of electric and magnetic field strengths vary.

It's the reason why mains frequency transformers may need to be shielded with a suitable grade of mumetal rather than copper or aluminium.

You need some ferrite element to shield against H-fields. Similarly microphone input transformers are typically fitted with mumetal shields.

 

 

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