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Prototype F4 short scale
- Thread starter wilser
- Start date
EWww!, Mr. PJ!, How 'bout NOT-ee pine!(sorry about that BAD pun)
Oy, Wilser, look what you started with this "uncle" stuff.
Seriously, I've been doing occasional renders in appreciation
for all the extra effort/upgrades Wilser's been putting into my fretless 7.
Normally, I charge an exorbitant fee!
EWww!, Mr. PJ!, How 'bout NOT-ee pine!(sorry about that BAD pun)
Oy, Wilser, look what you started with this "uncle" stuff.
Seriously, I've been doing occasional renders in appreciation
for all the extra effort/upgrades Wilser's been putting into my fretless 7.
Normally, I charge an exorbitant fee!
and well worth it, if you ask me.
I agree about the renderings...Robert...you are truly gifted when it comes to bringing the graphics to life...before birth!!!
Wilser..the bass will be absolutely fantastic no matter what...I guarantee it...and I ain't even the guy building it...(Now that's strange...)
Anyhoo...what influenced your decision on the pickup configuration? It looks a bit odd to me...but who cares about the status quo? Go for it!
Wilser..the bass will be absolutely fantastic no matter what...I guarantee it...and I ain't even the guy building it...(Now that's strange...)
Anyhoo...what influenced your decision on the pickup configuration? It looks a bit odd to me...but who cares about the status quo? Go for it!
Cool idea on the pickup. Are you doing it with the P bobbin magnets reverse polarity of the J magnets, so it's kind of a wide aperture humbucker, but split in positions?
no need. the split P will be reverse in relationship to each coil (as an independent P) and the J is stacked. Both will be wired in series in relationship to each of the coils and each of the separate "pickups". I added the stacked in order to add some "zing" to the P sound.
OK, but aren't you then going to get different magnetic fields set up for the EA and the DG strings? This idea needs some modification once I have a better idea of how a stacked humbucker works, but my general idea is:
- if the for example the J is north up; the P-EA is N up, and the the P-DG is S up;
- then, looking from edge-on from the treble side, for the EA strings, there will be two coils, both N up, with "butterfly" field lines around each, like two single coil pups side by side, and the field lines "diving" down between them, and providing two different narrow apertures, one on each coil;
- but for the DG strings, two coils, one N up and on S up, so the field lines bridge across them, arcing from the core of one to the core of the other, like a conventional humbucker; thus creating a single wide aperture for both coils, and the same basic response in each.
That's how I imagine it working with a plain SC J in there. With the stacked J, I'd want a better idea of how that's designed to figure out the effects.
Maybe for a true single-field humbucker effect you need the magnet bridging the two coils underneath, which is missing here. But wouldn't it act some something like how i've described, or am I totally off base?
wiring...that's more my "specialty"...the "P"s should be in series...the "J stack" in series and then those two pieces in parallel...
however...I'd wire it to a 3-way...P/Both/J
the wide stagger on the P will bring a definite "old school" vibe to the bass, by emphasizing the bass on the E/A and the treble on the D/G...
this pickup would KILL on a long-scale fretted...a slap-worthy instrument for SURE!
you are, in essence, correct, but what do you think this will do to the sound? I don't understand what you are suggesting.
a stacked humbucker works like so:
imagine the rod magnet from the side one polarity up the other down. You wind one coil in one direction over the UP polarity, then another coil (in series) in the opposite over the DOWN polarity. It's basically a regular humbucker, but you're harnessing the single magnet and using the DOWN coil just for humcancelling purposes, not to pickup string vibrations.
hey Wilser,
Im a little confused - if youre only using the lower coil to cancel hum, why would you need the lower magnet?
it's not a separate magnet, it's the same magnet polarized end to end. So you're just using the same product as you would a single coil, but offer it as a stacked for a different sound.
So, you've got long, single polepiece magnets running full through bothe coils, such as N on top and S underneath?
I'l do a drawing of what I'm trying to say re the field lines and "apertures."
I'l do a drawing of what I'm trying to say re the field lines and "apertures."
Okay, I posted a similar question to this in another thread, but nobody's replied.
Everyone always says it's "like a regular humbucker" but it's really not. In a regular humbucker you have reverse winding, reverse magnet. In a stacked, you have reverse winding only.
How does the bottom coil not pick up string vibrations? just because of distance?
-Nick
How do you have reverse polarity though? the magnet is facing the same direction.
I suppose it's just the increased distance which prevents the bottom coil from sensing the strings.
If this is the case, you might be able to get higher output by having the magnet only in the top coil, with a piece of soft iron as a shield between the two. If the inductance is mismatched, you could probably correct it by adding an unmagnetized soft iron slug in the bottom coil.
you would probably want to air-gap the shield at each magnet though, so you don't end up with a shorted turn.
-Nick
Yeah, but in this case, the bottom coil is not sensing the strings, because of -- why? I always assumed a stacked coil bucker would have a plate emerging from between the upper and lower coils, allowing the field to wrap around under the first coil before hitting the second. Is that not right?
Here's the diagram I was talking about.
- First is a single coil (magnetized polepiece), seen edge on. With field lines, and with the "most sensitive area" or what I think is generally called the aperture as a shaded area.
- second is a humbucker. Note the bar magnet between the plepiece extensions at the bottom; how the field only goes through the air at the top; and how there is a broad aperature created.
- third is how I imagine two closely mounted single coil (magnetized polepiece) pups working if both have the same pole up--similar to your J and one half of your P split pup. I figure there would be two narrow apertures, one for each coil.
- fourth is how I imagine two closely mounted single coil (magnetized polepiece) pups working if both have they have opposite poles up--similar to your J and the other half of your P split pup. It somewhat resembles a humbucker wide aperture.
These are just what seems right to me, figuring superposition of fields and and "attraction" of fields towards high permittivity objects (such as the other nearby polepieces). Maybe someone else has a different, better idea of this.
Field lines through air are shown; lines through magnets and polepieces not shown.
Here's the diagram I was talking about.
- First is a single coil (magnetized polepiece), seen edge on. With field lines, and with the "most sensitive area" or what I think is generally called the aperture as a shaded area.
- second is a humbucker. Note the bar magnet between the plepiece extensions at the bottom; how the field only goes through the air at the top; and how there is a broad aperature created.
- third is how I imagine two closely mounted single coil (magnetized polepiece) pups working if both have the same pole up--similar to your J and one half of your P split pup. I figure there would be two narrow apertures, one for each coil.
- fourth is how I imagine two closely mounted single coil (magnetized polepiece) pups working if both have they have opposite poles up--similar to your J and the other half of your P split pup. It somewhat resembles a humbucker wide aperture.
These are just what seems right to me, figuring superposition of fields and and "attraction" of fields towards high permittivity objects (such as the other nearby polepieces). Maybe someone else has a different, better idea of this.
Field lines through air are shown; lines through magnets and polepieces not shown.
Attachments
My thoughts exactly, though I think the plate should be isolated, and have air gapping slots cut in it to prevent it acting as a shorted turn.
I think if you just put a plate on there directly it'll drop the output of the coil and have a slight magnetic braking effect on the string. How significant it would be, I have no idea.
-Nick
