Sidewinders, Multi-coils and other hard to find pickups

[bassvirtuoso]

Sounds Good Dave!
Does that bridge pickup cut through the Mix?
T

It does in practice but saw no use at the live show. The neck pickup however sounded great in the mix when I solo'd that!

I held an Omaha GTG last weekend and had a former Wal owner try out the bass, he thought the 4 coil pickups were a bit more P bass-ish than Wal-ish. I'm sure switching over to the 8 coil pickups would change that tone a bit.

 

[big_teee]

I agree on the P tone, but IMO Your MCs are more balanced sounding.
The 8 poll does have a bit more of a compressed tone.
Another thing that is different on these is the Alnico 5 magnets.
A P bass pickup also uses Alnico 5, but the real Wal pickups use Ceramic.
Alnico has a rounder tone, than Ceramic magnets.
T

 

[bassvirtuoso]

Thanks Terry, not sure I knew these were Alnico compared to the original Ceramic, but that makes total sense then.

Are you able to do these Ceramic given the parts you use today?

 

[big_teee]

All my Multi-coils are using the exposed Alnico Rod magnets that stick through the covers.
I use Ceramic bar magnets on Sidewinder soapbar, and Mudbucker clone pickups.
If anyone wants a Ceramic Wal pickup, I recommend Marko, and goes by MPU a TB member here, and has been on this thread.
He is in Finland, and makes a true Wal copy.
My 8 coil is a Music Man / Wal Hybrid, but I like it.
T

 

[big_teee]

Here's some pictures of the internals of a Artec Mudbucker.
These pictures show pics of the new bobbins with internal magnets, and the old bobbins with the bobbin bar and external magnets.
I'm scrapping the old bobbins, bobbin bar, and the 4 external magnets.
Rebuilding it with new bobbins, with internal magnets.
This will make the Sidewinder a narrower aperture pickup, and is much more efficient.
I will take pcis of it fully assembled later.
T

 

[Fender Mute]

If I may ask, the aperture is how wide of an area the pickup senses? What would the real world differences be between narrow or wide aperture?

 

[Bruce Johnson]

If I may ask, the aperture is how wide of an area the pickup senses? What would the real world differences be between narrow or wide aperture?

Well, there are two parts to the idea of "aperture" or "sensing area":

First is the aperture of the magnetic field. Think of the magnetic field like the spray of water from a nozzle. The field can be narrow and focused, with a high concentration of field strength in a small area. Or, the same strength can be fanned out over a large area, with lower strength per area. This shaping of the magnetic field is the result of the geometry of the magnet, and the steel parts that are within the field. Tall narrow magnets vs short fat magnets vs steel slugs with a bar magnet on the bottom, etc. That's all about forming the shape and the "density" of the magnetic field.

Second is the sensing area of the coil. This is about the size and geometry of the coil of wire, and how the wire is positioned around the magnets and within the magnetic field. Coils can be short and wide, or tall and narrow, and they can wound very tightly (high density) or looser (lower density). The size and geometry of the coil is partly determined by mechanical factors, such as the physical space available, and the need to pack in enough turns of wire to get an acceptable signal level.

Here's how these work together: The string is wiggling within the end of the magnetic field, just above the pickup. As it wiggles, it causes the field itself to wiggle, including the part of the field that passes down through the wires of the coil. The wiggling of the field through the wires creates the current, which is the signal that goes to the amp.

Now, if the magnetic field is narrow and focused around the string, it will do a more efficient job of making the field wiggle. More wiggle power, more detail of the exact vibration of the string. Usually, more clarity and more frequency range, less mud.

BUT, that depends on getting that wiggling field through the coil efficiently. That's where the sensing area of the coil comes in. You want the turns of wire to be packed in tight within that wiggling magnetic field to maximize the coil's ability to "read" the movement clearly. If half of the wire is hanging outside the strong part of the field, the signal will be weaker and mushier.

The main point is, aperture and sensing area aren't so much about how the overall pickup is seeing the string, as they are about the matching of the magnetic field shape to the geometry of the coil.

Pickups that have a tight, focused magnetic field and a tight, compact coil to fit will have a wide frequency range, clarity, and high detail. That's what we usually call a Hi-Fi pickup. They are difficult to build, because there are practical problems with squeezing it all together, and having enough signal level. And they aren't right for all instruments. Most pickups will have some compromises, for various reasons. Builders will shape the magnetic field, change the geometry of the coils, work with the number of turns and wire gauge, etc., to soften the tone or boost particular parts of the frequency curve.

To answer your question, pickups with a narrow aperture will usually be in the Hi-Fi range; wide frequency range, clear, etc. Pickups with a wider aperture will usually be softer and muddier.

Edit: For visual reference, here is a narrow-aperture Hi-Fi pickup coil:



This is one of the coils for the pickups that I'm building for the Transformer (Fender Performer-style) bass project over on this thread:
Fender Performer Build | Page 22 | TalkBass.com
More details about it there.

 

[big_teee]

I finished the rebuild of the Artec Mudbucker.
With the new bobbins and internal magnets, All 4 strings are equal in strength.
The pickup now has good highs, mids and Lows.
Here are final pictures.

 

[BTL]

Just a quick PSA note that Sentell seems to build a sidewinder pickup in a variety of configurations:

Sentell Pickups bass guitar pickups

Also, the Fralin Hum-Canceling P90s (HCP90), a sidewinder variant that I have custom-wound for my basses (on the right and below) look and sound pretty spectacular:

 

[Snaxster]

I didn't read the whole thread so they may have been mentioned, but this guy makes some interesting pickups : Sentell Pickups electric guitar pickups

They have various weird multi-coil designs for guitars, as well as a few for bass. They also sometimes have interesting one-off pickups on their Ebay store.

Here's an example :

View attachment 588496

Two years on...

Background

Recently after re-reading part of this thread, I liked the sound of @MPU's 1-pole-per-string multi-coil J pickup set, then was intrigued by the look of the 2-poles-per-string multi-coil J pickup in the photo attributed to Sentell Pickups, in the post I'm replying to here (thank you, Antisyzygy). What interested me was these pickups' coils that were tall, but wider than those of their 1-pole-per-string counterparts.

After confirming with Jerry Sentell that the photo was of his pickup, I ordered a set from him. Sentell shipped two weeks later, as promised.

Observations

Seeing that their bobbins were wedged and potted tightly into their cases, effectively sealed in, I realized that I wouldn't be able to take photos of their internals. (I like photo-documenting stuff... in detail.) But I understood the wisdom of this construction, since the potential for coil damage was in these pickups four times that of a traditional J bass pickup. (No user serviceable parts inside!)

Also related to the non-traditional construction, I thought, were the apparently handmade pole piece holes in the cases. One of the cases came pre-scratched. Overall these pickups bore a look and vibe consistent with the slightly "mad scientist" image that the Sentell Pickups website conveys. It is subtle, but there.

Speaking of which, I'll just say it now: In correspondence I found Jerry Sentell to be a good guy and straightforward. But getting any information from him was like pulling teeth. After the first exchange, I realized that I should be as concise a possible thereafter. Yet he answered more briefly still. That was fine; but when I asked a direct question, he would fade left. Then when I followed with another to pin it down, he would fade right. Unavoidably the word "obtuse" came to mind. Eventually I gave up and counted myself lucky to have the set of rare pickups.



Performance

Some fun facts about this Sentell set of multi-coil J bass pickups:

1. made with FormVar coil wire, they have DCR readings about triple that of a traditional single coil set
   
   
2. they are out of phase with each other (which I corrected by switching the positions of one pickup's leads at the solder points)
   
   
3. though the bridge pickup has a wide magnetic aperture, the neck pickup has a very narrow aperture like a 1951 Precision Bass pickup
   
   
4. the bridge pickup especially may introduce a slight phasing in upper harmonics, most noticeable on the lowest notes when sustained
   
   
5. the 'both pickups at equal volume' J bass pickups sound is not nearly as dramatic as with single coil pickups (unsurprisingly, I would think).

Of those, I consider 2 and 3 to be mistakes. 3 is interesting, but quickly gets old if you bend single strings deeply often, which I do. 4 can sound dramatic and cool, but cannot be controlled; still unconfirmed, I'm willing to attribute it to any two or more neighboring coils being slightly out of phase with each other, though it could be simply that the pickup is so much more revealing than what I'm accustomed to, that I am hearing an aspect of the instrument's sound that never was presented by traditional pickups.

Sound

Quirks aside, I found these pickups to be musical and useful. Definitely they feature the ultra-high harmonics and big, even low bass of their genre. But they don't sound as utterly clean and revealing as, for example, MPU's multi-coil J pickups set of two years ago. Notable, too was a lack of midrange honk or growl compared to single coils. However, they have a nice wooliness that makes them more akin to single coils.

And that's how I coined these pickups to myself: wide bandwidth multi-coil J bass pickups for players with single coil sensibilities.

'Not ready for prime time' is what I thought at first, but I amended that to be 'not ready for the mainstream'. "musical and useful" is the key. For the right player, instrument and music, these pickups could be perfect.

Sample

This is not a proper demo, since it doesn't focus only on the raw sound of the pickups and a range of balance between the two pickups. But it is music, of a kind I am making fairly often these days, so it's representative of... some music.

The bass guitar is a one-off passive J type by New England Custom Guitars. Strung with roundwounds, it has a heavy, dense ash body and a maple neck/fingerboard. I know it well, getting it at first to be a test bed for pickups, but along the way becoming enamored with its rich, snarling voice.

The signal chain was bass guitar > TC Electronic Ditto X2 Looper > Baer Valkyrie amp (preamp in non-tube mode) > MA Soundworks MAS-112 Eminence (with its B&C tweeter engaged). The are no half-speed dubs, but one in reverse and a composite of double-speed ones.

Sorry, but the live sound was freaking fantastic. I'm not a tweeter player mostly, but the B&C tweeter so sweetly presented the high harmonic info conveyed by these pickups. And the Valkyrie/MAS-112 combo is always huge and fine-sounding. Especially the double-speed tracks sounded like a live zither presented spatially out in front of the rest of the mix. Crazy.

At the least, I should have played through the amp first, then fed the phrase sampler with the preamp out. Since I didn't, I "mixed" the track with the Audacity multiband compressor, trying to approximate the live sound. There is some pretty deep bass, so listen on nice headphones or speakers:

[Invalid or Expired Link Removed]

 

[ctmullins]

Um, wow. That is a hella cool track.

 

[Snaxster]

Um, wow. That is a hella cool track.

Thank you!

 

[Antisyzygy]

Two years on...

Background

Recently after re-reading part of this thread, I liked the sound of @MPU's 1-pole-per-string multi-coil J pickup set, then was intrigued by the look of the 2-poles-per-string multi-coil J pickup in the photo attributed to Sentell Pickups, in the post I'm replying to here (thank you, Antisyzygy). What interested me was these pickups' coils that were tall, but wider than those of their 1-pole-per-string counterparts.

After confirming with Jerry Sentell that the photo was of his pickup, I ordered a set from him. Sentell shipped two weeks later, as promised.

Observations

Seeing that their bobbins were wedged and potted tightly into their cases, effectively sealed in, I realized that I wouldn't be able to take photos of their internals. (I like photo-documenting stuff... in detail.) But I understood the wisdom of this construction, since the potential for coil damage was in these pickups four times that of a traditional J bass pickup. (No user serviceable parts inside!)

Also related to the non-traditional construction, I thought, were the apparently handmade pole piece holes in the cases. One of the cases came pre-scratched. Overall these pickups bore a look and vibe consistent with the slightly "mad scientist" image that the Sentell Pickups website conveys. It is subtle, but there.

Speaking of which, I'll just say it now: In correspondence I found Jerry Sentell to be a good guy and straightforward. But getting any information from him was like pulling teeth. After the first exchange, I realized that I should be as concise a possible thereafter. Yet he answered more briefly still. That was fine; but when I asked a direct question, he would fade left. Then when I followed with another to pin it down, he would fade right. Unavoidably the word "obtuse" came to mind. Eventually I gave up and counted myself lucky to have the set of rare pickups.

View attachment 1125495 View attachment 1125496 View attachment 1125499

Performance

Some fun facts about this Sentell set of multi-coil J bass pickups:

1. made with FormVar coil wire, they have DCR readings about triple that of a traditional single coil set
   
   
2. they are out of phase with each other (which I corrected by switching the positions of one pickup's leads at the solder points)
   
   
3. though the bridge pickup has wide aperture sensing, the neck pickup has a very narrow aperture like a 1951 Precision Bass pickup
   
   
4. the bridge pickup especially may introduce a slight phasing in upper harmonics, most noticeable on the lowest notes when sustained
   
   
5. the 'both pickups at equal volume' J bass pickups sound is not nearly as dramatic as with single coil pickups (unsurprisingly, I would think).

Of those, I consider 2 and 3 to be mistakes. 3 is interesting, but quickly gets old if you bend single strings deeply often, which I do. 4 can sound dramatic and cool, but cannot be controlled; still unconfirmed, I'm willing to attribute it to any two or more neighboring coils being slightly out of phase with each other, though it could be simply that the pickup is so much more revealing than what I'm accustomed to, that I am hearing an aspect of the instrument's sound that never was presented by traditional pickups.

Sound

Quirks aside, I found these pickups to be musical and useful. Definitely they feature the ultra-high harmonics and big, even low bass of their genre. But they don't sound as utterly clean and revealing as, for example, MPU's multi-coil J pickups set of two years ago. Notable, too was a lack of midrange honk or growl compared to single coils. However, they have a nice wooliness that makes them more akin to single coils.

And that's how I coined these pickups to myself: wide bandwidth multi-coil J bass pickups for players with single coil sensibilities.

'Not ready for prime time' is what I thought at first, but I amended that to be 'not ready for the mainstream'. "musical and useful" is the key. For the right player, instrument and music, these pickups could be perfect.

Sample

This is not a proper demo, since it doesn't focus only on the raw sound of the pickups and a range of balance between the two pickups. But it is music, of a kind I am making fairly often these days, so it's representative of... some music.

The bass guitar is a one-off passive J type by New England Custom Guitars. Strung with roundwounds, it has a heavy, dense ash body and a maple neck/fingerboard. I know it well, getting it at first to be a test bed for pickups, but along the way becoming enamored with its rich, snarling voice.

The signal chain was bass guitar > TC Electronic Ditto X2 Looper > Baer Valkyrie amp (preamp in non-tube mode) > MA Soundworks MAS-112 Eminence (with its B&C tweeter engaged). The are no half-speed dubs, but one in reverse and a composite of double-speed ones.

Sorry, but the live sound was freaking fantastic. I'm not a tweeter player mostly, but the B&C tweeter so sweetly presented the high harmonic info conveyed by these pickups. And the Valkyrie/MAS-112 combo is always huge and fine-sounding. Especially the double-speed tracks sounded like a live zither presented spatially out in front of the rest of the mix. Crazy.

At the least, I should have played through the amp first, then fed the phrase sampler with the preamp out. Since I didn't, I "mixed" the track with the Audacity multiband compressor, trying to approximate the live sound. There is some pretty deep bass, so listen on nice headphones or speakers:

[Invalid or Expired Link Removed]

I like that track too. However, great post! Very detailed and interesting.

 

[Snaxster]

I like that track too. However, great post! Very detailed and interesting.

Hello. Thanks on both counts, and again for posting that photo two years ago.

 

[Toptube]

I contacted MPU recently. Unfortunately, he is busy with life. Is not making pickups : (

His 4 coil J sounds quite good.

 

[bass_69]

I will revive this thread as I think it is a good one. I have been fascinated by multi coils to the point that I have bought myself a ACG Uber Finn. It is a very nice bass and has me hooked on MC pickups. I now want to try them in a DIY fretless. I heard MPU's jazz bass ones earlier in this thread and liked them. I have a question on how they hum cancel. I would like to try some jazz bass style pickups from Vejo Rautia as I like the jazz bass positioning (60s spacing) of the pickups on a bass. It is also easy to find a bass that is routed accordingly. I just wonder how a row of 4 coils bucks 50/60 cycle hum ? I understand that the ACGs have 2 rows per pickup (like a WAL). Each string has 2 coils wired together in series and I assume that each string is a single humbucker that is then summed by a mixing board on the back of the pickup. There is also a filter preamp (Lusithand) that electronically sums each coil that would be interesting. Thoughts ?

 

[ctmullins]

Hum cancelling can be done with any even number of coils. Half are RWRP from the other half.

 

[MPU]

And 3/2 configuration is humbucking as well.
Four coils are in pairs.

 

[BTL]

Lindy Fralin will be winding a couple of 5-string Big Singles for me with custom blades and bobbins I'm fabricating. I'll post pics soon.

 

[claudel]

Anyone winding a 4 string multi-coil in a "J" format?