Stacked vs. side by side hum canceling designs

[Inflames626]

I was wondering if someone could tell me the tonal difference between stacked and side by side hum canceling designs.

I thought of this when I noticed Duncan's introduction of its new Apollo jazz bass side by side hum canceling pickups.

In my experience, I tend not to like hum canceling designs. They lack something--transients or dynamics--that give true singles their character. This was my experience with an old Duncan STK S1 hum canceling single. Once I wired it to split, it sounded livelier and more like a single coil should, but with noise of course.

I can see the use for hum canceling singles in live situations with interference from stage lights, wireless units, etc., but for recording, to my ear hum canceling singles lack something. They just end up sounding like low output humbuckers to me.

Clyde from Bartolini told me he doesn't like stacked hum canceling designs. I noticed that most hum canceling pups are made this way, so I thought that side by side hum canceling pups might have a different, possibly superior, character.

I doubt I'll try the Apollos, as I prefer true singles, but if anybody tries a stacked vs. side by side hum canceling single, I'd be interested in their opinion on the differences.

 

[Funkfingers]

Re: Stacked vs. side by side hum canceling designs

I invariably find that passive, noise-cancelling, interpretations of classic single coil designs are compromised in one respect or another.

Bartolini side-by-side coil replacement pickups for Jazz Bass are fine, provided that you desire the Bartolini sound rather than the traditional Fender.

Amongst active replacement designs, I tend to prefer side-by-side coils over stacked. Much depends upon how much importance you place on the transient attack qualities provided by rod magnet polepieces. The SD Lightnin' Rods are stacked coils. The ol' Active EQ "switch" pickups are side by side coils. These have the additional benefit that the P and short J pickups are identical innards in differently shaped housings.

One thing that I would like to comment on - but have not had the opportunity to try yet - is the Fishman Fluence range.

 

[uOpt]

Re: Stacked vs. side by side hum canceling designs

Stacks are misguided, IMHO. The worst are P90 stacks. That can never work right because you need the lower coil to have no magnetism, but a proper p90 has the magnets on the bottom. Rod magnet pickups suffer quite a bit less but hey what do you expect when you simply cut the rod magnet in half.

I say misguided because the proper way to do it would be to have full magnets and (one) coil in the pickup, then have a blind coil somewhere else in the guitar. The full magnet setup would be a huge improvement.

Now, to get the general characteristics where you'd want it you have to do one of two things:

• Make all the coils lighter and put them in series with the blind coil
• Make all coils heavier and put them in parallel
• Have normal coils everywhere and change impedance before adding them electrically

 

[freefrog]

Re: Stacked vs. side by side hum canceling designs

The worst are P90 stacks. That can never work right because you need the lower coil to have no magnetism, but a proper p90 has the magnets on the bottom.

Chris Kinman has put the noise cancelling coil below the magnets but has shielded the upper ensemble, as it's the case in several similar designs (It can vaguely be seen here: http://dt7v1i9vyp3mf.cloudfront.net...XbiXgc_gzubFTfi8Q6RZqZKzpTIXkP=&itok=-uPe4ofz)...

This design is based on a low DCR noise sensing coil wound around a multi-layer bobbin made of insulated laminated steel. It avoids eddy currents and increases the noise cancellation altogether, which is clever IMHO and efficient IME.

I was wondering if someone could tell me the tonal difference between stacked and side by side hum canceling designs.

IME, stacks tend to produce a dual resonant peak. Ain't got the time to post pics now but I've a bunch of screenshots about that in my archives.

"Side by side" models haven't this dual peak but if you put a coil below 3 strings and another coil below the 3 adjacent strings, strange things happen when you bend the G string :-/ (although it's not the case with "one coil per string" Zexcoils because Scott came up with another clever and efficient design, based on slanted magnetic poles and bobbins).

Finally and if we forget the advanced designs that I've evoked , the simplest solution might be rails pickups: they still don't sound like SC's but at least they avoid the downsides mentioned above...

EDIT - although another interesting design is the sidewinder imagined by Lace: http://flemingmusic.com.au/index.php?route=product/product&product_id=238

 

[Mincer]

Re: Stacked vs. side by side hum canceling designs

I think the Classic Stack Plus for Strats works well, and keeps a lot of the chime of a regular single coil. I have no problem at all using them over regular singles. For bass, the Apollo Jazz bass are side by side humbuckers that really sound like traditional singles, more than stacks. I would think that a P90 designed this way would be better than a P90 stack.

 

[freefrog]

Re: Stacked vs. side by side hum canceling designs

In order to complete my previous post but to avoid a too long explanation, I post a link about an experience with a "side by side" (Fender) design in a guitar (a bass player wouldn't have the same issues with the G string, obviously). See the posts 43 and 45 here:

http://www.strat-talk.com/threads/new-fender-super-55-split-coil-pup.221210/page-3

I'll try to add a few things here about stacks if time permits.

 

[Funkfingers]

Re: Stacked vs. side by side hum canceling designs

All of the P90 Stacks that I have ever seen sandwich the two bar magnets between the coils. Anywhere else and they would be too far away from the strings.

 

[Mincer]

Re: Stacked vs. side by side hum canceling designs

Many people, across many forums, complain about P90 stacks, and not just ours. It isn't that they are bad, they just don't sound much like a P90 should, I guess. I wonder if it is time to revisit the design.

 

[Funkfingers]

Re: Stacked vs. side by side hum canceling designs

I am of the opinion that the workable compromise is two run the stacked coils in parallel, as recommended in the official installation instructions, but to add a trim pot in line for the lower coil. This should be used to dial in the best balance between single coil tone and hum cancellation.

 

[Mincer]

Re: Stacked vs. side by side hum canceling designs

Actually, that is a really good idea. Set it once and forget about it. Kind of a 'choose the amount of hum cancelling you want'.

 

[Demanic]

Re: Stacked vs. side by side hum canceling designs

Well, the P-bass pickup is hum cancelling from what I recall. Isn't this same design used in something called Z-coils by MFD or something like that?

 

[freefrog]

Re: Stacked vs. side by side hum canceling designs

Stacks… As promised in one of my previous posts, let’s try to discuss what they do to the tone.

WARNING – long boring post. nobody's forced to read it. )

NOTE - I won’t mention ANY brand nor model below. This post is supposed to share freely a thin slice of my experiments and not to promote nor to bash such or such winder or pickup.


Firstly, what happens if we put a regular single coil in series with a noise cancelling dummy coil?

See this PIC 1: in white is the resonant peak produced by a normal single coil. In green is the resonance of the same pickup in series with its “humbucking” dummy coil… There’s two resonant peaks now (I won’t dig here why it’s the case).




Does a stack do the same? See the PIC 2 below: it shows in white the resonance of a Tele stack with crudely symmetrical coils while the green line is the curve due to a symmetrically wound low DCR humbucker. Hmm... the regular humbucker exhibits a "normal" resonance with a single peak but the stack, once again, produces two peaks.



Another glance about the influence of added coils? See the following PIC 3: this time, we have a (hot) Strat style stack in green (and once again, two stacked coils create two peaks). In white, we see a (hot) humbucker wired in parallel with a symmetrical dual (“humbucking”) dummy coil. IOW, the white line involves two coils in parallel with two other coils… Result: we have now three resonant peaks and two dips.



So, apparently, the more non magnetic noise cancelling coils we add, the more the resonance of a pickup is altered in its EQing… [NOTE for the specialists: yes, it’s a blanket statement; I explain these things schematically in order to make them the most understandable possible for all other members].

Is there ways to prevent the “splitted resonant peak EQing” due to noise cancelling coils? Yes. Shielding the coils or adding resistors are attempts in this direction.

In the PIC 4 below is the curve obtained from a regular single coil P90 compared to a P90 stack that I’ve modified with my own recipe of "old fart tinkerer" ®… It’s still noiseless (the pickup, not the old fart who writes this) but now it has the resonant peak of a normal P90 and sounds accordingly.



So, stacks aren't always so bad, finally. As suggested above by other contributors, all depends on how we deal with their design and what we do with them.

 

[freefrog]

Re: Stacked vs. side by side hum canceling designs

Stacks… As promised in one of my previous posts, let’s try to discuss what they do to the tone.

WARNING – long boring post. nobody's forced to read it. )

NOTE - I won’t mention ANY brand nor model below. This post is supposed to share freely a thin slice of my experiments and not to promote nor to bash such or such winder or pickup.


Firstly, what happens if we put a regular single coil in series with a noise cancelling dummy coil?

See this PIC 1: in white is the resonant peak produced by a normal single coil. In green is the resonance of the same pickup in series with its “humbucking” dummy coil… There’s two resonant peaks now (I won’t dig here why it’s the case).

View attachment 69435


Does a stack do the same? See the PIC 2 below: it shows in white the resonance of a Tele stack with crudely symmetrical coils while the green line is the curve due to a symmetrically wound low DCR humbucker. Hmm... the regular humbucker exhibits a "normal" resonance with a single peak but the stack, once again, produces two peaks.

View attachment 69436

Another glance about the influence of added coils? See the following PIC 3: this time, we have a (hot) Strat style stack in green (and once again, two stacked coils create two peaks). In white, we see a (hot) humbucker wired in parallel with a symmetrical dual (“humbucking”) dummy coil. IOW, the white line involves two coils in parallel with two other coils… Result: we have now three resonant peaks and two dips.

View attachment 69437

So, apparently, the more non magnetic noise cancelling coils we add, the more the resonance of a pickup is altered in its EQing… [NOTE for the specialists: yes, it’s a blanket statement; I explain these things schematically in order to make them the most understandable possible for all other members].

Is there ways to prevent the “splitted resonant peak EQing” due to noise cancelling coils? Yes. Shielding the coils or adding resistors are attempts in this direction.

In the PIC 4 below is the curve obtained from a regular single coil P90 compared to a P90 stack that I’ve modified with MY own recipe of "old fart tinkerer" ®… It’s still noiseless (the pickup, not the old fart who writes this) but now it has the resonant peak of a normal P90 and sounds accordingly.

View attachment 69438

So, stacks aren't always so bad, finally. As suggested above by other contributors, all depends on how we deal with their design and what we do with them.

 

[jmcorey]

Re: Stacked vs. side by side hum canceling designs

Chris Kinman has put the noise cancelling coil below the magnets but has shielded the upper ensemble, as it's the case in several similar designs (It can vaguely be seen here: http://dt7v1i9vyp3mf.cloudfront.net...XbiXgc_gzubFTfi8Q6RZqZKzpTIXkP=&itok=-uPe4ofz)...

This design is based on a low DCR noise sensing coil wound around a multi-layer bobbin made of insulated laminated steel. It avoids eddy currents and increases the noise cancellation altogether, which is clever IMHO and efficient IME.



IME, stacks tend to produce a dual resonant peak. Ain't got the time to post pics now but I've a bunch of screenshots about that in my archives.

"Side by side" models haven't this dual peak but if you put a coil below 3 strings and another coil below the 3 adjacent strings, strange things happen when you bend the G string :-/ (although it's not the case with "one coil per string" Zexcoils because Scott came up with another clever and efficient design, based on slanted magnetic poles and bobbins).

Finally and if we forget the advanced designs that I've evoked , the simplest solution might be rails pickups: they still don't sound like SC's but at least they avoid the downsides mentioned above...

EDIT - although another interesting design is the sidewinder imagined by Lace: http://flemingmusic.com.au/index.php?route=product/product&product_id=238

Excellent description, freefrog - you definitely know your stuff. I feel like the real Bill Lawrence just chimed in here. (That is a huge compliment, BTW!)

FWIW, over on the Bill and Becky Wilde-gate in the Fender Info Forums, many believe that Bill pioneered the sidewinder design in the old single-rail L-250.

 

[freefrog]

Re: Stacked vs. side by side hum canceling designs

I feel FAR to have the same knowledge than Bill Lawrence (RIP) but having the uttermost respect and admiration for people like him and Seymour, I also hear what you say as a "huge" compliment and I fully appreciate it (even though I post to share information and not to promote myself).

Beyond my non important case, thx to evoke Lawrence pickups, jmcorey: the rail models designed by Bill are another proof that talented designers always succeed to transcend musically the inner limitations of a design. All the names of winders mentioned in this thread are well known for a good reason.

EDIT for a FOOTNOTE - I've evoked the Lace Sidewinder and not those formerly designed by Bill because Lace has added his twist to the idea with asymmetrical coils (AFAIK, Bill used regular bobbins, like Fralin in his sidewinder P90; correct me if I'm wrong).