Blade pickup turned 90 degrees

[bassjase128]

Hi,
Most pickups seem to centre around a small area of the string using say a 5mm bar just underneath a string and then we put 2 or 3 pickups over the length of the body to pickup several areas under the strings. What would happen if a design was put in that was like a blade design turned 90 degrees so it ran parallel with the string and was individually wound for each string so the magnetic pickup area was a lot higher. Obviously there would be space issues but would there be any advantages just out of interest??


Jason

[FunkyKikuchiyo]

Now, THAT would settle some of the aperture arguments!

Sounds like you should try it and let us know. I would think you'd have winding issues - you'd have a pickup the size of your hand, that's a lot of wire. There wouldn't be many space issues if you got a strat with the big swimming pool rout and simply modified a pickguard.

[Steve Conner]

I think it would cancel a lot of the string harmonics and make a really dull sounding pickup.

When you turn on two pickups in your Strat, you get that nasal sound because a range of frequencies gets cancelled, and which frequencies depends on the distance between the two pickups and the speed of sound in guitar strings. It works like a comb filter, or a phaser pedal without the sweep.

So now imagine a Strat with an infinite number of pickups all turned on at once. (Douglas Adams probably owned one.)

[David Schwab]

I think it would cancel a lot of the string harmonics and make a really dull sounding pickup.

I agree.

I've seen it done on bass with lipstick tubes. They stopped making this bass.

[Mike Sulzer]

That is a lot of magnetic pull on each string.

The total inductance would be huge (unless you used a separate preamp for each string.

So in addition to losing high harmonics due to the wide aperture, you would lose high frequencies from the huge inductance.

OK, it might not be the worst sounding pickup ever made, but it would be right down there.

[bassjase128]

Thanks for the replies, I wont waste my time then !!

I actually like the looks of that bass, I've never seen anything like that.

[Stealth]

Figured you'd pull the Italia Modulo bass out of your hat, David. I don't think any other company went down that lane after them, and it's a shame because I haven't heard any soundclips around.
Let's not mention the Crocodile Tolex/barstool finish. Ick.

Anyhow - I've no idea what it would sound like, but I'd say in theory a few things would likely happen or can be modified "to fit":

• The pickups needn't have a huge inductance. If you wire to a relatively low turn count, one that, say, produces 2 kΩ of DC resistance, the inductance shouldn't go too high either considering the low turn count once they get into series.
• In case the inductance does get as high as that, a simple solution would be to wire alternating pairs of pickups into parallel banks, then putting that into series, i.e. with a 4-string bass you're have E||D + A||G configuration. Will try some calculations to see what that'd do to a coil with reasonable R and L.
• Then again, there's the active approach Mike suggested.
• The string pull differs with the magnet underneath, so either a weaker magnet, a shorter magnet (which comparatively diffuses the magnetic field into a larger blade) or segmented magnets (as in multiple small magnetic "chunks") might pull it off. No pun intended.

Of course, I could be wrong - am I way off mark with the simplified theory here?

[David Schwab]

I actually like the looks of that bass, I've never seen anything like that.

They make some very stylish instruments. Most are a variation of these Hagstroms.

I love those old funky instruments from the 60's/early 70's.

[Mike Sulzer]

Anyhow - I've no idea what it would sound like, but I'd say in theory a few things would likely happen or can be modified "to fit":

You are right; you can make this work. It would be fun to try a "reduced" version, where each blade is just long enough so that the resulting coil fits in a standard humbucker space. Then you do alternate ones reverse electrical and magnetic polarity to make it humbucking. This would be a bridge pickup since it would not be good for string bending in the neck position.

David S, do you have a steel type you would suggest for a blade in this application?

I would use multiple small neos on each blade as suggested, adjusting to keep the magnetic strength just below what would cause bad string pull.

[Bruce Johnson]

I've been using a variation of this idea for about five years as the forward pickup on my Scroll Basses. It's an individual oval coil for each string, along the line of the string. I use 3 1/4" A5 rod magnets in each.

Here's a picture of a recent Scroll Bass:
Gallery AUB-2 #067

As compared to P-bass pickup of similar power and specs, this pickup tends to level out the harmonic points, so the tone and output levels are very even all the way up and down the string. These are fretless basses with flatwounds, so this is important. There's no loss of high end with this configuration. It's very clear and full range. Remember, the magnetic field shape across the string is tight and focused, as compared to a conventional pickup.

The reason you don't see this on production basses is because it's expensive and non-traditional.

[Mike Sulzer]

As compared to P-bass pickup of similar power and specs, this pickup tends to level out the harmonic points,...

The harmonic fall off is certainly different from a standard humbucker which samples two narrow regions along the string, making a quite complicated pattern of roll off and nulls. This is simpler; wider spaced nulls. It does start falling off at lower harmonics than a single coil with one narrow sampling region.

[Stealth]

You are right; you can make this work. It would be fun to try a "reduced" version, where each blade is just long enough so that the resulting coil fits in a standard humbucker space. Then you do alternate ones reverse electrical and magnetic polarity to make it humbucking. This would be a bridge pickup since it would not be good for string bending in the neck position.

As an alternate idea I'd look into using a blade core that's similar in shape to an I-beam (or, a railway track, if you will) - that sounds like it would diffuse the magnetic field enough to make string bending work even in the bridge position. Even then, the I-beam (or, rather, the top and bottom "flanges") would only need only be as wide as, say, the distance between the center-poles of a J-bass pickup (that is, the pair that sits underneath a single string).

Of course, this is all just theory. I'm still struggling to get around to winding my first "common" pickup. Soon-ish.

[Bruce Johnson]

Yeah, the harmonics are leveled out at the low end too. It doesn't have any notes with booming or missing sub-harmonics that I can hear. It has plenty of bottom end; in fact the whole frequency curve was surprisingly flat on my first prototypes. I experimented with the coil geometry and windings to give it a low-mid boost on the production version, because that's what I wanted on this model bass. The four coils are a true humbucker as a set, with alternating coils and magnets.

The main reason why I went with this configuration is because I use a 4" fingerboard radius on these basses. Cross-wise bobbin designs get really cumbersome trying to reach up to the center strings. I've also found that customers of this type of basses have a lot of variation in how they pluck with their right hand. It was hard to make everyone happy with the relative output levels of the strings on my previous models. This four-in-line configuration is easy for them to adjust to their own preference.

There's a thousand ways to make pickups, many of which still haven't been tried.

[Stealth]

By the way, Bruce, is it normal that opening any links from that page of yours (incl.the pickup page) now produces a 404 error? Did you remove the page on purpose or is it a server fault? I remember reading that page and you really had a plethora of useful info there - definitely interesting directions in pick-up design.

[David Schwab]

David S, do you have a steel type you would suggest for a blade in this application?

I use low carbon steel.. it's listed as "Alloy 1008, 1010".