Anyone ever put a pick-up onto a handsaw?

[rjb]

I'm thinking that if you want to try a DIY pickup, you could stick a small magnet on the blade and mount a pair of coils to the handle, on either side of the blade.

Maybe house the coils in jar lids for combined physical protection and electrical shielding.
Gee, this is getting to be fun.

[Bruce Johnson]

Since it's not an acoustic instrument, insofar that it has no acoustic resonating body, I think a low wind magnetic pickup would sound just fine.

I've got to disagree on that, David. A musical saw actually is an acoustic instrument. The wide, flat strip of steel is flapping forwards and backwards and pumping sound out to the audience. If it were just a steel rod, you couldn't hear it. A larger steel sheet would be even louder. I've been playing bluegrass for 20+ years and have had saw players sit in with us. A saw can actually be pretty loud on stage! For real fun, try singing harmony accurately with a saw player sitting next to you!

I tend to agree with RJB that I'd try to work out the best combination of mic and position. I wonder about placing a mic on the player, facing forward towards the back side of the saw? Maybe clipped on his belt, at his side? It depends how he holds the saw. I'd think that you want the mic 6"-12" from the saw.

I'm just speculating, but I doubt that a piezo pickup would sound very good. Most of the character of the sound of a saw is in all of those beautiful harmonics resulting from the blade flexing in compound shapes. I'm not sure that a piezo would be able to capture much of that.

A magnetic pickup would probably capture a nice rich sound, but the problem is that you'd need to have some kind of a stationary reference frame for the pickup to be attached to. Some kind of a backbone frame behind the blade. I'm not sure that you could do that and still be able to play the saw the way they do. The guys I've watched bend the saw quite dramatically.

Just my thoughts.

[Bruce Johnson]

Since it's not an acoustic instrument, insofar that it has no acoustic resonating body, I think a low wind magnetic pickup would sound just fine.

I've got to disagree on that, David. A musical saw actually is an acoustic instrument. The wide, flat strip of steel is flapping forwards and backwards and pumping sound out to the audience. If it were just a steel rod, you couldn't hear it. A larger steel sheet would be even louder. I've been playing bluegrass for 20+ years and have had saw players sit in with us. A saw can actually be pretty loud on stage! For real fun, try singing harmony accurately with a saw player sitting next to you!

I tend to agree with RJB that I'd try to work out the best combination of mic and position. I wonder about placing a mic on the player, facing forward towards the back side of the saw? Maybe clipped on his belt, at his side? It depends how he holds the saw. I'd think that you want the mic 6"-12" from the saw.

I'm just speculating, but I doubt that a piezo pickup would sound very good. Most of the character of the sound of a saw is in all of those beautiful harmonics resulting from the blade flexing in compound shapes. I'm not sure that a piezo would be able to capture much of that.

A magnetic pickup would probably capture a nice rich sound, but the problem is that you'd need to have some kind of a stationary reference frame for the pickup to be attached to. Some kind of a backbone frame behind the blade. I'm not sure that you could do that and still be able to play the saw the way they do. The guys I've watched bend the saw quite dramatically.

Just my thoughts.


The site created a duplicate post, and it won't let me delete it! Danged computers.

[rjb]

The site created a duplicate post, and it won't let me delete it! Danged computers.

Deleting posts is kind of tricky, but can be done.
You have to say to delete 3 times.

Here's how:
Click "Edit Post"
Click the rectangular "Delete" button.
The edit window will expand.
You will see a message "Delete this post in the following manner"
Click the radio button "Delete Message"
Click the rectangular "Delete Post" button

[rjb]

I wonder about placing a mic on the player, facing forward towards the back side of the saw?

Be aware of the mic's pickup pattern- and avoid pointing it at the monitors....

A magnetic pickup would probably capture a nice rich sound, but the problem is that you'd need to have some kind of a stationary reference frame for the pickup to be attached to. Some kind of a backbone frame behind the blade.

I'm not sure I follow. Are you wanting to pickup near the middle of the blade?

Do you have any comments on the idea of magnetizing the blade with a permanent magnet and placing a pair of air core coils on either side of the blade (either smallish coils on the handle or giant coils on either side of the player)?

Remember, this is for a Surf band.
Coils on the handle may sound like a guitar bridge pickup - tinny/treble-y may be a "good" thing.
Giant coils surrounding the player would look silly (a plus) - and may enable Leslie speaker effects by spinning in a swivel chair.

[tubeswell]

Deleting posts is kind of tricky, but can be done.
You have to say to delete 3 times.

and wave your wand...

[Bruce Johnson]

rjb;

My point about the magnetic pickup is this: A magnetic pickup depends on relative physical movement between a metal thing (the saw blade) and the coil. You can do this in two ways:

1.) Put a magnet in the center of the coil, which creates a magnetic field around the coil. Then the metal thing hangs right near the magnet. As it wiggles within the outer edge of the magnetic field, it creates a signal in the coil. That's how most conventional magnetic guitar pickups work.

2.) The other option is to make the metal thing itself carry a magnetic field. For example, stick a big 'ol magnet on the saw blade, with the magnet dangling through the center of the coil. Now, when you wiggle the saw, the magnet and its magnetic field will wiggle in relation to the coil, creating a signal in the coil. That's called a "moving magnet" style pickup. I use them on several of my model basses.

Either of these methods will get you a signal, but they both have the same basic problem. You have to have relative motion between the metal thing and the coil. You can't just stick a magnetic pickup onto a saw blade. If there's no relative motion, you've got no signal. You have to somehow hold the coil still in mid-air, while the saw blade wiggles right near it. That's what I meant about the backbone frame. You have to attach the coil to something that doesn't move along with the blade. But yet, the clearance between the coil and the blade has to be quite small, like 1/4" or less. Maybe there's an answer, but I'm not seeing how you're going to do that without messing with your ability to bend and play the saw.

The reason I suggested trying a mic on the back side is that you may be able to hold it much closer to the saw blade. The closer you can get it to the blade (without hitting it!) the less gain you have to give it, which makes it less sensitive to feedback. I'm thinking that you drape the mic cable over your shoulder, with the mic hanging down on your chest, right behind where you hold the saw. Maybe clip it to your shirt or strap it to your chest somehow? That way, you can play the saw with two hands, and move around some, but you can move your chest to keep the mic real close to the blade. And keep the gain low so it doesn't feed back.

It's an interesting problem.

[rjb]

2.) The other option is to make the metal thing itself carry a magnetic field.

That is my suggestion.

If there's no relative motion, you've got no signal. You have to somehow hold the coil still in mid-air, while the saw blade wiggles right near it. That's what I meant about the backbone frame. You have to attach the coil to something that doesn't move along with the blade. But yet, the clearance between the coil and the blade has to be quite small, like 1/4" or less. Maybe there's an answer, but I'm not seeing how you're going to do that without messing with your ability to bend and play the saw.

OK, I've got your drift.
(Nonetheless, I may try making a "magnet on the blade, coil on the handle" pickup just to see if I can get a signal out of it- I'm betting there is some relative motion between the blade and the handle.)

The reason I suggested trying a mic on the back side is that you may be able to hold it much closer to the saw blade. The closer you can get it to the blade (without hitting it!) the less gain you have to give it, which makes it less sensitive to feedback.

I know fiddlers who play at pretty high stage volumes with an omni clip-on mic. You might think an omni would feed back, but it doesn't because the gain can be set really low.

[Bruce Johnson]

rjb;

Here's what I would suggest as a first attempt for the magnetic pickup: Make up a wooden "arm" that attaches to the handle and extends along parallel to the blade, like 1/2" away from it, to a point maybe 8" away from the handle. Attach your hollow-center coil out at the end of that arm. Then stick a magnet to the blade, so that it extends out through the center of the coil. At that point, about 8" from the handle, you should have a pretty good amount of movement of the blade in relation to the arm, which will give you a reasonable signal output in the coil. But, it's hard to say what it will sound like. You may have to experiment with the position of the coil in relation to the handle to find the best tone and avoid any nodes in the blades movement. A key thing is the wooden arm needs to be rigid enough that it isn't flexing around in relation to the handle, creating its own sound.

Something else to remember in all this: When you rig up some kind of a pickup so that it detects the physical movement of the blade, you are actually creating a giant microphone! You are holding up a large sheet of metal into the wind, with a pickup connected to it. When any nearby speaker starts pushing the air around, it's going make the saw blade flex, putting a signal into the pickup, and starting feedback. What I'm saying is that the feedback problems from a magnetic or piezo pickup mounted on the saw may be much worse than they are from a mic. I ran into this with my Bass Banjo project (Banjozilla); a 24" diameter mylar head with a pickup becomes an enormous microphone, which was beginning to feed back before you could even hear it. With the saw, you hopefully have control over the blade with your hands, so you can constantly damp it as needed. It could end up sounding like a big squealing Theremin. Which could be very cool as an instrument. Or maybe not.

[Mike Sulzer]

Yes, an arm from the handle was what I was thinking of. You might want to use an arm on each side: symmetrical. Now we need to think of an analogy to the guitar. We have the acoustic saw, so now it is time for the electric saw. The first change is to put a hole in the blade. This would allow the use of a high efficiency magnetic pickup, a closed core design. Think of a toroid with a section cut out for the blade to pass through. 180 degrees around the core/coil passes through the hole in the blade. You could use a small neo on each side of the blade, or the disk neos could go on the toroid slot faces. In the latter case, you might want to cut another small hole where the blade goes through the slot in the toroid, possibly off center. The idea would be to optimize the strength/divergence of the flux lines from the magnetized blade to maximize the flux change through the coil when the blade vibrates.

I agree that the feedback problem is just about as bad with the magnetic pickup as with a small mic near the blade, but who knows for sure till you try it? But the next step in the evolution of the electric saw is another analogy to the electric guitar, in this case to the solid body guitar. This involves making the blade interact less with the air while still having interesting dynamics and harmonics. The blade would have a lot of material removed so it would have large holes. You might end up with a design involving spring steel and other materials. Sounds like fun!

[Mike Sulzer]

Oh, I forgot to say that the toroidal pickup coil would have a steel core, possibly laminated. You would use two of these pickups to get a humbucking effect. You could consider using the the two halves of a singe pickup in a humbucking mode but this would probably involve a loss of signal strength, and difficulty in keeping the magnets in place.

[rjb]

Here's what I would suggest as a first attempt for the magnetic pickup

I think we're pretty much on the same page.

I might also try:

- Before building the arm, try the coils close to the handle. Might sound like sh*t, might not be sensitive enough, but might also be less sensitive to external sound pickup. Just guessing.

- The arm might be plexiglass or some other plastic. Could be up to as wide as the saw handle. Might need wax or felt damping between the handle & arm, and the arm & coil.

- Before going the DIY route, try mounting traditional guitar pickups close to the blade. Pickups with mounting tabs (like "floating" jazz pickups or old DeArmond pickups with tabs for mounting in a round soundhole) might come in handy.

Maybe try the neck and RWRP middle pickups from a cheap-o ceramic "Strat" set, like this: Vintage Strat Set- White-Reverse Wound- BLOWOUT! ; if they aren't sensitive enough, try replacing the ceramic magnets with neos.

Hey tubeswell, does any of this sound reasonable? I don't play saw myself....

[big_teee]

Hey tubeswell, does any of this sound reasonable? I don't play saw myself....

After all these Gyrations, He may have jumped off a Bridge By Now!
T

[rjb]

The first change is to put a hole in the blade......

Yikes... all that just to play the intro to Good Vibrations?
Some fiddlers like carbon fiber bows... any chance you could make the blade carbon fiber?

Hoowee,
-rb

[bbsailor]

I do not have access to a musical saw so my answer below is simply a mental exercise to explore with a quick experiment to test the possibilities. Here is how to do it.

Use the concept of a "moving coil pickup" (search this forum for this phrase) where the vibrating string in a magnetic field produces an output except that the saw blade is now the moving string. Mount a magnet on a stick or bracket hanging over a location near where the blade is being bowed. Attach a wire between the handle (between the lags) and the saw-tip-handle with that wire looped through a 1000 turn toroid current transformer (CT). Try it with 1 turn and then 2 turns. Attach the blade to the ground wire of a 2-conductor mic cable. Attach the CT output to the two microphone center conductors. Experiment with strong neo magnets and weaker ceramic magnets. Maintaining the distance between the magnet and the saw blade surface requires some experimentation. Stewart Mcdonald has a nice 1" strong round neo magnet with a center mounting hole. Radio Shack sells a 5-pack of ceramic magnets 1" X .75" X .125" thick with a .187" mounting hole in the center. You can experiment with the location of the magnets and the amount of magnets that capture the right harmonics to make the amplified saw signal sound pleasant.

If you try this, let us know if it works?

Joseph Rogowski