Hello again, electric viola project starting

[Eric Knapp]

Hello,

After the initial chaos of retirement, and dealing with some health issues, I’m finally working in my shop on a consistent basis. I’m more of a general woodworker than a luthier but I want to make some instruments. I’ve had a few false starts and I’m trying to get started again. My daughter is now in college as a music major on the viola. She would love to have a 5-string electric viola. I can do the woodworking parts but I am searching for a solution for pickups. This will be a solid-body instrument and the extra string will be lower than the standard viola strings. I don’t know much about pickups and would love some advice from the wizards.

Thanks,

-Eric

[Eric Knapp]

Here’s what I have found so far.

The Barbera pickups look very nice but are pretty expensive. I wonder if they are worth it. Here’s a link for the violin pickups but they have ones for viola too.

http://barberatransducers.com/violinpickups.html

The Fishman series look like they are designed for acoustic instrument but might work for a solid-body. They are cheaper and might be a good starting point.

https://www.electricviolinshop.com/fishman-v-100.html

The Starfish pickups also look nice and are also expensive. I’m not sure they are made anymore, they don’t exist on any site other than a few retailers. I can’t find a company site with these.

https://www.electricviolinshop.com/pick ... ucers.html

I’m sure there must be others out there. Also are there ways to make pickups from raw parts? I’m trying to find all the alternatives.

Thanks,

-Eric

[Alan Carruth]

The only solid body instrument I ever made was a 5-string viola, with frets. The customer insisted on the frets... Big mistake.

For a pickup I used a small piece of PZT-5 piezo ceramic. I got some years ago in pieces about 1/4" wide by 2-1/2" long and 1/16" thick, metalized on two surfaces, and figured out that I could scribe and break them to make smaller elements. You could use a piece of material from a piezo tweeter just as well; cut it to size with an abrasive cutoff wheel. Slip it under the bass foot of the bridge, where it can 'read' the pressure changes. I make them up as encapsulated elements, based on the UST that Takamine uses. The smaller the elements the better they work. These things put out enough power that you don't really need a pre-amp, but they sound a lot better if you use one.

Be sure that you use something that works like a violin bridge; a bit flexible, and with some damping. If the string is not damped somehow it can take a long time to get it going, and a long time for it to stop. Jigs and reels become impossible.

[Eric Knapp]

The only solid body instrument I ever made was a 5-string viola, with frets. The customer insisted on the frets... Big mistake.

Ha! My daughter won’t make that mistake. She has a very nice acoustic viola and I’m trying to copy the feel of it for her.

For a pickup I used a small piece of PZT-5 piezo ceramic. I got some years ago in pieces about 1/4" wide by 2-1/2" long and 1/16" thick, metalized on two surfaces, and figured out that I could scribe and break them to make smaller elements. You could use a piece of material from a piezo tweeter just as well; cut it to size with an abrasive cutoff wheel. Slip it under the bass foot of the bridge, where it can 'read' the pressure changes. I make them up as encapsulated elements, based on the UST that Takamine uses. The smaller the elements the better they work. These things put out enough power that you don't really need a pre-amp, but they sound a lot better if you use one.

Very good information, thank you. I was planning on using a preamp, I just didn’t know where to get a pickup. I see a lot of them offered for what seems like a lot of money for what they are. I’ll start looking for these piezos.

Be sure that you use something that works like a violin bridge; a bit flexible, and with some damping. If the string is not damped somehow it can take a long time to get it going, and a long time for it to stop. Jigs and reels become impossible.

I am copying a viola bridge and making it wider for the 5th string. The widest one I could find was 52mm and it will need to be closer to 60mm. Is the damping accomplished with the cutouts on the bridge?

Thank you,

-Eric

[Alan Carruth]

Again, the easiest way to get piezo material is to salvage a tweeter from an old boom box. They usually consist of a disk of metal about 1"+ in diameter that has a piezo element, about half that diameter, in the middle. The ceramic is tinned on one face for the contact, and the metal side is ground. You can cut a slice out of this with an abrasive wheel in a Dremel. I like to sandwich this sort of thing between two pieces of brass shim stock; the ceramic is soft (as such things go) and brittle, and soldering a wire onto it usually doesn't hold up well as it will peel loose at the slightest pull. By sandwiching it you can also devise ways to shield it from florescent hum, which is helpful.

On an acoustic fiddle the bridge is a bell crank, pivoting around the more or less fixed point of the top of the sound post. the crosswise motion and force of the bowed strings is converted into a vertical force over the bass bar, which droves the top in a way that can pump air and make sound. The bridge also has resonant modes which act to filter the sound. Putting a single piezo element under one foot of the bridge thus produces the same sort of signal the top is seeing from the string.