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Constructing an Under-Saddle Transducer

Constructing an Under-Saddle Transducer

by R.M. Mottola

Originally published in American Lutherie #68, 2001 and Big Red Book of American Lutherie Volume Six, 2013



Piezoelectric transducers or pickups (I use the terms interchangeably) are popularly used to “electrify” acoustic instruments, and are increasingly found embedded in the bridge saddles of electric instruments as well. Manufactured transducers are available from a number of sources, but this article provides instructions for making an undersaddle piezo pickup for a flattop guitar from basic materials. If you know which end of a soldering iron to grab hold of, you can build this pickup.

Piezo material will generate an electrical charge when mechanically deformed. There are four types of piezo materials used in the manufacture of instrument transducers: lead zirconate titanate (PZT) ceramic chips, PZT ceramic “bender” disks, polyvinylidene fluoride (PVDF) plastic film, and PVDF coaxial cable. PZT chips find their way into first-generation undersaddle guitar transducers, transducers for various bowed instruments, and manufactured archtop guitar and mandolin bridges. PZT disks consist of PZT material bonded to thin brass disks, and are commonly used for soundboard pickups for flattop guitars and for bridge-mounted pickups for upright basses. PVDF film may be found in all sorts of transducers from undersaddle guitar transducers to under-bridge-foot transducers for bass viols. PVDF coax cable is manufactured just like the single-conductor shielded cable used to make instrument cables, except that instead of an insulating material between the center conductor and the outer shielding braid, we find PVDF material. It is used in manufactured undersaddle pickups for acoustic guitars and is the material that will be used to construct a transducer in this article.

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Questions: Amplifying Flattop Bass

Questions: Amplifying Flattop Bass

by Harry Fleishman

Originally published in American Lutherie #65, 2001 and Big Red Book of American Lutherie Volume Six, 2013



Mark Brantley of Appleton, Minnesota asks:

I recently ordered Tim Olsen’s plans for the Flattop Bass (GAL Plan #13). Do you have any advice on a good electric pickup for it?


Harry Fleishman of Boulder, Colorado responds:

It’s difficult to offer too much advice about amplifying your acoustic bass without more input about how loud you need to play, how high a fidelity to the instrument’s actual acoustic voice you want, and what your budget is; but here goes anyway.

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Transducers

Transducers

by Reagan Cole

Originally published as Guild of American Luthiers Data Sheet #54, 1977



The purpose of this particular article is to project one man’s opinion about the theoretical whys and wherefores of the transducer for acoustic instruments. This is not a consumer’s report analysis of commercially available products. Anyone interested in this information may consult the series which is currently running in Mugwumps Instrument Herald. A full market report and commentary has been promised. I have never had the money to run out and A-B all the stuff that crops up in the pages of Guitar Player; anyway, I have never used any of the commercial units since I build my own systems.

There seems to be several major camps regarding the amplification of acoustic instruments. These I would categorise as follows: (1) Only microphones should be used. These devices are, after all, an electrical analogue to the human ear, so if the mike is good all will be well. Absolutely nothing should be attached to an existing acoustic instrument. (2) Transducers are a necessary evil. They do allow musicians playing acoustic instruments to compete in an electric or an electronic ensemble. At any rate, if they are used they should be easily removable, leaving no trace. (3) The acoustic-electric is yet another evolutionary phase. The performance of the instrument transducer system is of paramount importance; It may be necessary to modify the instrument or even to design a new type for acoustic-electric use. I don’t believe that there are grounds for a serious feud lurking in any of these arguments; all are correct from their own frames of reference.

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Questions: Making Your Own Amp

Questions: Making Your Own Amp

by Dave Raley

Originally published in American Lutherie #73, 2003 and Big Red Book of American Lutherie Volume Seven, 2015



Joe Oliver from cyberspace asks:

Do you know of a manufacturer of guitar amp kits? Years ago my father bought me a Heathkit, smug in the knowledge that I would never complete it. I fooled him. I played it through high school and into the local club scene up until 1980 or so; my interests changed and about 1990 I sold it to a friend, who promptly lost it.

Now I’m starting to play again and would like to build a bigger and better amp to go with my handmade bass. Of course, there is no kit maker alive anymore, so I’m kind of stuck. I would settle for a good book that catered to nonelectronic-type people.


Dave Raley of Laurel Hill, North Carolina responds:

Jim Oliver has rattled the cage of a die-hard tube man. I’ve been building and working on them since the early ’50s. I can furnish him a diagram or two if he wants to make up his own kit, transistor or tube. Transistor amps are much simpler to build for a given output power, but you can feed a tube amp into a reflex baffled speaker or a Klipshorn and get more and smoother loudness from 10w than you would from 100w solid state into a closed baffle. Solid state amps, lacking output transformers, handle the back EMF from open baffles poorly.

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Electric Violins: The New Frontier

Electric Violins: The New Frontier

by George Manno

Originally published in American Lutherie #12, 1987



In the past, my contributions to this journal have been of the more traditional subject matter. From repairing cracks to varnish recipes, I lend my knowledge of the violin to all our readers. Although this article is not about the traditional violin, I have the same enthusiasm to share the following information with you.

Twenty years ago, electrifying a violin was a simple matter of attaching a DeArmond pickup clamp to the tailpiece and plugging the cord into an amplifier. Not much attention was given to the quality of sound that came out of the speaker. Players were more concerned that the violin could be heard over the drums and other electric instruments.

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