Sunday, June 24, 2007
New Old Stock Shure Starlite Model 215 Ceramic Microphone
I came across two of these unopened, sealed, mint, preserved examples of the Shure Model 215 ceramic.
It has the directions for use (here is a pdf of the spec sheet) and the warranty card, and that nice looking red, white and black tag. The mic is wrapped in Illinois brown paper like a sandwich might have been, and the external colors of the box are unblemished and unmarked. There is a small stain on one of the labels, but the other is perfect.
Hamfests and ham radio flea markets are excellent sources of all kinds of arcane microphonia. This one has been added to the Microphone Museum at Crowley and Tripp for visitors to enjoy - but they can't unwrap it!
Ceramics mics and other ceramic or crystal transducers utilize the piezoelectric effect, where a voltage is produced in proportion to a strain on an oriented crystalline or crystalline/composite substance. Many materials exhibit the piezoelectric effect, even many hard plastics, even the plastic in an XLR connector, which I found ut about when I dropped a cheap cable end on the concrete floor, the other end connected to our preamp and headphones, and I could hear the impact! Aha, I thought, here is the ultimate mic for recording large explosions, even nuclear detonation. Just use the connector! Check it out for yourself.Go get one of those really cheap RS cables and listen, then go out and get a good cable.
Piezoceramics are composite ceramic, generally hard materials, sort of like the same material that a teacup is made of. They can be shaped and made into transducers, pickups, microphones, and buzzers, beepers and nanoactuators. We use them to make ultrasound transducers for use in Intravascular Ultrasound or IVUS, to see blockages in the arteries of the heart.
Posted by Bob Crowley at 7:59 AM