Microphone Choices:

At the Harp-End of the Wire!

MIC DUNGEON DOSSIER #12,402: It's happened again! A beautiful example of a highly coveted harpmic has come into the MIC DUNGEON and, once properly connected to a little Masco test amp, DIDN'T MAKE A PEEP! The owner of this particular mic—a pristine example of a very early and quite uncommon ASTATIC MODEL A produced in Youngstown, Ohio (it looks just like a brown JT-30 but has a thicker grill flange inside and a hard-wired output cable held in place by an 8x32 setscrew)—was heartbroken to find his pride-and-joy had gone mute, silent. Dead-dead-deadski… What shall I do, sez he. She's led a good life and I've always treated her with respect and care. Well, she IS a crystal, sez I, and prone to give up the ghost with little warning. BUT, let's not be so hasty to invoke Last Rights…

SO, do you remember that box under the backseat of the HARPMOBILE we were digging around in? The one labeled SWISS ARMY KNIVES? Do you recall the six foot length of audio cable with a quarter-inch phoneplug at one end and two alligator clips attached to the opposite bare ends? Remember the many examples sited of just how handy this little assemblage of scraps can be? HEY! FABRICATING ONE OF THESE WAS YOUR HOMEWORK! Just kidding… we'll use mine.

Extract the two 4x40 machine screws that hold the deco grill onto the teardrop body of the MODEL A—a design of simplistic beauty and incidental utility in the hands of a TIN SANDWICH JOCKEY. Once the innards are exposed, inspect the internal wiring for corrosion, fatigue (physical twists, bends, mechanical “pinches” that can occur between body and grill), decomposition of the insulation, and “cold” (non-conductive) solder joints.

Upon inspection it's clear that this mic's a virgin. She's never been opened for repairs. Solder joints are original and clean. Even the early foam ring gasket's in nice shape. So… What gives? Here comes that six feet of Wonderwire with the alligator clips. Connect one ‘gator clip to each of the obviously original crystal element's solder lugs and plug the opposite end's quarter-inch into the Masco… Still we get “Zippo,” to quote Private Hudson from “ALIENS.” At this point the mic's owner is near tears. He'll do anything to revive the patient. “Replace it with another vintage crystal! You can do that, right?”sez he. Once again, let's not be so hasty to swap cloned body parts. Leave that to Dick Cheney. SO… Using surgical hemostats to conduct potentially destructive heat away from the delicate crystal, I de-solder the POSITIVE LEAD from the element's wire lug. Onto the element's positive wire lug goes the “PLUS” alligator lead again… !BRIZZZTTZZZVVVTZZZ! “IT'S ALIVE! IT'S ALIVE!” he shouts in his best Colin Clive impression. “But, how? Why?”

Once again, that word CONTINUITY comes into play: There was no output signal from the crystal element to the amp—not because it had been damaged or had failed—but because there was an unintentional complete circuit “short”/CONTINUITY caused by that 8x32 setscrew wearing through the insulation between the center conductor and the woven ground/shield of the cloth-insulated cable at the base of the mic. I fear that MANY perfectly good vintage elements meet their ends due to the misinterpretation of these symptoms.

I'LL SAY IT AGAIN: THESE MICS WERE NOT DESIGNED TO BE HANDLED—even in the reverent paws of a proud TIN SANDWICH JOCKEY. BUT—with care, they can be adapted to lead long, productive lives. This particular example lives on gig after gig with its original element intact—thanks in part to the addition of a Switchcraft 2501MP thread-on connector in place of the trouble-prone hard-wired output cable. AMEN…
 
YOUR QUESTIONS ANSWERED! NEXT TIME WE VISIT…
THE MIC BENCH!

For pictures and descriptions of most of the microphones listed visit: http://www.harmonicamasterclass.com/vintage_collection.htm