So you bought a Lifetime Model six (or some other ancient double-button carbon mic) on eBay; how the hell do you get sound out of it? Yr prolly gonna need one of these. A carbon mic P/S. Allows a double-button Carbon mic to hook up to any mic preamp.
And for some examples of how these crazy mics can sound… check out these earlier posts: click here for acoustic gtr and here for drum kit…
Here is a one-of-a-kind unit using a re-purposed Thordarson transformer. IT works great, and the vintage Shurite (made in New Haven CT!!!) DC voltmeter is a bonus.
On the ‘business-end’ (topmost image) you can see XLR output jack (for connection to the input of your mic preamp), on/off switch, pot for controlling the DC voltage that mic receives, and at right the cable-exit for the seven-foot cable harness that connects to your double-button carbon mic. At right: red and black wires connect one-to-each button, and the clear wire connects to the metal shell of the mic.
For an explanation of WTF this thing is, and why you might possibly need it in your life, see this previous post.
Picked up a few interesting pieces today. Above, an Altec 660B microphone circa 1958. I already had a 660A (same thing, but fixed impedance) but this was too good a deal to pass up. Altec marketed these as ‘broadcast mics’ but both of my units, while having pretty good top end, have a pretty weak bass response. The 660B sounds a little bit better to my ears.
The 660B came mounted on this beautiful Shure S36 tabletop mic stand; that’s a push-to-talk DPDT switch mounted on the front.
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Moving on to stranger fare: above, a “Little Mike” as made by the Brooklyn Metal Stamping Company circa 1930. This one confused me for a minute as it had no markings on it other than a patent date on the rear:
This was enough information to coax Google into revealing the origins of this artifact. See here and here for the details.
The Little Mike’s rather long stretch of two-conductor cable terminates in these unusual copper discs. As it turns out, these discs are intended to be attached thru two of the pins on a radio’s detector tube; this will allow the mic signal to come out of the radio speaker.
The question is, naturally: which pins? The grid and the ground-side filament, I assume? I can’t figure out how to get sound out of this thing. I get no DC resistance reading across the two terminals, and no sound when I connect the terminals across a high-gain, high-impedance input. I am guessing, based on the patent date, that this is a single-button carbon mic, which would mean that I would need a low voltage source and a signal transformer that can handle DC on the primary in order to test it. Anyone have any suggestions/advice?
***update: read the comments section for implementation information courtesy of M. Shultz, as well as the not-so-thrilling conclusion to the saga of Little Mike.
Download a four-page catalog scan of the microphones of offer from Allied Radio in 1942:
DOWNLOAD: Mics_Of_1942
Models covered, with photos, text, and some specs, include: Astatic T-3, JT-30TT, GT-3, N-30, and DN mics; Shure 708-A, 750-B, 730A Uniplex, 55c, 55a, and 555 Unidyne, Shure 7A, 705A, and 70H Crystal microphones; Electrovoice 630, 640, and Cardax dynamics, and V-2, V-1 ribbon mics; Amperite PGL Dynamic and RBHK and RBMK ribbon mics; RCA MI-6205 Aerocrystal Microphone; Bruno WS, SS, and HS high-impedance ribbon mics; plus more.
Bruno Microphones Circa 1942
Astatic Crystal Microphones Circa 1942
Electrovoice and Universal Crystal Microphones of 1942. The most primitive of microphones. I recently got the chance to use my ancient Lifetime Model Six Carbon mic on a contemporary vocal session. It actually worked out great. This is ATLANTIC CITY, my studio project with T.W. LISTEN: Ten Past Midnight
Electrovoice and Amperite Ribbon Mics c. 1942
Shure Cardiod Mics c. 1942
Download a four-page article from the Summer 1987 issue of “The Antique Radio Gazette” which details the development of early broadcast microphones as made by the Westinghouse corporation for use in their own radio broadcast studios. The article is written by microphone collector/expert Bob Paquette.
DOWNLOAD: Paquette_Microphones_of_the_1920s
In this early post on PS dot com, we looked at the early double-button carbon mic, so popular as a prop in music videos and other fashion-representation. As primeval as the double-button carbon mic is, it was of course the offspring of even older technology. Dig into Paquette’s article and go even deeper into the well; we are looking backwards, running through time into the past, taking retro to its logical conclusion…