Category Archives: Classic & Antique Microphones

Information on classic, old, and antique microphones.

The StudioMicZone Microphone Collection

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Here’s a little break from the usual high-tech talk. Since my microphone collection shows up in studio photos every now and then, I thought I’d describe each of the mics on the shelf and their significance. These are older microphones that I have for display purposes, some are functional and some are not. This is different from my “Mic Locker” which are the microphones I actually use for recording. I collected most of these years ago when cheap old microphones were easy to find at flea markets.

Microphone Collection (Left to Right). Electro-Voice 726 Cardyne I, Electro-Voice V2 Ribbon, Shure 556 Unidyne I, Shure 55S Unidyne II, Shure Cardiline 664, Turner 598, Lafayette PA46, Turner 99, Sony ECM-22P, Astatic JT-31, Kellogg T-48-C Carbon

Electro-VoIce 726 Cardyne I Microphone – This is a uni-directional dynamic microphone from the late 1940s. It’s similar in size to the Shure 556 “fat boy” microphone, and likely was Electro-Voice’s competitive answer to that microphone. (More Information)

Electro-VoIce V2 Ribbon Microphone – Unfortunately the nameplate is missing on this microphone so I can’t make a firm identification. I have verified that it is a ribbon by disassembling it.

Shure 556B Unidyne I microphone – This is Shure’s Unidyne I, Model 556B “Fatboy” microphone that I bought at a flea-market, probably about 20 years ago. It was one of the original Unidyne, 55 series mikes, and I bought it mostly for decorative purposes. This one works, but the response is rather thin. I have another working one that we use occasionally. (More Information)

Shure 55S – This is an old working Shure 55S Unidyne II microphone. It is smaller than the original Model 55 (and 556B) The Shure 55S, often called the “Elvis Microphone” is without a doubt the most iconic microphone ever made. Shure still manufactures them, although equipped with their latest Unidyne III cartridge.

Shure Cardiline 644 Sound Spot Shotgun Dynamic Microphone – This is a highly directional dynamic often used on a boom in early TV broadcasting. This one is non-working, but I have a gray non-reflective one as would be used on a set that works well.

Turner 598 – This was a popular PA microphone from the 1960s. This model was the first microphone that I ever repaired. I used to set up sound for assemblies in High School and we had a broken 598. I opened it up and found that the wire from the voice coil to the transformer had broken. Somehow I affected a repair on that thin wire with my trusty Wen 100 soldering gun and the mic was back in service.

Lafayette PA46 Dynamic – This model of microphone was the first one I ever owned. My parents bought it for me to go with my Lafayette tape deck in the early 1960s. The mics were a Japanese import and sold under several brand names.  The mic came with a bad capsule, but I found another with a good capsule and corroded body and replaced the capsule in this one and now it is a working microphone.

Turner 99 – The Turner 99 was their most rugged Dynamic microphone of the 1940s. I t was used wherever a microphone was needed that would stand up to abuse. There is no special significance to me other than that it is another classic microphone from the 1940s.

Sony ECM-22P – This is an electret condenser microphone from the early 1970s. This was one of the first condenser microphones I bought. I have four of them and they all still work. (More Information)

Astatic JT-31 – This is an inexpensive crystal microphone made in the 1940s by Astatic Corp. which is now CAD. This microphone has become a favorite for blues harp players and one in working order will fetch a good price. The crystal element has decayed in this one and it is for display only.

Kellogg T-48-C Carbon Microphone – This was a communications microphone, possibly military, from the early 1940s. This is likely the oldest microphone that I own. Carbon microphones were used originally for telephone communications and then for broadcasting in the early days of radio. In the late 1960s, between high school and college, I worked at a ship-to-shore radio station, WMI, in my hometown of Lorain, Ohio. All of the operator positions used microphones similar to this one as the operators provided communication to all of the ships on the Great Lakes in the days before satellite and cell phone communications.

Growth of the Microphone Industry

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The growth of the microphone industry and the growth of the home recording industry are entirely intertwined. The home recording revolution began in the 1970s with Tascam Model 10 console and Series 70 recorders. This equipment made home recording affordable and also spawned the opening of many small commercial studios. I opened my studio in 1973 and benefited from the new, lowcost, electret condenser microphones hitting the market.

At the beginning of the home recording revolution, there were only 10 – 15 manufacturers making studio-quality microphones. According to the Recording Hacks website, which contains probably the most comprehensive listing of studio-quality microphones on the web, over 151 manufacturers were making microphones for recording studios in January of 2020.

Frank Sinatra at Columbia Records recording on an RCA 44B ribbon microphone.
Frank Sinatra at Columbia Records recording on an RCA 44BX ribbon microphone.

The manufacturers got it right the first time. Classic microphones from the 1940s, 1950s, and 1960s were made exceptionally well and had a superb performance. The RCA 44BX and 77DX,  AKG C12, Neumann U47, U67, and U87 are still very desirable today and bring high prices, not only because they are collectible, but because they always produce excellent results. These classic microphones were used on many hit recordings, not primarily by choice but because they were the only ones available. At that time, the selection of microphones was minimal.

Progress in microphone design over the past 75 years has been one of evolution rather than revolution, with only a few significant innovations.

The first notable innovation was the invention of the FET (field effect transistor). Condenser microphones required a preamplifier in the microphone body because of the high impedance of the capsule. A vacuum tube and the associated high-voltage and filament power supply were needed for that preamp.  The FET allowed manufacturers to get rid of the large high voltage tube supply and miniaturize the components in condenser microphones. Vacuum tube condenser microphones were replaced by new FET microphones that were battery powered.

The next innovation was the implementation of phantom power to power the microphone over the standard 3-wire balanced cable. The expensive batteries became an option and soon disappeared as phantom power became the norm in the 1980s.

The innovation of the electret condenser microphones allowed for smaller microphones because their permanently polarized diaphragm eliminated the need for an external bias power supply. The elimination of the bias supply resulted in a cost reduction and a smaller microphone. Lavaliere microphones got more compact, and low-cost electret condenser microphones hit the rapidly growing home recording market. My first condenser microphones were a pair of Sony ECM-22P microphones I purchased in 1973. They still work well.

The steady progress in dynamic microphones and ribbon microphones was given a shot in the arm with the discovery of the metal compound, neodymium. Neodymium was discovered independently by General Motors and Sumitomo Special Metals in 1984. Magnets made from this metal are the material of the smaller magnets and higher outputs in dynamic and ribbon microphones because of their intense magnetic fields. Neodymium spawned a new generation of more compact ribbon and dynamic microphones.

During that time there was a continued improvement, re-design and re-engineering that produced a continuous forward movement in the quality and features of studio microphones.

Seventy-Five years of design experience plus precision CNC machining equipment automated the production of many microphone parts, bringing the cost down and providing considerably improved quality control. The takeaway here is that because of significantly increased sales volume and lower automated manufacturing cost; there is a greater variety of quality microphones with many options available at reasonable prices than ever before.

Electro-Voice 726 Cardyne I Microphone

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Electro-Voice 726 Cardyne 1 Microphone

Electro-Voice 726 Cardyne 1 Microphone

I’ve had this Electro-Voice mike in my collection for a number of years, but never bothered to test it since it had an Amphenol MC-3 connector on it and I didn’t have the proper cable. But, I acquired a box of Amphenol connectors recently, so I thought it was time to check out this classic mike.

This is a large microphone, comparable in size to my Shure 556 “fat-boy, Elvis” microphone. It weighs in at about 2 ½ pounds. The best I can tell, it first appeared on the market in the late 1940s.

According to the EV spec sheet:

The CARDYNE microphones are cardioid unidirectional dynamic types operating on the E-V Mechanophase principle. They utilize dual phase shifting diaphragms to produce a high degree of uni-directivity at all frequencies.

The CARDYNE models are designed for extremely accurate reproduction of music and speech. The directivity gives it unusual versatility in increasing the working distance from the user by reducing reverberation and acoustic feedback. High output provides an excellent signal-to-noise ratio for broadcasting studio pick-up.

My unit is in excellent physical condition externally, but I decided to open up the mike to make sure the insides were OK before wiring up the new cable. Two screws on the back loosened the rear of the case and two screws under that loosened the front cover.

Electro-Voice 726 Cardyne 1 Microphone, internal back view.

Electro-Voice 726 Cardyne 1 Microphone, internal back view.

The insides were clean and not corroded, but all of the rubber shock-mount material had hardened and some of it turned to powder. Since the cartridge assembly just flopping around inside the case, I needed to replace all of the shock-mount material.

This microphone achieves its cardioid directionality by means of a resonance chamber that is part of the dynamic cartridge assembly. This assembly rests against a block of sponge rubber that is about ½ in. thick, 1 inch high, and two inches long. I was easily able to cut a replacement piece from a piece of ½ rubber that I had and glued it into place. There were a couple of bumpers on the front of the cartridge assembly that rested against the front of the case. These I replaced with pieces of self-adhesive rubber that I cut from a sheet that I bought from a craft store.

The shock mounts that held the back of the resonator to the mike frame were not as simple. What I needed were eight ½ inch diameter rubber washers, ¼ inch thick, with a ¼ inch hole in the center. I used a hole punch to punch the ½ circles out of a sheet of rubber, and then punched a ¼ inch hole in each one of those. These were close enough in size that I was able to re-assemble the shock mounts with the new rubber pieces, tighten the screws, and verify that is worked properly.

Electro-Voice 726 Cardyne 1 Microphone, internal front view.

Electro-Voice 726 Cardyne 1 Microphone, internal front view.

I double-checked the wiring inside of the mike to make sure that I hadn’t broken any wires, and then put the mike back together.  I didn’t have any silk or thin foam to replace the windscreen inside the shell, but it was in fairly good shape, so I’ll save that for a later date.  I then used my Dremel tool with a brass brush to remove oxidation from the exterior of the mike, and it cleaned up nicely.

I wired up a new cable for the mike to go from the Amphenol connector on the mike to a standard male XLR connector. I set the impedance switch on the back of the mike to “Low” and plugged the mike in. It worked.

Amphenol MS-3 connectors.

Amphenol MS-3 connectors.

Then, into the studio for some comparative recordings between this E-V mike and the Shure 556. The E-V is brighter and has a higher output than the Shure. Both mikes seem to have a significant amount of distortion. I am guessing that the capsules in both mikes are showing their age and may have some damage. Replacement capsules of the same type are not available. I could upgrade to a newer capsule, but then they would no longer be vintage mikes.

So, I’ll just be on the lookout for NOS capsules on eBay. There was a NOS capsule for a Shure 55S on eBay this week, but the mounting is entirely different that the 556, so I passed on it even though it is probably the same capsule. These mikes will be mostly for decoration, except for that occasional funky recording project that pops up now and then.

What is interesting is the amount of mechanical apparatus that was needed back in the 40s to create a directional mike. My new Electro-Voice N/D 468 microphones provide hyper-cardioid directionality and great sound in a package that has probably 1/8 the size of the old 726. We’ve come a long way in the past 70 years!

View of internal wiring.
Internal view of the microphone showing the wiring of the impedance switch and the transformer.

Shure 556B Dynamic Microphone

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Classic Shure 556 Unidyne dynamic microphone.I’m starting to organize some of the stuff I brought from the old studio and found this old Shure Model 556B “Fatboy” microphone that I bought at a flea-market, probably about 15 years ago. It was one of the original Unidyne, 55 series mikes, and I bought it mostly for decorative purposes.

The 556B is the mike that Elvis and others used at Memphis Recording Service during some of their early recordings for Sun Records. (Not this particular microphone, but the same model.)

The 556B that I have is a broadcast mike, whereas the 555 is a general purpose microphone. Bob LaJeunesse tells me that the data sheet has a 1942 date, so the mike could be pretty old. The “B” indicates that the impedance is 200-250 ohms. Strangely, when Shure introduced the Unidyne II in 1951 which is about 2/3 the size of the original Unidynes, they kept the same model numbers for the new microphones. So there was a Unidyne 556 like mine and a smaller Unidyne II 556. Very confusing. The smaller Unidyne II was re-issued several years ago, with a more modern cartridge, and is still available new.

Model number trivia aside, I plugged the mike in this morning, which I thought I had never done, but Kevin Mileski reminded me we used it on his first album – the memory is going. A quick check proves it still sounds really great. Rumor has it that we’ll be using it on some vocal sessions shortly, stay tuned.

Sony ECM-22P Microphone

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Sony ECM-22P Microphone

Sony ECM-22P Microphone

When I started in the recording business in 1973, my work was primarily live concert recording for schools and churches. My location setup was a Teac 7030 2-track reel-to-reel recorder, a Shure M-688 stereo mixer, and two Sony ECM-22P Electret condenser microphones.

Sony’s ECM series of electret microphones were a game-changing innovation in condenser microphones when they were first introduced in 1968. First of all, the electret capsule in the microphone did not require a separate bias voltage. Electret technology allowed a permanent electrical charge to be applied to either the diaphragm or the backplate of the microphone capsule, similar to the way a permanent magnet is magnetized, except in this case it is an electrical field rather than a magnetic field.

Elimination of this need for external bias meant that there was less circuitry inside the microphone and no external bias power supply was required. Phantom power had only made its way into microphone technology a few years prior, so most condenser microphones still had an external power supply.

The other innovation was the use of a JFET transistor amplifier for the electret capsule. Solid state circuitry was only introduced into condenser microphones a few years before this, so many condenser microphones still required heavy, bulky power supplies for their vacuum tube amplifiers. In fact, the Neumann U-87 solid state microphone was released in 1972.

So the ECM-22P was a real innovation and quite revolutionary. It brought the cost of a quality condenser microphone within reach of the small and home studio owner and was one of the products that helped fuel the home recording revolution. I paid about $100 each for the pair of microphones at that time.

Sony ECM-22P Microphone Internal View

Sony ECM-22P Microphone Internal View

This mike was powered by an Eveready 206 9V battery which was expensive and hard to find, or from phantom power. I didn’t have a phantom powered mixer at the time, and there were few, if any, available. If you forgot to turn the switch on the mike off, it was likely the battery would be drained the next time you needed to use it.

The circuitry in the microphone was very simple with a single JFET driving an output transformer with a switchable 600 or 250-ohm output. The power switch had three positions, Off, Music, and Voice. The voice position engaged a low-frequency roll off filter.

The ECM-22P is a cardioid microphone with a rated frequency response of 40-15,000 kHz. The signal-to-noise ratio was 66 dB, which is quite noisy by today’s standards, but a little better than the signal-to-noise of a reel-to-reel recorder running at 15 ips. with high-bias mastering tape. So the mikes performed well for me for some years.

I bought another pair of the microphones when I moved from my home studio into a commercial space in 1976. I still have all four of them, and they all still work even though I don’t use them anymore. I eventually replaced them in the early 1980’s with Shure SM-81 microphones which still get a lot of use today.