PULSE MIC-3000LJ Headset Condenser Microphone.

Not long ago I saw a large sign on the wall in a theatre dressing room which read:- 



It turned out that a local dramatic society had been in doing a show the week before, and apparently this was a necessary reminder!

Allowing performers anywhere near your valuable and fragile microphones is always a risky business! Even in the secure, ordered environment of a studio, accidents can occur, but in the out-of-control world of live performance, anything can happen!  

All microphones are vulnerable to damage, but in theatre-land, lavalier/tie clip and headset microphones are particularly at risk. Ruining microphones is not just the prerogative of amateurs. A few years ago I was working with a well-known TV personality who, on the first night of the tour, marched confidently onto the stage whilst somehow detaching his clip-on mic. It landed on the boards directly in the path of his descending left foot! There was a loud bang through the PA followed by silence…. followed by me running on with the backup mic. So that was £300 straight down the drain!  However, these tiny, delicate mics are often trashed in a far less dramatic manner. Hairspray, makeup and sweat have caused the demise of many an expensive transducer, and headset mics have often been known to end their lives tangled up in a costume or a wig, bent and twisted beyond repair.

Sadly, I have never found a way of stopping performers from inadvertently wrecking their personal microphones. The best I can offer is a suggestion to cut the costs of the disasters! Twenty years ago the only way to deliver a quality professional performance was with an expensive, top-of-the-range lavalier or headset. However, over recent years, as new designs and manufacturing techniques have evolved, the cost of high quality miniature microphones has dropped greatly. Whilst there are still plenty of expensive models to choose from, for the more budget conscious production, there are now some excellent cheaper models to consider.

I was first introduced to PULSE headset mics a few years back whilst working on a rock ’n’ roll musical. The PA company brought in a couple to try out as replacements for the somewhat pricey microphones that we had been using. Whilst no one claimed that they were any better than the previous expensive model, we quickly concluded that there was not a lot to choose between them (apart from the price!).

PULSE MIC-3000LJ Headset Condenser Microphone.

Costs around £50 – £60

Tech Spec.

There are 2 different versions of this microphone:-  


This model has a frequency response tailored to compensate for proximity effect and is somewhat less susceptible to feedback when working live in a very loud environment.

Omni directional.

Has a near flat frequency response aimed at producing a smooth, natural sound.

NB. The mic featured here is the Omni version. 

PULSE MIC-3000LJ Headset Condenser Microphone

So…….. What does it sound like?  

CLICK HERE for some Rock ‘n’ Roll Vocals 


It is not often that I recommend a budget microphone but I do think that the PULSE MIC-3000LJ does a great job and is worth every penny!

1950’s VITAVOX Microphone

VITAVOX 1950's Microphone

This is a story which begins and ends in a radio repair shop.

Vitavox was founded in 1930 by Leonard Young, an ex-Merchant Navy seaman and radio repair shop owner. Right from the early days, the Royal Navy was an important customer for Leonard Young’s new company. Over several decades (apart from building a considerable reputation as a loudspeaker manufacturer) Vitavox has continued to produce a wide range of naval communications equipment, including a number of microphones.  

The model featured here appears to be a Vitavox Admiralty Pattern 12936 from around 1953. Unfortunately the back plate has been damaged in an accident, and has no model number displayed, just part of the serial number. This microphone and the earlier Admiralty Pattern 1359 (from around 1944) were both manufactured under patents licensed from ST&C. Indeed, both mics look very similar to the famous STC 4017C (as used by the BBC). Although this particular microphone looks physically identical to the Admiralty Pattern 12936, the absence of a model number on the back plate may indicate that it was a version sold for civilian consumption and therefore the Admiralty model number was omitted. I have previously written to Vitavox on two occasions hoping for clarification but so far my emails have gone unanswered.  

The 2 screw holes in the bodywork would originally have had a threaded mount attached for fixing to a microphone stand.

VITAVOX Admiralty Pattern 129336 Stand Mount

Sadly this has gone missing, perhaps when the mic was dropped. The 12936 weighs 933 grams! Not something you would want to land on your foot!

VITAVOX  1950's Microphone
VITAVOX  1950's Microphone front view

The diaphragm pictured below is identical to the Admiralty pattern 1359 but somewhat larger than the STC4017C.

VITAVOX  1950's Microphone Diaphragm

The magnet and voice coil assembly is very heavy and looks somewhat different to the STC, although it is basically the same design.

VITAVOX  1950's Microphone Magnet and voice coil assembly

STC 4017C below.

STC 4017C  Magnet and Voice coil assembly


VITAVOX  1950's Microphone Broken terminals connected

Apart from the obvious vulnerability of the screw terminals and the Bakelite back plate, the rest of the microphone is very solidly constructed. After soldering a lead direct to the broken terminals it burst into life as soon as it was plugged in.

So What Does It Sound Like?   CLICK HERE

The design of the Vitavox Admiralty Pattern 1359 and the 12936 date a back to the original 1930’s Western Electric 618A and the STC4017C.  By 1953 these Vitavox models were looking, and sounding, somewhat dated. This was the same year that Sennheiser released the MD21, with a near flat frequency response from 40Hz to 18kHz, taking dynamic microphone design to a whole new level, and leaving the likes of Vitavox and STC trailing in the dust! 

As I mentioned at the beginning, this story also ends in a Radio Repair Shop. An old school friend of mine Alan Marchant owns The Vintage Wireless Company in Manchester. It is an Aladdin’s cave of radio related vintage hardware. On a visit last year I found this Vitavox microphone sitting all alone on one of his shelves. He very kindly made me a present of it.      


BBC L2  (STC4104 A) Lip Ribbon Microphone Circa 1955

BBC L2 STC4104 A.  Carrying case

When this BBC L2 (STC4104 A) first arrived, I thought that I might lavish some TLC on it’s battle-scarred wooden case to make it look a bit smarter. However, the more I look at it, the more I think that I shall leave it just as it is. This microphone has clearly been around the block a few times and has history. The two stickers on the lid are REPAIR and TESTED labels from the BBC Equipment Department in the mid 1980’s. By then it had already been in service for 30 years!

BBC Equipment Department labels 1980's

I always feel a bit sad when I see a vintage microphone advertised on a selling site as being “Unopened in original box”, or simply “NOS”. No history, just old. Certainly not the case for this BBC L2 (STC4104 A). Opening the lid of the box reveals a microphone which has had a lot of use!

BBC L2 . STC4104 A in case with Equaliser

Most high quality microphones spend their lives cosseted, and looked after by skilled engineers, in the well regulated environment of a recording or broadcasting studio. This BBC L2 lip ribbon microphone has spent its life on the road with journalists, commentators and broadcasting crew. What is really amazing is that it is still in great working condition, along with its original 3 position Equaliser.

The only down side to this piece of kit is that the microphone, equaliser, and case have a combined weight of 13lbs! Most of this is the equaliser. Later models dispensed with the EQ. Instead the MED BASS roll-off was built into the microphone. However, it is pretty clear from the big splodge of red paint, that even with this mic, MED BASS was the preferred setting.

STC4104 A in case with Equaliser

History Lesson

The BBC designed the L2 in 1951 as an updated version of the L1 which had been in service since 1937. It arrived just in time to play a starring role in the televised Coronation of Elizabeth II, when it was used to capture the famous commentary by Richard Dimbleby in Westminster Abbey. Dimbleby was known as the “Voice of the Nation”, and so on this occasion the L2 was perhaps the “Ear of the Nation”, into which he delivered his stately measured tones. It was the first mass-televised event in Britain. Shops selling televisions ran out of stock as people bought them for the first time!

Richard Dimbleby Westminster Abbey 1953 Coronation of Elizabeth II

(Watch from 3.30m)

STC4104 A Side view.

STC4104 A Back view
STC4104 A side
STC4104 A B  top view. Nose guard.

The BBC L2 (STC4104 A) also made it possible to clearly broadcast commentary from even the noisiest of environments.

This microphone has an extraordinary ability to cancel out and reject unwanted surrounding sounds. It is particularly insensitive at the sides of the mic in the dead zones of the ribbon.

Here is Kenneth Wolstenholme at the 1966 Football World Cup.

CLICK LINK below to hear the end of the match !


STC4104 A Lip ribbon microphone

CLICK HERE to hear my STC4104 A in action!

CLICK HERE to hear the STC4104 A delivering a VOCAL. (Great new look for any singer!)

Technical Information

In previous posts I have occasionally (often) moaned about the difficulty of finding information about various vintage microphones. In the case of the L2 lip ribbon microphone, because it was designed by the BBC, there is a wealth of documentation available. Rather than writing a lengthy technical description myself, I would recommend reading the BBC Monograph which appears below. This explains the design and usage of this classic microphone in great detail.

P.S.  Today a version of the BBC L2 (STC4104) lip ribbon microphone is still made by Coles and is widely used by journalists and commentators all over the world.


As Always, Merry Microphones And A Happy New Year!

AYM A6 PRO Large Diaphragm Cardioid Condenser and the Mice MC-40 Small Diaphragm Cardioid Condenser

AYM A6 PRO with shock mount and pop filter

MICE MC-40 with mic clip and pop filter


Ningbo AiYinMei (AYM) Electroacoustic Technology Co. Ltd is a large manufacturing company based in Ningbo, China, specialising in the production of microphones and loudspeakers. AYM offer extensive OEM, ODM and R&D services to a wide range of client brands all over the world. Even though, if like me, you are unfamiliar with the name AYM, the chances are you will have come across their wares included in the product ranges of other manufacturers.

In the microphone industry there is a long and illustrious history of Original Equipment Manufacture and Original Design Manufacture extending back many years. In the1930’s Siemens produced the SM3 ribbon microphone which was also marketed as the Telefunken ELA M25b and ELA M201/1 and as the Klangfilm ELM24. In my own collection is yet another variation of the original Siemens model with unknown badging (possibly American).

In the 1960’s and 70’s German and Austrian manufacturers designed and made microphones and components that were sold by a number of different companies and re-badged accordingly. Beyerdynamic made microphones which also appeared under the Strasser and Dynacord brands. AKG produced several different models that were also marketed by Telefunken, Dynacord and Philips. The Philips LBB9050/05 dual capsule dynamic is an interesting example because the external bodywork is Philips own design, but when you explore inside it contains the components of an AKG D200.  Across the Atlantic in America, Shure and Electrovoice microphones appeared in various re-badged versions. The famous Shure 55S was also marketed by Dukane as the 7A65 and the Electrovoice EV664A appeared as the Dukane 7A160. A number of Electrovoice models were also sold under the University Sound label.

In the 80’s and 90’s MB Electronic (MBHO) designed a whole range of microphones that were manufactured under license by Polish state owned company UNITRA TONSIL.  

The examples listed above are just a few of many to choose from. Today the expertise and manufacturing capability required for this type of OEM and ODM has now largely moved from Europe and America to the Far East, in particular China. This takes us back to Ningbo AiYinMei (AYM) Electroacoustic Technology Co. Ltd.  The two microphones pictured above are typical, quality products, from their current range of microphones, kindly sent to me for review.

Technical Specifications    



The styling of the A6 PRO not only harks back to the classic condensers of the 1950’s but also looks very contemporary. It also comes with a neat and well-designed shock-mount. These microphones are visually very pleasing and appear to be just as good on paper. (See tech specs above.) However, as we all know good looks and great specifications are never the full story with microphones…….

What is really important is what do they sound like? 






The AYM A6 PRO and the MICE MC-40 are serious quality condenser microphones aimed at the professional market. The audio clips above suggest that they are suitable for a wide variety of studio and live applications. To check out full the range of services and products available from Ningbo AiYinMei (AYM) Electroacoustic Technology Co. Ltd, and to view their impressive facilities, I would recommend a visit to :-  https://www.aymaudio.com/


STC4105A  Grill
STC4105A Connection socket

Released in 1955, the STC4105 is a small, black, unobtrusive, dynamic PA microphone, boasting a cardioid polar pattern and a brand new design of plastic diaphragm. Previous STC dynamics were made with aluminium diaphragms which were much more susceptible to changes in temperature and more easily damaged. The 4105 was also the first true cardioid, single diaphragm, dynamic produced by STC. Previous models such as the 4035 were essentially omnidirectional, but with some directionality at high frequencies.

Here below is the original STC4105A brochure with a full description and technical specification.


I have often seen it claimed, online (mostly in web forums and on selling sites), that the STC4105 was used by the BBC.  So far, I have found no detailed evidence to support that claim! The National Science and Media Museum here in the UK have one in their collection, which I am told came from the BBC, and the catalogue simply says “Used as hand-held reporter’s microphone”. However, as far as I can ascertain, the STC4105 does not appear in any BBC R&D technical report or in any BBC Training Manual. I can also find no photograph of it in a BBC studio or on an outside broadcast. Indeed, I can find very few period photographs of it in action anywhere! I had been hoping to unearth a wealth of pictures of it on stage with the rising stars of rock ’n’ roll, but sadly all I could find were a few images of British politicians of the 1960’s pictured at conferences. I think that the sad truth about the STC4105 is that although it had a good deal to recommend it, it was not a popular choice of microphone for either broadcasting or PA.

Pictured below.

Labour Party Leader Hugh Gaitskell,  

Labour Prime Minister Harold Wilson and

Conservative Prime Minister Edward Heath. (Loving the look of boredom on the faces of the 3 guys on the left!  Is the bloke in the corner asleep?) Interesting to note that Heath is not addressing the mics and would probably have been better off with a pair of 4035s!

Labour Party Leader Hugh Gaitskell,
Labour Prime Minister Harold Wilson
Conservative Prime Minister Edward Heath

Pricing could have been a factor influencing the popularity of the STC4105.  In 1962 a Reslo RB/L (as used by The Beatles and The Rolling Stones) cost £9.12s. A Grampian DP4 (also popular with young performers) cost £8.0.  On the other hand the STC4105A cost £22.10!  In today’s money that would be more than £500.

So what does the STC4105A sound like? 

CLICK HERE for a Voice Test followed by Kalimba and Rainstick!


The early 1960’s saw the arrival of exciting, and technically superior models from Germany, Austria and the USA. The days of the STC dynamic microphones, with their limited frequency response, and somewhat out of date styling, were numbered.

However, reading this warning from the brochure;

I can’t help wondering if the fortunes of the 4105 might have been different if   STC had followed their own advice and simply manufactured the mic with a ‘simple windshield’……….Perhaps a wire mesh ball with foam inside?  After all the frequency response is not that different to the Shure SM58, which came 10 years later!

Shure advert 1970

Sennheiser LABOR W MD4 Noise-Cancelling Microphone.

Following on from my posts about the LABOR W MD7 and the MD21, here is another gem from the early years of Sennheiser.  Released in 1951, the MD4 is an unusual looking, handheld, noise-cancelling, dynamic microphone designed to suppress feedback and ambient noise.

Sennheiser LABOR W MD4 Noise-Cancelling Microphone.
Sennheiser LABOR W MD4 Noise-Cancelling Microphone. Back view
Back view.

So How Does It Work?

The MD4 is side addressed. Sound can enter through the openings on either side of the capsule. When the user is speaking in close proximity to the front of the microphone their voice is strongly reproduced and very little sound is entering at the back of the diaphram. On the other hand, unwanted sound arriving at the microphone from further away, and in particular at the sides, will enter front and  back simultaneously. Bearing in mind that the back of the diaphragm is 180 degrees out of phase with the front, these sounds will be cancelled in varying degrees. This capsule design achieved a considerable degree of off-axis rejection, making it much less likely to pick up unwanted sound from PA loudspeakers or other sources.

Outside of the military and commercial aviation, the MD4 was the first purpose designed, dynamic, noise-cancelling microphone that I can think of, on sale for domestic use.

N.B. Sadly the original Grosse Tuchel connector has gone missing but at some point I will replace it. For now it works fine direct wired.

Sennheiser LABOR W MD4 Noise-Cancelling Microphone.

In a market previously dominated by feedback-prone omnis, the MD4 gained considerable popularity for use in public address and continued in production until 1973. Although initially intended for use with speech the MD4 also found favour as a vocal mic.

Here is the legendary Sonny Boy Williamson II pictured at a folk/blues festival in Germany in 1963. 

Sonny Boy Williamson II pictured at a folk/blues festival in Germany in 1963. 
Sonny Boy Williamson II pictured at a folk/blues festival in Germany in 1963. 

So what does it sound like? 

Here is a Voice Recording Demonstrating the Noise-Cancelling properties of the MD4

CLICK HERE to listen.

And now for something completely different ………….

Close-Mic’d Guitar Amp

CLICK HERE to listen.

N.B.   In the context of a live gig the noise-cancelling properties of the MD4 will provide considerable isolation from other performers.

Below is some technical information on the MD4 from the 1953 LABOR W catalogue.

Microphones featured in the 1953 LAOR W Catalogue. Page 1
Microphones featured in the 1953 LAOR W Catalogue. Page 2

English Translation 

Moving coil microphones

Moving coil microphones have two major advantages over other types of microphones:

  • They are robust and insensitive to weather influences.
  • Due to their low source resistance, they can be easily connected via lines of several 100 metres.

Moving coil microphone MD 2

Universally usable microphone for particularly rough operation. Well suited as a table microphone because of its elegant shape in combination with a table base. Frequency range 50-10,000 Hz. Sensitivity approx. 0.1 mV/ub at 200 . Dimensions: 54 Ø x 120mm. Table base available as an accessory.

Moving coil microphone MD 21

Thanks to a new design and modern production methods, we have succeeded in creating a high-quality universal microphone that, despite its low price, is top class. Frequency range 50-15,000 Hz. Sensitivity 0.20 mV. Dimensions: 120 x 46 x 46 mm. An elegant table base is available as an accessory.

Stand microphone MD 3   

Very popular as a stage microphone because of its barely visible input stage. The high-quality moving coil element housed in the base ensures high transmission quality. Frequency range 30-10,000 Hz. Sensitivity approx. 0.08 .V ub and 200 Ω. Spherical polar pattern. Dimensions: base 170 mm Ø, 60 mm high, tube 900-1 500 mm long.

Stand microphone MD 3 Studio

In a frequency range of 30 to 15,000 Hz, it has an effective treble boost from around 6,000 Hz. Externally, it can only be distinguished from the MD 3 by the form of the input stage.

MD 3 and MD 3 Studio are supplied with an attachable Plexiglass panel, which gives the microphones a slight directivity.

Probe measurement microphone MD 3 M

The extremely small sound absorption of only 8 mm Ø does not cause any distortions in the sound field. Therefore particularly suitable for many acoustic measurements. Frequency response 50-10,000 Hz + 2.5 db.

Moving coil microphones (page 2)

Table microphone MD 3 T

A particularly elegant table microphone for first-class transmission of speech and music. Base plate can be unscrewed and has a thread suitable for mounting on a photographic tripod. Balanced frequency range 50 -10,000 Hz. Sensitivity 0.08 mV/ub at 200 Ω. Omnidirectional polar pattern. Dimensions: ball 60 mm Ø, plate 70 mm Ø, projection 450 mm.

Hand microphone MD 4

The MD4 has proven to be excellent for all voice transmissions where there is a risk of acoustic feedback. Through particularly effective compensation, any sound coming from a greater distance is very strongly suppressed. The MD4 is therefore just as suitable for transmissions from very noisy rooms. Frequency range 50-10,000 Hz. Internal resistance 200Ω. Voltage emitted during normal discussion 4mV. Dimensions: case 60 mm Ø, length 180 mm, weight 380 g. – The MD4 is available with a talk switch and also in a switchable high-impedance version.

Hand microphone MD 42

Field of application like MD4; but is end addressed. Frequency range 200-10,000 Hz. Internal resistance 200Ω. Voltage emitted during normal discussion 2.5 mV. Dimensions 47mm Ø. Length 120 mm, weight approx. 135 g.

Moving coil microphone MD 5

Universally usable microphone in a favourable price range. Can be used as a hand, table or tripod microphone. Excellent reproduction, especially for voice transmission. Available in low and high resistance, with and without a switch. Sensitivity approx. 0.25 mV/ub or 7mV/ub. Dimensions: 86 x 65 x 52 mm.

Speech microphone MD 7

Particularly good speech intelligibility due to emphasis on high frequencies. Therefore recommended for announcement and dictation systems. The soft rubber housing makes the MD7 insensitive to rough use. Available in low-impedance and high-impedance versions. Dimensions: 76 x 48 x 48 mm.

Microphone Accessories

Tripods, flexible necks, table bases, cables, couplings in various designs available.


Throughout the decade following the establishment of LABOR W in June 1945 Fritz Sennheiser and his colleagues at Laboratorium Wennebostal worked hard producing a range of innovative microphones for a variety of purposes, aimed at different sectors of the market. They offered microphones for the home, the office, the stage, journalism and TV and sound studios. As we can see from the catalogue above they demonstrated a remarkable degree of ingenuity, technical expertise and creativity. These are characteristics which distinguish the Sennheiser brand to this day.


Many thanks to my old school friend Alan Marchant for kindly donating this fascinating microphone. Alan is owner of The Vintage Wireless Co in Manchester at 174 Cross St, Sale M33 7AQ. His shop is an amazing Aladdin’s cave of ancient wirelesses, car radios, gramophones and phonographs. Well worth a visit!

Thanks also to Keith Thompson for sparing the time to record the tasty blues guitar clips.

And thanks to Hazel Hanson for the English translation of the LABOR W Catalogue.

Beyerdynamic MPR 210  (Horizontal Line Array)


A few years ago I was employed to operate sound for a big charity fund raising event at a posh London hotel. The guest speaker on this occasion was a senior member of the British Royal Family who was a patron of the charity. After dinner HRH arrived on stage to deliver her speech. The microphone supplied by the event company was a good old Shure SM58! The Princess positioned herself about 2 feet from the microphone and spoke in a very quiet and suitably regal tone. Throughout the speech she continuously turned her head from side to side without ever once actually addressing the microphone! Meanwhile, back at the sound desk, I had run out of gain, and was desperately tweaking EQ and compression in a fruitless search for level. The system was flat out!  Anyhow, at the end of the speech the audience applauded politely, even though I’m sure that most of them never heard a word of it! As the Princess turned to leave the stage, and before I had chance to grab the gain control, the somewhat inebriated TV host, who was compèring the show, leaped forward and grabbed the mic shouting “THAAAANK YOU VERY MUCH”!!!!!!!!!!!!!!

Anyone who has worked in event and conference sound for a few years will almost certainly have their own similar experience to relate!

So what could be the solution to this common problem?

A few weeks ago, out of curiosity, I purchased a Beyerdynamic MPR 210, a horizontal line array microphone specifically designed for use in conference venues and lecture theatres.

Beyerdynamic MPR210W
Beyerdynamic MPR210W Rear view showing output sensitivity control

Having tested it both in the studio and with a PA in a large conference venue I can honestly say that it does exactly what it says on the tin, and may well be the solution we have been seeking!

Here below is the Beyerdynamic MPR210 Manual and tech spec.

The information sheet below also covers the Classis RM30 which is Beyerdynamic’s vertical line array.

So what does it sound like dealing with a problematic speaker?

CLICK HERE to find out!


The current list price for the MPR210 from UK distributer Polar Audio is £746.41. This might seem like a lot of money for a desktop microphone. However, if you are in the business of conferences /events and lectures, this could be the perfect tool for the job!


If you are curious to know more about line array microphones, a while ago I penned a post about my experiments with a homemade vertical line array. https://martinmitchellsmicrophones.wordpress.com/2016/11/03/experimental-line-array-microphone/  

MB – UNITRA TONSIL MDO 23 (Circa 1975-80s)

Between 1973 and ‘75 German microphone manufacturer MB Electronic (today known as MBHO) designed a range of quality microphones that were licensed to Polish state owned electronics company UNITRA TONSIL.

Back in May 2020 I wrote a post about the UNITRA Tonsil MCU-53, an excellent cardioid condenser. Now, (from the same stable) here is the MDO 23, a slender, omnidirectional, studio dynamic.


So What is it Good For ?

The thing I have always liked about omnidirectional dynamic microphones is the absence of proximity effect coupled with the ability to handle high SPLs. This makes them perfect for close-micing loud guitar amps without having to mess around EQing unwanted boominess caused by proximity effect. I have often used a Sennheiser MD21 on rock ’n’ roll theatre shows for this purpose.

Omni dynamics also make excellent speech mics and are very often used in TV and radio for interviews. Once again the absence of proximity effect is useful, allowing a good deal of freedom of movement without significantly affecting the frequency response.

Picking up sound from 360 degrees, Omnis are also just the job when it comes to capturing ‘atmosphere’.

CLICK HERE to hear a range of sound sources recorded with the MB UNITRA TONSIL MDO 23

Technical Specifications


Frequency Response graph


Standard 3 pin small Tuchel  connector

MB UNITRA TONSIL MDO-23  Tuchel Connector


Having scoured the internet for information about this microphone I have come to the conclusion that it is somewhat rare! Apart from a couple of photographs, the tech spec and frequency response graph pictured above were pretty much all I could find. Sadly, it would appear that company records of this period have long since vanished in the mists of time.

In common with the MCU-53 I wrote about previously, this microphone has been generously sent to me by a friend in Poland, Adam Wilma. It is a serious quality professional microphone with a myriad of uses, and a very welcome addition to the Polish section of my collection. So thanks once again Adam!

Martin Mitchell Polish Microphone Collection

UNITRA Tonsil MCU-53

Acel GM-17B


The Ronette ‘CORONATION 53’ Crystal Microphone

What is a Crystal Microphone.

When pressure is applied to a crystal of Rochelle salt (sodium potassium tartrate tetrahydrate), causing it to flex, a tiny electrical charge is induced on its surfaces which is proportionate to the amount of pressure applied. Below is a simple diagram illustrating how this piezoelectric property is utilised in a crystal microphone.      

As sound waves cause movement of the diaphragm, varying pressure is applied to the crystal. The electrical signal thereby created can then be amplified to produce audio.

Rochelle salt is fragile and susceptible to damp and the passage of time has not been kind. These days it is becoming increasingly difficult to find crystal microphones that are still in working order. Even though later crystal microphones used ceramic materials such as lead zirconate and barium titanate which were somewhat more durable than Rochelle salt, the stock of working crystal microphones has been steadily dwindling. In the 60’s with the arrival of cheap, reliable, dynamic and electret-type condensers the crystal microphone was quickly superseded. 

During the 1950’s home tape recording became a popular hobby, and there was a super-abundance of budget machines aimed at the amateur recordist. Although some of the more upmarket models came with a dynamic microphone, most of these tape recorders were supplied with a cheap and cheerful crystal microphone…………… Which brings us to the Ronette ‘CORONATION 53’


The ‘CORONATION 53’ is a high impedance microphone and comes with a standard 1/4inch balanced jack.

To record my voiceover on the video I used an inline Hosa MIT-129 50k Ohms- 200 Ohm transformer which enables connection to an XLR mic input.

Ronette CORONATION 53 Advert and Tech Spec

Not perhaps the flattest frequency response graph, but nevertheless a bargain for the princely sum of 52 shillings! (20 shillings to the pound in 1953). Based on the Ronette 088-u7 ‘Soundball’ already in production, Ronette spared absolutely no expense in creating the ‘CORONATION.53’. A quick mod to the plastic moulding to create a short handle, and the words ‘CORONATION.53’ in small raised letters on the ball. Job done!  


BBC TV live coverage of the Coronation launched mass television viewing in the UK. Demand was so great that electrical shops everywhere sold out of TVs. Unlike today, the British royal family were at a high point of post-war popularity. Amidst all this flag-waving and razzmatazz Ronette saw a marketing opportunity. However, even in 1953, I really can’t imagine many people rushing out to buy a cheap, plastic, crystal microphone just because it called itself the ‘CORONATION 53’!

Ronette CORONATION 53 crystal microphone

Today they are somewhat rare. Until I bought this one I had never seen one before. However, in fairness to Ronette it does sound a lot better than I thought it would, and might still come in handy for something!

Ronette CORONATION 53 crystal microphone

And it is very shiny!