American Microphone Company D9A/ D9AT ‘Skyscraper’ (1938- circa 1958)

American D9AT Where's Wally

Where’s Wally/Waldo?

When the American D9A was launched in 1938 it was notable because of its fashionable Art Deco ‘look’ inspired by the skyscraper skyline of New York and other great American cities. Indeed the side elevation of the mic appears to directly reference Manhattan’s famous Chrysler Building constructed in 1930.

American D9 Side View Chrysler Building

This was the age of Jazz, and Rock’n’Roll was just around the corner. Microphones increasingly appeared centre stage in photographs and on screen as part of the performer’s visual image. Over the following couple of decades the American Microphone Company kept ahead of the game producing a number of stunning designs which appeared in movies and featured in commercials.

Katharine Hepburn, Spencer Tracy, Van Johnson, and Angela Lansbury in State of the Union (1948)Katharine Hepburn, Spencer Tracy, Van Johnson, and Angela Lansbury in State of the Union (1948)

The transducer design of the American D9 is also interesting and unusual.

The D9A /D9AT is often incorrectly identified as a ribbon microphone! This matter can simply be resolved by undoing 4 screws!!American D9AT Interior Front viewAmerican D9AT Rear inside viewAmerican D9AT Interior side view

Does this look like a ribbon motor??!!  In the advertising blurb below it is described as being ‘a pressure-velocity combination microphone’ which may have led some folks to think that the ‘velocity’ element must be a ribbon (like the Western Electric/Altec 639). However, the 2 elements are clearly both dynamic. One pressure element (omni) sealed at the back, and one velocity element (Fig of 8) open at the back. The signals from these 2 elements are combined to produce a cardioid directional response. I can’t off hand think of another microphone that is configured in this way using 2 separate dynamic elements.American Microphone Company D9 Advert

Although I can accept most of the description given above, the notion that the DA9 has ‘qualities of ruggedness’ is somewhat farfetched. Sadly, the bodywork appears to be cast in a cheap zinc alloy which is brittle and easily damaged. The yoke is also made of the same material. These days it is hard to find one without bent, cracked or broken ribs.American D9AT Damage to bodywork

Some years ago I was working on a theatre show in which an over-excited actor, (playing the part of Jerry Lee Lewis) unintentionally launched my treasured Electro-Voice EV664 right across the stage. It landed 30 feet away with a sickening thud. Apart from a slightly damaged switch the mic was unmarked and still worked perfectly! That is rugged! I wouldn’t want to try that with my D9AT. This is definitely not a mic to drop by accident. As well as the fragile body the chrome plating is remarkably thin. Even though my D9AT is from the tail end of production in the mid 50’s much of the chrome has worn away. Nevertheless it is still a stylish looking object.American Microphone Company D9AT

BUT………….. More importantly what does it sound like?  CLICK HERE for Voice Recording

The American Microphone Company D9A / D9AT was not designed as a high quality studio instrument. It was recommended for P.A. and installation use. In 1938 most dynamic P.A. mics were feedback-prone omnis. American’s dual element cardioid with its promise of higher gain before feedback could therefore be seen as an exciting new development. However, the following year Shure launched their game changing Unidyne 55 featuring a single cardioid capsule. The new single capsule design was soon adopted by most manufacturers as it was clearly cheaper to make and capable of producing excellent results. American carried on manufacturing the D9A/ D9AT for another 15-20 years. In 1955 the company was bought by Elgin-Neomatic,Inc. whose main business was watch making. At the time Elgin had the notion that they would develop miniature parts for microphones but this idea soon faded. My D9AT featured here is from the Elgin period.Badge ELGIN American Microphone Company D9AT

Around 1960 American was sold again to General Cement Company Rockford, Il (AKA G.C.Electronics). Several years later the company was finally bought by Electro-Voice who soon retired the brand.

In Conclusion

Although the American Microphone Company D9A/AT may not win any prizes for its audio quality it nevertheless provides an interesting link in the development of directional microphones in the first half of the 20th century.

Electro Voice DO56L Dynamic Shock Mount Omni circa 1980

Perfect for the socially distanced interview!Electro Voice DO56LElectro Voice DO56L OmniElectro Voice DO56L with original case

Following in the company’s long tradition the Electro Voice DO56L is a triumph of innovative design and precision engineering. The 11 and a half inch 56L is the Long version of the DO56 and was intended as the perfect tool for TV news gathering or Talk Show Hosts. Even the dull ‘Silver tone beige’ finish was carefully chosen to be unobtrusive and none-reflective under TV lighting.

Electro Voice advertising material from 1980 featured below explains in detail the design of this exceptional new microphone. The clever arrangement of the internal shock mounting is particularly impressive.

Electro Voice DO56L Literature. page1Electro Voice DO56L Literature. page2Electro Voice DO56L Literature. page 3

Phil Donahue Edit

Can’t beat a bit of subtle product placement/celebrity endorsement!

So What Does it Sound Like?  CLICK HERE for spoken word clip.

What else can it be used for?

Back in the 1950’s when AKG came up with the D12 they fondly imagined that they had designed a general purpose instrument and vocal mic. The marketing blurb featured photos of pretty girls warbling sweetly into the new microphone and indeed it was a great success with singers. Then along came the studio engineers who took a look at the tech spec and said, ‘Hey…. I bet with that frequency response curve and high SPL rating the D12 would sound great on bass drum’!  Within a few years it was on bass drums all over the world! In fact these days it is often referred to as the ‘legendary bass drum mic’ (no mention of vocals). So when I see marketing literature declaring a microphone to have a particular purpose I always find myself imagining (based on the tech spec) what else it might be good for.

Although the Electro Voice DO56L was very much designed with demands of TV journalism in mind and a frequency response tailored to the human voice, I feel sure that it could also have a range of other uses. So let me see now……………

More Sound Clips to follow as soon as COVID-19 allows!

 

Steane’s ‘Ellipsoid’ Ribbon Microphone Circa 1948. A Sorry Tale!

Steane's 'Ellipsoid' Ribbon Microphone circa 1948

Steane’s ‘Ellipsoid’ was a budget ribbon microphone made in Melbourne Australia in the late 1940’s. The advertising literature from December 1948 declares it to be the ‘World’s Smallest Ribbon Mike’!Steanes-1948-advert

Other claims made in the blurb also raised my curiosity, especially the bit about ‘No boom or puff’!  (Never previously on my list of ribbon mic problems!)   So when my newly purchased Steane’s ‘Ellipsoid’ arrived I had to plug it in straight way. However………….. As I turned up the volume on my headphones I was horrified by the sound that assailed my ears. It had a very unpleasant nasal honk and a gratingly harsh high end! This was not what I was expecting! The previous owner had assured me that this shiny gem was fully working and all original. Hmmm!

On opening it up this is what I found. Whaaaaaaaaat TF!

Astatic MC-127

The ribbon motor and transformer had been removed! The body of the mic was filled with grotty, yellowing, wading and a crudely soldered Astatic ceramic element dumped unceremoniously on the top.The whole horrifying confection was sort of held in place with a couple of random bits of grey foam.

Astatic MC-127 back view.

The grill was also stuffed with wading to stop the lose element from rattling around (and maybe improve the tone?) Perhaps it was an attempt to get rid of some of that legendary Aussie ‘Boom’ and ‘Puff’!   Anyhow, I sadly stuffed it all back together as I found it and bunged it back in the post to the previous owner for a full refund. What a disappointment!

P.S.

If like me you are unfamiliar with Steane’s microphones here is their Microphone catalogue circa 1948/9. The mics listed here offer a range of applications for both the professional and the amateur user. I notice that the Dynacard model also guarantees ‘No Boom or Puff’!  🤣  The Home Studio shown on the last page is interesting as it appears to be an early form of Karaoke system allowing the user to sing along with the radio and thereby add ‘zip’ to any party!

Steane's Microphone Catalogue 1948/9 Steane's Microphone Catalogue 1948 P.1 Steane's Microphone Catalogue 1948 P.2 Steane's Microphone Catalogue 1948 P.3 Steane's Microphone Catalogue 1948 P.4 Steane's Microphone Catalogue 1948 P.5 Steane's Microphone Catalogue 1948 P.6

Anyhow, perhaps one day another Steane’s microphone will come my way.

JrF ‘D’ Series Hydrophone.

JrF D Series Hydrophone and matching transformer

The optional matching transformer is well worth buying to use with XLR inputs.

JrF D Series Hydrophone

Expanding on my recent forays into the wonderful world of outdoor recording I am now starting to explore the possibilities of recording underwater using my newly purchased JrF D-Series Hydrophone. These are handmade to order in the North of England by the acclaimed sound artist Jez Riley French. I was looking for a high quality, lightweight device that is quick and easy to deploy. It is also very reasonably priced!

Hydrophones and the world underwater.

Hydrophones utilise piezoelectric transducers to detect underwater vibrations and pressure differences. A piezoelectric transducer is a device that produces an electric current when a mechanical force is applied to it. No external power source is required. Piezoelectric materials are able to flex under pressure, converting mechanical energy into electrical energy. Because sound is a form of pressure wave that physically moves particles, it produces a mechanical force as it comes in contact with a hydrophone. The first widespread use of hydrophones was during WW1 when they were used to detect enemy submarines. This 100 year old technology is still alive and well! Today they also have wide ranging use in underwater exploration, seismology, aquatic research, and deep sea recording. Apart from these important scientific functions, hydrophones can also simply be used to capture fascinating and unusual sounds with which to delight the ear!

My first Hydrophone Recording

Some friends of ours have a pond in their garden and this seemed like a good place to start. Dropping the hydrophone into clear open water the initial results fell somewhat short of the whales and dolphins I had been imagining…………….  absolute silence!!

However, we persevered. Moving the hydrophone into a patch of water weed suddenly produced this strange sound!  Perhaps some alien life form sending code?   CLICK On Photo

The Ford

This next recording features a delivery van driving through a shallow ford across a stream. The hydrophone is positioned in the middle of the weir about 2 feet out into the stream. As the van passes we hear the initial waves caused by the wheels followed by a strange ‘phasing’ sound produced by the reflected waves bouncing back off the wall on the opposite bank.

The Duck

This final recording is a strange one from another local pond. I dropped the hydrophone into the water close to a large rock just below the surface about 3 feet out from the bank. Along came a duck and started to rub it’s beak on the stone only inches from the hydrophone. I thought at first it was sharpening it’s beak but I am informed by knowledgeable folk that this is in fact a sort of conditioning that ducks carry out. Who knew?

To Conclude

The JrF D-Series hydrophone is a great addition to my microphone collection and has opened up a whole new world of sound exploration. Thoroughly recommended.

 

 

UNITRA Tonsil MCU-53 Cardioid Condenser (1970’s/80’s)

History

In the early 1970’s MB Electronic (now known as MBHO) produced the MB C540. This was a high quality battery powered condenser microphone. It boasted an almost flat frequency response from 20Hz to 20kHz with a slight dip at the low end. The MB C540 was modular in construction and had the option of 2 capsules (omni or cardioid).

MB C 540 AdvertMB C 540 Frequency response

In the UK it appeared as the PEERLESS MBC-540.

Reviewed here in Studio Sound May 1977.Review. Peerless MBC 540 - Studio Sound - May 1977

Meanwhile in Communist Era Eastern Europe.

This German design was also manufactured under licence by the Polish state owned electronics company UNITRA Tonsil and marketed as the MCO-30 (omni) and the MCU-31 (cardioid). According to Polish sources, the only difference between the German and Polish versions appears to have been variation in quality control at the Tonsil factory. This lead to some Polish mics reputedly sounding rather better than others.

Around 1980 the design was modified and updated. Whether this was done by MB Electronic or by Tonsil’s own engineers is not clear. (MB licenced a number of different designs to Tonsil but sadly MBHO now have no records relating to this microphone !)…….. Anyhow, the resulting microphone was somewhat shorter in length, the battery powering was changed from 2 x 15v to 1 x 6v and the previously unbalanced output was upgraded to balanced. The WCU-31 and WCO-30 capsules were retained and the frequency response appears pretty much the same. The new model was the UNITRA Tonsil MCU-53 (cardioid) / MCO-52 (omni).  The Tonsil 50 series continued in production through the 1980’s. In the late 80’s a further modification was carried out to provide 48v phantom power. This model was the MC-265.

UNITRA Tonsil MCU-53

UNITRA Tonsil MCU-53UNITRA Tonsil MCU-53 exploded view

A clever modular design. Well constructed and finished in shining nickel plate.

Tonsil WCU-31 Cardioid capsule. Front view

WCU-31 Cardioid capsule.

WCU-31 Cardioid capsule. Rear view.

Unusual 5 pin DIN connection.  (below)

Pins 4&5 in the plug are shorted together to provide a ‘switch’ for the battery. When the cable is plugged in the power is thereby switched on. N.B. This also means that if you accidently leave it connected when not in use you end up with a flat battery!! Arrrgh!

5 Pin DIN socket on Tonsil MCU-53 5 Pin DIN plug Tonsil MCU-53 Tonsil MCU-53 5 pin DIN Plug

Technical Specifications.

Pages from MCO-52/ MCU 53 Owner’s Manual UNITRA Tonsil MCU-53 ManualUNITRA Tonsil MCU-53 Manual P2UNITRA Tonsil MCU-53 Manual P3

In Conclusion.

Being battery powered made the MCU-52 /53 suitable for use with cameras and tape machines which in the 70’s and 80’s often did not provide phantom power. This made it a popular choice for wildlife and location recording.

When there is once again an opportunity to record music I will be interested to see how the MCU-53 compares to the AKG C451E as their frequency responses appear to be somewhat similar. I suspect the Tonsil may have a bit more self-noise but tonally may give the AKG a run for its money. Let’s wait and see…………

Credits.

Many thanks to Adam Wilma for sending me this pristine example of the UNITRA Tonsil MCU-53. Very generous. And thanks to my old mate blues guitarist Keith Thompson for bringing it back from Poland. His March tour was sadly cancelled after only 2 shows as Poland went into COVID-19 lockdown. Luckily for me the second gig was in Adam’s home town of Torun and he kindly dropped the mic off for Keith to bring back before the borders closed!

 

An Audio Postcard From The COVID-19 Lockdown 2020

AKG C451E (Circa 1970) A Classic from The Golden Age of AKG

Today AKG is little more than a brand name owned by a multi-national corporation. Like a tired old rock star it rests on the laurels of its former glory whilst still churning out a few old favourites.

However, if we go back to the late 1960’s and into the 70’s AKG was a powerhouse of innovative design and high-tech engineering. Major achievements include the D200 series which took dynamic microphone design to a peak which even today sees few competitors. This period also saw the legendary C12 condenser evolve into the C414 which continues to be a favourite in studios across the world.

In 1969 AKG launched its newly developed Condenser Microphone System (CMS) using audio frequency circuitry with Field Effect Transistors. This was a fully modular microphone system based around the C451E, the inherent features of which were claimed to be;

  • Low noise level,
  • Extremely high reliability and
  • Life-long sta­bility.                                                                                                    

AKG C451E with old style logo

AKG C451E no serial number

A selection of interchangeable capsules and extension tubes could be purchased along with a variety of accessories covering a wide range of recording and live sound applications. The CMS proved to be enormously popular with broadcasters, TV companies and studios throughout the 1970’s and beyond, and can be seen on many BBC music programmes of the period.

These contemporary AKG brochures/guides explain the features of the CMS in detail.

AKG C451 CMS Technical Specifications

Technical Info AKG CMS microphones.

AKG CK1 CapsuleAKG C451E with capsule removed.AKG C451E body with CK1 Capsule

C451E original case interior AKG C451E Original case

My C451E

Judging from the old style of logo and the lack of an externally stamped serial number on my newly purchased C451E (see top 2 pics), I think that it must be a fairly early example. It is in perfect condition and even the case is hardly marked. As always it was a bargain!

So What Does it Sound Like?    

Sadly, like many, many other people I am stuck at home at the moment practicing social distancing, and so recording music with my beautiful new C451E will have to wait until the current COVID-19 pandemic dies down and we can all get back to work!

Meanwhile Stay safe!

P.S.   Went for a walk today and recorded this:-    https://www.youtube.com/watch?v=k5MHEL6ZPHI

 

Today (and every other day) Has Been Designated INTERNATIONAL CLEAN THE GERMS OFF YOUR MICROPHONE DAY!

My mate's 58

As most of us haven’t any work at the moment now might be a good time to clean up our act! Vocal mics have always been a bit of a health hazard, especially those that get shared on a regular basis.

Now might even be a good time for singers who don’t own their own microphone to think about making a purchase. Maybe even choose a microphone that really suits your voice rather than settling for whatever piece of old junk the PA company throws at you!

Meanwhile those of us techies that work in theatre, events or studios could spend a useful morning with a cloth dampened with isopropyl alcohol or similar disinfecting agent wiping down our stock of mics. With dynamic vocal mics such as the Shure SM58 the grill can be unscrewed and thoroughly cleaned and disinfected. The foam inside is also washable. In the case of older mics the foam might need to be replaced. This is not difficult to do for most modern microphones and can be easily purchased online, as can new grills.

N.B. However, exercise caution if you are dealing with expensive condensers or vintage mics as these may require specialist help. (If you own vintage mics I probably don’t need to tell you that!)

If on the other hand you own the SM58 pictured above you may need a blow-torch and a big hammer!!

Stay Safe.❤

 

Recording Marimba a New Experience!

One thing I really love about this job is that there is always something new to learn! Having worked as a Sound Engineer for more than 30 years, until last week I had never recorded a Marimba.Marimba One

What an amazing instrument! With a very wide frequency response and huge dynamic range the marimba produces a stunning variety of colour quite unlike any other percussion instrument I can think of. Such tonal subtlety coupled with a battery of rapid transients requires a careful choice of microphone/s.

I did consider using a pair of Sennheiser MD441 dynamics as they have the required frequency response and have an excellent track record on other varieties of percussion, producing a big ‘punchy’ sound with plenty of attack.  I also considered going down the condenser route with a pair of AKG C414s. Great frequency response and bags of detail.  But………… In the end I realised that what was really needed to capture those rapid transients and subtle detail was a high quality stereo ribbon!  In many respects a ribbon microphone has the best of both worlds. Being a variety of dynamic it can pack a great deal of attack and ‘punch’ and on the other hand has an incredibly light diaphragm (ribbon) which can react to transients and fine detail with incredible precision. There is also an intangible ‘smoothness’ to ribbons that even the best condensers just don’t seem to have.

Extinct Audio’s ‘Valkyr’ BM9x2 Stereo Ribbon Microphone was placed on a tall stand, stage centre, about 2m away from the instrument.  The mic set in M-S configuration.

CLICK HERE to hear an excerpt from virtuoso percussionist 18 year old Darcy Beck (winner of Gloucestershire Young Musician of The Year 2020) performing ‘Prism’ by Japanese composer Keiko Abe.Darcy Beck marimbaDarcy Beck marimba

In Conclusion

Apart from capturing the fine detail of even the most rapid passages the ‘Valkyr’ also delivers a very pleasing impression of the reverberant acoustics of the hall.

Acel GM-17B. A ‘Mystery’ Polish Microphone (Circa 1987)

This wonderfully shiny and somewhat obscure vintage microphone was kindly sent to me as a Christmas gift by Adam Wilma, one of my Polish readers!

It is interesting, not because of its fabulous quality, but because it provides a small window into a fairly grim chapter of Polish history.

Acel GM-17B Cardioid Dynamic Microphone

GM-17B Cardioid Dynamic Stage Microphone

GM-17B Box

After 30 years of Communist misrule, the Polish economy was in an extremely precarious state with serious shortages of many goods. Shops were empty with long queues in the streets. In March 1979 the Ministry of Internal Trade listed 280 products for which demand was difficult to satisfy and the list grew longer in the following year. 1980 saw the formation of the free trade union Solidarity and the end of Communism seemed to be in sight. However, in 1981 General Jaruzelski declared martial law and Solidarity was banned. The USA imposed sanctions and for the next 10 years the Polish economy struggled along in a state of collapse. This lead to the rapid growth of a black or ‘grey’ market. In these conditions a ‘second’ or ‘parallel’ private sector economy flourished.

Acel GM-!7B Dynamic MicrophoneSmall scale private businesses were broadly tolerated and allowed to function supplying demands that could not be met by the ‘official’ economy. However, if a company became too large and successful it risked attracting unwelcome attention from the Communist bureaucracy and might be shut down and its assets seized. This probably explains why the Acel GM-17B microphone pictured in this post, with its original packaging, gives away little clue about the company who made it or their whereabouts! So far all attempts to trace the manufacturer have failed! Goods like this were sold through local craft associations/co-operatives, which was a way of avoiding the many permits and licences that were officially required. All we know is that this particular microphone was sold in 1987 by the Multi-Branch Co-operative in Leszno. The previous owner informed me that it cost 15,330 old zloty. (For comparison, in the same year a kilo of carrots cost 50 zloty, and a kilo of tomatoes 200 zloty).

1980’s Polish Music Scene

For musicians this was a difficult time and few could afford good quality equipment imported from abroad. The electrical industry had been particularly affected by shortages of raw materials, components and machinery. Local manufacturers did their best to meet demand with limited resources. Sadly the resulting equipment was often somewhat less than ideal! Paradoxically, this decade saw a flowering of rock music in Poland. In no other communist country was there such freedom for musicians. It was not by accident – the communist authorities calculated that for young people it would be a good way to neutralize frustration. Freedom for various subcultures also served to draw young people away from the Catholic Church, which was perceived to be their greatest threat. It was not by chance that the dates of the biggest music festivals coincided with important dates in the Catholic calendar.

Polish Plug Problems!  

One Acel GM-17B Connector.slightly annoying feature of Polish-made gear of this period is the non-standard connector! Although this may look like a standard Klein Tuchel socket (as found on German and Austrian mics of the 60’s and 70’s), the locking ring is slightly larger with a different thread. I am told that Polish-made guitars often came with non-standard jack sockets. Slightly bigger or smaller! Presumably this meant that you would have to purchase a special lead from the maker at extra cost. Or maybe it was to avoid patent infringement? Who knows?………….Anyway, an ordinary Tuchel plug on the GM-17B can be kept in place with a piece of gaffer tape!

So What Does it Sound Like?  

During the Communist era, here in Western Europe we were always lead to believe that products made in the USSR and Eastern Europe were bound to be inferior to anything made in the West! Indeed, even now I am assured by a musical connection in Poland that Polish-made gear of this period was very poor and that this microphone can probably be summed up by one word: ‘CRAP’!!  Anyhow, I don’t like to jump to conclusions so I thought I would give it a fair trial……………..

CLICK HERE TO HEAR THE GM-17B in action…….. and reach your own verdict!

Many thanks to Keith Thompson for the tasty guitars and vocals (I played shaker and programmed the kick!) and thanks once again to Adam Wilma for sending this interesting and unusual microphone.