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.

 

Season’s Greeting to All My Readers! (Just in case you need some more Christmas Music!)

Usually at this time of the year I post a slightly crazy photo, but this year I thought you might like an audio Christmas card! This video is a piece of Christmassy joy captured by the Extinct Audio BM9x2 ‘Valkyr’ Stereo Ribbon Microphone. Apart from the fabulous audio quality and detailed stereo image this microphone is also extremely unobtrusive (see pics), making it perfect for this type of live performance.

No EQ or processing has been used.

Many thanks to Pam Smith at http://www.petalpics.co.uk/ for the great photos.

Martin Mitchell’s Music For 3 Saucepan Lids and Spatula ! Recorded by the Gaumont-Kalee Type 492. 😊

Inspired by washing up! I did this recording for a bit of amusement on a cold rainy Saturday morning (crazy sound engineer’s idea of having fun!) ……… but I really love the way this beautiful old ribbon mic reproduces the ring and detail of these sounds. I suspect that the 492 would also make a great drum overhead. Anyhow, enjoy!

Gaumont-Kalee Type 492 Ribbon Microphone (Circa 1950) A rare piece of British cinema history.

Gaumont-Kalee Type 492 Side viewGaumont-Kalee Type 492 Side view2Gaumont-Kalee Type 492Gaumont-Kalee Type 492 Box

I bought this microphone out of curiosity! It caught my attention because I had never seen or heard of it before (shock, horror!).  It came in its original felt lined wooden box, of the kind normally reserved for valuable scientific instruments. The name Gaumont I recalled from the old UK cinema chain but beyond that I knew nothing.

Researching this microphone has proved to be a challenging task.

It would appear that the Gaumont-Kalee Type 492 was never on sale to the general public. It was marketed along with other Gaumont-Kalee equipment purely within the cinema industry. So far the only contemporary references I have found have been in trade journals such as British Kinematography and Cine Technician.

It was manufactured by British Acoustic Films Ltd (B.A.F.), which by 1947, along with Gaumont-Kalee, was one of the many companies which made up The Rank Organisation.

Specifically designed as a boom mounted microphone, the Gaumont-Kalee Type 492 was most likely used to record dialogue and music for the classic British movies made at The Rank Organisation’s studios in the 1950’s. By this time The Rank Organisation in Britain had become one of the biggest film companies in the world. They owned 5 major studios including Pinewood and Ealing and Denham. Rank also owned and controlled distribution for several hundred UK cinemas.

B.A.F., under the Gaumont-Kalee brand, produced a number of sound recorders for the cinema industry, both optical and magnetic. Below is an advert from Cine Technician March-April 1953. My assumption based on this is that the Type 492 ribbon mic (and the Type 493 condenser not covered here) were designed for use with these machines. A 1947 BBC technical report on The G-K Sound on Film Recorder also makes passing mention of 2 microphones being supplied with the machine.

The Gaumont-Kalee Portable Recording Equipment pictured here features 35mm or 17.5mm sprocketed magnetic film which could be run in sync with a professional movie camera. In post-production this enabled easy editing and transfer.Gaumont-Kalee Portable Recording Equipment

These days when we talk about portable sound recording equipment we are maybe thinking of something the size of a mobile phone. The ‘portable’ equipment described above would have filled the boot of a car and required fairly muscular crew to carry it! However, its mobility nevertheless extended the possibilities of location recording both for TV and film production. (Also worth mentioning that magnetic film made a considerable improvement to the available frequency response.)

From this advert it can be noted that other users included BBC Television, Universal, a number of Newsreel companies, San Angel Inn (Mexico) and Dear Film (Rome).

 

Technical Information on the Gaumont-Kalee Type 492

In the absence of any detailed manufacturer’s literature, below I have made some observations and speculation about the design of this mic.

Noise has always been the enemy of the motion picture sound recordist, whether it be camera and equipment noise, on-set noise, tape hiss, or electrical interference generated by lighting. Trying to obtain clarity, especially in dialogue, has always been something of a challenge. This was particularly true in the age before shotgun mics.

  • In common with all figure of eight microphones the dead zones at the sides of the Type 492 could be directed to minimise unwanted mechanical noise from cameras and other equipment.
  • The yellow wiring around the ribbon is cunningly arranged to form a humbucking loop, helping to reject electromagnetically induced–noise. This is very useful when operating in the vicinity of lighting equipment and large mains transformers radiating strong magnetic fields.
  • In addition, the interior of the grill is lined with ultra-fine wire mesh which not only provides a certain amount of blast protection and back pressure for the ribbon but also creates an effective Faraday Cage.Gaumont-Kalee Type 492 inside 1Gaumont-Kalee Type 492 inside 2
  • The interesting-looking baffle arrangement on either side of the ribbon has the effect of producing a boost to the high end frequency response. This may provide greater clarity to dialogue, especially when recording at a distance (in order to keep the boom mounted 492 out of the camera shot). It was also common practice at this time to boost signals going to magnetic tape at around 4kHz on the way in and cut by the same amount on playback. This returned the desired signal to flat and reduced unwanted tape hiss by several db.Gaumont-Kalee Type 492 inside 3Gaumont-Kalee Type 492 inside 4
  • The connector pictured above is a Reslo. This mic came with a 3 pin Amphenol. When I took the mic apart it became clear that this was a modification as it was chipped and had been filed to fit! Stewart Tavener at Xaudia informed me that the two 492s he had previously repaired had Reslo connectors. The Reslo fitted perfectly. Thanks Stewart!
  • Unlike many of the ribbon microphones of the period which have impedances of 50 ohms or less, this Gaumont-Kalee Type 492 has an impedance of 300 ohms with a strong output signal which requires considerably less amplification than many of its contemporaries.

So what does the Gaumont-Kalee Type 492 sound like? CLICK HERE.

 In Conclusion.

Having emailed academic institutions, museums, collectors and fellow sound engineers all over the world, so far I have only tracked down a handful people who have come across the Type 492. The serial number on mine is 132 and I assume from the complete dearth of information that only a limited number were made. Sadly, much of the recording equipment from that period has long since gone in the bin along with company records, technical literature and drawings. Trying to unearth information about the Gaumont-Kalee Type 492 has highlighted to me the growing problem of vanishing history in the field of audio technology. Living links to the past are dying out and records are being lost. It is therefore important to preserve what we can before it is too late!

NEWS FLASH UPDATE  12 Nov.2019  

   have kindly unearthed this single page ad for the Gaumont- Kalee Type 492 and Type 493  in a May 1951 GB-Kalee product catalogue ‘Everything for the Cinema and Theatre’.  GB Kalee Type 492 Advert 1951

UPDATE 28th Nov.

Stroke of luck! Have just purchased this GB-Kalee Catalogue for 1950 on ebay and here on page 4 are the frequency response graphs for the Type 492 and 493!

GB-Kalee 1950 Catalogue. Cover

Gaumont British-Kalee proudly projects it’s brand across the world! The British Empire is marked in pink. Within a couple of decades the Empire was gone along with GB-Kalee and most of British industry!  (N.B. Even by 1950 the map above was out of date. India got rid of us in 1947 !)

 


Gaumont-Kalee Catalogue Page 4

Useful Links.

https://www.gettyimages.co.uk/detail/news-photo/an-engineer-works-on-a-laboratory-set-up-to-develop-news-photo/90777079?adppopup=true   Taken at B.A.F. factory at Mitcheldean in Gloucestershire in 1953, on the workbench is a Gaumont-Kalee Type 492. The zeppelin shaped mic up in the air is the Type 493 condenser.

http://xaudiaelektrik.blogspot.com/2014/02/motm-gaumont-kalee-type-1492-ribbon-mic.html  It is interesting to note that the microphone featured here has a 1 inserted in front of the 492. Apart from having an impedance of 50 ohms, what the difference was I have no idea.