Xaudia offer microphone re-ribboning and repair services.


Ribbon Mics in Action: Tidal Love by Nothing Places

Thanks to Oswaldo Terrones, who works in Madrid and Barcelona in Spain, for sharing the album Tidal Love by alternative rockers Nothing Places.

Oswaldo made extensive use of ribbon microphones for the recordings, using a B&O BM5 stereo set for the drum room mics, an RCA 74B for guitar cabinets, Coles 4038 as the overhead and Beyer 160s on the lead guitars, percussion, etc. The music itself defies description, but you can listen for yourself at their bandcamp page.

The album was released on Spanish indie label Foehn Records, which champions new artists and "the less traditional facets of pop, rock and electronics."

Having myself once tried (and failed) to run a little record label, I have the utmost respect for those who have the tireless enthusiasm to make it work!


Witnesses of Words by Marco C. van der Hoeven. (Book Review)

This beautiful book arrived in the post last week. There aren't enough good books about the history of microphones, so it was a pleasant surprise to discover that Marco van der Hoeven had written this wonderful volume. Marco is a musician, engineer and historian, and he has a very impressive collection of microphones too.

But Marco's book is much more than a history of the microphones themselves - it is also a potted history of the 20th Century, as witnessed by the microphones of the era. Whenever and wherever a crowd was rallied, a war started or a peace brokered, there was a man or a women addressing the public - with a microphone and some kind of PA system.

A large part of the first half of the book shows how microphones were used by some of history's heroes and villains -  scientists and singers, actors and astronauts, dictators and comedians alike are shown with the current technology.

Marco identifies who used which microphone, and gives little discourses about them and why they did so. Perhaps many readers may already know that Hitler favoured the Neumann bottle-shaped microphones, but here you can also find the microphones used by Mahatma Gandhi, Margaret Thatcher and Marilyn Monroe, amongst many others.

And often the choice of equipment would have made a political statement: for example, Charles de Gaulle is shown addressing a liberated crowd through a Melodium 42B. It was very important for the new leader of a country recently freed from occupation during WW2, to be pictured with a French microphone.

The book is rich in detail, anecdotes and Marco's unique perspective, showing his passion for the history of recording and broadcast, and a wider view of its global context.

All the microphones shown are part of his own impressive collection, which includes everything from rare examples that would be at home in a museum, through recording studio and broadcast classics, to numerous small, cheap microphones that might have been used for amateur radio, taxi ranks and tape recorders.

This reminds us that most people who needed to communicate did not always need a Neumann or AKG recording classic, and had probably never even heard of them!

The latter pages of the book show numerous, diverse examples, along with various microphone-related paraphernalia such as advertising documents, stamps, toys and record sleeves. It is the combination of the social, historical and technical perspectives that makes this book unique. And it would make a great Christmas present for the microphone lover in your life!

Witnesses of Words is available for €27.95 from WitnessesOfWords.com 


Microphones of the Month: Toshiba type A vs RCA PB144 / 44A

Toshiba are well known for making mid-range consumer electronic equipment. Once upon a time they used to make some fine ribbon microphones too! 

Toshiba A (left) and RCA PB144 ribbon microphones

The microphone on the left is generally know in internet-land as the Toshiba 'Type A', although it is labelled SN-1631. It is a very close copy of the RCA 44A and its relatives. I have been informed by a Japanese expert that this was made under license by RCA, most likely in the post-WW2 era. Having looked carefully at the Type A and compared it to my own RCA PB144 (right), I have no reason to doubt this assertion.

The mics look similar outside - my PB 144 has a film set style hanger mounting, whist the Toshiba has a simple cast yoke, and the grill hole size differs.

Inside the microphones there are many similarities and few differences. Both use three large horseshoe magnets to provide the magnetic field, and and the ribbon dimensions are very close.

Perhaps the biggest difference is that the RCA uses cast pole pieces, whereas in the Japanese version they are milled. This probably reflects the tooling and machinery available at the time. Casting is an expensive process for low quantity products.

Beyond the cosmetics, the Toshiba has a 200 ohm output transformer whereas my PB 144 is a 50 ohm microphone, with these no doubt being in line with the broadcast standards of Japan and USA at that time.

(Thanks to Takayoshi Sumitomo for his expertise) 


Is the MB301 Cardioid ribbon microphone a Beyer in disguise?

I recently had the opportunity to service a pair of MB301 cardioid ribbon microphones. I had always understood these to be rebranded Beyer M260s with a custom grill, but this is not the case.

The MB301 does use a Beyer pistonic ribbon, but the motor is completely different. The Beyer M260 uses four glued rectangular magnets to make the motor,  but the MB301 employs a single large cast ferrous horseshoe magnet. In this respect it looks more like an RCA BK5 or Oktava ML19.

MB301 (left) and Beyer M260 (right)

I think it more likely that the magnet is taken from the Beyer M320 / M360 models, with different pole pieces, although I have not had the chance to compare these on the bench at the same time. Either way, the MB301 is a microphone in its own right, and not a copy of something else.

Despite the ugly oversized grill, they sound pretty good with plenty of top end and bass, and the big magnets give a stronger output signal than the early M260s.


Beebs in action: Aria ca Spira by Cordasicula

Thanks to Saro Tribastone for sharing his band Cordasicula's new album Aria ca Spira.

Cordasicula come from south-east Sicily and are inspired by the traditional music of their own island, as well as the southern Italian regions of  Calabria, Campania and Puglia.

Saro explained to me that "all these styles, mainly defined by their rhythm, are coming from those areas where 2500 years ago we had Greek people living there, globally known as Magna Grecia (Big Greece)." Their songs are a mixture of original compositions with some traditional tunes, and collectively they have a beautiful, haunting and slightly melancholic quality.

Many of the instruments were recorded with one of our customised Reslo 'Beeb' ribbon microphones. The Beeb was used to record the Greek Tzouras, violin, cello, double bass and Battente guitar for the album. For those who like technical details, they were tracked through a DAV BG1 preamp and Mytek Stereo 192 ADC converter.  It is nice to hear the Beeb working so well with these traditional acoustic instruments. Here is a photo of the  Pier Paolo Alberghini playing double bass, with the Beeb microphone up close to the sound hole.

Marilena Fede's voice was recorded with an AKG C414B, again using a DAV BG1 preamplifier.

Saro has kindly allowed us to share the Spotify playlist for the album, which should appear below.



Beebs in Action: Majetone calfskin drum heads

I have said many times before that we have fantastic, creative customers, and it is always nice when someone takes the time to share what they are doing. Sometimes their stories are amazing!

James Yates makes custom hand-made calfskin and vellum drum heads, under the guise of Majetone Industries.

Here's a video clip of James playing his drums and skins, recorded using two of our Reslo 'Beeb' microphones as top & side mics in a Glyn Johns arrangement, along with a CAD M179 in cardioid in front of the kick drum.

I think these really do sound fantastic, with a classic yet contemporary tone. I could imagine these sliding very easily into a mix without need for much processing.

You can find out more at the Majetone Industries website.

Melodium RM6 XLR conversion

It's nice to keep things original, but better to make them usable. Let's face it, the definition of a microphone is 'something that records sound', and not 'a chunk of metal that lives in a box'. :-)

Like many old connectors, it is hard to find good quality used Melodium connectors, so here is a nice simple XLR upgrade for a Melodium RM6.

I removed the base of the microphone and cut off the old connector on the lathe. Then I turned a Neutrik XLR socket to fit into its place.

Solder three wires back in place and this RM6 is now ready to record music!


MOTM - Unknown French Broadcast microphone

The Microphone of the Month column has been sadly neglected this year, simply because a record number of mics came in for repair, and it has been a challenge to keep up. But some rare and fascinating microphones have passed through the workshop this summer, amongst them this broadcasting beauty from France.

I don't know the make or model of this one and it has no markings or badges on the outside or within, but it looks fantastic. The body is made of two cast metal grills, with a cast yoke.

The connector is an unusual three pin affair, which the owner informs me is a SOCAPEX model which was common in France in the 1960s.* The yoke would sit on a custom mic stand adapter, secured by the thumb wheel.

The motor is nicely machined and uses four large wide U-shaped magnets to provide the field through custom pole pieces.

One quirk of the design is that the magnets must be removed to fit the new ribbon. This takes an extra couple of minutes, and on the plus side this means that one's tools are not pulled by the magnets. Care must be taken to get the magnet polarity right when putting it all back together.

The transformer sits in a (presumably) mumetal can at the base. This one is a 50 ohm model, like most of the Melodium broadcast mics of the era.


Replacement yoke mount for Western Electric RA-1142

Here is a replacement mount that we made for a Western Electric RA-1142 ribbon microphone.

It consists of a folded steel yoke mated to a brass barrel, threaded for 5/8" mic stands. The mount works well in practice and looks similar to the original.

Many thanks to Cicely and Darrel at Gearbox Records for the photograph.


If King Midas had a microphone...

…this would be it.

Good BBC-Marconi Type-A ribbon microphones are scarce, and perhaps one reason is that too many were decommissioned, mounted and given away as gifts or ornaments, for retirement, achievement and occasionally as trophies.

Here's a good example. This one was gold plated and became a trophy for the winner of the 'Radio One Production Saloon Car Championship', which ran in 1975 and 1976. They may look great on a mantlepiece, but they are even better in a studio!

Luckily in this instance the internal parts are present and in good condition, so it just needed a very thorough cleaning and new ribbon to become a working microphone once more.

As for gold plated microphones - the jury is still out. It would perhaps look great in a certain genre of pop video, but for my tastes, the classic bronze finish has more class and style.


Melodium 42B Yokes

Xaudia has commissioned a small number of replica yokes for Melodium 42B ribbon microphones.

Melodium 42B with new brass yoke

These are cast from solid brass, using the original 42B yoke as the template. If your Melodium has a cracked or missing yoke, then you need one of these!

Melodium 42B yoke


Stereophonic Star Girl!: Katy Bødtger with her BM3.

Here is an advertisement for B&O equipment, including the BM3 ribbon microphone, which appeared in the Danish publication Se og Hør (See and Hear), 11 December 1959.

Photo captions
(Main photo) 
Katy Bødtger with her B&O microphone which is engraved with her name.

(Top photo)
Using a B&O stereo gramophone with the new stereo pickup and stereo speakers, Katy Bødtger -the first national stereophonic singing star- listens to the results (of her recording session) from London.

(Right Photo)
Even when Katy Bødtger's busy life calls for a visit to the hairdresser to style her frisky locks before the evening's performance, her indispensable B&O Beolit all-transistor reciever is always nearby.

The sweet and fresh Katy Bødtger, who provided the vocals for the new B&O stereophonic test record, has sung her way to success in only 2 years

Many thanks to Ben Cahill for sending this in and for the translation from Danish.


Xaudia mount-a-mic in Sound-on-Sound

Our mount-a-mic adapters received a nice review in Sound-on-Sound magazine this month. These little gadgets are designed to make it easy to mount any mic with an XLR fitting.  You can read the full article here.


Reslo RV in action - Jose Estragos

Here's a new video of our friend Jose Estragos from Spain, using his Reslo RVs in his song 'Buscandote'.



Repairing an STC 4033 with a cracked casting

The STC 4033 cardioid microphone was a stalwart of British broadcasting and an early solution to the the challenge of making a cardioid directional mic. The 4033 contains both dynamic and ribbon elements, and in cardioid mode the microphone blends the two transducers together via a capacitor and inductor - you can read more about the filter and switching circuit at the wonderful Coutant.org website. The mics are still quite popular with some recording engineers, but of course there are no spare parts available after half a century or so.

Omni and Figure 8 suming to a cardioid pattern - from SOS website

I was recently asked to repair a 4033 with a cracked bottom bell, which is made from some kind of zinc alloy. When I took the microphone apart it became clear that the casting had collapsed into several pieces, only held in place by the rest of the microphone. The job looks like a challenge, and we like a challenge.

It isn't clear how this became so damaged but it is possible that the alloy itself was at fault. Zinc Pest is a notorious cause of failure caused by impurities in zinc alloys, particularly those from the 1930s and 1940s. Like this one.

The alloy is pretty much impossible to solder or weld back together, and I don't believe that any glue would be strong enough to hold when the mic is bolted back together. A new part is required but impossible to find, so we need to make one, or at least persuade somebody else to make it. Metal casting requires specialist skills and equipment, so I asked Abbey Casting to copy a good part from another 4033, and they did a fantastic job to produce this part in bronze.

The raw casting needs various holes drilling and tapping, but with a little work we have a perfect fit.

The 4033 is not the easiest thing to work on - everything is tightly packaged and the transformer is set in wax into the stem of the mic, so I had to use a hot air gun to dismantle it. Whilst the mic is apart it makes sense to replace that Hunts capacitor* with a nice NOS Mullard, and re-solder all the old joints to lower noise and improve future reliability.

With the new part in place I can put it all back together again.  The casting could be painted or powder-coated to match, but in this case the owner prefers to see the bronze.  These are 50 ohm microphones and work nicely with our impedance matching transformer boxes.

Thanks to Liam at ToeRag Studios & Richard at Abbey Casting.


MOTM - Tannoy Ribbon Microphones Part 2. Cardioid ribbons

Tannoy's Cardioid ribbon microphones

As well as the bi-directional microphones described in my previous post, Tannoy also produced several cardioid models. In the picture below, the mic on the left is the MD422. I don't have a model number for the centre and right hand microphones, but they are the same basic microphone inside, with very different grills and bodies.

The internal design of these two microphones is very simple, with a huge heavy horseshoe magnet providing both the magnetic field and creating an internal cavity to help control the pattern. The ribbon pole pieces are simple rectangular steel plates screwed into position.

There is a layer of felt behind the ribbon. I also expected to see the cavity behind the ribbon stuffed with horse-hair or cotton wadding, but in this example it was completely empty. There is a small transformer in the base of the microphone - in this example the output impedance was 2000 ohms, but I'm sure that other output options would have been available.

Despite the size, the output level is rather low.

The MD422 uses the same ribbon motor as the Type 2 bidirectional mic, and we can safely assume that they were contemporary models.

As well as these large cardioid microphones, Tannoy also produced this smaller directional model which looks rather like a dynamic mic:

The motor inside this mic is reminiscent of that from the STC 4104 lip microphone. It uses the same base and connector as the MD422 and MR425 models.

Update March 8th 2015

Tannoy were developing directional ribbon microphones from the mid 1930s onwards. I have never seen this model on the bench, but this sketch appears in Wireless world in September 1937:

Tannoy and the Houses of Parliament

Tannoy ribbon microphones were used in the British Houses of Parliament. According to Chris McClean's article for the Institute of Professional Sound, twelve 'brass barrel' microphones were fitted by Tannoy in 1951, and the system was further upgraded in the 1970s, again by Tannoy, with a system than lasted until 1991. 

Here's the problem: I have seen several of these brass-barrel Tannoy mics on sale that claim to be ex-Parliament. Too many, certainly more than twelve, and some at very inflated prices. Either Parliament kept a huge number of spares (which is possible, I guess), or this model was not exclusive, and was sold elsewhere. I have heard anecdotally of these being salvaged from church PA systems, and also the Canadian government.

Additionally, I have seen, and bought, Type 3 bidirectional Tannoy mics that claimed to be ex-HOP., although when I asked for documentation as proof of the claim, the seller was unwilling or unable to do so. Were these fitted in the 1970's refurbishment? Again, it is possible, but I have yet to see any proof of this claim. If you know better than please get in touch and show me!

The lesson here, as always, is Caveat Emptor, particularly when buying used microphones.

Update March 8th 2015
Thanks to one of our readers for sending in a link to this announcement in Tape Recording magazine (1962, issue 5). This adds to the Houses of Parliament microphone debate.

The article announces two new 'Slendalyne' ribbon microphones from Tannoy - a cardioid and a bidirectional version. Yet the cardioid version looks very much like the brass-barrel mic that was supposedly installed into the Houses of Parliament 11 years earlier! This sentence is particularly intriguing: 'Although they have manufactured microphones for internal use before, this company has never made their instruments available to the public before'. The statement is not quite true as their earlier models were widely available. But this implies that these specific models had previously been supplied to select customers, and became available widely from 1962 onwards.

Thanks to Tom McCluskie, Jamie Neale of Real World Studios, and Marco van der Hoeven of Vintage Mic World, and everyone else for sharing information and photographs of their microphones.