The Xaudia Blog

05-11-2015

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) 

03-11-2015

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.

31-10-2015

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.

 

30-10-2015

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!

23-09-2015

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.
14-08-2015

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.
07-05-2015

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.