Xaudia now make P90 shaped hexaphonic guitar pickups!
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| P90 sized hexapup stereo pickup, installed in a Fender guitar. |
A good customer brought in his Coles 4050 stereo microphone for show-and-tell, which gave us a good opportunity to compare and contrast with some of the STC-Coles mics from the past.
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| STC4033, 4038 and Coles 4050 microphones |
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| Frequency sweeps of 4050 (top, red & yellow) and 4038 (bottom red) |
We ran a frequency plot of both halves of the 4050, and of the 4038.* Both mics sound very good, and although the old 4038 had a smoother top end roll off, the 4050 had an extended about +6 dB higher output and an extended frequency response. We were also very impressed with how well matched the two 4050 ribbons were – less than ±0.5dB across the range, and mostly much better than that.
The 4038 is prettier though!
* Taken at 30 cm distance. Please note that some of the bumps are due to our test chamber – there are issues with calibration when comparing a figure 8 ribbon with an omnidirection reference mic.
Thanks to John Gooding
This nice Fi-Cord 1200A tube microphone arrived without a power supply… so we built a new one!
The problem with these mics is that they are filled with resin, and it is almost impossible to get inside them. The mic has a Nuvista tube (like the AKG C28c) somewhere deep inside. Thankfully this one was working well so it just needed a new cable and an Xaudia custom power supply….
These mics were designed and built by Calrec, so it should be no surprise that they sound really good! There is a bit more information about Calrec Fi-Cord mics at Saturn Sound.
Thanks to Santiago Ramos
Our microphone of the month for September is this a rare and lovely BBC-Marconi ‘type B’ ribbon microphone. The type B is closely related to the ‘A’ series of mics (AX, AXB and AXBT) which were made from around 1935 onwards. The model B was made from 1937 onwards and used the same motor assembly, but with a smaller (yet still massive) magnet and without the ribbon tension adjustment facility.
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| BBC Marconi type B, side view |
The smaller magnet format allowed the mic to be packaged into a smaller cylindrical body, and these were apparently were often used for outside broadcast, attached to the chest of the broadcaster! One would have to be pretty strong to carry that around all day.
Although this is widely know as the model ‘B’, the nameplate calls it 8559A.
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| BBC Marconi type B badge |
As well as the outer grill, there are two extra windshields inside the mic, which would have protected the ribbon from wind blasts and dirt. These windshields did their job well – in this example, the ribbon is unbroken, but this has oxidised and stiffened over the years and will need to be replaced.
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| BBC Marconi type B ribbon motor |
The magnet and motor assembly are held in place with foam rubber, which has mostly survived the years. The output transformer is hidden behind the magnet. This had a break in the secondary winding, but luckily I was able to unwind it by a single turn and bring the mic back to life.
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| BBC Marconi type B, transformer |
At the rear of the mic, connection to the outside world is made by three screw terminals, and square bulge at the bottom shows the location of the transformer.
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| BBC-Marconi ribbon mic, rear |
Overall, the mic sounds warm and rich, although the metal can gives it a certain ‘boxy’ sound that instantly defines it as a very old microphone!
There is some more info about the BBC-Marconi ribbon mics at the Coutant and Orbem websites.
Thanks to Tom Barwood
Here is a trio of American model R331 ribbon mics…
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| American R331 microphones |
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| Is this the DeLorean of microphones? No. |
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| Impedance settings for the R331 |
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| American R331 ribbon motor assembly |
There is a lot more information about the R331, DR330 and DR332 at Coutant.org
Thanks to Myles Davis
I see a lot of Lustraphone VR53 mics around that have lost their original badges – like the ones on the left and right. The glue that was used wasn’t great, and they look rather sad without their original nameplate.
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| Replacement Lustraphone badge |
I am delighted to say that we have just taken delivery of some replacement badges for these that look absolutely fabulous. They have a silver logo on a vintage cream background, just like the originals.
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| Lustraphone VR53 with new badge! |
They of course also fit the Grundig, Pamphonic and Mimco badged versions of the VR53, and also some of the small Lustraphone dynamics too.
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| Lustraphone dynamic with new badge! |
The badges are £5 each plus post from the Xaudia website.
(Thanks to Best Badges for their excellent service!)
Today on the bench we have an unusual microphone from France. I have never heard of this brand!
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| Ervox R58 ribbon mic |
The Ervox R58 is a high impedance ribbon microphone designed for public address or home taping to a reel-to-reel recorder. It is made from a two part cast body, perhaps inspired by the RCA Varacoustic, and is nicely finished in hammertone paint. Paint still covers two of the screws, so I can see that I am the first person to look inside this one, which is always a nice feeling, like unwrapping a present!
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| Ervox R58, rear |
Inside the mic everything looks nice and clean. The motor is built around a sturdy block of clear plastic with a large horseshoe magnet to the rear, and the ribbon itself is a piston-style design similar to those found in B&O and Altec microphones.
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| Inside the Ervox R58 |
Unfortunately the transformer is not working properly – the inductance measures only 14 microhenries, which for an (estimated) 0.2 ohm ribbon would make a HPF filter at around 2KHz… I’m sure it can’t have been designed like that, so one suspects either insulation breakdown and a short, or the laminations have deteriorated with age and lost some permeability.
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| Ervox ribbon motor assembly |
I’m not sure if it is worth the effort of re-winding this one, particularly if the lams are below spec. Luckily we can make a new low impedance tranny for it and bring it back to life.
The previous owner kindly included this scan of a wiring diagram for the mic.
We have just shipped this rather lovely set of Reslo microphones to Thomas at Le Lupanar Studios in Belgium. He will be recording a brass section with two of our ‘Beeb’ Reslos, and a pair of upgraded cardioid Reslo CR mics on goosenecks.
His studio is still under construction but Thomas has been making a photo diary of the project – from the pictures so far it will be an amazing facility in a great location! How’s this for soundproofing…
Good luck with the building, and we will watch with interest as it all comes together.
🙂
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| Reslos at St Peter and St Paul Church, Kimpton |
Organ recording with Beeb Reslos – Andy Wright.
The recording was made with the mics plugged straight into a Tascam DR100 mk 2 and recorded in wav mode, then compressed to mp3 in Soundforge.
In the eighties and early nineties Hyperion Records used the organ to record classical music, including string quartets, piano solo and the Kings Consort doing The Four Seasons. Eventually Luton Airport, about 8 miles away, got too busy!
The Reslo RB mics are perhaps most famous for being used by the Beatles in their Cavern Club days. As a young photographer, Andy was assigned to one of their early gigs, and here are some of those photos at the Daily Mail website.
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| One of Andy’s photos of the Beatles |
Carrying on from my previous post….
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| 3 channel guitar switch box |
It’s a very simple custom 3 channel foot-switch box, which lets him control each of the bass, treble and rhythm channels separately. I was pleased with how it came out. Hammertone paint always gives things a 1950s industrial look.
