November's microphone of the month is a British long-format ribbon that was sold under the names "Lustraphone" and 'Grundig".
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6UVTOZWbmI9xWsIsrtM4jvcZfZmpBzgdz9kQPEvIPKgJBxXxjGM1AMxt1oRXmVsi5RgS4Fus37FhyphenhyphenngKnCErYbW0_x9LubA2E54FWZjS-gRaXdpkX63Mbxnn7O3hX9huyUzPujizLI38/s400/Lustraphone_1.jpg) |
A Lustraphone-badged ribbon microphone in glorious brushed stainless steel finish |
This mic was available in at least three different impedances, and I have come across 30, 200, and high impedance models. Unfortunately the badge often falls off so you don't always know what you are getting! Most of the models I have seen are finished in a bronze hammerite colour, although there is a deluxe low impedance model which has a gorgeous brushed stainless steel finish. Despite the different badges and finishes, the mics are exactly the same on the inside (transformer aside).
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZwBd4Czyz4-UtK_kYXQIEUyqUjh2VXe07TeMP7nbcOt_2PZ-oj4HjTxLr8oDQsgb_A-Jvlh72vQCtAsy3pt6G04SLkuMnFtNHNToHER9P2IrfpGTYXzSS-aD8n-BfLQ9D0SQTIFLmr1o/s320/Lustraphone_2.jpg) |
Lustraphone ribbon microphones on the bench |
One of the ribbon clamps sits on a spring-tensioned screw thread, which allows fine adjustment of the ribbon tension. This makes tuning the ribbon very straight-forward, and allows the owner a little bit of grace if the ribbon becomes a little stretched over time. This feature should probably be mandatory on all ribbonmics!
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPEfSSzhEAoKk9BXzBrjKimb1c1iGIw9gVdiKEalyjU3-FK3o0ouPMMrIAJnxxiFJQ5oqJAiHwOLAIC1mm6ju674SEilym6hV0Q4Qy-dFra8jB1BRcUVW8HPJ7ZRGRL7ULHhNRH4ric6U/s320/Grundig_ribbon.jpg) |
Grundig badged lustraphone mic, opened up for service |
The magnetic field is supplied by a pair of horseshoe magnets (which unfortunately sometimes age with time, losing their strength). Connection to the rest of the world is made by a balanced three-pin paxolin plug, which are hard to come by now. The middle pin is ground, with the audio on the outer two pins.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSv8xsws8-jd-JdVNNzmRb16H6pKWaXdH_6nDTIH-KBD809yRlriaOz1aq60_PXx9ESVUqekognXYNGpPj6CJKCiytFaFgmxKhVdYWN-QCvb4Wp9RQsEHIQmrpPP-9itHnkauiIEqivzU/s320/Lustraphone_3.jpg) |
Rear connector and original plug. |
Fortunately, a male XLR connector can be modified to fit by slicing off part of the barrel.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg46QE8c_Q2vr9RjKW6Hyl2XgV5ABpLTgJxkrMD-VRgrNe4NV0lBoQc-HQv4G8KOukfYBQpO2G4MDbh7jmIYn6H2NTrBDJsUrWGRT2SxJDGPlBy9eA5198v8V2LpHLNmnvT2yn-BLxtAqQ/s320/Converted_XLR.jpg) |
XLR connector modified to fit the mic. |
The long ribbon and motor design gives these mics a full bottom end and a pronounced proximity effect. Here are the frequency plots for three of these mics that we have serviced recently:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmEnpcfBxRJnv5bsqSY4RYHPu1YO75KK5MH97yHMHBgm837IxEM3RGo-bxlpmg8mI5g4JapeGPWv12leRLxOW6JZtiaM12SBix5NIa5i_dmbysD5OMy2UyS1JqXUkYCQ1kIcuc3YDVmBo/s400/Lustraphones.png) |
Lustraphone ribbon mic frequency plots. |
(Thanks to Mark Stevens for additional information).
Update 23/1/12. These microphones were also sold under the brand Pamphonic. One appeared recently on ebay:
Update 29/2/12. And here is one with a Mimco badge!