In the days before XLR became the standard microphone connector, most manufacturers made their own custom connectors. The British companies Reslosound, Grampian, Cadenza and Film Industries all followed this practice.
I guess at the time it was a good idea and meant that the company could earn extra revenue for spares and replacements, but 40 or 50 years down the line it is becoming increasingly hard to find good quality connectors for these mics.
Here is a humble Film Industries mic that arrived without a connector. It was converted to XLR at the owners request. With a bit of care the new connector can be fitted without spoiling the look of the mic. Now it is good to go back into service. Better than being stuck in a box!
Cadenza ribbon microphones are quite common, but there seem to be more microphones than there are connectors for them. The mics were originally supplied with an integrated stand & connector, which was ideal for desk recording, but not very effective for hanging over a drum kit.
This mic was missing its connector, so here is a chop-job to convert to XLR output….
The connector was removed from the mic and the bottom thread cut off and filed flat. Then a piece of brass rod was machined to fit snugly into the base of the mic, and this was bored to accept a standard three pin XLR insert.
The XLR has the added advantages of making a good earth connection, and also gives a way of mounting the mic on a stand as it can be slipped into a standard mic clip. I think elongating the base makes the look more elegant too.
At Xaudia, one of the most common enquiries that we get is for replacement cables and connectors for vintage microphones. Very often we can help, but some of the connectors are becoming impossible to find in good condition and at reasonable prices.
Grampian GR1 ribbon mic with connector & cable
One example is the Grampian plug that was used for their GR1 ribbon and other microphones. These connectors are hard to find – they can be obtained by buying a less valuable Grampian dynamic mic, but we have found that the plugs come with various slightly different threads, which means that one plug cannot be guaranteed to fit another microphone. And the connector is not ideal in the first place – it has two prongs and for balanced use the screen of the cable is connected to the plug casing (and therefore the microphone) by pressure only. Grounding issues are therefore common.
There is, however, another approach, which is to dispense with the connector entirely, and replace it with a modern, industry standard XLR connector. This microphone arrived without a plug and with a rather battered and bent connector at the bottom of the mic.
The decision was made to replace it with a silver-plated XLR output, which also solves any grounding issues as the third pin may be connected to the body of the mic.
The old connector was cut off, and the housing threaded to accept the new connector.
The new XLR output is then simply screwed in place… and the mic rewired and put back together.
XLR modified Grampian
Everything works nicely – just plug a standard XLR mic cable and it is ready to record.
Some may see this as vandalism, and perhaps from a collectors point of view, it is. However, the conversion is sympathetic, and it is far better for the mic to be making recordings, than to be languishing in a box unused.