Coles 4038 Ribbon Microphone Repair

Originally developed by the BBC in the early 1950’s, and manufactured by STC and then Coles, the 4038 is known for being a somewhat fragile, but excellent sounding ribbon microphone.

We have been servicing the 4038 for more than a decade, using original ribbons and replacement parts from the manufacturer if necessary.  Average turnaround time is 2-3 days.

The ribbon in this microphone is .6 microns thin, it is amongst the thinnest ribbons used in a production microphone, so is prone to damage if not placed carefully.

Ribbon imprint occurs when extreme excursion pushes the ribbon into the screening with enough force to imprint the screen on the ribbon.  This is usually due to close placement of the microphone on guitar amplifiers.  If the cabinet is moving too much air, it forces the ribbon against the screen, imparting the pattern of the screen on the ribbon.  In several of the gallery photos, you can see this checkerboard patter