Coles 4038 Ribbon Microphone Repair

4038_fullOriginally 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.

Coles 4038 ribbon replacement

$200.00Add to cart

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.  Here are are a few examples of what can go wrong:

Torn ribbon in a 4038 ribbon microphone
Torn ribbon in a 4038 ribbon microphone

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.

This ribbon has ribbon imprint as well as a tear at about halfway

The ribbon in this microphone appeared to be OK, but suffered from extremely uneven frequency response.  Closer inspection revealed some clear glue used by another repair facility that had dried to the pole piece and ribbon, impeding it’s movement.


I can only imagine the life this ribbon lived.

Destroyed Ribbon