The Coles 4038 is a ribbon microphone produced by Coles Electroacoustics. The microphone was designed and patented by the BBC in the 1950s^[1] and was originally known as the STC 4038.^[2] The sound of the microphone has been described as "British" with a "BBC politeness",^[3] and its appearance has been likened to that of a waffle iron.^[4] It is used in both sound recording and radio broadcasting.^[5]

The microphone was designed by the BBC in 1953 and the prototype was assigned the model number BBC PGS/1.^[6] It was designed as a result of the BBC's request for a strong and affordable microphone that was smaller than previous models^[7] (such as the Type A). The 4038 was an improvement on the Type A's frequency response, and was described as "less obtrusive".^[8]

The microphone was produced by Standard Telephones and Cables^[9] before their manufacturing was transferred to Coles in the mid-1970s.^[10] Since its design in the 1950s, the technical specifications of the 4038 have remained unchanged.^[11]

In recording environments, the 4038 is often used as drum overheads and on brass instruments.^[3][12] The microphone became a favourite of British recording engineers in the 1950s and 60s, but did not receive widespread use in the United States.^[12] The microphone was described as recording sounds "bigger than life" – such as drums or amplified guitars – some Beatles and Led Zeppelin recordings featured 4038s as overhead microphones on the drum kit.^[13][14]

In a 1994 interview, Steve Albini said that "if [he] owned one mic, this would be it".^[1] Albini has also commented that "really nothing beats them as an overhead on a drum kit".^[14]

At one point, Bush House (home of the BBC World Service) used the 4038 almost exclusively.^[15]

The 4038's frequency response is flat, with a range of approximately 30–15,000 Hz.^[16] The attenuation of high frequencies reduces sibilance on vocals, but also reduces detail.^[3]

The microphone uses a bi-directional polar pattern.^[17]

The microphone is connected using a Western Electric jack connector designated 4069, which adapts the microphone's 3-pin output to a standard XLR connector.^[18]

Sensitivity (at 1,000 Hz Open Circuit Voltage)

-65dB re: 1 Volt/Pa^[19]

Impedance

300 ohms

Produced

1950s–present

• Shorter, D E L; Harwood, H D (1955), "The Design of a Ribbon Type Pressure Gradient Microphone" (PDF), BBC Engineering Division's Monograph #4, London: British Broadcasting Corporation