The story of the man behind the RCA 44 and 77 ribbon microphones

The RCA 44 and 77

Without a doubt, the two most famous ribbon microphones are the RCA 44 and 77. Both invented and patented by Harry Olson. The 77 microphone was the very first ribbon microphone invented and introduced by RCA. It was rumored to have been in development as early as 1929 but wasn’t officially announced until 1932. The first 77 model was the rarest of all RCA microphones and featured two ribbons and an “acoustic labyrinth” which allowed it to be uni-directional.

The 44A was a smaller and lower priced version of the 77A. The lower price point was a large contributing factor to this microphone’s success and popularity. This is the microphone you think of when you picture Elvis or Frank Sinatra or an old radio broadcaster. The look of the microphone might even be more legendary than the actual performance. The 44B/BX were both a slightly larger version of the 44A. The BX has the ribbon mounted further towards the back giving it a smaller figure 8 pickup pattern on the rear side.

The BBC noticed the 44 being used in American broadcasting and wanted one for themselves, the only problem was it would cost them £130 ($8500 in 2017). This was way out of the BBC’s budget so they decided to make their own ribbon microphone. F W Alexander who worked in the BBC research department invented the Type A whose successor the 4038 is still being made by Coles Electroacoustics.

Coles 4038
Coles 4038

Ribbon microphones today

Today, ribbon microphones vary in price. modern technology has made it so manufacturing cost is low enough to make entry level ribbon microphones possible.  There are also companies working hard to make accurate reproductions of the classics. AEA is one of those companies and have even expanded on older designs. One of their more recently designed ribbon microphones is a stereo microphone that look likes a huge 77 and sounds absolutely breathtaking. You can hear it being used to mic an entire band on the YouTube channel “One Mic.”



The RCA 44 was discontinued in 1957, yet they are still seen in studios all across the world and are still going for thousands of dollars on eBay and Harry Olson’s impressive legacy has left us with these indispensable tools that have dramatically and greatly impacted the history of audio.

David Silverstein

David Silverstein began engineering at the age of 14 when he purchased a Fostex four track cassette recorder. After high school he enrolled at Five Towns College where he graduated with a Bachelors of Professional Studies in Business with a concentration in Audio Recording Technology. He has worked under renowned engineers and producers Jim Sabella (Marcy Playground, Nine Days, and Public Enemy) and Bryce Goggin (Pavement, Spacehog, The Ramones and The Lemonheads). David currently works out of Sabella Studios in Roslyn, NY.