AEG Magnetophon K 4 specifications

Category : Tape machines

In 1938 the further developed device K4 was presented. This device, which was very stable due to the experience gained, was used in all major recording studios and broadcasters. Not only the better handling compared to the wax plates offered advantages, also the durability and storage of the sound recordings was now certainly possible.

The tape running speed from this device was 77 cm / s. This results in playing times of just over 20 minutes with a tape length of about 1 km = 1,000 m. This is also a quantum leap compared to the wax plates used so far. International standard later became 30"/sec. This is justified by the transfer of war-captured equipment to the USA. The "conversion" to the standards applicable there brought this change with it: 60Hz instead of 50Hz mains frequency and inch or inch instead of the metric system. Since the factories of the German manufacturers and also AEG were in ruins and many patents were lost, American manufacturers implemented the new data internationally as a standard.

With audio sample on youtube:

https://www.youtube.com/watch?v=cLjD0B6QoaM

You can find pictures in the radio Museum: