[Promick]

I already published a post here about a clone of these Playback 60 headphones:

https://www.head-fi.org/threads/vintage-playback-60.938678/

For half a year I hiccuped information about them on the Internet! And I found it! In this article on the 1975 Tokyo World Headphone Festival:

http://20cheaddatebase.web.fc2.com/gossip/FESTA2.html

From this article we learn that these headphones are equipped with the rarest SDM (Stretched Duralumin Membrane) diaphragm - to combine the advantages of orthodynamic / electrostatic and dynamic headphones.

Why is the name IZUMI CIS-3000? But because the Swedish company Alarik called all its headphones exactly the same as IZUMI - there is Izumi CIS-150, there is Alarik CIS-150, there is Izumi CIS-330, there is Alarik CIS-330 ..

Other names for this model: Alarik CIS-3000 (Sweden), Playback 60 / Muskat CES-3000 (USA), Howland West CIS-3000 (England).

 

[GREQ]

I found the same driver in the Rank Arena SK-600.
Very interesting driver. Too bad it doesn't sound so great aside from very good transient response.

You might want to post in this thread: https://www.head-fi.org/threads/show-us-your-vintage-headphones.420490/
as it's the most active vintage thread on head-fi.