Just wondering if anyone knows anything about these headphones I've found?
Do open the cups and offer a shot of the driver.
Probably a standard 8 ohm plastic dynamic driver.
But I don't mind surprises.
You may find those headphones also as HERU HP-120 and TEAC HP-120 OPEN AIR in natural metal silver and as ASTROSOUND HV-310 painted in white.
I'm not shure if ECHO was the original OEM manufacturer back in 1978-79...