[Jergh]

Hello! Somebody is offering me a pair of Koss K/6ALC headphones. They're from the late 70's and apparently still in very good shape (conditions? - non-english-native-speaker!).
In the koss virutal museum I only found the k/6LC with no further details. Does anybody know anything about these headphones?

 

[Eagle_Driver]

Jergh, those old Kosses were heavy (at least as heavy as the current Sony MDR-CD3000 - 14 ounces!). And the K/6ALC was an "updated" version of the K/6LC (the "LC" in the model name implied the inclusion of a volume control on one or both earcups at that time). I didn't bother looking up its impedance or sensitivity, but I knew its frequency response range being 10-16,000 Hz. Sound-quality-wise, the K/6ALC suffers from the typical "old closed Koss" boominess and muddiness.