General Information
From the MID 70's ,And got them from the CBC vaults 
as a gift
as a gift-
Venture Electronics (VE) Pro Supernovathe first on-ear headphones developed by Venture Electronics -
ETA Audio O2From the ETA Website: "The legacy Mini Open headphone was an exercise in maximum minimalism -... -
PRIMO CD-3On-ear open-back headphones from the Japanese company PRIMO -
ETA O²The legacy Mini Open headphone was an exercise in maximum minimalism - stripping down the... -
HIFIMAN HE6se V2The second generation of HIFIMAN's HE6SE headphones.
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Stanton Dynaphase FiftyThink they are from early 80's not sure because i could not find any info. -
AKG K140Not sure when they were built but purchased around early 80's
