there are no legal questions absent an active patent for circuits - I have gone to dozens of IP seminars for engineers/entrepreneurs as a electronic equipment designer over my 30+ year career, have a patent, have searched for prior art for companies I worked for
only an active patent can protect a circuit - publish and don't file a patent application within a year and you have "open sourced" the circuit - it is free for any to use without any restriction, it becomes "prior art"
most discrete headphone amp circuit are much older often "textbook" or application note circuits - were never subject to patent at all
even if patented - anything over 20 years old that was patented has expired - again becomes the common heritage of all - that was the deal if it was patented - a Limited time monopoly in exchange for disclosing the idea for all to see, use freely after the term
asserting that circuits like CMOY, A47, Diamond Buffer, B22, O2 are proprietary is actually attempting to Steal from the commons
Ray can't keep anyone from selling bridged OPA541 industrial power op amps in a sexy case as long as they don't call it Dark Star, use his, his company's name
Glimore doesn't legally "own" any of his freely published circuits - Justin does have permission to use Gilmore's name, project names in the commercial versions
you could in fact argue that several of Gilmore's balanced circuits were covered by Nelson Pass' SUSY patent - care to ask Kevin Gilmore about his "stealing"?
and the head-fi community is totally hypocritical on the "clone" issue - it is agreed that clones of current production products are in poor taste - shouldn't be published in the DIY forum or linked to elsewhere at head-fi
but how many "lovely cube" threads are there - many with the Lehmann Black Cube product name spelled out in them, in the titles even
Edited by jcx - 10/20/14 at 7:33pm