Thanks, did that and got general spec, I gues I should have asked for a schematic. Sorry for the vague request. Short of a schematic I welcome any comments from users as to pro's and cons for various applications. eg. works well for ******** or when used to ****** etc. ya get the idea. Shortcomings, pluses that sort of thing. I do know they are solid as a rock, damn near indestructable. Also, in terms of performance, how do they stack up against other di boxes. I love mine as I said and have had nary a problem for almost 20 yrs. Good in my book. Comments welcome.