[sdiy] Polivocks opamps

[gino wong]

I am ready to do the Barielle Polivocks filter clone.  It specifies a
Russian kp140ya12 as orignal and as what he says is a working only
substitutes UA776, MC1776, LM4250.  I can't say I know any of these
parts very well.  Was given to understand that the UA776 is the best
replacement.  Anybody build this filter yet ?  Where can I find the
critical parts in descending order  from  the original Russian.  I
write and speak Russian so I'm game to order from Russia.

Thanks to anyone who reponds.