[sdiy] Is a LM301 == LM301a

[Mike I.]

>From what I gather the LM301A replaced the LM301 after the first or second
year of manufacture back around 1967-1968.  The LM301A has some minor
on-chip circuit changes to give it better DC specs than the LM301. If you do
indeed have a genuine LM301 from 1967 it's probably worth auctioning on
ebay.... and you probably would want a more recently manufactured  LM301A
to use in anything you build, to take advantage of later improvements in
packaging and chip reliability.  Oftentimes, surplus suppliers  neglect to
give the full part number, listing the part as "LM301" when it is actually
"LM301A" or "LM301AH" etc. In some of the ARP circuits TL071 could be subbed
directly for LM301A, for filters you would need to be more careful as the
301A actually has a larger gain-bandwidth product than TL07x when
feedforward is used.
Cheers, Mike