[sdiy] AD515's and other super-old, but once awesome IC's

[aankrom]

So I have an AD515 - the original, not the monolithic redo. I was just 
wondering if there was anything synth-diy that this would be better 
suited than anything that I could get toay. The spec sheet says that 
with a +/-5V supply the offset cuurent (or bias, I forget) was in the 
femto-amp range. It used to be in a UV-vis spectrum detector for an HPLC 
unit (even had a deuterium arc-lamp). It was the amp for the detector. 
This unit also yielded up some LF398H's and LM308AN's. I know that 308's 
are pretty obsolete, but the 'A' suffix makes them a little better and 
they do make a decent ProCo Rat clone (my Peavey Hotfoot sounds awesome 
with an LM308AH...). The LF398's have obvious uses even now. I was glad 
to have some fall into my lap. I also have a number of OP07's of recent 
manufacture. Are they really better that the originals? Oh and the LM301 
shows up in so many classic synth circuits, is there any reason for not 
substituting them? I have a lot of those too. I seem to recall a single 
IC 24dB LPF designed by Juergen Haible that he said works only with 
LM301's - I'm guessing because of a feedforward design?

I could see using the AD515 in a S/H application maybe.

AA