Vintage Synth Repair

--- In vintagesynthrepair@y..., "ethanzer0" <ethanzer0@y...> wrote:
> Hello,
> 
> I am trying to identify 
> the two ICs on the ARP
> 4072 submodule.  The
> schematic shows no ICs
> nor does the parts list.
> 
> TIA,
> 
> Ethan

Ethan, both IC's are linear types. One is the LM3900N (national 
semiconductor) and the other is a LM1458 (also national part) you can 
also use a RC4558 instead of the 1458. The LM3900 is drawn as 4 
seperate amps in the schematic because there are four OP Omps in the 
one 14 pin IC package.  You should be able to get these from Digikey 
on line. (digikey.com?)

Regards,
John