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previous: Smitty Does anyone know of a source for th... -- 8/25/1999 10:29 PM

Re: RC4739 Dual op-amp

8/25/1999 11:34 PM
R.G.	Re: RC4739 Dual op-amp There isn't any magic about the 4739. It was just a low noise opamp when opamps in general were noisy. You can replace it with a TL072 (it's dual, isn't it?) if you note which pins on the 4739 have the (+), (-) and output designations on them, and connect those points to the corresponding symbol on the TL07x parts; this will be on a different pin number. Also, you have to connect the most positive voltage to the + power pin on the TL07x and the most negative voltage to the - power pin on the TL. The easiest way to do this is to glue the replacement part upside down, legs up (a process known as "dead bugging") and run wire wrapping or other fine wires to the pins from the appropriate holes on the PCB. This is a simple way to rescramble pinouts. I guess I really ought to just draw up diagrams for this and put it in the FAQ. Someone asks about once a month.

8/25/1999 11:34 PM

R.G.

Re: RC4739 Dual op-amp

There isn't any magic about the 4739. It was just a low noise opamp when opamps in general were noisy.

You can replace it with a TL072 (it's dual, isn't it?) if you note which pins on the 4739 have the (+), (-) and output designations on them, and connect those points to the corresponding *symbol* on the TL07x parts; this will be on a different pin number. Also, you have to connect the most positive voltage to the + power pin on the TL07x and the most negative voltage to the - power pin on the TL. The easiest way to do this is to glue the replacement part upside down, legs up (a process known as "dead bugging") and run wire wrapping or other fine wires to the pins from the appropriate holes on the PCB. This is a simple way to rescramble pinouts.

I guess I really ought to just draw up diagrams for this and put it in the FAQ. Someone asks about once a month.

Replies:

Dave James The 4739 is a dual op-amp but may n... -- 8/26/1999 1:05 AM
Smitty Thanks< I'll try the dead bugging i... -- 8/26/1999 1:28 AM