/diy/ - Do It Yourself

>>1204173
>a good go-to device for many simple applications

I'm currently working on something quite exotic for an equally exotic purpose: a x10 dc-to-lf preamp for my multimeter, powered by a single CR2032. This is sub-millivolt stuff. Guess what I use? A 358, designed in 1972 and first introduced as the quad version 324, which then arguably became the most popular industry standard opamp ever.

Of course this cannot work because the 358 has a worst-case input offset of about 10mV and no pins for balancing. Or can it? I found a way to solve that problem. Should it drift too much I will have to zero it now and then, why not. It's not for mass production, it's for me and it's DIY.

The good thing is that almost all (?) DIP8 dual amps have the standardized pinout 1out2-3+4GND5+6-7out8V+. So if nothing goes I can easily upgrade to one of the modern low voltage rail-to-rail amps like the MCP6002 my dealer offers for 43 cents. So why then try the 358 at all? Erm.. I have a bag full of them. 5 cents per piece, original NS and TI, couldn't resist..