[sdiy] discrete SSM2018?

[jhaible at t-online.de]

> btw.: also a differential mode is possible : 13700 ota 
> pair, 
> one drives inverting, the other not. Guess: dc offset may 
> cancel 
> at the output (diff amp).

... assuming both OTAs have more or less the same offset voltage.
Is this realistic ?
I know the 13600 has a tight matching of *gm* for both amps, but
why would the vos be matched as well ? (Excuse my ignorance about
chip design, but I'd expect if they manage to build two amps
with almost perfect matching of two vos of two amps, they should be
able to build a single amp with much lower vos with the same technique,
shouldn't they ?)

JH.