[sdiy] Buffers on the LM13x00

[JH.]

> In particular, I can't figure out how some designs deal with the fact that
> there should be a 1.4 volt drop through the Darlington buffer. The designs
> just look like they ignore the drop altogether.

In most applications, a tight (at DC) feedback loop takes care of this.
An OTA + cap + buffer is an opamp, with I_abc you just change its
transit frequency and slew rate. Yes, the DC too, but to a much smaller
degree.

JH.