[sdiy] Matched transistors - critical parameters?

[David G Dixon]

> Is this a critical factor in, say, a VCF, or is it the actual 
> matching that is of greatest importance?

In my experience, with multistage filters, if you are sending the same
current to the Iabc inputs of OTAs, you don't even need to mirror the
current -- just connect all of Iabc's directly to the current source.  Each
one should suck the same amount of current.