matching transistors

[Jay Martin]

Electronics Now had a circuit (last year I think) that made that job real
easy.  If I remember it took the transistors under test and biased them the
same.  It then sent the outputs into opposite sides of a standard op-amp and
introduced a sweeping signal to the transistor pair.  If the transistors
were "matched" there would be no output (or very little anyway) from the op
amp.  

I'll see if I can find it over the weekend.  Otherwise the above should be
enough to re-create the idea.

Jay Martin

-----Original Message-----
From: Bipin E Butala [mailto:buta0006 at tc.umn.edu]
Sent: Thursday, June 29, 2000 4:12 PM
To: synth-diy at node12b53.a2000.nl
Subject: matching transistors


hi i was curious is anyone knew where i could find instructions
on how to match transistors. i heard that it is described in old
moog manuals but unfortuantly i don't have one of those..:-(

thanks,

bipin