[sdiy] dragging down op-amp CV output?

Neil Harper metadata at gmx.com
Sat Jan 15 06:29:31 CET 2022


2022 - the future is now!

a pretty basic question, but I'd like to follow best practices. I have a
little envelope generator that outputs 0-5V and the output stage is a
TL074 opamp.

i'd like to send this CV to a few places internally in my project synth
but also have several external output jacks. so my first intuition was
to grab all of those outputs at the output of this single opamp cell,
maybe with a 1K resistor in front of each.

my concern is that if anything unpredictable happens to the external
outputs (like getting grounded while being plugged into a jack or
something) then it will drag down the outputs that are also going
somewhere internally.

i know i can just take the CV and send it through a buffer-follower for
every output i want and definitely be safe. but the design space is
getting a bit cramped and i'm also just curious.

if one of the external outputs does get grounded when sourcing the full
5V it draws 5mA thru the 1k resistor.. can the TL074 handle that? does
it pull the other outputs down, or can it eventually overheat and freak
out? Datasheet suggests that it's meltdown-protected, but I can't see
how much current it can source and maintain the 5V.

thanks for all of the help everyone, and a happy 2022. this mailing list
is a rare truly helpful corners of the internet not attempting to
commodify my attention.

--
/// Neil Harper
/// Every Wave is New Until it Breaks




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