Are opamps interchangeable? (Stupid question I bet)

[rockgardenlove]

Are opamps interchangeable?  I've heard somewhere you can just swap one out for any other...no biasing issues?

[Zero the hero]

It's not a stupid question!
The answer is "it depends".... Usually, op-amps are interchangeable, but some circuit uses some blips and features that are unique to the op-amp used: some envelope followers and LFO are examples of op-amp sensitive circuits.





Sorry for the English, I'm drunk.

[rockgardenlove]

Alright thanks for the explanation.


So can anyone think of a clean booster that would work with almost any opamp?

[Mark Hammer]

Op-amps will vary in terms of the conditions under which they show their best side.  If the circumstances are fairly bland and mundane, then very often the range and diversity of op-amps that will work well is immense.  If the circumstances are fairly specific, then sometimes the range than can substitute is fairly narrow.

A good example is the old E-H Dr.Q envelope controlled filter.  The design depends upon a certain quirk in the 1458 dual op-amp.  I tried a bunch of differen possible replacements and none of them provided the same kind of sweep that the 1458 did.  When Jack Orman redesigned the Dr. Q as the Dr. Quack, he incorporated a design aspect that compensated for this quirk in order to make a wider array of op-amps substitute, or rather simply work.

If you want to drive a low impedance load like headphones, there are a few op-amps that will comfortably deliver current to such a load, such as the NE5532, NE5534, LM833, LM837.  A great many "better" op-amps just can't do it though.

If all you want to do is make a simple mixing stage, very often that can be done with just about any op-amp.

Take a look at the article in DEVICE (http://hammer.ampage.org  around page 10 or 11) about op-amps.  It nicely explores dikfferences between different types in the context of noise.  You can see that there are no clear winners.  Rather chip A that looks good under these circumstances start to look worse than chip B under those circumstances.

[rockgardenlove]

I've got some LF351N opamps...how "quirky" are those...

I'm rather new to all this stuff as you can tell.  But I'm learning

[Unbeliever]

So can anyone think of a clean booster that would work with almost any opamp?

http://www.muzique.com/lab/boost.htm
Bottom of the page.