Re: [sdiy] Question about LM301A

[jhaible at debitel.net]

The 301 is _old_, and you will most likely find a better opamp today
for most applications.

But it has some nice features which makes it still interesting today, such
as clamping the output voltage in the opam's *driver* stage, or the various
methods of compensation.

Jim is probably  right about the troublesome feedforward compensation -
there are plenty of opamps today which are faster and have the compensation
all inside. But with so many different possibilities to compensate the 301,
there were also possibilities to (ab)use it for filter applications:

Take a look at http://home.debitel.net/user/jhaible/jh_storm_tide_2.pdf .
This was inspired by the Eventide Instant Flanger, and it has a very
interesting input filter, built around a 301. (Eventide's design, not mine.)
And I have found no other opamp that could replace the 301 in this 
application without completely fucking up the filter response. Of course
 you could build a similar filter from
two stages with a TL072, but if you try to swap the 301 with a 071 (and
discard the external compensation), you woul be lost.

JH.