Opinions: On op amp replacement

[Brigman, Corley]

>They are OK, if you use them with reduced bandwidth, I once used 741 in a
>poweramp and it was noisy as hell, until I reduced the bandwidth to some
>7-8 kHz, (I used this amp to drive a 15" speaker)

i don't know if this directly applies, but I was recently reading about op
amps,
and they talked about "large signal" vs. "small signal" operation, with some

definition about where the cutoff point is. basically, the summary was that
an 
op amp works best with either small signal/large bandwidth or large
signal/small
bandwidth, and you can trade one off towards the other. this seems to
follow. 
this is due to the slew rate (if the slew rate is 1V/100MS, for instance (a 
fictional and VERY SLOW slew rate, it takes only 50 ms (20HZ) to go
full-scale 
for a .5V square wave, but 1000ms (1 second = 1HZ) to go full-scale for a
10V 
square wave. so, at 10V, the 20Hz signal will look like a triangle wave. not

necessarily "noisy", but at least "distorted"....this seems to explain
somewhat 
what you are seeing..

corley brigman
intel corp.
corley.brigman at intel.com

speaking for me, not for intel.