Is a 1458 op-amp better than 741?
Brad Mayes
using a 1458 in an audio circuit and read somewhere that the
1458 can replace two 741s. Since I've seen may negative comments
on this newsgroup about the poor quality of 741s, it made me
wonder if my circuit was inferior if a 1458 is the same as two
741s. I first tried a LM324 quad op-amp and found them very poor
quality for driving 600 ohm loads. But the 1458 seemed to be
better. Any comments on 1458 would be helpful.
Thanks...Brad
R.Duane Officer
>Does the 1458 dual Op-Amp have better specs than a 741?
<snip>
To the best of my knowledge, the 1458's specs are _identical_ to the
741's with the obvious exception of quantity of op amps contained in
the IC. Variances will occur, of course. The packaging that the IC
comes in or the catalog, etc., you order from should have the primary
stats for comparison if you wish...
For slightly better audio quality, if you please, I would go with a
JFET based op amp. It's been a while (that's why I'm lurking here, to
try and refresh the old memory. 2 years out of school with no
application of component-level or formula practice and it all goes to
mush ; )
but I believe the JFET version is a 386...it's a 3-something, anyway.
Radio Schack and most "legitimate" suppliers should stock it.
Luck...
=======================================
R.Duane Officer (du...@pluto.njcc.com)
Field Services Engineering
Technical Resources International
=======================================
Booth, Thomas G
Well, IMO the 1458 really isn't much (if any) leap forward from a
741...about the only advantage you could get w/ a 1458 is better slew rates
(if you get the 1458S version, if memory serves).
Neither the 741 or the 1458 was really intended to directly drive 600 ohm
loads - minimum load spec for these devices was around 2.2k ohm, though you
could get by w/ lower load impedances at reduced voltage swings. A better
alternative, if you intend to drive 600 ohm loads directly and want a dual
amp in an 8 pin DIP, is the NE5532N or equivalent; it is spec'd to deliver
+/- 10 volt swings into 600 ohm loads (w/ +/- 18 volt supplies). While not
"state of the art" in performance, the 5532 is a better performer than
741-era devices for audio circuits and should be available at reasonable
cost.
Good luck -
TGB
\\ The opinions expressed herein are my own. //
Joe Gurney
: In article <4gtu7m$i...@ccshst05.cs.uoguelph.ca>, bma...@uoguelph.ca (Brad
: Mayes) wrote:
: >
: > Does the 1458 dual Op-Amp have better specs than a 741? I'm
: > using a 1458 in an audio circuit and read somewhere that the
: > 1458 can replace two 741s. Since I've seen may negative comments
: > on this newsgroup about the poor quality of 741s, it made me
: > wonder if my circuit was inferior if a 1458 is the same as two
: > 741s. I first tried a LM324 quad op-amp and found them very poor
: > quality for driving 600 ohm loads. But the 1458 seemed to be
: > better. Any comments on 1458 would be helpful.
: > Thanks...Brad
: Neither the 741 or the 1458 was really intended to directly drive 600 ohm
: loads - minimum load spec for these devices was around 2.2k ohm, though you
: could get by w/ lower load impedances at reduced voltage swings. A better
: alternative, if you intend to drive 600 ohm loads directly and want a dual
: amp in an 8 pin DIP, is the NE5532N or equivalent; it is spec'd to deliver
: +/- 10 volt swings into 600 ohm loads (w/ +/- 18 volt supplies). While not
: "state of the art" in performance, the 5532 is a better performer than
: 741-era devices for audio circuits and should be available at reasonable
: cost.
Most if not all pro audio gear uses the 5532 op-amp. They will drive a
600 ohm load quite nicely and the specs are much better than a 741
--
Joe Gurney
Director of Engineering
CHTZ / CKTB
Standard Broadcasting
email: jgu...@freenet.npiec.on.ca