[sci.electronics] Subject: A QUESTION ABOUT OP AMPS

Mike Ranta (miker@polari.UUCP) (04/20/91)

An LM741 would probably work for you application.  It normally
requires a bipolar powersupply (a positive and negative supply)
which may be a problem.  It's also not especially fast or quiet
(low noise).  If these things are not problems, you're on the
right track.  If they might be, I'd suggest an LM833 which is
a low noise op-amp specifically designed for audio use.  Any
electronics distributor (either local, or mail order i.e. Digi
Key) should have them.  If you need single supply operation,
an LM324 would give about the same performance as the LM741.

kludge@grissom.larc.nasa.gov ( Scott Dorsey) (04/22/91)

In article <3816@polari.UUCP> Mike Ranta (miker@polari.UUCP) writes:
>An LM741 would probably work for you application.  It normally
>requires a bipolar powersupply (a positive and negative supply)
>which may be a problem.  It's also not especially fast or quiet
>(low noise).  If these things are not problems, you're on the
>right track.  If they might be, I'd suggest an LM833 which is
>a low noise op-amp specifically designed for audio use.  Any
>electronics distributor (either local, or mail order i.e. Digi
>Key) should have them.  If you need single supply operation,
>an LM324 would give about the same performance as the LM741.

Please don't ever use a 741 or an LM833 for audio.  This is 1991, and
there are far better choices.  The Motorola 34082, the AD712, and a whole
raft of nifty stuff from PMI and even TI.
--scott

raoul@eplunix.UUCP (Nico Garcia) (04/23/91)

In article <1991Apr22.135312.20413@news.larc.nasa.gov>, kludge@grissom.larc.nasa.gov ( Scott Dorsey) writes:
> Please don't ever use a 741 or an LM833 for audio.  This is 1991, and
> there are far better choices.  The Motorola 34082, the AD712, and a whole
> raft of nifty stuff from PMI and even TI.

Scott, you silly person, why not? I do analog design work for a lab where we
work on synthetic hearing and I use 741's all the time. They're cheap,
low-power, easy to debug, robust, and almost idiot proof. For a professional
high-quality audio application, install something better.  But for
prototyping and home use, where crossed leads and power glitches happen
frequently, why not use something a bit more robust? And 1/10 the price?
-- 
			Nico Garcia
			Designs by Geniuses for use by Idiots
			eplunix!cirl!raoul@eddie.mit.edu

kludge@grissom.larc.nasa.gov ( Scott Dorsey) (04/23/91)

He said:
>I said:
>> Please don't ever use a 741 or an LM833 for audio.  This is 1991, and
>> there are far better choices.  The Motorola 34082, the AD712, and a whole
>> raft of nifty stuff from PMI and even TI.
>
>Scott, you silly person, why not? I do analog design work for a lab where we
>work on synthetic hearing and I use 741's all the time. They're cheap,
>low-power, easy to debug, robust, and almost idiot proof. For a professional
>high-quality audio application, install something better.  But for
>prototyping and home use, where crossed leads and power glitches happen
>frequently, why not use something a bit more robust? And 1/10 the price?

Okay, I concede.  The 741 is cheap and indestructable.  I should point out,
however, that he was talking about a high quality audio application from the
specifications which he gave.  However, I have this evangelical streak which
leads me to point out that every audio application should be a high quality
one; this is a religious issue and not an article of NASA policy :-).
--scott

gt0869a@prism.gatech.EDU (WATERS,CLYDE GORDON) (04/23/91)

In article <1065@eplunix.UUCP> raoul@eplunix.UUCP (Nico Garcia) writes:
>In article <1991Apr22.135312.20413@news.larc.nasa.gov>, kludge@grissom.larc.nasa.gov ( Scott Dorsey) writes:
>> Please don't ever use a 741 or an LM833 for audio.  This is 1991, and
>Scott, you silly person, why not? I do analog design work for a lab where we
>work on synthetic hearing and I use 741's all the time. They're cheap,

Why use a 741 when a TL072 or Tl074 is almost the same price and is orders of
magnitude better in noise, bandwidth, etc? You can get 074's for <$1 around 
here, at least (quad op-amp- neat for crossovers-LP and HP in one chip)
I use these extensively and have not observed any problems. Of course,if
I intended to build something to go with high-end audio gear, I would
probably use something like a 5539, for no holds barred.Expensive but 
VERY clean.But , for general use, the 074 does fine.
My $.02
Gordon.

-- 
WATERS,CLYDE GORDON-Georgia Institute of Technology Atlanta Ga 30332 
******<LANGUAGE IS A VIRUS! - Laurie Anderson-Home of the Brave>******* 
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