IC's single or dual. Are they interchangeable ?

Started by Krinor, October 12, 2007, 11:32:25 AM

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Krinor

I'm playing around with a Distortion+ circuit and was wondering: What will happen if I throw in an Lm386 N-3 instead of the standard 741 ? Will it work at all, or will it create some kind of havoc ?

Mark Hammer

#1
Pinouts are different.  Functions are different.  A bit like asking if a screwdriver and a chisel are interchangeable.  Well, they both fit in the rack I have on my workshop wall, and they both have handles, but.....

Using half of a dual op-amp to sub for a single is okay, though.  Just remember that the pins for each section will all be on one side of the chip for a dual, buit distributed on both sides for a single.  You will probably notice that many PCB layouts from several of the regular layout/project sites here stick a dual where only a single is needed.  The logic behind this is that dual generally cost the same as singles thesedays, and it is simply easier to order a bunch of duals for building than to order single AND duals.

David

Quote from: Krinor on October 12, 2007, 11:32:25 AM
I'm playing around with a Distortion+ circuit and was wondering: What will happen if I throw in an Lm386 N-3 instead of the standard 741 ? Will it work at all, or will it create some kind of havoc ?

Well, it sure won't work properly!   :o

The 386 is an audio amplifier chip.  It is most emphatically NOT an op-amp.  Regarding the question in your heading, single op-amps can often be substituted for other single op-amps (there are some caveats) and duals for other duals.

About the only useful way I can think of to swap a dual for a single is when you're breadboarding or using perf or stripboard.  You'll have to modify your circuit layout to account for the difference in pinouts.  IIRC, you'll probably have to ground out the inputs of the unused op-amp.

Krinor

Thanks for taking time to answer my utterly imbesile question.  :icon_biggrin:
I haven't really studied these chips much yet. I'm still only a tiny embryonic effects hobyist, so please have me excused.  :icon_wink:
I just read somehwere that it's possible to use transistors as clippers, and so I thought - "hey, how about interchanging ic's ? After all they have the same pinout"... Thanks for the input. I'll put my beloved 386's away for now. But while we're at it: is it possible to exchange a washing machine for a refridgerator ? Ha, ha  :icon_wink:

petemoore

  Nice cheep good duals can have the 'other' side open for use in some other application [like buffer, or gain recovery for tone control, boost, etc.]
Convention creates following, following creates convention.

Krinor

Oh heck: Since this is my personal "Kristian makes a fool of himself" thread I might as well ask another obvious question for lack of not being way too lazy. Here it comes:  What on earth is a Buffer ? Why do I need one, and which one should I build ?  :icon_rolleyes:

David

Quote from: Krinor on October 12, 2007, 12:01:18 PM
Thanks for taking time to answer my utterly imbesile question.  :icon_biggrin:
I haven't really studied these chips much yet. I'm still only a tiny embryonic effects hobyist, so please have me excused.  :icon_wink:
I just read somehwere that it's possible to use transistors as clippers, and so I thought - "hey, how about interchanging ic's ? After all they have the same pinout"... Thanks for the input. I'll put my beloved 386's away for now. But while we're at it: is it possible to exchange a washing machine for a refridgerator ? Ha, ha  :icon_wink:

Kristian:  no excusing necessary and you're no imbecile.  I made the same mistake myself.

Krinor

Quote from: David on October 12, 2007, 12:12:32 PM
Quote from: Krinor on October 12, 2007, 12:01:18 PM
Thanks for taking time to answer my utterly imbesile question.  :icon_biggrin:
I haven't really studied these chips much yet. I'm still only a tiny embryonic effects hobyist, so please have me excused.  :icon_wink:
I just read somehwere that it's possible to use transistors as clippers, and so I thought - "hey, how about interchanging ic's ? After all they have the same pinout"... Thanks for the input. I'll put my beloved 386's away for now. But while we're at it: is it possible to exchange a washing machine for a refridgerator ? Ha, ha  :icon_wink:

Kristian:  no excusing necessary and you're no imbecile.  I made the same mistake myself.

Just trying to be a proper gentleman.  :icon_cool:

David

And you succeeded!  As for buffers,  look up Jack Orman's article on "Basic Buffers".  Just click AMZ toward the top of the page.  :icon_mrgreen:

Krinor

Thanks David.  :icon_wink:
Now let's let this thread hurry on down into the murky depths of pages past.

CGDARK

Quote from: Krinor on October 12, 2007, 12:08:10 PM
Oh heck: Since this is my personal "Kristian makes a fool of himself" thread I might as well ask another obvious question for lack of not being way too lazy. Here it comes:  What on earth is a Buffer ? Why do I need one, and which one should I build ?  :icon_rolleyes:

Read this, it will answer your questions.

http://www.muzique.com/lab/buffers.htm

CG ;D

Mark Hammer

Don't pack your 386 chips away just yet.  While the 386 does not sub for the 741 or TL071, it HAS been used for distortion pedals.  For instance, the Frantone Hep Cat ( http://www.frantone.com/hepcat.html ) uses one, and so do several DIY projects here.


Krinor

Thanks Aron. I love the name of that one! I've been aware of it for a while now. Guess I'll just go ahead and build one. Right now. Is there a layout anywhere ? Perf or vero ?