Op amps? LM1458

[nathan Dodd]

is the LM1458 useful as a 4558? is it the same thing? i've seen them on the same board plus i have a shematic for a knight rider light effect (oh the days of computer modding!) and the op amp that's called for is a 4558 but the supplied part number is for the LM1458. any help would be very appreciated.

thanks,

Nathan.

[RDV]

Unless I'm mistaken(which is quite possible, having made a couple today already), the LM1458 is simply a dual LM741.

RDV

[mlabbee]

http://www.national.com/pf/LM/LM1458.html

It's a dual op amp just like the 4558.  Look at the data sheet and make sure the pinouts are the same (they usually are).  It should work.  Might sound different, but I'm guessing the LEDs don't care.

[nathan Dodd]

:?:  :?:  :?:  is that a yes or no? :| I haven't before looked this deep into the operations of IC's and have a basic knowledge of the other components - I can follow schematics and layouts but I cut my teeth in electronics when I was a young lad - my grandfather was the head lecturer in the institute of radio and electrical engineers (now the institute of electrical and electronic engineers) and his hobby was radio electronics. Sadly he passed away before I could take an interest in the theory so as a grandfather as apposed to a lecturer he allowed me to solder away at his instruction without the theory in my head. I’ve since done a basic electronics course in collage - my lecturer was actually taught by my grandfather lol so I fancy my chances at these circuits but would like to understand what I’m doing too. I suppose it'll come with hands on.

If you've read this well done! It’s useless but it explains me for future references.

Nathan.

[nathan Dodd]

http://www.national.com/pf/LM/LM1458.html

i want to use it in a pedal so I’m conscious of the sound

[mlabbee]

LOL!  That's a yes.  What you may want to do is solder in a socket so you can change out the chip and see if there's any difference.  I am in the process of building a TS-clone and tried a bunch of different op-amps in the breadboard.  All the dual op amps interchanged just fine - there was a difference in sound, though.

[RDV]

Yes, it is almost the same thing. You can use it anywhere that you can use a 4558.

K?

RDV

[nathan Dodd]

right you are!

[Paul Marossy]

Just a side note... don't be surprised if the noise level increases with a 1458. I believe that the 4558 is a quieter chip for use with audio.

[Mark Hammer]

Worth noting that one can (and often should) distinguish between chips that are pin-for-pin (functionally) replaceable and those that are *sonic* replacements.  The 1458 does "the same thing" as a 4558, a 5532, a TL072, and OP-275, a CA3240, and a list of other chips so long it would make your head spin.  That is, it provides two operational amplifiers that conform to the same pin layout for ins, outs, and power, and it conforms to the same basic principles of what required changing to alter the gain, etc.

Chips which are pin-for-pin replacements, though, will not always possess the same electronic characteristics.  So, a 1458 will "work" in the slot formerly occupied by a TL022, but the TL022 will "work" with a much lower supply voltage than a 1458 will.  NE5532's and 1458 can "sub" for each other, but the 5532 will have a much quieter and cleaner output than the 1458, as well as being capable of feeding very low impedance loads, like headphones.

In some cases, "lower quality" subs are anticipated in the design.  Some years ago, I made a Doctor Q clone, and installed a socket for the chip.  The ONLY dual op-amp I had (and I tried probably over a dozen different categories of them) that would produce usable sweep was a 1458 (what was used in the original).   Op-amps costing 5-10 times as much would not do the trick.  Luckily, Jack Orman studied the problem and came up with the solution in his Doctor Quack design, which made it possible for people to build a workable unit using virtually any dual op-amp with the same pinout.

So, the short answer is that sometimes, there are many similarly-priced or higher priced alternative replacement chips that will perform a task more effectively than the original.  In other instances, the design may rely heavily on the strengths or shortcomings of a particular chip and only that chip, or others possessing similar *electronic* characteristics, will do.  In still other instances, there may be many choices, but those choices resuolt in audible differences that could be to your taste or not.  Fortunately, most of what is posted around will be accompanied by a note/comment indicating how much latitude you have in chip choice.

[EdJ]

I really like the 1458 in a shakka brada3.Had tried tl072 and jrc4558 and 4559 but in my opinion the 1458 brings the unit alive.
Greetings,Ed