# Good Opamp that replace JRC4580? Anyone?



## DSlayerZX

My creative sound card refuse to work me any longer, so I guess that card is going onto the FS section soon.
 But because of that, I actually decided to get a Juli@ for future possible upgrade (DAC) and just for its sound.

 Here are my questions.

 After do some online research on the card, I realized that the opamp use on Juli@ is JRC4580. I would like to replace since when I replace the opamp on my x-fi yield a significant change on my sound qualities.

 [size=x-large]COTDT, LOOK AT WHAT YOU HAVE TURNED ME INTO[/size]

 but anyway, what opamp do you guys recommend me to replace them by, and also, if you can, can you also provide me with US sites that sell those OPAMP. (not National Semiconductor since they don't ship to boxes)Thank you


 After a short research, I came up with AD815AY, AD8610
 but those info are a bit old... so any recommendation? thank you


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## Filburt

Well, one op-amp I use generally for this sort of thing is the AD8397. Just make sure you bypass across the rails (e.g. connect something like a 2.2uF cap between pins 4 and 8 of the op-amp). AD815 can't be used for this application without substantial modification of the circuit and an adapting apparatus.


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## cotdt

MWAHAHAHAHA!


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## cotdt

Quote:


  Originally Posted by *Filburt* /img/forum/go_quote.gif 
_Well, one op-amp I use generally for this sort of thing is the AD8397. Just make sure you bypass across the rails (e.g. connect something like a 2.2uF cap between pins 4 and 8 of the op-amp). AD815 can't be used for this application without substantial modification of the circuit and an adapting apparatus._

 

Mr. Opamp speaks!


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## Filburt

Quote:


  Originally Posted by *cotdt* /img/forum/go_quote.gif 
_Mr. Opamp speaks!_

 

LOL

 There are many other op-amps that could be used, but I noticed people seem to have an affinity for driving stuff from the output of their sound card, so I thought this may be a good choice.


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## DSlayerZX

no, i would not be driver stuff from my output, it will be directly connected to my amp, so, anyone opamp recommend for this purpose?


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## DSlayerZX

Also, I just read the AD8397 chip set, by means of "bypass" do you mean that I will solder a 2.2 uf capacitor onto those two pins and leave those two pin alone? or should I also solder pin4 pin8 onto the SMD area alone with the capacitor connecting to them.

 But yes, my sound card will be connection to my headphone amp, so ..... any good opamp that is suited for this purpose?


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## DSlayerZX

I just spent some extra time on the internet, it seem the LM4562 (used in the x-fi) will work as a replacement of the opamp, is this true?


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## MisterX

Filsburt:
 How long do you think it will take for the magic smoke to get out of the regulators if he does that?


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## Filburt

Think so? Even this POS SB Live that came in the computer I got as a hand-me-down can handle the 8397.


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## DSlayerZX

wait... I am not quiet sure what do you guys mean there... so if I connect the v+ and v- together, there is a potential that I might damage the card?

 Also, seems like 8397 is similar to a 4580, what is the point of adding the capacitor anyway?


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## Filburt

Solder all of the pads, then solder each lead of the cap to each pin specified. The AD8397 has considerably better performance than the NJM4580. I don't know if your card can handle the quiescent draw; I haven't had a problem with that on other cards but I don't know the Juli@ very well.

 The capacitor is to keep the impedance that the op-amp sees at the rails low so that it performs properly (e.g. sufficient power is available on demand), otherwise you risk oscillation and it's more than the regulators that may smoke


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## DSlayerZX

interesting, I am currently looking at LM4562, AD8397, AD8620, wonder which one perform better.... and wish that they will fit my card without explode to pieces..

 one more question though, If I want to get the AD8620, which one from the digikey should I get, 


http://www.digikey.com/scripts/DkSea...?KeywordSearch

 and most importantly, would it work with my sound card?


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## Seaside

Adding cap at opamp means, that op amp is very sensitive. In other word, the OP is very hard to use. It could go crazy when other parts of the circuit is not designed for it. We do not know your sepcific circuit, in this case the Juli@, is working with the OP without a problem or not. Adding cap is one of the way to prevent OP being go crazy.

 I would personally say... avoid sensitive OP even if it has good sound.. at least... until you know how to deal with it. There're plenty of other OPs that is less demanding with good sound.


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## cotdt

i would say forget the AD8620, it's like an inferior version of the LM4562. Try the AD8397 instead!


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## Filburt

Bypassing means you're practicing sensible technique for the use of op-amps, including of course high-speed op-amps. I wish people would stop acting like it's some sort of terribly difficult thing to deal with and discouraging people new to the hobby from pursuing higher performance solutions because of these simple additional steps. It holds people back and I think greatly contributes to the eventual view that commercial solutions are somehow more refined or 'tuned' versus what is available in the DIY sphere.


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## DSlayerZX

Alright, I just pulled the trigger, I bought 3 LM4562 and two AD8397, hope I will like them. Also, it is time for me get some capacitors from the lab hehehe


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## Seaside

edited ;p
 .


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## Seaside

And glad DSlayerZX made his decision. I think he made good choice.


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## Filburt

I'm not judging you in particular. I've just noticed a trend of people giving strong warnings against dealing with bypassing and higher speed op-amps when they really aren't that scary if you just apply a basic level of care in installation. I don't think it's bad to suggest to people to be careful, but I also don't think it's necessary to make it sound like it's not worth trying. The AD8397 is a great general purpose op-amp for many applications and, in my experience and opinion, worth taking the time and effort to use. If you have a high impedance on the input, it can be worth looking at a FET input op-amp due to lower current noise, though...although it's not always the case that there will be enough noise to make SNR a problem; size of the signal will come into play.


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## MisterX

Quote:


 Think so? 
 

Don't think so. 
 I know so.


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## DSlayerZX

wait... now I am confused..... did you actually used the 8397 and ended up ruining the sound card? if not, then how can you tell


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## tola555

Hello,

 I just soldered 2x LM4562MA chips to ESI Juli@ but I'm not happy 
	

	
	
		
		

		
		
	


	




 There's less detail, no kick, soundstage is not as good as it was. It's veiled and no detail. And balance does not work any more 
	

	
	
		
		

		
		
	


	



 If I play track with only left or only right channel then it's not mono.

 If I did all work OK, then I need more dynamic op amp.

 from: http://www.diyaudio.com/forums/showt...hreadid=137160

 "LM4562 does not work very well at 5V. I know, I tried. Replacing a 4558 with a 4562 in a SB Live! card I had required me to hack up the power line (cut trace) and rework it to supply 12V to the chip, with a RC filter so it finally was around 10V). "


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