JRC 4560 Replacement?

[blearyeyes]

Working up a distortion pedal that calls for a JRC4560. I have everything but. What would be best?  JRC4558, JRC4580,  TL062, 72, 82, NE5532. Started to look at data sheets but I'm called blearyeyes for a reason....  

I am going to experiment but any technical reasoning to pick one over another would be appreciated.

[Scruffie]

The 4580 is fairly close in specs.

[blearyeyes]

The 4580 is fairly close in specs.

Thanks Scruffie.
Is the 4560 newer?

[Scruffie]

Not a clue, see if there's some dates on the datasheets.

[somnif]

I have learned it is annoyingly tricky to nail down release dates for a lot of the ubiquitous chips we use.

That said, I can find info on the 4560 going back to 1991, and the 4580 to 1994.

Were these when they were released? Not a clue! I'm not even sure where one would go to look and google is just confusing matters!

[blearyeyes]

I'm usually overwhelmed with the onslaught of information. It's a freaking guitar pedal.  I should just get a few fakes off of eBay and I'll enjoy the effect of thinking it is correct for the design.

Always sounds better that way.

[Scruffie]

I should really check the datasheets again before I say this but as i'm feeling lazy i'll go off memory and say I think the 4560 & 4580 are pretty much lower noise/higher bandwidth versions of the 4558 with slightly improved slew specs but the slew rate is still much lower than say a TL072, so they could potentially distort a bit nicer depending on the circuit and depending on what your definition of 'nice' distortion is.

But yes, I think you'll get most of the actually audible qualities of those specifications from a relabelled mystery dual opamp.

[reddesert]

I looked at the datasheets for the 4558/4559, 4560, and 4580, and the equivalent circuit diagrams. They're all pretty similar, though as the ID number goes up you get significantly faster slew rate and the 4580 also has a better noise rejection spec.  But even the 4558 has a slew rate of 1 volt/micro-sec, which ought to be plenty fast for audio applications. (Figure that a maximum slew would be 5 volts at 10,000 Hz, which is 0.05 volts/micro-sec.) I would be comfortable with swapping any of these around.

Sometimes, different types of op-amp designs behave differently when hitting the supply rails, which might make an audible difference (for distortion - clearly in an undistorted application you don't want to hit the rails). But the 45xx designs all seem pretty similar to each other.

[blearyeyes]

I'll put the 4580 in to test and ordered 4560s from china.  Case closed.