XR4558CP

[rooster18]

I have a pile of these from way back, made by Raytheon, I think, from the "XR" logo. I have a friend out in CA who wants a few of them for some tube screamers he's fixing up. Has anyone tried this in a TS? I don't have one to try it out, and I figured I'd ask here and see if any of you have experience with these chips. I would normally think they were pretty good, just because the only "XR" chip I've ever used was the 4739, and that was always a very nice quad.

If you've tried it, how did it stack up next to the original JRC in that circuit?

Thanks.

rooster.

[Electric_Death]

I know this is slightly off topic and sort of a stupid question but have you ever bothered to try any other chips in a tube screamer?
While they're the most popular, the 4558 and 072's are about the worst chips around in my opinion. I'm not the veteran builder but I've done a hell of a lot of mods and DIP sockets have been a standard.

Try an OPA2604 and I bet it smokes anything you put up against it. Second place would be the 5532 but in some circuits it takes 1st. I rave about the 5532 because it's the best all around performer, more focus and definition and I was able to get more volume before needing to back off on my EQ. The only thing I notice about the 4558's I've used is they're mellow and dingy in comparison to my favorite 2 chips but if you're into grunge or dirty rhythm tones I suppose it's exactly what you're looking for and in fact, I don't think there's a better chip for it.

A bit more back on track though, I see those XR versions every so often on Ebay and pedal building supplier's sites.

[jonathan perez]

yeah, i cant think that theyd sound "better."  compare data sheets, then see if either sound different. most likely, you wont hear a difference.

go by ear, not by mojo.

[benfox]

Not much differences in a OD stomp but maybe in a tremulus lune or in booster it coud make it clearer than a basic 4558.
I've try those in a shred master copy and not much differences appears....