The TS-808 established itself back in the late 70's and since then the tube screamer has become one of the (if not THE) most popular pedals of all time. Many people claim to be experts about what makes the early tubescreamers authentic and better than those which came later. There is a simple truth, the original designs had a multitude of component changes during their runs because on the scale of things the number of chipsets Ibanez and Maxon were using was tiny compared to the major electronics manufacturers and therefore they took what was on offer/available at the time. The original designs called for a 4558 chip but didn't specifically state which 4558!
Most commonly the JRC4558D is regarded as THE tubescreamer chip, these chips were seen in other pedals of course including certain Boss pedals. A chip which gets us nerds pretty excited is the TL4558P ... can you feel the mojo .. . . This chip has been well regarded by those who have been lucky enough experience it, they are super rare and therefore also super expensive. It's worth noting that legendary pedal builder Analogman uses these chips in his tuberscreamer mods (when he can get them), its suggested they're a little bit cleaner and more open sounding.
It's up to you to decide so here we've tonecaptured one of the rarest tubescreamers ever, let us know what you think!