JRC4558DD/1637 Glossy, Set of 4! Tested and Working!! Product Description Thank you for viewing. This listing is for a set of 4 glossy JRC4558DD/1637 chips! Tested and working!! Early 1980s Glossy 4558DD 1637 All ICs are used, but have been tested for functionality using an IC check device (headphone amplifier). I have removed as much solder as possible, but some may remain. How about for the creation, modification, or research of distortion or overdrive pedals? These are very valuable JRC 4558DD chips with the lot number in the 1000s. Shipping will be via Click Post, wrapped in aluminum foil and protected with air padding. Thank you.