Thank you for viewing! JRC4559DD9834 Glossy VINTAGE Op-Amp, Used, Removed Parts! This is a set of 2. This is a set of two 1980s glossy JRC 4559DD op-amps (9834), which are said to be used in the Timmy OverDrive and Paul Cochrane Tim Over Drive. This is an improved, low-noise version of the 4558 op-amp. You could try swapping the op-amps in your TS-series pedals to check the distortion, or you could experiment with different manufacturers and eras of the same model, as there are differences. I will not comment on the sound changes due to the replacement, as there are circuit and individual differences, but changing the op-amp, especially in an overdrive, can drastically change the character, so it's very interesting to play with. Please perform the replacement at your own risk. For the listing, I have checked the operation using the IC check equipment shown in the photos. Please note that the listing is only for the JRC 4559DD glossy VINTAGE op-amps (2 pieces), and the checking equipment is not included. Also, since these are used, removed parts, some solder may remain. How about for production, modification, or research? Shipping will be via Click Post, wrapped in aluminum foil and protected with air cushioning. Thank you.