The Ibanez TS10, the successor to the legendary TS9, saw an increase in distortion due to changes and demands of the times. It provides distortion and compression to large stack amps. This also became a legendary piece of equipment. Stevie Ray Vaughan used it in his last albums after his recovery from alcohol addiction in the late 80s, and it became a favorite among SRV followers. This unit has been modified with a Motorola MC4558CG op-amp. Here are the details of the op-amp: Motorola MC4558CG (Op-amp) Features: A dual op-amp in a metal can (CAN) package made by Motorola. Applications: Primarily used in amplification circuits of audio equipment. Especially in vintage overdrive effects like the "TS-808," it is known for producing high-resolution sound and thick distortion. Status: Discontinued and considered a "very rare" vintage part with high market value. Notes: The 8-pin metal can type may require modification, such as shortening or shaping the terminals, to fit into a standard IC socket. My impression is that it has a slightly fizzy distortion. Perhaps a fuzzy, smoky distortion. It's also a good product for those who are looking to modify it in the future. Please consider purchasing only if you understand that this is a used instrument.