The Parhelion Vintage Overdrive is a pedal that is based on the Boss OD-1 OverDrive, which was released in 1977. The OD-1 was one of Boss’s first compact pedals and it was notable for being the first overdrive effect to use diodes in a negative-feedback arrangement for clipping purposes.

The original OD-1 had two different versions. The 1977 version used the Raytheon RC4303 quad op-amp, while the second version from December 1980 used a single 4558 dual op-amp. The original quad version is said to have a better sound and it is what the Parhelion project is based on.

The Parhelion Vintage Overdrive adds two toggle switches for added flexibility. The clipping switch allows you to select between three different sets of diodes, while the EQ switch changes the gain structure of the op-amp clipping stage for higher gain and more bass.

It’s worth noting that the Parhelion Vintage Overdrive was originally called the Corona in its earlier 1590B version. However, it was given a new name upon its release in 2021 due to obvious reasons.

Summary created by AI from the original source.