PEQ-1 is an active portable RIAA-flexible equalizer designed to be built and replicable with DIY techniques. Due to the high amount of different pre-1954 vinyl playback curves, the EQ also includes the possibility of modifying the low and high filters to help with material equalized with these other curves such as NAB, BBC, AES, Victor-78, Orthacoustic, etc.
Although the PCB and design implementation are mine, the schematic was heavily inspired by Douglas Self’s work on RIAA networks.