The op amp preamp is inspired by the MusicMan HD65 and HD130, resembling a Fender preamp in its topology. The impedances are adjusted to suit op amp operation instead of vacuum tubes. The preamp is known for its clean tones, but also offers a unique op amp distortion. It is compatible with any dual op amp that matches a TL072. Using an LM1458, considered a “bad” op amp, might actually enhance the sound at high gain. The original models used LM307 op amps, similar to the LM301 in design. The original models also ran the chips at +/-16V, but this version uses a charge pump for +/-9V bipolar operation to save PCB space. The gain is slightly reduced to prevent clipping at the input.

Summary created by AI from the original source.