The Soma 63 is a vintage preamp based on the tone and feel of the vintage brown-ear amps from California, and it's the first stompbox in Greer's new pedal range called the XFR Series. The pedal calls to mind that vintage vibe by simulating the entire preamp, phase inverter, power section, and feel of the vintage 10-inch Utah speakers found on those amps, and features a tone stack designed for versatility to boot.