Vintage Versatone Pan-O-Flex tube combo

The best-known Versatone amplifier, the Pan-O-Flex, used a bi-amplification design with separate power amplifiers for the high and low frequencies, with output through a single 12-inch speaker. Notable users of this amplifier included bassists Jack Casady of Jefferson Airplane, and Carol Kaye of The Wrecking Crew. The series of amplifiers including guitar and bass guitar models was noted for its high fidelity (unusual for the time), attention to detail, point-to-point wiring and unique ported and baffled enclosures, and unusual tube sections (with 7591 power tubes often used in older Ampeg designs).