Mainline

About the Mainline

The Bottlehead Mainline is a premium DIY tube headphone-amplifier kit designed and manufactured by Bottlehead. It uses a fully balanced, zero-global-negative-feedback circuit with parafeed output transformers, regulated tube power supplies, active C4S loads, selectable low/high output impedance, and both single-ended and balanced headphone outputs. The amplifier is intended to work with a broad range of headphones, from low-impedance Grados and Focal models to high-impedance Sennheiser and Beyerdynamic headphones, as well as relatively demanding planar-magnetic headphones. Construction is by the purchaser; it is not a factory-assembled amplifier. The current product listing is for the revised Mainline 1.1 kit.