The Pathos InPol Legacy Pure Class-A Tube Integrated Amplifier is the reference statement piece of the Pathos Acoustics lineup — created, in the company’s own words, with “no limits” on size, weight, or ambition. Named as a tribute to co-founder and owner Gaetano Zanini, the InPol Legacy takes the listening philosophy Pathos has refined over 25 years and pushes it to its logical extreme, aiming to match or exceed even the company’s InPower and Adrenalin power amplifiers.

At the heart of the InPol Legacy is a totem-pole tube input stage using two Tung-Sol ECC803S valves and one Sovtek 6H30 “SuperTube” per channel, each channel benefiting from its own dedicated power supply with a separate toroidal transformer. This tube stage handles all voltage amplification, while Pathos’ latest-generation double-InPol circuit — a patented, fully balanced, zero-feedback topology — supplies the current gain needed to drive even the most demanding loudspeaker loads. MOSFET output devices are individually measured and grouped for uniform bias, ensuring consistent performance across the amplifier’s massive power envelope.

Output is rated at 100W per channel into 8Ω and 170W into 4Ω — with the InPol Legacy’s power not simply doubling as impedance halves, a deliberate design choice tied to the thermal limits of true Class-A operation. Independent measurement has shown the amplifier can exceed its rated output, delivering as much as 160W into 8Ω loads before distortion limits are reached. Volume control is handled by a 100-step passive attenuator using low-noise precision resistors switched via insulated relays, operated through an “infinite-turn” rotary knob set into the padouk wood fascia.

True to its reference-class ambitions, the InPol Legacy makes no compromises in its construction. The chassis weighs approximately 140kg (309 lbs) and ships in a custom wooden crate on wheels with detachable lift bars, as installation is a multi-person task. Pathos even offers a dedicated equipment cabinet built specifically to support the amplifier’s weight. Unlike other Pathos integrated amplifiers, the InPol Legacy does not accept the optional HiDac Mk2 DAC card — a deliberate decision by Pathos to keep the Legacy “a pure amplifier,” free of any digital circuitry in the signal path.

As with every Pathos product, the InPol Legacy is designed and hand-built in-house at the company’s facility in Vicenza, Italy, using premium components including capacitors from Itelcond and ICEL and resistors from Vishay, reflecting Pathos’ complete control over its manufacturing process from raw materials to finished amplifier.