HP4

About the HP4

The EAR HP4 is a high-end, transformer-coupled Class A vacuum-tube headphone amplifier designed by Tim de Paravicini. It uses 6SL7 triode valves and EAR’s Enhanced Triode Mode circuitry, with proprietary output transformers matched for both high- and low-impedance headphones. The amplifier accepts both single-ended and balanced signals and provides four headphone outputs: two intended for high-impedance headphones and two for low-impedance headphones. It also includes a built-in volume control and line-level outputs. Published specifications vary slightly by source and production description; the data below consolidates the reported technical information. The EAR HP4 should not be confused with the unrelated PreSonus HP4 headphone distribution amplifier.