Integrated amplifiers — Audio Note OTO Line SE

The OTO Line SE is a distinctive single-ended-triode integrated amplifier from Audio Note, a well-established British manufacturer known for storied, purist single-ended-triode electronics engineering, built with a minimal power output and considerable mass. The OTO Line SE brings Audio Note's most storied engineering heritage to a substantial single-ended-triode integrated chassis.

Key specs that matter

Five single-ended inputs are provided. Input sensitivity is 220mV, with input impedance at a substantial 100,000 ohms single-ended. Output power is a minimal 9W into 8 ohms, rising to 10W into 4 ohms - a classic single-ended-triode figure. At 140 x 440 x 410mm and 17kg, the OTO Line SE's considerable weight for its minimal power output reflects serious internal transformer engineering consistent with quality single-ended-triode design.

Sound and use context

Expect the exceptionally rich, harmonically resonant character single-ended-triode amplification is broadly celebrated for among tube enthusiasts, with the minimal 9-10W output requiring high-efficiency loudspeakers.

Pairing

The minimal 9-10W output requires high-efficiency loudspeakers, typically horn-loaded or high-sensitivity designs exceeding 95dB.

Alternatives

Audio Note's own Empress monoblock offers a related single-ended-triode alternative within the same broader catalogue.