Integrated amplifiers — Octave Audio V 40 SE

The V 40 SE is a tube integrated amplifier from Octave Audio, built as a direct descendant of the brand's successful V 40 and V 50 models with improved stability and low-leakage capacitor technology. Founded by Hofmann and now led by his son Andreas since 2000, Octave Audio built this model's reputation on winning the prestigious "Stereoplay Highlight" award from a leading German high-end audio magazine.

Key specs that matter

Four line-level inputs plus one home-theatre bypass are provided. Input sensitivity is 180mV with 50k ohms input impedance. Rated output is 40W per channel into 4 ohms. Frequency response at 10W is 5Hz to 70kHz at -2dB. Signal-to-noise ratio is an exceptional -110dB at full power. Distortion is 0.1% at 10W into 4 ohms. The tube complement is four KT88 output pentodes plus one 12AX7 and one 6922 dual-triode for phase inversion and line-level gain, though the BIAS Control and Monitoring System allows using pin-compatible alternatives like KT90, KT100, 6550, 6L6, KT66, KT77, 5881 or EL34 tubes to suit personal taste, with the caveat that only the specified KT88 complement delivers the full rated 40W. A single-impedance output transformer provides absolute stability against unstable loudspeaker impedance keeping the amplifier stable down to a demanding 2 ohm load regardless of impedance mismatch. At 15.9 x 6.2 x 16.2 inches and 40.9 lbs, ECOMODE electronics automatically reduce power consumption when no signal is detected for over 10 minutes, and an optional external Black Box power supply adds four times the storage capacitance for even greater stability with difficult loudspeaker loads.

Sound and use context

Expect powerful, clear bass fundamentals and captivating high-frequency resolution - the single-impedance output transformer design makes this amplifier equally at home with average-efficiency speakers around 85dB sensitivity and considerably more efficient designs, broadening the range of loudspeakers this amplifier pairs well with.

Pairing

The stable 2 ohm minimum load rating and exceptional signal-to-noise ratio suit both moderately demanding and high-efficiency loudspeakers, and the optional Black Box or Super Black Box external power supply further extends compatibility with difficult, low-impedance speaker loads.

Alternatives

Octave Audio's V 70 SE sits above this model with 70W peak output per channel in the same family lineage, worth the further investment if this V 40 SE's already substantial control and dynamics still leave ambitions unmet for a specific loudspeaker pairing.