Octave Audio V70SE

The V70 SE is a valve integrated amplifier from Octave Audio, belonging to the same family as the V40 SE but delivering higher power. It uses circuit technology derived from the V70 while housing these circuits in a larger chassis, inherited from the V80. This larger casing allows for improved internal architecture and more precise shielding of sensitive electronic circuits.

The power stage relies on two 6550 tubes per channel, for a claimed continuous power output of 2x70 W into 4 ohms. Octave's proprietary BIAS system allows the use of tubes with the same base, such as KT88 or EL34, offering flexibility in the choice and replacement of the valves. The amplifier is built on a pentode configuration designed to maintain output stage stability even with speakers offering a sensitivity from 84 dB upwards, and it tolerates impedance variations down to 2 ohms without sonic degradation. The power supply has also been optimised to reduce sensitivity to mains disturbances, limiting the risk of sound dropouts in the event of fluctuations in the electricity network.

In terms of measurements, the frequency response extends from 10 Hz to 80 kHz at 70 W (±0.5 dB), with total harmonic distortion below 0.1% at 10 W into 4 ohms and a signal-to-noise ratio above 110 dB. Input sensitivity is 120 mV, and current draw with no load stands at 28 mA in low bias and 34 mA in high bias.

Connectivity comprises four stereo RCA inputs, one stereo XLR input, one AMP in input, one stereo RCA REC output, one stereo RCA pre-out output, as well as a pair of screw terminals compatible with banana plugs. The unit also features an Octave Black Box audiophile power connector, an On, Eco and Off operating mode selector, and an earthing connector.

This type of amplifier is aimed at a user who already has a demanding system in place, with speakers capable of making the most of 70 W per channel and a balanced XLR input. The presence of an AMP in input and a pre-out output also leaves the possibility of integrating it into a more complex system, as a preamplifier or in combination with other units.