Интегральные усилители — Octave Audio V 16 Single Ended

Built by Octave Audio in Karlsbad, Germany, the V 16 Single Ended is a valve integrated model that also works as a headphone amplifier. Rather than a push-pull design, each channel uses a single KT 120 in triode connection running in Class A, and the narrow chassis is offered in Ice Grey or Metallic Black.

Key specs that matter

Set to High, the selector yields 2 x 8 W RMS into 4 ohm, and on Low 2 x 5 W RMS. Frequency response is 10 Hz to 80 kHz at 5 W within 0 and -3 dB. Distortion is 0.5 percent at 3 W into 4 ohm, signal to noise ratio is -110 dB at 8 W, and output noise stays below 30 uV between 50 Hz and 400 Hz. Gain is 26 dB, input sensitivity is 400 mV, and input impedance is 50 kohm on RCA and 25 kohm on XLR. Channel separation is 40 dB. The amplifier measures 210 x 335 x 380 mm and weighs 19 kg. Consumption is up to 200 W at full power.

Engineering and use context

The driver stage uses one ECC 82 and two EF 800 valves. The KT 120 output valves can be swapped for KT 150, KT 88 or 6550 types. Idle current is 50 mA on BIAS Low and 70 mA on BIAS High, and 25 mA in the headphone setting. Octave calls its bias scheme Dynamic Class A Control, an adaptive three step mode at 100, 65 or 35 percent that follows the load, cutting heat and extending valve life. Negative grid voltage is controlled electronically for each output valve. The output transformers are wideband types on a silicon steel PMZ core with magnetic field compensation, and the mains and output transformers are placed apart to lower noise. It remains stable without a load connected, and minimum load impedance is 2 ohm. Eco Mode reduces idle current during pauses, and a soft start protects the valves.

Pairing

The V 16 accepts line sources on two RCA sockets plus one balanced XLR. For loudspeakers there is one pair of posts, and headphones get a 6.3 mm headphone jack and a 4 pin XLR headphone socket, with headphone loads of 6 to 32 ohm on Out Low and 8 to 2,000 ohm on Out High. Octave specifies speakers of 3 to 32 ohm with efficiency above 93 dB. A regulated RCA preamplifier output is a factory option only, with 40 ohm output impedance and 5 V RMS maximum level, and it stays in phase with the speaker output, which itself is inverted relative to the input. Crosstalk between inputs exceeds -90 dB, and two external supply extensions, Black Box and Super Black Box, can be added. Volume is set with a metal remote control.

Alternatives

The Octave V 70 Class A is a Class A integrated amplifier in the V range with a push-pull pentode output stage.