Integrated amplifiers — Vincent SV-700

The Vincent SV-700 is a Class-A hybrid integrated amplifier belonging to the German maker's tubeLine collection. Valve circuitry handles the preamplifier stage, a transistor output stage drives the loudspeakers, and a built-in converter accepts digital sources. Vincent builds the unit on a consistently symmetrical layout, intended to minimise crosstalk between channels and to lower distortion.

Key specs that matter

Nominal output is 2 x 100 W RMS into 8 ohm and 2 x 160 W RMS into 4 ohm when operating in Class AB, with the option to run in pure Class A at 2 x 50 W into 8 ohm. Frequency response is quoted as 20 Hz to 20 kHz within 0.5 dB and 20 Hz to 50 kHz within 2 dB. Harmonic distortion is below 0.1 percent at 1 kHz and 1 W, while noise sits more than 90 dB below the signal. The case is 430 mm wide and deep and 192 mm tall, and the amplifier weighs 24.2 kg, with a maximum power draw of 533 W.

Engineering and use context

The preamplifier uses three tubes per channel - one 12AX7 and two 12AU7 - wired in a Shunt Regulated Push-Pull arrangement, and a 6Z4 brings the total to seven valves. Power is supplied by a 500 VA toroidal transformer. Toshiba transistors form the output stage, and the circuit works without negative feedback. Switching between Class A and Class AB operation does not require the amplifier to be powered down. The converter section is built on a Burr-Brown PCM5100 chip. Analogue sources connect via three RCA pairs and one balanced XLR input, joined by digital inputs in optical and coaxial form. Outputs comprise a stereo pre out, a fixed-level stereo recording output, speaker outputs for pairs A and B and two 3.5 mm power control jacks. A window in the front panel shows the tubes, and its lighting can be adjusted. No cooling fan is fitted, and a full-function aluminium remote control is supplied. The SV-700 has no headphone output and no phono input.

Pairing

A turntable therefore needs a separate phono preamplifier ahead of one of the line inputs, and Vincent lists the PHO-701 in its tubeLine range. The XLR input accepts sources with balanced outputs, the optical and coaxial inputs take digital sources, and the pre out can pass the signal on to an additional power amplifier. With A/B switching, two sets of loudspeakers can be connected at once.

Alternatives

The SV-737MK is another Class-A hybrid integrated amplifier from Vincent's tubeLine series.