Предусилители — Accustic Arts PREAMP V

The PREAMP V is a line-level control unit built by hand in Germany by ACCUSTIC ARTS. Its signal path stays fully balanced from the inputs to a Class A output stage of the high end type, and a newly designed main board is used in this version. New features in this generation are a high resolution display and a 4-channel digital volume control, which the maker introduced for the best crosstalk figures.

Key specs that matter

Measured frequency response runs from DC to 120 kHz within +0 and -0.5 dB, and crosstalk between left and right is better than 115 dB. Signal-to-noise ratio is 99 dB unweighted and 102 dB A-weighted, with total harmonic distortion plus noise under 0.001 percent. Input impedance is 2 x 50 kOhm balanced and 50 kOhm unbalanced, while output impedance is 2 x 50 ohm balanced and 50 ohm unbalanced. Maximum output reaches 11 V rms. Power draw is about 20 W in use and under 0.5 W in standby. The case measures 128 x 482 x 393 mm (height x width x depth) and weighs 14.5 kg.

Engineering and use context

Line sources connect through three XLR sockets and two RCA sockets, while one further RCA input is configured as a surround bypass. The main outputs come as two balanced XLR and two RCA sockets - in each pair one is AC-coupled and one DC-coupled - and a fixed-level RCA socket is added to them together with one unbalanced XLR output. A phase switch selects 0 or 180 degrees. The parts list includes Burr Brown OPA 627 operational amplifiers, and all relays have gold-plated contacts. Power comes from one magnetically shielded, encapsulated 50 VA toroidal transformer of German manufacture. The front panel and the cover are made of massive solid aluminium, and the control knobs are solid chromed brass.

Pairing

For headphones the unit provides a switchable 6.3 mm stereo jack fed by the preamplifier itself. Listeners who prefer a separate headphone amplifier can use two unregulated, switchable outputs, one in RCA and one in XLR form, to feed it. The balanced outputs suit power amplifiers that take XLR connections, and the DC-coupled pair offers a route without coupling capacitors in the signal path. The surround bypass input lets a multichannel processor use the same power amplifiers and speakers for its front left and right channels.

Alternatives

From the same maker, the TUBE PREAMP V is a fully balanced reference preamplifier using a tube hybrid design with four tubes, two per channel.