Предусилители — Nagra PREAMP II-S

The PREAMP II-S is a valve line preamplifier from the Swiss company Nagra, launched in January 2026 as the first product of the new Series II line and placed between the Classic and HD ranges. Earlier Nagra valve preamplifiers include the PL-P, built from 1997 to 2009. Pricing is USD 24,500 for the unit alone and USD 27,900 with the Compact PSU.

Key specs that matter

Connections comprise one balanced XLR input and four single-ended RCA inputs, with two balanced XLR outputs and one RCA output. Gain is switchable on the front panel between 0 dB and +6 dB, and output impedance follows the setting at 9 ohms for 0 dB and 18 ohms for +6 dB. Frequency response runs from 10 Hz to 50 kHz within +0 and -0.5 dB. Nagra quotes a dynamic range above 125 dB, THD below 0.01% at 1 kHz and 1 V rms output, and crosstalk better than 85 dB at 1 kHz. The aluminium chassis measures 380 x 280 x 76 mm and weighs 4.8 kg. Power consumption is 12.6 W at most and under 1 W in standby.

Engineering and use context

The tube complement is two 12AX7 (ECC83) and one 12AT7 (ECC81), types selected by the Nagra laboratory for availability and consistency, and the circuit uses what Nagra calls HD Tube Technology. Volume is set by a precision rotary encoder with a finely fluted aluminium knob taken from the HD PHONO. A high-brightness OLED display, shared with the HD PHONO and the Reference DAC, gives sharp, bright characters sized for reading at a distance. The Nagra Modulometer, which traces back to the meter of the IV-S tape machine, shows the left and right channel levels during playback. Nagra describes the design as drawing on engineering from its Reference products. A phenolic damping layer sits beneath the bonded aluminium top cover to control vibration. Power comes from an external supply - the standard Compact PSU delivers a regulated 12 V at 2 A through a LEMO connector.

Pairing

With twin XLR outputs, the PREAMP II-S can feed two power amplifiers at once, while the RCA output serves single-ended amplifiers. The version sold without the Compact PSU is meant for owners who already run a Nagra MPS or Classic PSU and can draw power from it. The four RCA inputs suit several line sources like a disc player, network streamer or radio tuner, and a phono stage or DAC with balanced output can take the XLR input.

Alternatives

The Nagra Classic Preamp is the brand's other valve line preamplifier, introduced in 2016 and priced from USD 21,450 to USD 22,500.