Nagra HD pre-amp

Traded in and now available: a truly exceptional Nagra HD PREAMP, one of the most ambitious pre-amplifiers ever developed by the Swiss firm Nagra. The HD PREAMP was developed without the usual constraints of size or cost and formed the heart of Nagra’s prestigious HD series for many years. The design combines Nagra’s background in professional audio engineering with an unprecedentedly refined mechanical and electronic construction. At its heart lies a fully dual-mono valve circuit, featuring two specially selected NOS E88CC double triodes. It is striking that Nagra does not implement the volume control in the usual way, using a potentiometer or resistor network. Instead, the output signal is controlled via specially developed transformers, with different secondary windings switched by relays. This delivers extremely precise control in steps of just 0.5 dB across the most important part of the range and exceptionally good channel balance. The power supply is also unique. The HD PREAMP consists of two separate chassis: the preamplifier itself and a separate power supply. This power supply generates various individually regulated voltages which are fed to the audio section via two high-quality LEMO connectors. This ensures that sensitive audio circuits are physically isolated from transformers and the mains supply. Typical of Nagra, of course, is the iconic Modulometer on the front panel, but here it is combined with a much larger and more luxurious chassis than found on classic Nagra components. Even mechanical resonances have been given extensive attention, with a specially developed low-vibration support system. Musically, the HD PREAMP is not designed to sound explicitly like a valve preamplifier. The guiding principle is, rather, maximum transparency, speed and dynamics, combined with the natural texture and fluidity for which the finest valve circuits are renowned. A rare reference preamplifier that is not only technically impressive but also beautifully demonstrates what Nagra is capable of when virtually every compromise is set aside. This unit is in mint condition and comes complete with its original packaging and accessories.