NuPrime ST-10M

The ST-10M is a mono power amplifier from NuPrime, built around the V4 amplifier module already found in the stereo ST-10. By releasing it as a mono unit, NuPrime was able to completely rethink the power supply and chassis to make greater use of this module's potential, with each channel now having its own dedicated supply.

The stereo ST-10 had to work within the space constraints of a single chassis shared between the two channels, limiting the power supply to 150 W per channel. The ST-10M removes this constraint thanks to a fully redesigned power supply, boosted to 300 W for its single mono channel. The original 10A rectifier bridge is replaced by a 50A Schottky diode, the capacitors' capacity is increased to 30,000 microfarads, and the power transformer is now sized for 300 W. These changes, combined with a revised circuit layout and a more rigorous component selection, lower the noise floor compared with the ST-10.

The mono configuration also reduces interference between channels, as one channel per chassis eliminates the coupling that can remain in a shared stereo architecture. This design results in a sound described as fuller and richer, with an immediacy and power perceived as superior to the ST-10, a deeper soundstage and more solid imaging.

The ST-10M is aimed at high-fidelity enthusiasts who already own a stereo system with two mono amplifiers, or who wish to move to a bi-amping architecture to maximise channel control and separation. It suits demanding listening, on speakers that benefit from a generous and stable power supply per channel.