MP1 Mk. II.3

About the MP1 Mk. II.3

The Atma-Sphere MP-1 Mk II.3 is a two-box, fully differential and balanced tube preamplifier designed to eliminate interconnect cable coloration using the Balanced Line system (AES48). It features a robust phono stage capable of supporting very low output moving coil cartridges (less than 0.2mV) and a line stage with 12 dB gain and low distortion. The phono section offers approximately 66 dB gain, with RIAA accuracy within 0.07 dB and a bandwidth from 0.5 Hz to 100 kHz. The line stage frequency response extends from 0.1 Hz to 400 kHz. The preamplifier uses a total of 16 tubes: 10 x 12AT7 for the phono section and 6 x 6SN7 for the line section. It includes a patented direct-coupled Circlotronic® output, zero feedback design, and a precision 24-position stepped volume control. The power supply is housed in a separate chassis, providing 170 Joules of storage, and the unit can drive 32-ohm headphones. The MP-1 Mk II.3 has dual XLR outputs (with optional RCA outputs) and supports balanced XLR inputs for phono and auxiliary sources. Dimensions per chassis are 13" deep x 17" wide x 5.5" tall, weighing 42 lbs each. It comes with a three-year transferable warranty and one year warranty on tubes. The design emphasizes low noise, high dynamic range, and the ability to drive long balanced interconnect cables without sonic degradation.