Power amplifiers mono — MasterSound Monoblock 845

The Monoblock 845 is a single-ended-triode monoblock power amplifier from MasterSound, sitting above the Monoblock 300B with the more powerful 845 output tube. The Monoblock 845 brings MasterSound's most storied engineering heritage to dedicated single-ended-triode monoblock power amplification.

Key specs that matter

Input impedance is 50,000 ohms on both connections, matching the Monoblock 300B. Output power is 50W into 8 ohms - more than double the Monoblock 300B's 24W, reflecting the 845 tube's greater power ceiling. Frequency response spans a wide 8Hz to 90,000Hz within plus-or-minus 3dB - considerably wider than the Monoblock 300B's 45,000Hz. At 460 x 400 x 270mm and 30kg, the Monoblock 845 represents a somewhat more substantial commitment than the Monoblock 300B.

Sound and use context

Expect the exceptionally rich, harmonically resonant character single-ended-triode amplification is broadly celebrated for among tube enthusiasts, with the considerably greater 50W output combined with the wide 8Hz-90kHz bandwidth.

Pairing

As a monoblock, two units are needed for a stereo pair, and the 50W output pairs best with notably efficient loudspeakers.

Alternatives

MasterSound's own Monoblock 300B offers a more minimal-power alternative within the same broader single-ended-triode catalogue.