Интегральные усилители — MasterSound Compact 845

The MastersounD Compact 845 is a stereo integrated valve amplifier with a pure triode single-ended output stage in Class A, one 845 directly heated triode per channel, no negative feedback and automatic bias. It is built by hand at the MastersounD workshop in Arcugnano, near Vicenza, where the company has made valve amplifiers since 1994.

Key specs that matter

The current factory rating is 24 W per channel in Class A, while earlier production of the same model was specified at 30 W per channel. It runs two ECC802, two 6SN7 and two 845, with Psvane 845B output triodes and TungSol 6SN7GTB drivers fitted in some production. Connections are three line inputs on RCA, a balanced line input on XLR, plus one direct input on each connector type, and 1 V drives it to full power. Response extends from 8 Hz to 40 kHz within 0 dB, speaker loads of 4 to 8 ohms are supported, and power consumption is 220 W. The chassis measures 45 x 43 x 27 cm and weighs 34 kg.

Engineering and use context

MastersounD output transformers are designed and wound by hand at MastersounD on a mechanical winding machine, using a technique developed by Cesare Sanavio and refined by his son Luciano, who leads production. Each transformer has separate 4 and 8 ohm secondaries brought out to their own binding posts, so a speaker can be wired to the tap that suits its load. The two direct inputs bypass the volume control, so the Compact 845 can be driven at fixed gain by a separate preamp or AV processor. Volume is adjusted from the supplied remote handset. Before shipping, MastersounD measures the valves, aligns the two channels on the amplifier and runs each set for at least 48 hours. At switch-on a red LED flashes until the internal voltages settle, and the factory advises around thirty minutes of warm-up. The steel chassis takes side panels in wood or gloss black, and the valves are exposed on the top plate, so the unit needs open space above and away from radiators. Valves are excluded from the five-year warranty.

Pairing

Given its modest single-ended output, the Compact 845 suits loudspeakers of 90 dB sensitivity or more and a stable impedance, in rooms around 20 m2. The XLR line input takes balanced sources directly, and any MM turntable requires a separate phono preamplifier, as the Compact 845 has no RIAA stage.

Alternatives

The MastersounD Compact 300B uses the same chassis format and input layout with 300B triodes and 11 W per channel.