Усилители мощности моно — Vitus Audio SM-011

The SM-011 is a Danish monoblock made by Vitus Audio for its Signature line, able to work in pure Class A or in Class AB. It shares its chassis size with the SS-025 Mk.II stereo amplifier from the same series. Vitus explains that the SM-011 builds on the SIA-025 integrated amplifier and was designed for more power, a lower noise floor and higher resolution than that model. Six finishes are listed, three Standard and three Unique, with titanium grey among the latter.

Key specs that matter

Inputs consist of XLR and RCA sockets on every unit, both with a sensitivity of 2 V RMS and an impedance of 10 kohm. A single set of loudspeaker posts is provided. In Class A the SM-011 gives about 25 W RMS into 8 ohm and about 50 W into 4 ohm, while switching to Class AB lifts output to about 200 W into 8 ohm and about 400 W into 4 ohm. Output impedance is 0.075 ohm, frequency response extends beyond 800 kHz, and THD plus noise stays under 0.01%.

Engineering and use context

A custom 1.4 kVA UI transformer with losses under 2% powers each unit, backed by a capacitor bank of 240,000 uF. Signal paths stay fully balanced all the way through, and the design avoids global negative feedback, in line with other Vitus designs. The UI transformer type is what Vitus fits in the Signature Series and above, whereas its entry Reference Series amplifiers use EL transformers and run as high-biased Class AB. Surface mounted components replace leaded ones wherever possible, which lets a great deal of circuitry fit in a modest space. The construction is fully modular so that future upgrades can be added, and this version introduces two different modes of coupling the output, a feature first developed for the MP-S201 stereo amplifier of the Masterpiece Series.

Pairing

Two units are needed for stereo, one per channel, and because the case matches the SS-025 Mk.II the amplifiers line up visually with that model and the other full size Signature components. The choice between balanced and single-ended inputs lets the amplifiers follow almost any preamplifier, though a line stage with XLR outputs keeps the signal balanced from source to speaker, as the circuit is designed to be. The SL-103 Mk.II preamplifier and the SP-103 phono stage belong to the same Signature Series and share its styling.

Alternatives

The Vitus SM-025 is a newer Signature Series mono amplifier with a 180,000 uF capacitor bank per channel.