Усилители мощности стерео — Rotel Michi S5

The Michi S5 is a stereo Class AB amplifier in the Michi range of Rotel, built as a dual monoblock in which every channel gets its own supply. It carries a colour display on the front panel. The finish is black.

Key specs that matter

Rotel rates it at 500 W per channel into 8 ohm and more than 800 W into 4 ohm. Harmonic distortion stays under 0.008% and intermodulation distortion, measured with a two-tone signal in a 4 to 1 ratio, below 0.03%. Frequency response is 20 Hz to 20 kHz within 0.15 dB, and 10 Hz to 100 kHz within 0.4 dB. The damping factor is 350 at 1 kHz into 8 ohm. The balanced XLR inputs need 4.2 V for full output and present 100 kOhm, while the RCA inputs need 2.6 V and present 12.5 kOhm. Gain is 24 dB balanced and 28 dB unbalanced. Signal to noise ratio is 120 dB, IHF A weighted, and crosstalk exceeds 65 dB. The chassis is 485 mm wide, 238 mm high and 465 mm deep, with a 220 mm front panel, and weighs 59.9 kg.

Engineering and use context

Each channel draws on its own in-house toroidal transformer rated at 2,200 VA, housed in an individual epoxy filled enclosure that Rotel says suppresses noise and vibration. A bank of four British patented bulk storage capacitors totals 188,000 uF, and the output stages use 32 high current transistors between them. Speaker cables attach to Michi custom 5-way binding posts with rhodium plating, built for high current. Operation comes through the included remote handset, and RS232 and Ethernet connections support common control systems. The amplifier draws up to 1200 W, needs less than 0.5 W in standby and under 2 W with network wake-up active, and releases 3450 BTU/h when run at 1/8 power. Versions exist for 230 V 50 Hz in Europe and 120 V 60 Hz in the USA.

Pairing

With both XLR and RCA inputs, the S5 accepts either a balanced or an RCA preamplifier output, and the gain difference between the two input types is already accounted for in the published figures. Its reserve into low loads makes it a match for low impedance loudspeakers, and the network port allows it to join an automated control setup.

Alternatives

Within the main Rotel line, the RB-1590 stereo amplifier offers 350 W per channel into 8 ohm and 648 W into 4 ohm from twin toroidal transformers and eight BHC capacitors.