Усилители мощности моно — Msb Technology The M205 Mono Amplifier

The M205 is the monoblock version of the compact MSB Technology amplifier platform, built in California with a Class-A input stage and a Class-AB output stage. Compared with the S202 stereo chassis of the same size, each M205 devotes two custom toroidal transformers and a doubled capacitor bank to a single channel, and a pair is needed for stereo.

Key specs that matter

Continuous output is 220 W into 8 ohm and 400 W into 4 ohm at under 1 percent distortion. Each unit has two sets of binding posts, and when used in dual bi-amp mode it delivers 200 W into 8 ohm or 380 W into 4 ohm per output. Gain is 23.8 dB from a 150 ohm source, frequency response is within 0.03 dB from 20 Hz to 20 kHz, and signal to noise exceeds 130 dB, or 133 dBA. Equivalent input noise is 0.65 microvolt over a 22 kHz band, and output impedance is 0.01 ohm. The single balanced XLR input offers a user-selectable impedance of 75, 300 or 1,200 ohm. Static consumption is 90 W, and each block measures 404 mm wide, 483 mm deep and 165 mm high without feet, weighing 41 kg.

Engineering and use context

The input and gain stage is double balanced, impedance matched and fully discrete, with its own independent power supply, and it works without negative feedback. The output stage is balanced, runs at medium bias and provides current gain only. The chassis is machined from billet aluminium over 28 hours of CNC work and offers about 1.9 m2 of heatsink surface, with heat pipes spreading heat across it. Power-on timers and soft-start circuits manage switch-on, and the amplifier can be controlled by push buttons, remote commands or MSB 12V triggers. Multiple ground posts are fitted to help with interference. Mains voltage is set automatically for 120 or 240 V, with a separate fixed 100 V model, protected by a 10 A slow-blow fuse. The anodised finish comes in matte silver or matte black, and the base accepts M6X1 threaded feet.

Pairing

The XLR input takes a signal from a balanced preamplifier or from an MSB converter fitted with volume control, and the impedance switch lets the owner choose the load that suits the source output. With feet fitted each block stands 178 mm tall, and since there is one input per unit, a stereo system needs two balanced cables from the source. The dual output mode suits speakers with split terminals, where two blocks per side can bi-amp a stereo pair.

Alternatives

Above the M205 sits the MSB M500 Mono Amplifier, a monoblock with a 2.0 Farad power bank and double the transformer capacity.