Усилители мощности стерео — SMSL PA200

SMSL, the brand of Foshan Shuangmusanlin Technology in China, builds the PA200 as a small two-channel power amp priced at USD 419. Its output stage uses gallium nitride transistors, and the unit can be switched from two-channel operation to a bridged mono mode so that a pair can form a stereo system with higher output.

Key specs that matter

In stereo the PA200 delivers 160 W RMS per channel into 4 ohm and 85 W RMS per channel into 8 ohm. Driven through its XLR input as a mono unit, it gives 400 W RMS into 4 ohm or 250 W RMS into 8 ohm. Rated THD+N is 0.003 percent, the signal to noise ratio 109 dB and channel separation 75 dB. Input sensitivity is 0.68 Vrms in stereo and 2.1 Vrms in mono, each with an input impedance of 22 kohm. Normal consumption is 40 W and standby consumption is below 0.5 W. The case measures 220 x 45.9 x 175 mm and weighs 1.44 kg.

Engineering and use context

The output devices are Infineon GaN FETs switching at up to 1 MHz. Volume is set by a Texas Instruments PGA2311 chip, which SMSL chose for its fine volume steps and very low distortion, and the box includes a remote handset, an AC power cable and a user guide. Level adjustment works only on the RCA stereo input. A stereo pass-through mode bypasses the volume stage so a separate preamplifier controls level, and SMSL pairs this mode with its D200 DAC and preamplifier. In mono mode through XLR the volume is fixed, and the maker states that two units used this way raise output power about four times, letting it drive loudspeakers that tolerate high power. A high-power switching supply of audio grade is built in, and the protection circuits cover overheating and overcurrent among other faults. Many audio-grade parts appear throughout the circuit, and every input and output socket has gold plating. The body is aluminium alloy in silver. The speaker posts take bare wire as well as 4 mm banana or spade plugs, and a one-year warranty applies.

Pairing

Any source that has a level control of its own, such as the D200, can feed the PA200 in pass-through mode, while a direct RCA connection from a fixed-level DAC can rely on the internal PGA2311 control instead. Owners who need more power for demanding speakers can buy another PA200 and operate both in bridged mono fed by a preamp with XLR outputs.

Alternatives

Within the SMSL GaN amplifier range, the larger PA400 is rated at 250 W RMS per channel into 4 ohm in stereo.