Stereo power amplifier using Infineon GaN transistors switching at 1MHz, with a Texas Instruments PGA2311 analogue volume control. 250W per channel into 4 ohms, 140W per channel into 8 ohms and a bridged mono mode reached through the XLR input. Brand new, boxed, full manufacturer warranty. The SMSL PA400 is a compact stereo power amplifier built on Infineon gallium nitride transistors. It suits anyone who needs real power for demanding speakers without the size, heat or cost of a large conventional amplifier. It is finished in silver. This is brand new stock, supplied boxed with the full manufacturer warranty by Dreamcrest Audio as an authorised SMSL dealer. What it does A power amplifier takes a line level signal from a converter, streamer or preamplifier and provides the current your loudspeakers need. The PA400 accepts one balanced XLR input and one unbalanced RCA input and drives speakers through high current gold plated binding posts. It delivers 250W per channel into 4 ohms and 140W per channel into 8 ohms, and it can be run in a bridged mono mode through the XLR input where a single higher powered channel is needed. Volume is handled by a Texas Instruments PGA2311 resistor ladder, which keeps level control in the analogue domain while holding channel balance accurately at low settings. How it sounds and where it fits GaN transistors switch faster than conventional MOSFETs, which lets SMSL run the output stage at 1MHz and push switching artefacts well above the audible band. In practice this shows up as a clean, unforced top end rather than the hardness some older Class D designs had. The amplifier is a good match for speakers with a demanding impedance curve, and for larger standmounts or floorstanders in a medium to large room. It partners well with a balanced converter over XLR. If you run a pair of PA400 units in bridged mono, allow for speaker sensitivity and set gain carefully. Key features Infineon gallium nitride output transistors switching at 1MHz 250W per channel into 4 ohms and 140W per channel into 8 ohms Bridged mono mode reaching up to 500W total through the XLR input Texas Instruments PGA2311 analogue volume control Balanced XLR and unbalanced RCA inputs, both gold plated High current gold plated speaker binding posts Overheat and overcurrent protection circuits CNC machined aluminium alloy chassis Technical specifications Type: Class D stereo power amplifier with GaN output devices Output power: 250W x 2 at 4 ohms, 140W x 2 at 8 ohms, up to 500W total in XLR boost mode THD+N: 0.0004% at 1kHz into 8 ohms Signal to noise ratio: better than 115dB Dynamic range: better than 115dB Switching frequency: 1MHz Inputs: 1 x balanced XLR, 1 x unbalanced RCA Power consumption: under 550W, standby under 0.5W Frequently asked questions Do I need a separate preamplifier? Not necessarily. The PA400 has its own PGA2311 volume control, so a converter with a fixed output can be connected directly. How does the bridged mono mode work? Mono mode is used through the balanced XLR input and combines both channels into a single higher powered output for one speaker. Will it run hot? GaN switching is efficient, so the chassis stays far cooler than a comparable Class AB amplifier, and overheat protection is built in. If you would like advice on whether the PA400 suits your loudspeakers, use the enquiry button on this page.
Dreamcrest Audio Fidelity Ltd, Nicosia. Specialist hi-fi and high end audio, 20+ years in the audio business. Full details and photos: https://www.dreamcrestaudio.com/product/smsl-pa400-gan-power-amplifier-silver-brand-new/
