SMSL
SMSL PA400|GaN 500W|Infineon GaN FET & TI PGA2311|Hi-Fi Stereo Amplifier
SMSL PA400|GaN 500W|Infineon GaN FET & TI PGA2311|Hi-Fi Stereo Amplifier
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SMSL PA400 GaN 500W Hi-Fi Stereo Amplifier
Uncompromising acoustic drive. Engineered with German Infineon GaN FET transistors, TI PGA2311 precision volume control, and BTL bridging for up to 500W of clean mono power.
Six Core Pillars of Sound
Infineon GaN FETs
Incorporates Infineon's latest GaN transistors with a 1MHz switching speed for delicate high frequencies.
TI PGA2311 Control
Utilizes TI's advanced volume control chip for exceptionally precise level steps and zero analog mismatch.
500W Mono Bridging
Supports BTL mono mode. Couple two PA400 units to deliver a massive 500W @ 8Ω per channel.
Dedicated GaN Power
Equipped with a built-in low-noise GaN switching power supply, providing high efficiency and stable current.
Pure Amp Pass-Through
Features a straight pass-through mode, bypassing the internal preamp stage for pure power amplification.
CNC Shielded Case
Anodized all-aluminum chassis machined via CNC, providing structural isolation and gold-plated terminals.
The Speed of Light: Infineon GaN Power Stages
Speed translates directly into transparency. The SMSL PA400 stereo power amplifier implements German Infineon's latest Gallium Nitride (GaN) power transistors. Operating at an ultra-high switching frequency of up to 1MHz, these components process signals with exceptional rise time. By virtually eliminating traditional class-D high-frequency switching hash, the PA400 delivers a smooth, delicate, and resolving top-end reminiscent of fine class-AB designs.
TI PGA2311 Reference-Grade Level Attenuation
Preserve every decibel of dynamic range. The PA400 employs Texas Instruments' advanced PGA2311 volume control chip, enabling high-precision stepped level attenuation with zero channel drift or analog wear. Unlike standard carbon potentiometers that degrade over time, the PGA2311 maintains strict channel tracking, ensuring a stable, centered stereo image even at whisper-quiet late-night listening levels.
Structural CNC Isolation and Gold-Plated Interconnects
Precision construction defines the VMV chassis language. Milled from a single block of aerospace-grade aluminum and finished with refined anodization, the enclosure provides passive thermal dissipation and excellent electromagnetic shielding. On the rear panel, custom heavy-duty gold-plated XLR inputs and high-current speaker binding posts protect signal integrity, securing a solid, lossless connection to your speakers.
Acoustic Topology Matrix
The SMSL PA400 functions adaptively, offering three distinct system topologies to match different acoustic speaker loads and system setups:
Delivers up to 250W x 2 RMS into 4Ω (200W x 2 into 8Ω), driving standard high-fidelity bookshelf or floorstanding speakers with absolute grip and low distortion.
Bridge two PA400 units using BTL mono mode. Each unit delivers a massive 500W of power into an 8-ohm load, perfect for driving hard-to-tame tower speakers.
Select between 4-ohm and 8-ohm load modes in the menu. This optimizes current output delivery and safety circuits to ensure thermal stability under sustained loads.
Frequently Asked Questions
What is the advantage of the Infineon GaN FET transistors? +
Unlike standard silicon transistors, Gallium Nitride (GaN) switches at a much faster speed (up to 1MHz) with lower power loss. This drastically minimizes high-frequency distortion, delivering clear, natural treble extension and resolving high-resolution details without the harshness often associated with standard class-D amplifiers.
How do I set up BTL Mono Bridging mode? +
In the menu settings, switch the AMP MODE to "PURE AMP MONO". Connect your preamplifier output using the Left channel XLR input of the PA400, and connect your speaker cable according to the MONO (+ and -) labels on the rear binding posts. You will need two PA400 units to form a stereo dual-mono setup.
Can I use the PA400 as a pure power amplifier? +
Yes, indeed. The PA400 features a dedicated pass-through mode in its amp settings. Connecting it to a high-quality external pre-amplifier bypasses the internal volume control stage entirely, converting the PA400 into a pure stereo power amplifier.
Why does the volume control utilize the TI PGA2311 chip? +
Traditional analog potentiometers degrade over time, leading to static noise and channel imbalances (one speaker sounding louder than the other) at low volume levels. The TI PGA2311 is an electronic stepped level control chip that keeps channel matching perfect and preserves full dynamic range across all volume steps.
What does the "Load Type" setting do? +
The LOAD TYPE menu (4Ω or 8Ω) adjusts the amplifier's internal protection circuits and current limitation parameters to match the nominal impedance of your speakers. This ensures optimal power transfer efficiency and keeps the amplifier cool under sustained listening sessions.
SMSL PA400 Specifications
| Parameter | Details |
|---|---|
| Inputs | Balanced (XLR) / RCA Unbalanced / Mono (XLR) |
| Outputs | High-current Speaker Binding Posts (Stereo / Mono BTL) |
| THD+N | 0.003% |
| Signal-to-Noise Ratio (SNR) | 115dB |
| Channel Separation | 75dB |
| Input Sensitivity | RCA (Stereo): 0.96Vrms / 22kΩ XLR (Stereo): 2.1Vrms / 22kΩ XLR (Mono): 2.7Vrms / 22kΩ |
| Power Output (Stereo Mode) | 4Ω: 250W x 2 RMS 8Ω: 200W x 2 RMS |
| Power Output (Mono Bridged Mode) | 8Ω: 500W x 1 RMS |
| Power Consumption | 40W (At standard listening volume) |
| Standby Power | <0.5W |
| Dimensions & Weight | 254 x 47.7 x 242 mm (WxHxD) | 2.58kg (5.69lbs) |
In the Box
Every SMSL PA400 package includes a comprehensive set of accessories, allowing you to connect and synchronize your system components immediately:
- SMSL PA400 Stereo / Mono Power Amplifier
- Full-Function Remote Control (RC-8A)
- AC Power Supply Cable (Matched to destination country)
- User Manual / Guide
SMSL PA200 vs. PA400
Both the PA200 and the flagship PA400 share SMSL's reference-class GaN FET DNA—delivering a liquid, tube-like analog midrange via ultra-fast 1MHz switching speed. Explore their distinct physical, technical, and power differences below.
| Specification | SMSL PA200 | SMSL PA400 (Flagship) |
|---|---|---|
| Amplifier Topology | German Infineon GaN FET (1MHz) | German Infineon GaN FET (1MHz) |
| Volume Controller | Texas Instruments PGA2311 | Texas Instruments PGA2311 |
| Stereo Output Power (4Ω) | 160W + 160W RMS | 250W + 250W RMS |
| Stereo Output Power (8Ω) | 85W + 85W RMS | 200W + 200W RMS |
| Mono Bridged Power (8Ω) | 250W x 1 RMS | 500W x 1 RMS |
| Mono Bridged Power (4Ω) | 400W x 1 RMS | Not Recommended (Mono 8Ω Only) |
| Signal-to-Noise Ratio (SNR) | 109dB | 115dB (Reference Silent) |
| THD+N | 0.003% | 0.003% |
| Pure Amp Pass-Through | Yes (Bypasses preamp volume) | Yes (Bypasses preamp volume) |
| Enclosure and Build | Ultra-Compact, Sleek Sandblasting | Flagship solid CNC-milled aluminum |
| Dimensions (W x H x D) | 220 x 45.9 x 175 mm | 254 x 47.7 x 242 mm |
| Weight | 1.44 kg / 3.17 lbs | 2.58 kg / 5.69 lbs |
System Synergy & Application Guide
SMSL PA200 — The Compact Studio
DESKTOP & NEARFIELDBest Suited For: Desktop audio stacks, cozy listening dens, nearfield studio monitoring, and efficient bookshelf speakers.
Why it wins: With its smaller 220mm footprint, the PA200 slides effortlessly into compact modern workspaces. It provides incredible, uncolored high frequencies and is exceptionally efficient at standard nearfield listening distances.
SMSL PA400 — The Flagship Powerhouse
LIVING ROOM & TOWERSBest Suited For: Flagship home audio stacks, large living room environments, hard-to-drive dynamic floorstanding speakers, and planar magnetic speaker configurations.
Why it wins: Armed with a massive 500W mono bridged capacity and a silent 115dB SNR, the flagship PA400 controls demanding crossovers effortlessly. Its thick CNC-milled solid aluminum case provides absolute physical noise isolation.
