The Story
Powerhouse Performance in a Compact Design
If your old amp has been struggling to keep up with your power-hungry cans, itâs time for an upgrade. The H400 laughs in the face of high impedance, pushing out up to 15W per channel at 16Ω. Those 600Ω studio monitors youâve been eyeing? Theyâll finally sound the way theyâre supposed to. And for those days when you just want to kick back, the full-function remote control puts all the power in your handsâliterally. With a high-efficiency, low-noise power supply tucked inside, the H400 runs cool and quiet, even when youâre cranking it up for hours on end.
Serious power for your headphones
Ever tried to drive high-impedance headphones with an amp thatâs barely awake? Weâve all been thereâflat sound, no dynamics, frustration. The H400 laughs in the face of underpowered setups, pushing up to 15W per channel at 16Ω. Even those 600Ω studio monitors wonât make it break a sweat. Expect vibrant sound, punchy bass, and an overall kickass audio experience.
Gain for days
One gain fits all? Nah. The H400 understands that sometimes you need to dial it back or crank it up. With high, medium, and low gain settings, you can customize the output to match your headphones and mood. Whether youâre whispering through a pair of sensitive in-ears or blasting a set of demanding cans, the H400 has you covered.
No pops, no clicks, just clean transitions
Thereâs nothing like the heart-stopping pop when you turn on your gear. Itâs a jarring reminder that maybe your setup isnât as refined as it could be. The H400 keeps things classy with a design that eliminates power-on and switching noise. Power it up, flip those gain settings, and enjoy the silenceâuntil the music kicks in.
A preamp with a purpose
Versatility? The H400 nails it. Besides driving your headphones, it doubles as a high-end preamp. Connect it to your power amps or active speakers, and youâre in business.
Lazy-day approved
You know whatâs annoying? Having to get up to tweak your ampâs settings. The H400 takes that inconvenience and throws it out the window. Its full-function remote lets you control everything from volume to gain without moving an inch. Perfect for those âIâm not getting upâ listening sessions.
Fully balanced design for pristine sound
The SMSL H400âs fully balanced discrete component design keeps things in check, delivering cleaner sound, sharper separation, and a listening experience that feels like you're right there with the music.
Electronic relay volume control
Remember the days of scratchy volume pots and channel imbalance? Yeah, those are over. The H400 uses electronic relays for volume control, ensuring precise adjustments and flawless sound quality at every level.Â
Aluminium housing and low-noise power supply
Looks arenât everything, but they donât hurt either. The H400 sports a sleek, silver aluminium body thatâs right at home on any desk. And with its high-efficiency, low-noise power supply, it stays cool and quietâletting your music take center stage without a hitch.

Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.

Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Description
Powerhouse Performance in a Compact Design
If your old amp has been struggling to keep up with your power-hungry cans, itâs time for an upgrade. The H400 laughs in the face of high impedance, pushing out up to 15W per channel at 16Ω. Those 600Ω studio monitors youâve been eyeing? Theyâll finally sound the way theyâre supposed to. And for those days when you just want to kick back, the full-function remote control puts all the power in your handsâliterally. With a high-efficiency, low-noise power supply tucked inside, the H400 runs cool and quiet, even when youâre cranking it up for hours on end.
Serious power for your headphones
Ever tried to drive high-impedance headphones with an amp thatâs barely awake? Weâve all been thereâflat sound, no dynamics, frustration. The H400 laughs in the face of underpowered setups, pushing up to 15W per channel at 16Ω. Even those 600Ω studio monitors wonât make it break a sweat. Expect vibrant sound, punchy bass, and an overall kickass audio experience.
Gain for days
One gain fits all? Nah. The H400 understands that sometimes you need to dial it back or crank it up. With high, medium, and low gain settings, you can customize the output to match your headphones and mood. Whether youâre whispering through a pair of sensitive in-ears or blasting a set of demanding cans, the H400 has you covered.
No pops, no clicks, just clean transitions
Thereâs nothing like the heart-stopping pop when you turn on your gear. Itâs a jarring reminder that maybe your setup isnât as refined as it could be. The H400 keeps things classy with a design that eliminates power-on and switching noise. Power it up, flip those gain settings, and enjoy the silenceâuntil the music kicks in.
A preamp with a purpose
Versatility? The H400 nails it. Besides driving your headphones, it doubles as a high-end preamp. Connect it to your power amps or active speakers, and youâre in business.
Lazy-day approved
You know whatâs annoying? Having to get up to tweak your ampâs settings. The H400 takes that inconvenience and throws it out the window. Its full-function remote lets you control everything from volume to gain without moving an inch. Perfect for those âIâm not getting upâ listening sessions.
Fully balanced design for pristine sound
The SMSL H400âs fully balanced discrete component design keeps things in check, delivering cleaner sound, sharper separation, and a listening experience that feels like you're right there with the music.
Electronic relay volume control
Remember the days of scratchy volume pots and channel imbalance? Yeah, those are over. The H400 uses electronic relays for volume control, ensuring precise adjustments and flawless sound quality at every level.Â
Aluminium housing and low-noise power supply
Looks arenât everything, but they donât hurt either. The H400 sports a sleek, silver aluminium body thatâs right at home on any desk. And with its high-efficiency, low-noise power supply, it stays cool and quietâletting your music take center stage without a hitch.

























