Introducing SMSL H400 Hi-Res Headphone Amplifier 1000mW/300Ω,550mW/600Ω Earphone AMP

[Gymboy]

A70 Pro is more punchy and little weighter in a sound while H400 seems more sparkly and neutral as per Srboljub words. I have purchased used Aune S17 Pro and can tell this is a step up from Topping, even more warmer, with stage that extends more in all directions, sound seems definitely holographic while on A70 Pro like a wall, 2D. Up top, Class A Aune doesn't seem roll off at all, very sparkly with nice presentation and even more details. Only quirk, likes to heat up what is normal for Class A which conducts power at all times no matter is signal passing through or not. My brother also compared A70 Pro Vs Aune S17 Pro and he is getting Aune too.

 

[AudioQuality777]

This thread is not about Aune or Topping. To compare them. There is a corresponding forum.

 

[HiFiRobot]

SMSL H400 Hi-Res Headphone Amplifier 510$​

The SMSL H400 is a high-resolution headphone amplifier designed to deliver exceptional audio performance with high power output, making it suitable for a wide range of headphones. With its ultra-compact design and high-end preamp functionality, the H400 is an ideal choice for desktop headphone systems.

Key Features​

• Output power: 15W at 16Ω, 7.5W at 32Ω, 2000mW at 150Ω, 1000mW at 300Ω, 550mW at 600Ω
• Hi-End preamp design: Can be used as a Hi-End preamp
• Ultra-compact design: Perfect for desktop setups
• Gain control: Switchable high, medium, and low gain settings
• Wireless control: Comes with a full-function remote control
• Fully balanced discrete component design
• Ultra-high power output
• Electronic relay volume control: Eliminates channel deviations
• Built-in high efficiency and low noise power supply system
• Beautiful design: Silver shining quality aluminum with fully laminated color IPS display and tempered glass

Performance and Specifications​

Output Power​

The SMSL H400 delivers up to 15W of power at 16Ω and 7.5W at 32Ω, providing ample power for a wide variety of headphones.

Gain Control​

With switchable gain control, you can easily adjust the gain to suit your listening preferences:

• Unbalanced interface: Low: -11.8dB, Medium: 0dB, High: 14.4dB
• Balanced interface: Low: -5.8dB, Medium: 6dB, High: 20.4dB

Wireless Control​

The H400 is equipped with a full-function remote control, allowing for convenient operation and control from a distance. The remote control has a good hand feeling and better quality, making it easy to adjust settings as needed.

Design and Build​

The SMSL H400 features a fully balanced discrete component design with a beautiful silver shining or Black quality aluminum body. The device uses electronic relays to control volume, eliminating channel deviations. It also has a fully laminated color IPS display with tempered glass for enhanced durability and aesthetic appeal.

Power Supply​

The built-in high efficiency and low noise power supply system ensures reliable performance with minimal noise interference, making the H400 an excellent choice for high-fidelity audio playback.

In the Box​

• SMSL H400 Hi-Res Headphone Amplifier
• Power cord
• Remote control
• User manual

Hi, I assume this is for the balanced out. What is the power rating for single ended?

"Output power: 15W at 16Ω, 7.5W at 32Ω, 2000mW at 150Ω, 1000mW at 300Ω, 550mW at 600Ω"

 

[dunring]

I'm using one now with an SMSL DL200 5 volt DAC. The gain setting is different on SE so it's effectively less than balanced.
Balanced:
Low: -5.8dB.
Medium: 6dB.
High: 20.4dB.

Unbalanced:
Low: -11.8dB.
Medium: 0dB.
High: 14.4dB.

I'm still trying to find independent measurements of it, so far no luck. I tried the 68 ohm Hifiman He6se on single end and even with a preamp reduction it still goes louder than I'd ever safely listen to and sounds great. For 18 ohm IEMs it's a silent noise floor in low gain. I just stick with medium gain since I never have to switch modes. Usually SMSL amps don't have a performance penalty for low or medium anyway. It's simple to use, don't even need the remote since the menu is right there. Also the display turns completely off when it times out (you can adjust it for always on, but I set it to 30 seconds). Standby mode means it doesn't get hot like the H300 does on the bottom. It's not even warm compared to other stuff I've got. The power is effectively unlimited for all practical purposes. It's big though, I have the DL200 on bottom and the H400 on a slotted black metal monitor riser just so it looks nice (and keeps it cool).

 

[AudioQuality777]

Interestingly, the H400 simultaneously outputs the RCA and XLR to an external amplifier.
Even if a PCA or XLR is connected.This useful feature is not mentioned in the manual!

 

[lowrider007]

Does this have a fixed lineout option?

 

[RedEyeNinja]

 

[AudioQuality777]

Does this have a fixed lineout option?

For an amplifier, this function is unnecessary and useless.This function is used in the DAC.The H400 is an amplifier.

 

[lowrider007]

For an amplifier, this function is unnecessary and useless.This function is used in the DAC.The H400 is an amplifier.

It really isn't useless, many people have been asking for a fixed line-out on the Topping amps for years, my V550 has one and it's only an amp, it's very useful if you want to feed a signal to a stereo integrated amp, you take advantage or the pre-amp stage and also most DACs only have one line out or it is recommended to use only one of the line-outs on the DAC at the same time.

 

[AudioQuality777]

If you really want to use a full amplifier, then what's the problem with turning the volume control to 100%.And it is more correct to use it in the preamp mode with a power amplifier.

 

[lowrider007]

If you really want to use a full amplifier, then what's the problem with turning the volume control to 100%.And it is more correct to use it in the preamp mode with a power amplifier.

I would just prefer a dedicated fixed lineout, I don't like having to max out the volume as sometimes it brings into question the potential for clipping, not all equipment uses the same gain structure ie. line-out equalling max volume gain/voltage.

Yes a power amp would be better but this is not always an ideal or cost effective solution, and you loose features using a dedicated power amp, less inputs, no balance control, tone controls, can't be used independent of pre-amplifier, a fixed line-out gives people a lot more options, especially today with all the mini class-d desktop amps available.

 

[dunring]

I would just prefer a dedicated fixed lineout, I don't like having to max out the volume as sometimes it brings into question the potential for clipping, not all equipment uses the same gain structure ie. line-out equalling max volume gain/voltage.

Yes a power amp would be better but this is not always an ideal or cost effective solution, and you loose features using a dedicated power amp, less inputs, no balance control, tone controls, can't be used independent of pre-amplifier, a fixed line-out gives people a lot more options, especially today with all the mini class-d desktop amps available.

I just popped this H400 into preamp mode, and the volume is variable, no option in the menu to set it fixed. Menu is so simple I don't even use the remote. I have an A70Pro and think you can set it on that one though, tons of options in the menu and advanced for outputs and preset buttons for the remote for them. I can check tomorrow since I have a D70Pro Octo coming and going to pair this H400 with the D400 DAC and A70Pro/D70Pro for a group photo, for a review/comparison of the stacks.

 

[bequietjk]

The H400 just came in, and I've been using an A70Pro for a couple of weeks so it's easy to compare them.



The sound is so similar I don't think anyone could tell the difference in a true volume matched blind test. I'm using the same DAC and headphones (have the Hifiman HE6SE both the 68ohm and 50ohm versions). The menu is really simple and lacks the fancy display options like spectrum analyzer and Meter that the A70Pro has. The cables on the right and volume in the middle make it kind of annoying for anyone with the stack on the left. It's a really quiet amplifier, noise floor is just inky black. The display is monochrome, not the color IPS in many other models. When it auto shuts off, it's really off. Not like the A70Pro which dims down but still keeps active which you can see in a dark room (burn in down the road might be an issue).



Medium gain is all most people will use, the power just pours on for most headphones. I tried high gain with the HE6se and a big preamp reduction and no problem going as loud as you want with quiet recordings. The H400 is huge, just keep in mind when pairing a DAC. A 15" monitor riser will fit over it and stack anything you want, so it's easily solved. I left the E70 on it just so you can get an idea of it's size. The SMSL DL200 and newer DL100 are 5 volts, inexpensive DACs that will fit under the A70Pro but not the H400. The H400 has a nice standby mode, so it doesn't get hot or even very warm in use so you can leave it on without worry.
I'll write up a full review with temps and power consumption compared to the A70Pro. It just arrived today so wanted to be able to field any specific questions while I have them both out.

Do you have any opinions in terms of sound reproduction regarding the L70 vs H400?

 

[NexusOne]

@ Smsl:

Please produce a Do200 Pro + H400 + Tube Mode as All in one for a TV station scenario. I love your DL100 but I would be very happy to see a higher end product. I think lots of people would need it, too. Actually you can only decide between DL100 or Fiio KA19.

 

[smy1]

Decided to get h400 and d400 pro combo can’t wait to test them. I honestly think silver is the best color