双子记：双木三林 smSL SP400 （人民币售价约3000）

比较同门的smSL SH-9（人民币售价约1800）

There isn’t much to say about them design wise, one is smaller and one is bigger, one has 6 Watts on tap and one is doubling that number, one has a preamp output and SH-9 doesn’t have it. SP400 is pretty much a dual-mono version of SH-9 and it costs twice as much too. Apart from that, their UI is the same, I/O is the same, they look almost the same too.

在外观设计上，SH-9小一些而SP400要大一些。前者最高6W的输出，而SP400则是翻倍的12W输出。SP400有前级输出，而SH-9没有。SP400相当于双倍版的SH-9，当然价格也是两倍左右。除此之外，它们的操作界面UI基本相同，I/O输入输出也类似。

When it comes to sound performance, there are two instances that I will cover. If hard to drive planar magnetics are not on your daily menu, then SH-9 would be a better choice, since there is little to no difference between both siblings with desktop dynamic headphones or with easy to drive planars like Erzetich Phobos and Kennerton Wodan. Both are extremely neutral sounding with a slight tint towards naturalness and real textures. Wodan had a slightly better bass impact and a deeper stage on SP400, but others performed more or less the same on both devices.

说到声音部分，我会用两个例子来说明。如果你没打算用难以驱动的平板耳机，SH-9其实已经不错了，它和SP400差距不是特别明显，在使用大部分动圈耳机或者容易驱动的平板耳机，比如Erzetich Phobos和Keznnerton Wodan。两个耳放都是非常中性，音色自然并且质感真实。Wodan这副平板耳机，在SP400下有更好的低频与声场纵深，但两者并没有天上地下的区别。

SP400 was clearly leading the pack with harder to drive headphones as those sounded very differently on it. Susvara was a different animal altogether on SP400, the biggest improvements happened in the bass region where SP400 was able to sustain much longer 20 Hz notes, there was a better feeling of a physical impact when bass notes were landing. Compared to that one, SH-9 was struggling in offering higher dynamics, pace, rhythm and timing, especially with Susvara. Soundstage felt better spread on SP400, there was more air around every musical note, the void spaces were bigger, so I could easier focus on any note I wanted. SH-9 was smaller sounding, slightly cozier and more up-front, which some folks might even prefer to the wide and spacious SP400.

SP400在驱动一些难推的耳机时，比SH-9表现好太多了。Susvara在SP400上的声音，与SH-9完全不同，最大的提升在低频，此时SP400能显著地在20Hz的单音维持更长时间，这点在低频的质感与效果上，带来了非常大的提升。在驱动这些耳机时，SH-9明显吃力许多，无论在动态、速度、节奏感与响应上，特别是驱动Susvara，SP400优胜太多。声场的展开上，SP400能表现得更自然，每一个乐音的“空气感”都完全描绘，有更多的空间信息，如同真实的舞台般。SH-9听起来的规模就小一些了，感觉会直接一些。如果喜欢更宽广和更具空间感的声音，SP400是首选。

Frequency response and the rest of the technicalities felt pretty much the same on both devices. Do note that SP400 can also work as a dedicated preamp in a loudspeaker setup and I totally get it why one might want the SH-9 and others would pay twice for a more powerful and feature package device.

频率响应与其他技术指标上，两者是相近的。特别注意的是，SP400可以作为独立的前级用，特别是音箱用户。这也是不同人群选择SP400或者SH-9的原因，当需要前级的时候，SP400是更好的选择。

以小博大：SMSL SP400（人民币售价约3000）

Benchmark HPA4（换算人民币约20000）

If you are interested in driving headphones only and you own a single DAC, get the SP400 and move to the conclusions. If you want to drive headphones, but you also need a decent preamplifier for your loudspeaker setup: get the SP400 and move to the conclusion. If you have multiple audio sources (DACs, CD players, Turntables) and you need the most precise and uncolored headphone amplifier and preamplifier section then you should proceed with this comparison. People that are really interested in HPA4 would probably use it in a speaker setup too, as it’s still the best preamplifier bar none I’ve tried and don’t forget that it has 4 analog inputs! Two single ended and two balanced inputs. It’s so easy comparing two or even four DACs with HPA4. Via its graphical user interface, I can volume match each analog input so that I would have the same sound pressure level with 4 different DACs. All my DAC comparisons were done via HPA4, it is not only a headphone amp, but much more than that, hence the huge price difference.

如果你使用耳机并只有一个解码器，直接选SP400即可！如果你使用耳机的同时，但也需要一个不错的前级设备，用作喇叭系统，那么直接选SP400！如果你有很多音源（如解码器、CD机、调音台）并需要最准确且无染色的耳机放大器与前级，那么你要看接下来的比较。那些对HPA4感兴趣的人，很有可能会用来接喇叭系统，毕竟HPA4是最好的前级之一，并且有四路模拟输入。两组单端，两组平衡，用HPA4进行多组解码器的比较是很容易的。通过它的图形用户界面，我能保证每一个输入设备最终的声音大小一致。我所有的解码器对比，都是通过HPA4进行，这不仅仅是一个耳机放大器，还有更多的功能，当然价格也非常昂贵。

Performance wise, HPA4 has a very small lead in terms of transparency. SP400 was good when I’ve put it in between the Matrix Element X and Keces S300, driving a pair of KEF Reference 3, but HPA4 sounded cleaner and it had a better flow and easiness to it.

在性能上，HPA4在透明度上略微胜出。前级功能上，SP400非常好，当我接一对KEF Reference 3使用时，HPA4的声音会偏向于细节呈现，而SP400的听感也不错。

When it comes to driving easier loads as IEMs, portable headphones, even desktop dynamic headphones, I would give an edge to the HPA4 which was simply noiseless and was providing the cleanest power unleashing their maximum potential. SP400 was very close to it, but it wasn’t as crystal clear and transparent sounding.

当驱动低负载设备，比如入耳式耳机和便携耳机，HPA4略微好一点，因为它的噪声几乎听不见，声音如水晶般清澈，虽然SP400也相当接近。

Moving on to the hardest to drive headphones like Hifiman Susvara, well that’s an entirely different story. You see, with high dynamic range tracks at close to maximum volume HPA4 was simply shutting down, because it couldn’t provide enough current and instead of damaging its output stage, it went lullaby. Only with louder tracks, HPA4 was decently driving the mighty Susvara, but in all honestly SP400 trounced it on almost every level. SP400 had more control with Susvara, even higher dynamics, a deeper and a more impactful bass, it was awakening them from their deep sleep. Soundstage was deeper and wider and it had more headroom to play with. With Susvara alone, SP400 was a better amplifier and if smSL would further increase its gain from 11.6 to say 20 dB, then it would work even better with them and with other hard to drive headphones. When I moved to Audeze LCD-4, sometimes I wanted a better slam and more viscerality in my tunes and SP400 provided more of that, but sometimes I wanted more transparency and detail and HPA4 was doing that better.

而说到那些非常难驱动的耳机，这就完全不一样了。用大动态的音乐测试，在最大音量输出下，HPA4直接趴下了，因为它提供不了足够的电压，而触发了保护停止工作。只有用响一些的音乐，HPA4才能与Susvara这类的耳机很好地配合，但SP400毫无压力地播放所有这类型的音乐。SP400对于Susvara的控制力明显更强，并且有更大的动态，更深且更冲击的低音，SP400将这些部分发挥地淋漓尽致。声场更深更宽，动态余量明显比HPA4更充足。仅Susvara而言，SP400已经很完美，不过我感觉如果能将增益水平从11.6dB提高到比如20dB，那或许会更好些。用Audeze LCD-4测试，SP400能提供更爆棚更具感染力的表现，而HPA4则偏重通透与细节。

In some ways SP400 was better, in other ways HPA4 was better, but in a high-end loudspeaker setup there wasn’t a contest, as HPA4 was on another level altogether.

某些方面SP400是更好的，而HPA4在某些方面也有优势。前级功能上，HPA4因为有多组输入而更方便使用。

If you are interested only in headphone drive and you really despise the dryness of your Drop THX-789, then smSL SP400 should provide a warmer tonality, it would restore some lost midrange density, offer a bigger stage, a better driver control and more importantly a lot more power on tap to drive a wider variety of headphones.

如果你是耳机专精，不喜欢Drop THX-789略微干涩的音色，双木三林smSL SP400能提供温润的调音，并且中频的密度表现更好，声场更宽，驱动控制更强，并且功率更大，耳机的适应性更广。

Conclusion

SP400 总结

Here we are at the end of the road, telling a story about one of the nicest headphone amplifiers money could buy at less than one grand. I wish it had a higher gain, I wish it had at least one additional XLR input and I wish it didn’t have that fingerprint magnet on top, but everything else is really up there with the best there is. Sincerely, there is very little to nitpick about it and its biggest flaw will most probably be taken care of in the near future, I would really appreciate that.

SP400是市面上最好的耳机放大器之一，并且价格相较于声音表现而言，是非常低的。虽然我希望增益能更高些，多一组XLR输入，但它本身已经非常完美。老实说，我有点吹毛求疵了。

Apart from this, starting with IEMs and finishing with notorious headphones like Hifiman Susvara, SP400 was pumping a high engagement factor, it had a very high level of detail, offered an open wide soundstage and it had one of the best diaphragm control I’ve experienced with headphones. It stood shoulder to shoulder with my Benchmark HPA4 and it even outclassed it on several occasions, while costing about ~5 times cheaper. In terms of value, there isn’t much to add, it’s one the best ones that are costing south of $1000 and as such, I cannot move forward without awarding them for their work.

SP400从入耳式耳机到怪物级别的大耳机如Susvara，都有顶级的表现，细节丰富，声场表现出色，驱动控制是我听过的最好的耳放水平。与HPA4比，不分伯仲，甚至还比它某些方面强，价格实在是低太多，只有后者的五分之一，SP400没办法不列入我的最佳推荐名单！

PROS:

优点：

Simple yet beautiful design

简约而漂亮的外观设计

High-quality uni-body case

高品质的一体外壳

Its remote control and LCD screen are huge quality of life improvements 

遥控与屏幕提升了使用体验

Extremely linear frequency response, super extended at both ends

极度线性的频率响应，极佳的高低音两端延伸

Neutral with a slight tint of warmth and naturalness

在中性的声音基底下，更温润自然

Highly impressive levels of transparency and resolution

透明度与解析力极好

Very precise pin-point imaging, 3D sounding all the time

超精准的立体声定位与3D空间感

One of the best dynamics at less than one grand

此价位的产品下最好的动态表现

Pitch black background, IEM friendly amplifier

无底噪，对入耳式耳机友好

The most powerful THX-AAA based amplifier

驱动力最强的THXAAA技术耳放

Good preamplifier section

前级功能优秀

Amazing value

性价比超高

CONS:

不足：

Low gain design (only 11.6 dB on High Gain)

最高增益11.6dB

Tempered glass cover is a fingerprint magnet

玻璃顶板需要打理

An additional XLR input would be killer

希望多一组XLR输入

总体评分 97/100

性价比100/100

功率 98/100

解析 98/100

动态 97/100

频响 99/100

声场 96/100

做工 93/100