Aune B1 Class A Portable Headphone Amplifier

This good looking amplifier managed to catch my attention at Canjam this year through its build quality, looks and of course its sound. I have managed to get a review unit with the courtesy of avmall.ro so here we are.

Introduction and Specs

The first things that caught my eyes were the build quality and the design of the unit and I must say that I love both. It’s a handsom and sturdy brick of well finished metal. I also love the 2 little glasses that give you the posibility of looking inside the clean and symmetrical circuits for each channel.

The unit has a micro usb input for charging the battery, a 3.5 input and a headphone 3.5 jack output. The volume knob is unfortunately made of plastic as are the power, gain and current switches on the side.

I can’t say I like where the volume knob was positioned as it is right between the line in and headphone output, and of course when they are both occupied, it’s a little hard to get to the volume and use it properly.

Another thing that I am not very fond of is the gain switch which can be easily mistaken with the current switch or even activated by mistake. That wouldn’t be  nice for your ears or your headphones, as the low gain setting has +5db and the high gain +15 dB. A sudden +10db volume increase could be very disturbing to your ears or headphones.

The chassis is made of thick, high quality aluminium and it gives it a very solid feel.

Overall I think that the build quality is good and it would have been great if the switches and knob were also made of metal.

The design looks nice but the position of the volume knob and gain switches can be problematic on some occasions.

Specs

• Up to 10 hours playback
• Suitable headphone impedance:  16-300 ohm
• Size:  65 x 110 x 18 mm
• Weight:  230g
• THD:  < 0.0008% @ 1kHz
• SNR:  > 124dBA
• Frequency response:  +/- 0.15dB between 10 Hz – 20,000 Hz
• Crosstalk:  < 110dB @ 1kHz
• Power (class A mode): 25mW/16ohm, 500mW/32ohm, 100mW/300ohm

You can find more about the product on aune’s page.

There are some key features that this amplifier has and we’ll go through some of them right here.

Aune B1 is a Class A discrete amplifier. The main amplification circuit is made of individual triode components. I must say that I am always a fan of good class a sound. Usually it brings good clarity with good bottom end, rich midrange and good treble but also keeping a natural sound signature.

The unit also has a current switch. If you turn it on it will go from 20 mA to 40mA for more current hungry headphones. This uses more battery and it actually reduces the usage from 10 hours to 5.   With full size headphones I do prefer the high current mode, as the sound opens up and it also improves dynamics and energy.

I have played with power supplies and reached the conclusion that they are very important to the overall performance of the sound. Aune seems to know the importance of this factor and it included a +-9V positive and negative symmetrical power supply with special and low ripple, capable of large current, providing continuous power to the amplifier.

The main PCB of B1 is made of 4 layers. The earphone amplification parts uses stream typed circuit to ensure that the sound in the right channel is the same as the left one.

As you can see, the Aune B1 has some very impressive features and specifications. Let’s see if the sound performance can match the one on paper.

Listening Impressions

The tests were performed with FiiO X5, FiiO E12A, Ultimate Sound US3D, SoundMagic HP200, FiiO Ex1.

Muse – Pshycho

Oh yeah baby! The sweet sound of good class A amplification. The electric guitars were organic, energetic and full of life. The drum hits hard and deep, while the voice is very nicely textured and has good presence. Ah, and the energy it manages to give you… I was lucky I wasn’t at work listening to listen to this song for the first time on Aune B1. I am not sure how my colleagues would have reacted to me singing along the song ” I am a psycho killer!!!! “.

Noisia – Alpha Centauri

The bass is absolutely gorgeous. It’s hits with tremendous power, slam & control. It’s like a wave that goes back and forth and you are caught on it. This sound is addictive.

George Enescu – Vlatko Stefanovsky – Romanian Rhapsodie in A Major Op. 11/1

Aune B1 gave a new dimension to this song. The instruments sounded closer to real life, improving their textures, tonality and presence. The soundstage gained more holography as it gained more depth and width but also very good instrument positioning and coherence.

Tehran Vocal Ensemble – Jack Sparrow  

The voices with this amplifier are a pleasure to listen to. They gain a new level of presence, textures and natural tonality. You can feel the sounds getting out of the whole body/chest of the singers, not just from the mouth and throat.

The Chieftans – Carolans Concerto

So we know that Aune B1 excels at bass and midrange, but how about the treble? Well, you needn’t worry about it as it seems to be on par with the rest of the frequency range. The upper midrange and treble on this song were mesmerizing through detail, tactility and in the same time smoothness.

Summary

Bass

The bass on Aune B1 is just awesome. I have to many adjectives in my mind for it. It’s very clean but it also has a powerful attack, very good control and it goes incredibly deep without being lazy at all. I think this is the best bass I’ve ever heard on portable amplification.

Midrange

The midrange is rich, seductive and in the same time pure and detailed. Ah, let’s not forget natural, as every instrument / voice sounds very close to the real deal.

Treble

This was another surprize. The treble on this unit is wonderfully extended and linear but also full of details and sparkly without sounding bright at all.

Vocals

The voices also sound wonderful on Aune B1, with wonderful textures, excellent presence and natural tonality. They sound smooth and clean and went directly to my heart.

Details

This amplifier is very transparent and if offers lots of details, especially if your DAC is capable of that. In other words, I think it would be kind of hard to find a portable DAC with which Aune B1 would be the bottleneck.

Soundstage

The sound decompresses as the soundstage gains in depth and width making it big, natural, very coherent and holographic.

Transients

The transients are very nicely balanced as they have a strong attack and a fast but natural and detailed decay. It makes the sound tactile, natural and energetic but also smooth and natural.

Tonality

The tonality on this amplifier is lovely. Nothing seems to be brought in front in an unnatural manner or to catch your attention when it shouldn’t. It sounds incredibly natural and life like.

Imaging and Instrument Separation

Every sound has space around it and can breath in the scene with no problem. I almost forgot to write about this section. This comes so natural and effortless that it seems normal, but it’s a great achievement.

Transparency

This amplifier sounds very transparent and clean and it manages to open up a window to your music.

Small Comparison to FiiO E12A

I won’t loose too much time on this comparison. Overall I ended up preferring the Aune B1 and not by a small margin. B1 sounds considerably more natural and organic. The sound is more dynamic and decompressed on B1 (E12A sounding a little flat/dry in comparison) , with better transparency and details. The bass on B1 kicks ass compared to the one on E12A, the midrange is better textured and more detailed, while the treble is smoother and more detailed in the same time on Aune.

Conclusions

I think that Aune B1 is the best portable headphone amplifier I have ever heard. With some exceptions in the design of the amplifier, I cannot find any flaws in the sound performance of the unit.

Aune certainly did a great job with B1 and I must admit I fell in love with it. It offers exactly the type of sound I am looking for. It’s a natural sound with excellent bass, rich, emotional midrange, smooth but detailed and sparkly treble, transparent and life like / natural sound signature. What’s not to love?

I wholeheartedly recommend this product!

Pros

• Excellent bass with wonderful extension, control and punch
• Rich and detailed midrange
• Smooth, detailed and sparkly treble
• Excellent vocals
• Very natural and clean sound
• Very spacious and natural soundstage
• Very good transients
• Very good imaging and instrument separation
• Excellent price for what it offers

Cons

• The volume knob and switches are made of plastic
• Position of the volume knob and gain switch are not very fortunate
• Gets quite hot if you want to use it in your pockets. If it’s winter this is a pro :))