Bakoon International Products HPA-01M: For Ears And Years

Headphones

Of course the first headphones I tried were planar magnetic ones (Audeze + Hifiman). When I reviewed the HPA-21 I recommended the amplifier for use with these headphones but not really with dynamic headphones and that’s where the HPA-01M is different.

The Beyerdynamic T90 is a superb headphone. Besides the fact that it doesn’t have a removable cable, the other downside is that it’s not simple to find a solid state amplifier that makes it sound as good as it sounds on tubes (OTL). The Bakoon came to the rescue and the T90, using the Voltage output, sounds just as good, if not better than on tubes: huge sound stage, great bass, reference class transparency, detail and clarity. Especially the bass surprised me. The Violectric V281 makes the T90 sound pretty darn good, but the Bakoon takes it to another level. The T90 on the Current out however, doesn’t sound that good. Hit and miss, like I said.

While the HPA-21 made the planars sound even better, the result you get from the Miniature 01M is impressive. If you had no idea what you were listening to you would probably think it was a desktop sized amplifier with a lot more power. The M however does an excellent job driving planars and it makes using orthodynamics “on the go” a whole lot easier and enjoyable (see Theorem).

Some Headphones like the Sennheiser HD650 are great on both outputs and it will depend on your personal taste which one you’ll use. The Current output gives you huge bass and big mids with a more aggressive sounding HD650. Some will love that, others will hate it. The Voltage out makes it sound very detailed, smooth and laid back but you’ll hardly have any bass impact. I found myself switching the HD650 to a different output depending on my mood and the music I was listening to.

All the other dynamic headphones like the Philips X2, Beyer DT770, T51P and Vmoda XS all sounded better on the Voltage output. Most of the time the Current output made the dynamic headphones sound too forward and aggressive and their tonality wasn’t quite correct. As most of you know by now, I almost exclusively listen to custom IEMS as my ears don’t seem to accept universals (besides the superb fitting Inear Stagediver series, S4 review soon!) All my CIEMs were connected to the Voltage output as the Current output is way too loud. Sound wise, the more laid back and detailed sound of the Voltage out pleased me a lot more. That being said, using the very sensitive Legend R in example wasn’t easy. With the AK240 connected to the M, the Legend R, at zero volume, already sounded more than loud enough for me. Lowering the output on the AK240 was the only solution for me. As a matter of fact I ended up doing that for most of my CIEMs.

Portable Amps

I can’t think of a portable amplifier that comes close to the M’s sound signature. While the Theorem, which I love, is also renowned for its synergy with orthodynamic headphones, the type of sound is very different from the HPA-01M. The M does have the edge over the Theorem for the orthos but the Theorem does make all the other headphones more dynamic sounding. And don’t forget the Theorem is an (iDevice)DAC as well.

The Duet and Picollo both are extremely good amplifiers as well but again I’d give the M the edge over them for planar technology headphones. Just like with the Theorem, the dynamic headphones will prefer the Duet and your IEMs will prefer the Picollo.

Fiio’s E12 surely has enough power to drive your orthos but when you look at sound quality the M and E12 are miles apart. It’s like comparing a Ferrari to a Mazda (no offense to the Mazda drivers)

If you’re looking for a (trans)portable amplifier for your favorite ortho, the HPA-01M is the one to go for, it’s that simple. If you, like me, also have a full range of dynamic headphones and BA IEMs, the choice won’t be as straight forward and the Theorem, Duet or Vorzuge might be the amps to go to.

Conclusions

Purely looking at orthodynamic headphones, the HPA-01M is the best “portable” amp I have listened to. With the AK240 as DAP or with the Herus as DAC, the 01M really shines. When listening to orthodynamics, it will give you great clarity, detail, speed, and transparency. Dynamic headphones on the Voltage out will sound airy, detailed, clear, very open and laid back, all in a musical way.

Just like last time, we can fully recommend the Bakoon for use with orthos on the Current output. But with the HPA-01M, it isn’t limited to just that, dynamic headphones also sound great on the Voltage output and I didn’t really have that feeling back in 2013 with the HPA-21. The HPA-21’s current output was even better though. That being said, I do still prefer using most of my dynamic headphones, except for the T90, on the Duet and Picollo or on the Violectric V281 at home (just looking at solid state amplifiers).

If you’re looking for a transportable unit for your orthos with a desktop quality sound in this price range, the HPA-01M might be the ideal solution. I wouldn’t really advise the Miniature for use with in ear monitors unless you’re willing to lower the output volume of your source. If not, the M just might be too loud for you (it is for me).

The HPA-01M is selling for $1,295, which isn’t cheap. In short I could say orthos are superb on the Current output and dynamics and IEMs are good to great on the Voltage output depending on the headphone/earphone used. If you’re mostly using dynamic technology headphones, there might be better and cheaper options like the Vorzuge, Duet and the Theorem in example.

I have really been enjoying the HPA-01M on my nightstand and I am waiting for news from Mr. Chae, I mailed him to take over the amp you see. My HUGO is coming in this week and I can’t wait to pair it up with that.

5/5 - (20 votes)
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Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.

19 Comments

  • Reply March 17, 2015

    cs098

    Interesting, do you think it can power the hd-6? Sounds like a great amp for bright headphones. Or people who adores the dark sound.

    • Reply March 17, 2015

      Headfonia_L.

      The only HD-6 I know is the Sennheiser DJ headphone and that shouldn’t be any problem 😉

      Darker isn’t the right work, unless you find the LCD2 dark. I wouldn’t call it an amp for brighter headphones just cause it works great for the T90. The T90 will always sound like the T90, no matter the amp

      • Reply March 17, 2015

        cs098

        lol he-6 XD

        Yeah I find the lcd 2 to be dark

        • Reply March 19, 2015

          Headfonia_L.

          I’d recommend the HPA-01 or HPA-21 for the Hifiman

    • Reply March 19, 2015

      ohm image

      I’m really beginning to enjoy darker sound.

  • Reply March 20, 2015

    Shini44

    will you update the Hugo (as a dac) + this amp, in this review? or create a whole new one for the epic pair? i do own a hugo, yet not a fan of the amp section of the hugo.

  • Reply July 28, 2016

    John

    What amp should I get for Beyerdynamic T90? I am considering Bakoon HPA-01M, G109S, Beyerdynamic A20, RSA Raptor, and La Figaro 339? I really care for a wide and deep sound stage, and good imaging.

    • Reply July 28, 2016

      Lieven

      You list a lot of good amps there. First choice: do you want tubes or not?
      That would make it Crack or 339. No tubes, I prefer a warmer ss like the V200. the HPA-01M is good but it doesn’t easily have a good synergy with lots of other headphones, so I wouldn’t go there.

      • Reply July 28, 2016

        JOHN

        Thanks for your quick response. Based on your review on the HPA-01M, I thought it was the best SS amp for T90. I believe you said that you even preferred it to V281. Now I am a little confused lol. I think 339 with stock tubes are not that good and I do not know if I can find proper tubes for it (any suggestion?). Crack seems to be a safe bet but I do not know how resolving it is. The thing is I want to keep the cost of amp+DAC under 1200$ and I do not know which one is the determining factor for sound stage and imaging. What DAC would you suggest with 339 or Crack? It seems that Asus Essence One Muses edition has great sound stage and tempting performance/price. Could you make some DAC+amp suggestions for T90? What about the RSA Raptor? Have you ever heard it? 6moons’ says that it has unbelievable sound stage with Sennheiser HD 650. I guess it would become even better with a headphone like the T90. Am I right?

        Cheers

        • Reply July 29, 2016

          Lieven

          It is a really good amp for the T90 but if you’re planning on getting more headphones, the HPA-01M might not be the most versatile amp.

          Have you considered the V200? If you’re not into tubes I suggest to stay away from them, unless it’s something you will want to explore of course.

          There is a lot of good gear in that price range, but I haven’t had the Raptor with me, sorry. I doesn’t mean the T90 would be also great on it, but it could be. The Asus isn’t something I would recommend. How about a second hand Hugo?

          • Reply July 29, 2016

            JOHN

            The only headphone amp that I have is the the one built in the Asus Xonar ST sound card. It is OK with my Grado SR80 and the music genre (Rock by the way) that I am listening to but, for everything else, this combo utterly sucks. Although it is very clear and transparent, there is no sense of sound stage. Everything is played right at your ear drum. This works great for fast paced music like Rock but for movies and everything else is very disappointing. This is the reason why I want to upgrade my audio system a little bit. I read many reviews on different headphones, amps and DACs and realized that the T90 might be the headphone that suits me best. It seems to have great transparency and sound stage but quite picky on amp and DAC. I have never heard tubes but I guess they are superior to SS when it comes to sound stage and imaging which I am looking for. Also, I believe T90 is harsh on trebles which makes tubes better option. The reason I was considering the Asus Essence One as DAC was the fact that many people compared its sound signature to Fostex HP-A8. If this is true, at this price, I think it cannot be beaten. HP-A8 is twice the price, at least in Europe. I think Hugo as amp+DAC was perfect if I could go for something like LCD-2 but since this is not the case, I think using Hugo just as DAC is very expensive. I would really appreciate it if you could suggest some amp+DAC combos that you know pair well with the T90. By the way, I haven’t got the T90 yet and, by now, I know that you are fond of the HD 650. So if you think I can get what I am looking for with the HD650, I can go for this one as well if you think it’s more forgiving on amp+DAC synergy. The reason why I didn’t consider the HD 650 in the first place is that I am somehow used to Grado and I think H650 is on the extreme opposite side of Grado sound signature. Sorry for sch a long winded comment lol.

            Cheers

            • Reply July 29, 2016

              dale thorn

              For a headphone like the T90, if you do get a decent tube amp, you could probably use a DragonFly as the DAC. You might find a better DAC in the $2000 USD range, but below $1000 I wouldn’t bet on it. The amp will make the bigger difference.

              • Reply July 29, 2016

                JOHN

                If I can seriously get away with DragonFly as DAC, I could choose between Crack, RSA Raptor, La Figaro 339 and Woo Audio WA2. I have never heard any of them so I have no idea how better expensive ones are compared to the very affordable Crack. Any idea?

  • Reply August 1, 2016

    JOHN

    Any suggestion for me?

    • Reply August 1, 2016

      Lieven

      A DF DAC for a tube amp? Sure! I also advice the HERUS or the HD but there are plenty of others as well.

      DF Black + 339 + T90? Done. 🙂

  • Reply July 27, 2017

    julien-hifi

    Hello Lieven,

    You got me convinced and i bought a herus+ with the bakoon hpa-01m, and it’s quite special.
    I have 2 HP today, mr speakers ether c1.1 and hd800s. Both really go well with the current output, i was bit worried for the sennheiser, but also a good pairing to my ears.
    After reading your reviews, and that the bakoon goes well with Audeze (but i have a problem with their weight) and hifiman, i soon will get the edition x v2 to try as well, should be interesting.

    So my question is this, am looking at a different type of sound and also make use of a balanced output. So after some research, the cavalli liquid carbon would be my choice. I will try using the herus+ as a DAC.

    Did you try it with one of these HP and could give me some insight compared to a bakoon sound?

    Thank you

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