The Usual Suspects: 12 Portable Amps Compared



Moving up from the tiny amps gives us the slim amps, which come in larger footprints, but still remain quite practical due to their thinness. The tiny amps are excellent pairing if you really want to keep things super-compact, as the tiny amps make for a beautiful match with the Ipod Nano or Sansa Clip players.  But since the majority of people prefer the fuller screen Ipod Touch or the bigger capacity Ipod Classic, then the larger footprint of the slim amps actually fit better. The Headstage Arrow has a smaller footprint than the ALO or the TTVJ, but it happens to match beautifully with the Hifiman HM-602/HM-601 players.

All three amplifiers here are the result of years of design improvements, from the days of altoid-cased CMOYs to the current super-slim, digital volume control, rechargeable batteries, and high power outputs. Portability, features, power output level, and sound quality are top notch and are definitely among the best. The implementation of a digital volume control to the TTVJ and the ALO Rx gives these amps the same clear-cut articulation that I’m hearing on the Shadow and the Pico Slim, but with higher power output levels. Given the high quality sound of the three amplifiers, the first question that you need to ask is how each amplifiers are voiced, as I think their sound signature is first and foremost the most important factor when evaluating an amplifier.

The usual suspects for slim amps: (top to bottom) TTVJ Slim, ALO Rx MkII, Headstage Arrow.


Front and back views. That Headstage Arrow is the slimmest amp in this shootout, beating even the Pico Slim.


TTVJ “SLIM” ($349 standard, $449 with DAC)
The easy way to describe the sound of the three amplifiers is that the TTVJ comes with a good and full midrange, the ALO Rx has a spacious open soundstage with a clear treble and bass, and the Headstage is somewhat “in between” the two with its flatter tonal balance with a slight tint to a dark signature.

Personally, I enjoy the TTVJ the most out of the three as it has a full midrange to bass body while still having a good treble sparkle. Some people call it tube amp-like, and though real tube amps come with their own distinct signatures, I think the main point with the TTVJ is that you will never feel the amp to sound digital, as Todd is a heavy analog-gear junkie and it’s quite proper that he tunes his amp to give the sound that he likes. In fact, when I did a comparison of the TTVJ Slim with the older TTVJ Portable Hybrid Tube (that uses actual tubes), I find the sound signature between the two to be very identical.

The sound of the TTVJ Slim is indeed very analog. The midrange is full bodied, without making the sound overly thick or drowning the instruments. With the TTVJ Slim, the sound remains agile and lively, as it’s able to keep up with most fast-paced rock. You get a lively presentation of the instruments through what I hear to be a slight boost on the lower treble, and it follows down with a full bodied mids and down to the bass. The bass is more focused in the upper-mid bass, and although you don’t feel it to be rolled off in the lows, the ALO Rx noticeably hits deeper bass notes than the TTVJ. The soundstage is very good and deep, though not as wide and as open sounding as the ALO Rx. If there is any complaint I have, is that the lower mids and bass section can sometime sound a bit muddy and not as well articulated as the ALO Rx. Still, given the superb overall voicing, I think it’s not going to be a big issue for most people.

ALO RX MK2 ($449)
I think amplifier choices ultimately come down to your music preference, personal taste, and the headphones that you happen to be using. I enjoy the TTVJ very much, but my friend Sem happens to choose the ALO Rx as his favorite. The very clean, grainless sound of the ALO Rx, is probably one thing that got him hooked to it. Sem is also a big fan of strong bass impact, and while the TTVJ has more of the bass in the upper-mid, the ALO delivers more low bass impact than the TTVJ. The soundstage of the ALO Rx is also wider and very open sounding, and indeed it is one of its signature sound. Personally I feel the ALO’s midrange to be too flat and not as full as the TTVJ, and this is the deal-breaker for me. But at other times, I also wish that the TTVJ can be more ALO Rx like in delivering a clean bass frequency.

Although the previous paragraph sounds like a lot of points in comparison to the TTVJ, but ultimately amplifiers are not about collecting points, and so it boils down to a synergy game. I would consider both amplifiers roughly at the same level of “sonics quality”, and the choice would boil down to the sound signature. The ALO has a lively and open soundstage, with clean highs and more impactful lows. The TTVJ has a fuller midrange, and a different emphasis in the treble than on the ALO. Both amps are very fast and dynamic sounding, though the ALO is a bit faster in pace. The TTVJ comes with an option for a built-in DAC, which makes it a fun sounding portable DAC/amp box, for roughly the same price of the ALO Rx Mk II. The DAC resolution is quite decent, but the selling point is how you get a portable amp that also doubles as a DAC/Amp simple desktop set up. I think that’s quite a deal!

Some of you may also know that ALO has currently stopped production on the original ALO Rx and is now selling the Mark II version of the Rx. Both versions have pretty much the same sound signature, and it’s safe to say that the Mark II version is a good upgrade over the original while still retaining all the good things you find on the original. For a more complete comparison, please refer to my ALO Rx Mk2 article, HERE.

The third amplifier on this category is the even slimmer and smaller Headstage Arrow. A very, very impressive amplifier from Robert at Headstage (aka Headphonia, with a “ph”. For the record, Robert used the name before I did, and I think he deserves to be acknowledged for that fact.). The Headstage arrow is an amplifier that never fails to impress people at the first look. The super slim build and smaller footprint make the TTVJ and ALO look vastly overweight. Not only content at beating the two amps in the size category, Robert also implemented some very kickass features, some of them a first in the portable amplifier scene. The notable features are auto ON/OFF feature that turns the amp on when it detects an input signal, and automatically turns it off after one minute of inactivity (You ROCK, Robert!), automatic voltage adaptation (switches the amp between 4V and 12V depending on needs, to conserve battery life), two steps bass boost (my friend Peter is in love with the Headstage due to this switch), impedance matching switch, crossfeed switch, and three selectable gains. Robert brought all of these goodies at an incredible $299 pricetag, which directly cuts into the TTVJ ($349) and ALO Rx ($449) price.

The use of the AD8397 in the output stage is highly favored by owners of the AMB Labs Mini 3 amplifier, which naturally gives it a bit of similarity to the Mini 3’s sound. The tonal balance leans toward the “dark side” (by the way, the adjective dark is used purely to describe tonal balance, and absolutely no negative bias meant. ), similar to the RSA sound but with better presence on the upper mids. In a way the Arrow is also closer to the sound of the TTVJ, while quite different from the sound of the ALO Rx. The Arrow’s sound, is just a tad darker, mostly due to the difference in low-mid treble, where the TTVJ is more sparkly in those regions.

The treble of the Arrow is not as sparkly and not as present as on the TTVJ or the ALO, one reason why my friend Sem passed on the offer to buy a near mint Arrow at a great price, when he was offered one. If midrange and low body is important to you, but equally well you want to hear a sparkly treble, I would recommend the TTVJ sound, as it is still more lively than the Arrow. Generally the Arrow sound is quite pleasant, but the use of an analog potentiometer makes the Arrow not as good as the TTVJ or the ALO in instrument separation and articulation. Generally I would recommend the TTVJ more than the Arrow because of this factor, but if you’re considering to keep the size down while still packing serious power, then the Arrow is highly recommended as it makes the TTVJ looks rather big.

Ideally, you should base your decision primarily on the sound signature, while features and size should come second. I choose the TTVJ, but that doesn’t make it the best amp from the three. My friend Sem enjoys the ALO Rx very much, and Peter happens to be loving the Arrow a great deal lately due to the Bass boost and super-slim build. The bass boost switch is quite fun to use, as it boost bass levels up, though making the bass slightly boomier.

As I’d like to stand by that “sound signature synergy” statement, I know that in the real world, the $299 pricetag of the Arrow is a very strong point for potential buyers, and especially if you’re considering between the Arrow and the ALO Rx, which comes in at a full $150 price difference. Still, Sem is willing to dig deep into his pockets as he finds the ALO Rx to be most satisfying for him.

Rate this review

  • MSKrishnan


    I currently use an iPod classic + Algorhythm Solo + FiiO E11 + Westone 4. All music is in Apple Lossless format.

    I seek suggestions on how I could improve upon the above setup.


  • MSKrishnan


    My current setup is iPod classic + algo solo + FiiO E11 + Westone 4 with regular cables.
    All music on iPod is in apple lossless format.

    I seek advice on how to improve the the above.

    • Improve the amp section. There are plenty of amps to choose from, Krishnan.

      • MSKrishnan

        Hi Mike,

        Wanted to put in an update. I bought a ALO RX MK2 to replace the FiiO E11.

        The sound now is a whole lot cleaner and crisper. 

        Thank you for your advice. 

        • Yes for sure the two amps shouldn’t even be compared, the Mk2 is a much better amp. 🙂

  • Hi I have se 535 iem and was thinking of getting the cypher algorhythm solo what amp would you recommend for portability

  • addsa sadasdas

    Hi I have the JH11 Pro and thinking of getting HP-P1/Algorhythm solo, which amps would you recommend to go with this set up? Preferably, also able to drive the HD 700s too because I have pre-ordered them..

  • will the RSA Shadow power a set of Swnnheiser HD800

    • Not sufficiently.

  • Hi Mike, my current setup is teclast t51>headstage 3g>westone4 and I’m not satisfied… how can I improve my music…sud i change amp…or dap? or wat is a better setup? thank you for your suggestion.

    • What do you feel is lacking?

  • saeed zolfaghari

    hi mike, I recieve my arrow 4G recently, but I found it some dark to my taste
    I want to upgrade my IEM.
    personally I think about westone 4, do you think that I will be satisfied ?
    (I think that I will be satisfied with a natural sound ,clarity and instrument seperations .)

    • If the amp is too dark, why not change the amp?

      What IEM are you using now?

      • saeed zolfaghari

        it’s dark to me, I think that ipod touch 3g is better.

        I’m using shure se315

        I put the amp in my pocket, so the size of amp is very important to me

        do you think that I need to change the amp?
        ttvj is not so big?


        • It’s probably easier to get a brighter sounding IEM. Say the Fischer DBA-02.

          • saeed zolfaghari

            yes I think about the bright IEMs

            do you think that DBA-02 is on of the best choice?
            what’s about grado gr10 or ath-ck100? ( I can afford about 400$)


            • The DBA-02 is more popular than the Grado GR10 and the CK100 so I think it’s a safer recommendation. The GR10 is good but somehow lacking any special aspect. the CK100 is quite polarizing, I wouldn’t recommend it unless you can get an audition.

  • Ryan Sim

    Hi Mike-

    First off- great article! Really apreciates such insights being available for reference for confused people like myself. 🙂

    Question: I have a Shure se535 + a Grado sr325is headphone and am recently taken interest in the RSA amp line-up to get a better music experience from them.

    With portability in mind- can you help advice if RSA Shadow or Mustang will be able to drive both output with high efficiency and result?

    Thanks and looking forward for your advice! 🙂

    • Ryan,
      The Mustang if you’re gonna use the Grado. The Shadow is quite limited, afraid you can’t get enough loudness.

  • Time to update since so many great amps have been released or updated.

    • Yes for sure, Steve… I will do that when the opportunity comes up.

  • Jordan Ingram

    I’m using the JH11s and I’d really like to audition the Pico Slim, but I have no idea how to make that happen. There aren’t any portable amp retailers in my area, so are there other way to audition things (i.e. a “test drive”)?

    • Nothing that I can think of. Find a head-fi meet?

      • Jordan Ingram

        Yeah ok, I figured as much. Guess I’ll have to take my chances on something!

        • Good luck, Jordan.

  • Hey Mike,

    I’m looking for a portable amp with DAC to power my westone 4’s. I’m looking to add a tubish quality (warmth) to my music as well as enhance instrument separation and soundstage. Tighter bass is always welcome. I’m quite happy with the mid-high range i get right out of my iPhone or macbook (although it just doesn’t feel analog enough for my taste, if that makes sense). I’d appreciate any recommendations.

  • james74

    HI Mike,

    Just to update you on some advice you gave me 6 months ago on amps to use with Sony X walkman – JH16’s & Sony MDR-Z1000’s. Been bit of a delay but have finally picked up the TTVJ Slim from someone I know and is is the non dac version but have to say it was worth the wait as I am currently still without a desktop rig this is the best I have heard my MDR-Z1000’s since I have had them and despite those cans meant to be efficient to drive @ 24ohms they sounded as if they was lacking sonically even with my new Z series Walkman and now the TTVJ Slim has defined to me the Z1000’s are a keeper. The Slim is just what I was looking for and is a tad more fun to listen to than my old PB1/DB1 set up.

    So thank you for the past advice/ direction in making an informed decision that has been worth the wait but now I have the Slim (non dac version) I just have to ask one final piece of advice; What external portable dac would suit the TTVJ Slim as a good partnership?

    I had the DB1 Boomslang originally and was impressed with that when it was in conjunction with the PB1 but am not sure what other alternatives there are other than the DB2 that have the ability also with both optical & Coax digital input as well as usb for use with my laptop. I am not on a budget as such so just want a dac that has the above digital inputs that can pair well with the TTVJ Slim.

    Thanks again Mike ; )

    • Hi James,
      I’m glad to hear that you are enjoying the TTVJ!

      On the topic of portable DACs, what player are you using? You know that the Sony X can’t be plugged in to a separate DAC.

      • james74

        HI Mike,

        I should of clarified a bit more clearer, the dac will be for use with my HP Envy laptop which has the el-crappo Beats audio installed and then I will use my Arcam FMJ cd player via Coax which could be a Meridian 24bit G08 player later on. Then you never in the future could go down a Hi-fi Man/ DX100 route….

        • James,
          A bit confusing there. If you are going to use a Meridian G08, why are you even considering these Ibasso DACs?

          • james74

            Sorry Mike, long day @ work yesterday!, was meant to say I will use it with my cd player (arcam FMJ) until I get a Meridian G08 (not sure when that could be though) but ideally need the dac to have coax/optical as well anyway for if I go for a premium dap later.

            But other than the Ibasso DB2 dac I was not sure what else there was to consider that was as good with the same input options in portable form which would go well with the TTVJ Slim as a pairing. Sorry for confusion there ; )

            • So this is for a desktop set up yes?

              If it’s so I would recommend you to look into something desktop-based like the Cambridge Audio Dacmagic.

              I’ve never tried the DB2 DAC, but from my previous experience with Ibasso portable DACs, I don’t think they are good enough to take on the $300 level desktop DACs.

              • james74

                Hi Mike,

                I ideally needed a portable dac for when I take my laptop on my travels but yes I was looking at also getting a nice desktop dac later on with a budget up to £1K. So portable dac wise there is not much to choose from then?. Desktop – Dac magic looks intriguing, have you had experience with the Audiolab M-dac which also has a built in headphone amp also?

                • Hi James,
                  Sorry I haven’t auditioned the M-DAC til now..

                  • james74

                    Ok, Thanks Mike, I will audition the Dacmagic in the near future anyway along side the M-Dac.

                    For portable dac I might just have to get a usb only dac to widen the choice that is currently out there. Just need to find one that pairs well with the TTVJ slim. Thanks again for your advice ; )

                    • You’re welcome James. 🙂

  • Hey Mike,

    Which one would you recommend for the Cowon J3 and the Sennheiser
    HD25-1 II?

    • There’s a lot to choose from, Stephen. I think something small like the RSA Mustang.

      • How about the Sennheiser HD25-1 II with an Ipod Classic? Would that change your opinion on ‘somthing small like the RSA Mustang’? Will the Alo Audio National be better than the Mustang?

        I listen to mostly: Pop, Rock & Alternative.

        Thanks Mike.

  • Hey Mike,

    Which of these would you recommend for the JH5 custom Pro In-ear monitors?


    • Stephen,
      I like the JHs best with the Pico Slim.

      • Hey Mike,

        How about Universal fit IEMs? Would you still recommend the Pico Slim?

        • It would depend on the IEM. Some people pair bright IEMs with dark amps and so on.

  • Hi Mike,

    Now I have the HRT Music Streamer II, which amp would you recommend for the Ultrasone Pro 900?


    • Budget? Desktop/Portable?

      • Under $500 would be ok. Since I will use it at home, either desktop or portable one would be accepted. From this article, I think SR-71A, P-51 and TTVJ slim are good for pro900 but I’m not sure. So I wanna ask for your recommendation.

        • Boonh,
          SR71A is best, but no rechargeable batteries if you can live with it. P51 I think doesn’t have enough impact power for the Pro900.
          The TTVJ Slim can be a good pairing.

          • Thanks Mike!
            I will have a chance to try both SR71a and P51 soon. Hope I can also try TTVJ slim in the future.

  • Hi Mike,

    Which one would you recommend for the Westone 4R? I listen to mostly: Pop, Rock & Alternative.

    • You need bass impact with the 4R right? I’ve only listened to the Westone 4 and I think the main problem is bass impact.
      Try the RSA Shadow. Small, precise volume control for IEM, good bass.

      • Hi,

        Thanks for reply. Just wondering, are there any other cheaper portable amplifiers that would help the Westone 4R for Pop, Rock & Alternative? Yes, the bass is lacking.

        • The Shadow should help, but I doubt it can add that much bass.

          What I am talking about here is the bass punch. I find the W4 to have very weak bass punch.

          • Hi,

            Are there any other cheaper portable amplifiers that can suit the Westone 4R?

  • thethirty3rd


    Which tiny amp would you recommend for the HD25s, the Shadow or the Slim?

    • I would use a bigger amp, I’m afraid the Shadow and the Slim won’t have enough gain for the HD25

  • Hi there Mike,
    I’m deciding between the ttvj slim and the pico slim to go with my JH16’s and the Iphone 4s.
    I miss the lush mids of the sm3 when i changed to the JH16’s
    Do you think the TTVJ slim amp is a better choice?

    • James,
      I think you should look into the RSA Mustang. It has a really smooth and lush mids.

  • Digging up an old article but …..I have a Denon D7000 that I’m happy w/ on my home rig, but I’ve been spending more time away and would like to go portable. Any suggestions on what portable amp that would match up nicely w/ them? I would like to stay under $200 unless there’s something that is just out of that range that would be a good match. They would also be used w/ FS Atrio M5’s if that matters. Music variety is electronic, hip hop and acoustic being paired to an (gasp) iPhone. Thanks 🙂

  • Hi Mike, Your website is truly amazing though my credit card would disagree. From a technical viewpoint, why can’t someone build a USD100 portable DAC that can take a signal from an iDevice’s LOD and feed it into a portable amp? Right now I use a HRT iStreamer with my headphone amps but I can’t venture too far from the wall wart!

    • L.

      Maybe Fiio one day will, but I think it’s mostly related to the costing price of the apple Certification

      • I’m sure you’re right and if HRT can build that into the cost of their iStreamer, I agree that Fiio can do it for less.

        • Go Android. USB Audio support with all Jelly Bean updated devices.

          And down goes the pricey CLAS and Fostex HP…

    • Thanks, George.

      I really don’t know if that can be done. One thing we don’t have an idea on is the amount of money Apple demands from manufacturers before they get access to tap the iDevices’ digital data. As time goes and manufacturers come out with more affordable solutions, I think we’ll be able to see how low you can build one for.

  • Mark Edmondson

    Hey mike, just wondering your preferences for portable amplifiers for the T70 250 ohm?

    • Mark,
      I didn’t spend too much time with the T70 250 ohm, but it would probably be something with a good bass weight like the ALO national.

      • Mark Edmondson

        Thanks 🙂 ill have to think about it

        • Alright, Mark. 🙂

  • still confusing which amp is the best for my HD6500? headstage arrow, RSA 71A, alo rx MKii, Ibasso PB2. can you recommend me with the exception of price and size of the amp.

  • Justin Q.

    How does the DACport feeding 2Stepdance (sonically similar to stepdance) compare against the DACport feeding Leckerton UHA6s MKII?

  • Kenneth Ong

    Which amp would you pair with the JH16 Pro?

  • Michael

    Hello Mike,
    Would you please be so kind to recommend anything for Sony MDR-MA900?

    • I would go with the RSA or the ALO amps. The portaphile is also good. If you’re on a budget try JDsLabs.

  • If I listen at a low to moderate volume, will the mustang be enough for the hd600 or the sr-71a is better on lower volumes as well


    • The SR71a will still be better.

  • Great article Mike! I have a pair of Shure SE535’s, not overly pleased by the fullness / warmth of the bass. What gear would you recommend?



  • Robert Madison

    Here is an extremely creditable review about the Creative Sound Blaster E3. Check it out!