General Information



A100 TRUE BALANCE (hereinafter referred to as A100TB), is the fully upgraded version of A100 with more focus and perfection. With the experience from A100, A100TB focuses on maintaining its features during a complete reforming on the internal circuits, and chooses to only support 4.4mm balanced input/output. Unlike A100, taking factors such as market change and the optimization of circuits etc. into consideration, A100TB gives up the flexibility in input/output and decides to support 4.4mm balanced input/output only, in order to ensure that the sound is not only clearer, but also comes with power and in 3D.

There has been fair improvements in the appearance and the manufacturing process of A100TB. Optimized structure and the improvement in the metal processing technologies will bring better user experience to the customers; Well-designed appearance also adds more delicacy and character to the product. The power supply circuit of A100TB has been upgraded and optimized to a large extent. High current ultra-low noise constant voltage filter circuit is added to the power supply, controlling the ripple voltage at 20uV, and expanding the main filter energy storage capacity to 6800uF, supplying ultimate power to each unit as if it is directly supplied by batteries. Compared to A100, the power supply of A100TB has more powers and is much more pure, which is a qualitative leap.

The amplifier circuit of A100TB is designed as a symmetrical and fully-balanced amplifier circuit that has four channels. The overall circuit architecture maintains the two-stage inverting amplifying structure. First-stage inverting amplifier circuit is responsible for signal gain switching. Gain switches are set internally, with better quality switches and shorter traces to achieve best performance. After first-stage amplification, signals travel to the post-stage inverting power amplifier circuit through the four-channel digital potentiometer, then being output to the headphones. Compared to A100, the circuit of A100TB is less complicated and more refined, only for the purest and most authentic sound. The overall circuit design of A100TB and its selection of components underwent substantial optimization and upgrading. Vishay precision wafer resistances were used in the audio circuit units. Capacitance undergoes reasonable upgrade based on parameters and sound comparisons. Immersion gold process was added to PCB. The circuit parameters have been tested and optimized repeatedly, leading to the performance enhancement in all aspects.

A100TB continues with the design for quick op-amp replacement, enabling users to “mess with” the op-amps. A100TB can be charged with USB Type-C. The external power supply jack is kept at the back of A100TB to connect AROMA PS100 power supply or PS10 power supply to further amplify the audio.

Rated Power320mW - 16 Ω
530mW - 32 Ω
860mW - 100 Ω
310mW - 300 Ω
160mW - 600 Ω
THD=N:0.0006% @ 800mW 100Ω 1kHz
Resolution120dB @ 800mW 100Ω 1kHz
SNR:115dB @ 800mW 100Ω 1kHz
Dimensions:121x69x30 mm


Latest reviews


100+ Head-Fier
Aroma A100TB - The Black Magic Box
Pros: Incredible sound, transparent, portable, "affordable", lightweight, upgradable op-amps
Cons: Not much, finish prone to smudges and scratches, cover comes off too easily
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Greetings dear Head-fiers, it is my great pleasure and honor today to be reviewing the Aroma A100TB portable amp and accompanying PSU 100 Pro. Aroma might be fairly new on the scene in the west, but they have been around for quite some time, hailing from Hong Kong. They are predominantly an IEM company, if you’re not already aware, their Jewel has quickly become a crowd favorite in the TOTL category. I am personally smitten with the Jewel, so much so that I had it made into a custom, and I like the company a lot. There is something really magical about the Aroma house sound, not too Hi-Fi, a touch of old school, a perfect balance of energy, resolution, and dynamics. When I heard that they made an amp I was curious, when I heard many people whose opinions I hold highly praise it up and down, I knew I had to try it out for myself. Having owned the highly regarded Cayin C9, and finding it an amazing piece of gear, I was excited to hear what Aroma could bring to the table.

So, I was very happy when Andrew from MusicTeck asked if I would be interested to review Aroma’s newest foray into portable amplification, the A100TB, which I found out later dethrones their previous amp the aptly named A100. The TB stands for True Balance, as the newer model only features 4.4mm balanced in and out, which suits my purposes perfectly. The A100TB is a reasonably small portable battery powered amplifier, designed to further extend the output of your DAP. It is also possible to purchase the accompanying PSU100 Pro, which gives further performance, but more on that later. Quickly, before we begin, my full disclosure. I bought this unit myself, though I did received a discount from MT with promise of review. I purchased it myself because I was very interested, and wanted to hear it, would have bought it anyway. On the technical side I think all important specs should be taken directly from the Aroma, which is here. This review will focus solely on the sound, with a brief interlude on build quality and daily usage. All testing was done with the LP6 Ti AE and Cayin N8ii, and the Jewel and 64A 18t.

(The unboxing experience is something I have never understood. I open the box, take out the item I bought, and then immediately put the box in my closet full of other boxes arriving directly from my nefariously frivolous spending habits. The Aroma comes in a black box, it was immediately aside, end of unboxing experience.)

So without further ado, here we go!

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It’s hard to believe that a small black metal box can hold so much tonality, vibrancy and dynamics. If you’re asking yourself why one would choose to use external amp, let me explain. Some headphones need a ton of power, that’s a given, by why IEMs? While most modern DAPs have more than enough power to show off your IEM’s capabilities, scaling is a real thing and giving your gear more power doesn’t just mean louder it means better. Some power hungry IEMs - like the Jewel - really do need that extra juice to shine at their best. Why amp the LP6 then, doesn’t it have gobs of power? Yes it does, but adding a unit that was designed only for amplification without all the DAP abilities means you’re adding to your chain something that only serves the purposes of amp, and therefor can add something exciting. In the case of the LP6 I find it to be the best DAP I’ve ever heard, but it can be very mid forward, and with smaller more intimate stage. Adding in an amp changes that, but again, more on that later. The N8ii is also fairly powerful, but nowhere near the LP6 Ti AE.

The A100TB is just a small ball box. If you’re interested you can quickly slide the top plate off to see exactly what is inside. Other than that, you have a volume knob with nice firm resistance, and a balanced 4.4mm input and output. Power switch and charging on the back. That’s it. Very simple. You can tell that all the effort was put into the sound, and while the styling is very basic, I prefer this. Batman black with one loudness knob is all one needs! One thing to note, the brushed black satin finish is VERY easily smudged and scratched, after just a week I have several noticeable scratches which is a bit of a bummer. Also, the top cover, while it is super cool to slide it open to peer inside, it’s too easy to open, resulting in numerous accidental openings. A far cry from the Jewel box which requires instructions to open. What to do, not a deal breaker.

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The A100TB is battery powered, and charges via USB C. The accompanying PSU unit plugs into the back of the A100TB via a hardwired cable, and since it also has a battery it charges via a switching transformer wall-wart. (One thing to note, DO NOT turn on the A100TB while the PSU is plugged in and turned on.)

You can use the A100TB by itself, or plug in the PSU and then it takes over the power duties. The hardwired cable is a bit of an oversight to me, as they could have easily made it detachable on both sides to allow the amp to be more conveniently stored or traveled with, but perhaps they chose to keep the cable fixed so you’d never lose it. I find that it’s hard to put into a backpack or case, as you have to decide either to put the volume knob or the power cable against a hard surface, neither are a great choice. But I imagine that Aroma wasn’t putting much thought into transportation of the unit. I secured the PSU to the bottom of the A100TB with some small strips of Dual-Lok, so they are now one small stack and I never have to worry about them moving around, scratching each other or sliding apart. My OCD finds this to be a great solution. :) I put some small rubber feet under the PSU so it doesn’t move around on my desk, and now I have a very cute little stack.

By the way, the battery life is great, I’ve used it for several long listening sessions over the course of several days and never ran out of batteries. I did use it predominantly in the PSU powered mode, which has a larger battery, but I think the battery life of either is really quite good. Good enough not to have to think about it at all.

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Then the sound… this thing is magic for sure. Upon first plugging the amp into my LP6 I was stunned. Right out of the box this thing takes the whole sonic spectrum up about 5 notches. The staging is increased, more micro details, and the dynamics are increased as well. The bass is absolutely killer, extending deeper and with far greater authority and control. The mids are more open, with just a tad more weight and oomph to the notes. They are more clear, more detailed as well. There is more air in the high end, without being brighter, letting the highest frequencies magically dance about, floating above your head and out to the sides enveloping you in sonic bliss. The stage is wider, but also more spherical, letting sounds come at you all sides, especially behind you. There is more power, which in turn gives the sound more control, more taught and energetic, and better placement of the instruments on a pitch black background. It is also easier to power hungry IEMs like the Jewel, again the LP6 Ti has absolutely no “ need” for more power, but the extra headroom is well enjoyed here. Headroom is something that should not be discounted, volume is only part of the musical enjoyment combo. Headroom feels like control, like you could go louder but you don’t need to, because the full onslaught of sound coming from all around you is more than powerful enough at any volume. For bass players, it’s all about headroom, where you get the loudest possible volume, with great tone, in the the cleanest possible way. Headroom with IEMs is the same, you can go as loud -or quiet- as you want and the sound is always rich and full.

Dynamics are the A100TB’s bread and butter. While yes the details and staging are great, the increased dynamics is something to be experienced for yourself. It’s like everything got turned up to 11, but not distorted or feeling wildly off the rails, simply turned up to 11 with complete control, with myriad subtleties, thunderous power, and gentleness if called for. Everything is more tight, more wow and wham, more boom too. Dynamics are a result of all the headroom, you simply have more of everything to play with. The background is pure darkness, allowing the notes to come out of nowhere. Bass hits hard, with control, cohesion and better texture and tone. Drums thwack and slam harder, the ticks and clicks of the hats and ride jump out at you with clarity and bite. When the drummer opens up and wails you feel it in your chest. I’ve never heard drums like the A100TB and LP6 Ti, it’s sensational. Guitars have more body, more texture, more grit and raw energy. Vocals sit perfectly above your head, floating in space, with more micro details, spit and lip smacking included. It’s just more real, more wow, and more everything. A friend told with this amp literally “everything” will be improved; staging, details, power, control and I am inclined to agree with him. All across the board it’s all just better.

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The A100TB is actually quite transparent, not coloring the sound in the way that I felt the Cayin C9 did, adding that “tube” flavor to the mix. The Aroma allows the DAP to hold onto its original sonic signature. While the C9 is great, this is considerably better in my opinion. Those dynamics are something I always wished the C9 had more of. Comparing the two I would say the C9 is more thick and juicy, the Aroma is more tight and detailed, and more dynamic. It could be called intense perhaps, but not negatively so. It’s like the music is there right in front of you, and you’ve had a small espresso right before the concert, so everything feels more energetic, more inspiring and electrifying, more moving, more heartfelt, more… well everything as I’ve said previously. It should be noted that while the A100TB does have a lot of power, it’s not some kind of outrages powerhouse, and while I don’t own any full size headphones, I can imagine it will happily power the ‘medium hungry’ ones. Someone else might chime in here about that aspect.

Then you add in the PSU. I was advised the PSU was absolutely necessary and I would 1000% agree. If you buy the A100TB, buy the PSU, please. Yes the amp by itself is great, the PSU just takes it way further. It’s technically an optional accessory, and yes the A100TB will work great without it, but when you add them together, you hear what Aroma really hand in mind when they designed the A100TB. Dynamics are now completely off the chain, the background is even blacker, and the micro details and resolution have taken a HUGE step up. I cried the first time I plugged it in, I honestly had no idea that a portable system could sound like this. It is absolutely crazy, like having the band in your head, playing all around you with complete ease or thundering slam if called for. The bass is wild, bringing reach that I didn’t know the Jewel could do. Drums now sound like I am actually sitting behind the kit, and I can feel in my hands the snare every time it’s smacked and slammed. The kick drum and toms I feel in my gut, the crash lights my hair on fire. Again, when called for. I was listening to Kenny Garret’s Songbook album and the ballads are lovely, dynamic and sweet, this combo isn’t just crazy energy, it has all the subtleties and light touches anyone could ask for. Put on Rage Against the Machine, Tool or Trivium, and be ready to have your head blown off. Snarky Puppy, Pat Metheney, Alison Kraus, Bela Fleck, Asgeir, Coltrane, Lettuce, all just next level. To put it simply I am speechless.

If you think it couldn’t get any better, then there is the user swappable op amps. I have some experience with op amps from my vintage guitar pedals, so I know exactly how they can affect the sound, at bare bones to modest price points. So after gathering the best advice I could, I decided to order the Burson V5Di and the OPA1612, the two most popular with A100TB users. I know I am already gushing a lot, but the Burson is the real deal. This tiny little silver cube gives such an upgrade to the sound, I was simply unprepared. All the A100TB does out of the box, the Burson adds another 35% to that, no joke. I cannot describe it better than that, it just takes it all to another level. There is nothing out of place, no change to the balanced tonality, that wonderful mojo. It’s more like a veil was removed and the tone just comes bursting out at you. The clarity and fidelity are the most noticeable, as well as a sense of control and dynamics being further pushed out at you from all directions. It sounds like a much larger system, approaching desktop performance in a tiny package.

To note, with the Burson in the output stage the intensity is upped quite a bit, and I can imagine some could find it too much actually. In this case I recommend putting the Burson into the input stage, and either staying with the stock output, or putting in OPA 1612 in there. I like my music intense so there’s no issues there for me. Either way you’re sailing.

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So, since I have praised this thing all over the place, is there anything negative about it? Not much, just a few small squabbles. It’s hard to find faults, as it’s less than half the cost of the C9 including the PSU. It’s a lot smaller too. Yes, it doesn’t have the tube sound of the C9, but while the C9 isn’t a “real” tube, that might be the only thing going for it over the Aroma. In every other way I feel it is bested. The previously mentioned caveats are the cover coming off far too easily, and the back enclosure being prone to scratches and smudges. Also the A100TB and the PSU have slightly different shades of black which just seems silly to me. For some it could potentially be too intense in some specific configurations, but stock it’s golden for all ages.

To put it, again, very simply, this little black box is magic. It makes everything it touches sound better. Almost like it knows what the source needs to sound its best. With the LP6 it gives the stage some needed space, and brings back the sparkle and sub bass that L&P tuned out. Plug in the N8ii and it furthers its innate abilities while bringing a sense of warmth, which in my mind is also needed. Pretty kick ass. I hate to be one of those that just praise a piece of gear, but I simply am in love with this stack. It’s affordable, it sounds absolutely killer, game over.

I would like to thanks Andrew @MusicTeck for giving me the opportunity to review this beast, and to all of you that might read it. I hope it was helpful, perhaps insightful, or at least entertaining. :)

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Aroma A100TB is pure magic. It's not a device; it's something else. Levels above PA10 - like 10 - 15 levels up. Wow. Goosebumpy crazy good. Are they using AI?
Hi, great review. Any comparisons with MassKobo475?
is this adequate for headphone use?



Headphoneus Supremus
I am also smitten with the Jewel, listening to the demo right now. I haven't bought an IEM since my A18t, funny we both have it. Nothing made me want to replace it in my ears, I was happy with A18t until now. I'm currently running a Hugo2 + ALO CDM and it's a pretty spectacular combination, the Hugo2 even on it's own as well. I wonder if the Aroma setup could be better?