Aroma Audio A100TB

Where do I begin while reviewing this magical little thing? At the time of my search for a good amp, the options were limited, with Centrance facing some availability issues; the 475 received sparse reviews by then and it seemed too powerful for the IEMs. Aroma A100tb was the one that was easily available, and the price tag was quite good. There were all good things said about it everywhere, and no negative thing was said about it. Amidst all this, I came across the review of A100TB by @Tokpakorlo . The review was so precise and fluid that it convinced me to buy the Aroma amp stack. I bought the Aroma stack in August from @MusicTeck. Andrew was kind and patient enough with my queries, and it was overall a good buying experience as always. Since this unit was personally carried by a friend from the US, I had to wait for a long time, 3–4 weeks. Finally, the day arrived when the Aroma stack was in my hands. Throughout the waiting period, added to by discussions with various individuals, my expectations for the Aroma stack had reached a great height.


Rating Criteria:

I want to lay out my rating criteria before we start off. For me, the primary criterion for evaluating audio gear is its intrinsic value rather than its price tag. A higher price doesn't always correlate with superior quality, and similarly, a low-priced product can give enough listening pleasure for it to be called outstanding. I consider the build, features, and, most importantly, the impact on the listening experience. I think the fundamental purpose of audio gear is to enhance the listening experience. So for me, this degree of enhancement in the listening experience is a key determinant in rating a product.


Design and build:

A100TB is a small amp by design and will fit well even in your palm. You can charge the amp with a 5V/2A adapter using a USB-C cable, and it takes approximately 4 hours for a full charge. While I haven't precisely timed its battery life, it typically lasts for a commendable 7-8 hours. There is a battery indicator that tells you the amount of battery left on the device, which is really helpful at times. The battery on the amp is removable and can come off quite easily, which is another good thing about it in case the battery dies after long usage. The video below shows how to remove the battery easily. One of the major features of the amp is that you can change the opamps on it. From my discussions with fellow headfiers, I gathered that the Burson V5Di changes the sound and makes it a lot better than the default. I just cannot imagine what an improvement that could be for something that sounds so wonderful. I was also suggested by a friend to get the LM6172, which also changes the sound significantly. Regrettably, I haven't experimented with these enhancements yet, so I am not aware of the extent of change they might bring.



Sound impressions:

For the first time, when I plugged it into my LPGT, the sound through the amp was just unbelievable. I could not believe what I was hearing. It's magical to listen to the difference this amp can bring. And this was just the amp, without the power supply. I had previously used a few amps (Astell & Kern PA10, Earmen Angel, etc.), but none of them had hooked me this much from the start. I could appreciate the PA10 quite a lot when I first tried it, as it does darken the background quite a bit and improve some bit of dynamics. Similarly to the Earmen Angel, it also does quite a good job as it is quite powerful. But in comparison to these two, the Aroma amp is something else. It changes the whole listening experience. The level of dynamics it adds, the richness in sound that the iems produce, the enhancement in the overall perception of soundstage, the increase in musicality—everything is leveled up. It seems that the IEM that you are listening to is a different one.

I always used to believe and hear that amps were capable of creating such magic, but witnessing this thing was a whole new experience. There is quite a lot of change that comes with the power and the amp circuitry, which refines the audio signals. The A100tb has a transparent reproduction without changing the signature. To me, I cannot call it a reference sound or a neutral sound. It does add some warmth to the sound, but that added warmth is not much, so you won't feel any coloration. It's all about the dynamics that are added to the sound. It becomes quite intense, massive, but never too overpowering and overwhelming, and more engaging. The bass becomes quite tight, and the impact is quite noticeably different. The macro nuances and details are more pronounced, and these smaller details, which were somewhat faint earlier, have become quite noticeable. The sound is richer and fuller, and it gains a lot of weight without an actual change in signature.



Adding this to the LPGT gives some extra sense of spaciousness and a better head-stage. The bass and dynamics on it become quite good, though LPGT has a good bass by itself. The amp section on the LPGT is quite decent. Astell&Kern SP3K sees quite a decent improvement in sound, as the amp section on it is not as powerful as on the LPGT. I am not sure of the difference in specs, though. SP3K, by default, has an amazing soundstage and clarity in its sound. Adding A100TB makes the mids sound so sweet, full, and rich. The added weight to the overall sound does wonders. Talking about the IEMs, the amp gives them wings to fly. There is no doubt that IEMs scale quite a lot with good sources. I have tried many iems with the A100TB and seen them go to great levels: Fourte, Jewel, Kublai Khan and Ragnar, to name a few. Anyone who has tried Ragnar knows well that it needs quite a good source with enough power to show it's true colors. When I tried Ragnar on Lotoo Paw Gold Touch, Ragnar on PWAudio First Times, and Aroma A100tb, it sounded so incredibly amazing. I am very sure that for Ragnar, there are only a very few chains that can produce as great a sound as this. Aroma amps gave a new life to Ragnar when I demoed them. On a weaker source, Ragnar would just not sound right, but with juices flowing from A100tb, things were quite different. This same story happens with all the IEMs you try with this amp. The amp opens up the sound so much that everything sounds gigantic, like the IEMs are on steroids. Somehow, this level of craziness is not achieved when you use any other amp, such as the PA10 or Angel, which means there must be something different in the way this amp is designed. There is not just power that makes things better, but the clean, dark, and silent background, which makes it quite distinguished. There is never a hiss despise of so much power the amp delivers; that's one more thing to like about it.

Though I never use headphones, I've noticed that the power output on the Aroma falls somewhat short for driving more power-hungry headphones effectively. In my opinion, it can drive headphones, which are less power-hungry. I remember it could not drive one of my friend's HD660s quite optimally. In contrast, the other amps, Earmen Angel and iFi Signature, could play the headphones quite easily. I cannot say for sure if it is good enough for headphones.




Adding the PS100 Pro:

After enjoying a satisfying dinner and feeling comfortably full, indulging in a small dessert is an irresistible temptation—one that you never turn down. In this similar analogy, the PS100 plays the role of that delightful dessert, providing the final touch of satisfaction to an already amazing A100TB experience. On top of an already amazing sound, it adds the last bit of dark and silent background. In the first few listens, the change won't be that noticeable, but when you are accustomed to the sound of A100tb, you will start noticing the difference. I did not use the PS100 for quite some time after initial usage, and then later, when I put it to use, there was certainly a cleaner and more silent sound I could hear. The battery on the PS100 lasts for about 7-8 hours. I keep it attached to the amp most of the time. It's like having an extra power backup for the amp, reserving the power on the main amp, and using the power supply. The socket that connects the PS to the amp is quite weird in the sense that it does not connect easily, which is quite a struggle there. I remember that once it took me 20 minutes to connect the plug, so I always keep it plugged. The best part about the PS100 is that it's not costly, so it can be easily bought along with the amp. You won't miss a lot if you do not get it. Also, a word of caution: do not switch on the amp when the PS is plugged in. It may add an extra thrust of power, which may damage the IEMs.



Conclusion:

I took the leap in acquiring this stack—a blind purchase, devoid of firsthand experience. However, upon its arrival, it left me utterly speechless. I enthusiastically informed a lot of people about its exceptional sound quality. Eventually, it became a centrepiece for me, something I would show off to someone who visited my place for an audio meetup. Everyone from my audiophile community who has tried the A100TB echoes the same sentiments, and everyone is impressed by its abilities. It now has a different fan following in our group. For me, it was a blind buy, but that led six different people to join the gang, which in a way gives me a lot of satisfaction. It's such an exquisite little device that leaves everyone happy.

I am more impressed with Aroma as a brand. These people are doing some serious R&D on the products they are developing, creating unique and brilliant products one after another. Aroma Jewel and the recent Fei Wan are compelling evidence of their exceptional craftsmanship, and so is this amazing amp stack. To sum it up, the A100tb is one of the best portable amps on the market. With it's amazing power and driving ability, it turns the iems into different beasts. Imagine the finely tuned and strung strings on the guitar that produce the best sound note while still having enough strength to withhold vigorous strumming. In the same way, sound production through the amp is quite strong and optimal, yet controlled. The sweet and reasonable price tag on it makes it even more likeable. Along with the PS100 Pro, the stack is undeniably one hell of an experience. If you want to experience the joy of an immersive and unforgettable auditory experience, just go for it. A perfect 5/5 product.

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!



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.



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.



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.



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.



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.