Oriolus BA300S - Reviews
Pros: Life like tube sound, extra 3db push added to DAP amp
Cons: Battery life sux
Once i upgraded the P1 to a 16 core single crystal copper balanced cable I could use the M11 at the balanced 4.4mm output power is 550mwatts @ 32ohms .

Sound was well defined, ample power, but after a rec from BGGAR to pair the M11/w the BA300S tube amp, it simply gave the P1 an extra +3db of oooomph !!!

But the tube amp took the great M11 sound, which can be a bit analytical and sterile, to a fuller soundstage and more life-like in person sound. It actually gives the bass light P1 an acceptable well rounded bass, and brings some recessed vocals fwd.

My only complaint is the lousy battery life of the BA300S, but since I listen for 2-3 hrs max is not a prob to charge overnight.

Little Bear tube amps are great values, but the BA300S outperforms them significantly, sound is stellar audiophile grade IMO.
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Pros: Build quality
Fairly portable
Full 4.4mm input and output
Excellent real tube sound quality. Rich, full, great dynamics, large soundstage, timbre.
Cons: Micro USB
Only 4.4mm
Oriolus BA300s – Portable Tube Balanced Amplifier

Website – Oriolus

  • Frequency Response: 10Hz~50kHz (+/-0.5dB)
  • S/N Ratio: -111dB
  • THD+N: 0.02%
  • Tube / Op-amp Type: 6N16B
  • Analog Input Type: 4.4mm Balanced Standard-jack
  • Analog Output Type: 4.4mm Balanced Standard-jack
  • Maximum Power Output: 350mW+350mW (32ohm)
  • Input Impedance: 47k ohm
  • Output Impedance: 0.3 ohm
  • Headphone Impedance: 8~300 ohm
  • Gain: +3dB
  • Battery Type: Built-in Rechargeable Lithium-ion Battery
  • Charge Time : ~3 hrs
  • Usage Time: ~7 hrs
  • Color: Black
  • Dimensions: 57x16.5x120mm
  • Weight: 165g

Price: ~U$400.

The Oriolus BA300s unit was kindly arranged by Oriolus company together with MusicTeck store.

Links: MusicTeck store & MusicTeck Amazon store

The packaging is pretty simple. A standard black box with a magnetic closure, holding the BA300s unit at the top surrounded by foam material, and underneath a USB cable for charging, the interconnector cable (4.4mm to 4.4mm, G4 version here), and an adhesive pad to attach the amplifier to a portable player, instead of the traditional rubber bands. I would like to see at least a simple case to cover the amplifier for best and safer portable use.

Do note that there are a few versions of the BA300s. The differences lay on the included interconnector cables. ‘JP’ version arrives with a PW-Audio cable and is available in two options, G2 with 2.5mm and G4 4.4mm. The G2/4 cables have a dual cable connection to the source player, the 4.4mm (or 2.5mm) for sound output and the extra 3.5mm GND, intended to eliminate any possible noise. With the various players I’ve tried there was no noise without connecting the 3.5mm.


Build quality on the BA300s is as good as it gets for a portable amplifier. The whole outer chassis is made of black matte colored CNC machined anodized aluminum. The metal material is thick and the whole unit looks very solid. The finish is smooth and rounded on both lateral sides. The shape of the device is fairly comfortable. It appears so have very close dimensions to the Sony ZX300 DAP. It reminds of the xDuoo XD-10 which was designed to match the lower Sony A30~A50 players, where the BA300s aims for the higher model. Next to the Hiby R5, the BA300s is a bit longer but width and depth are almost identical, while the iBasso DX160 is wider but same in length, and the Shanling M5s is much closer as it is to the ZX300. It can be also connected to other players or even a smartphone with the corresponding interconnector cables.

The layout is simple too. At the front there are two 4.4mm balanced sockets labeled for input (left) and output (right) audio signals. It is fixed for 4.4mm Pentaconn balanced plugs but can always add a simple 2.5mm adapter. Both have large gold colored rings around that together occupy about half of the front side. In the middle, there is the small power switch labeled. There is no LED light that indicates whether it is on or off on this version, though they seem to be some units that hold one. At the back side, there is the single micro USB slot used for charging only with a small LED that goes from red to blue when fully charged. A Type-C option could had make this more modern and suitable for possible fast-charging.

The BA300s key feature is the real vacuum tube for its amplification, with a dual 6N61B tubes setup, small but perfectly suitable for the portable use. These are fixed tubes so tube rolling is not an option here. At the top cover of the device there is a small window that allows to see part of the inner panel and right above the two tubes showing a bit of the small tubes glow light mixed together with a blue LED light when the BA300s is on.

There is no dedicated volume control on the BA300s itself, so strictly adjusted directly from the playing source. No gain or EQ switches either, and the BA300s has a fixed 3dB+ volume gain. It rates an output of 350mW+350mW on 32ohm load, good numbers for a portable amp.
Power is not an issue for the BA300s, in spite of the lack of a volume control. Depending on the gears used, player and/or headphones, the BA300s needs about 10~20 less volume steps from the playing source to already match a comfortable listening level. Change from low to high gain from the players’ side is less significant than when powering the headsets directly to the players. On the other hand, the BA300s is not completely silent when using very sensitive IEMs. It may happen with low impedance or high sensitivity earphones, mainly hybrids or multi armature sets; for example, the iBasso IT04 shows some background noise it plugged directly to the 4.4mm output. It is noticed only when music is paused, but once playing it won’t be heard. With a bit lower sensitivity or a higher impedance rates there are not issues present. Driving the Dita Audio Twins or Hifiman RE-2000 there is no noise and the BA300s has plenty of driving power for them, and even with the Dunu DK-3001 Pro it has a quite clean background. If needed, a small extra impedance adapter will do the trick, and will also smooth down the sound presentation. I’ve used the HiBy 20ohm adapter and fixes everything out of the IT04.


Playing time is about 6 hours or a bit more, close to the rated maximum 7 time, it may depending on the headphones or earphones used, their impedance and sensitivity. The performance may sound nothing stellar for portable amplifiers, but considering the need to power the vacuum tubes inside, is a fair result. Full charging does take some time, close to 3 hours and the micro USB port does not feature quick-charging. Probably the main disadvantage of the BA300s.

Sound Quality

Tested with HiBy R5, R6 Pro and iBasso DX160 – all 4.4mm output
For comparisons, Shanling M5s, DX220 w/AMP9, xDuoo XD-10 (Poke)
Variety of IEMs and Headphones (4.4mm Balanced & 2.5mm w/4.4mm adapters)

The BA300s is no doubt a real tube amplifier that despite its portable size packs great driving power and true vacuum tube type of sound. Small tubes inside may not be swappable like large desktop tube amplifiers, but then again considering the portability goal of the BA300s there is really not much room for improvement as for what sound quality matters.

Epic. Euphonic. Musical. These are some words that first come to mind when listening through the BA300s in its full 4.4mm balanced mode. It may sound too much praise for the BA300s, and in fact it will not match every single gear perfectly, but when it does it truly delivers. The sound is more open and spacious with a very realistic natural timbre, that while can be a bit more lively and a touch more aggressive, also boosts greater dynamics with coherent imaging and larger stage dimensions. As expected for a tube based amp, the BA300s adds some color to the sound, however, it is very natural coloration. Tonality is more towards the warm side, with added weight and power on the low frequencies while less affected highs response if just a bit smoothen down on upper-treble region. Not to be confused as being dark or thicker, but yes rich and fuller tone with more solid texture.

There is a lift on the bass region with a coloration that is very natural. Not a specific bass gain that focus on the mid-bass but rather a more coherent improvement on the whole lows from the very low sub-bass area that continues very linearly through the mid to the upper-bass. The balance is excellent between quality and pure quantity. It is more powerful, no doubt about that, more bodied and weightier; however it’s much more extended and more spacious giving extra depth, layering and better separation that maintains the high control and speed. While it feels a bit more aggressive it also offers more natural decay and improved dynamics. The BA300s may not have a ‘bass gain’ option, but it would be hard to ask for more than the already offered.

Despite the fuller and strong bass response, the midrange remains very clear and detailed. The tube amp sound is so present through the whole midrange, and probably can be considered one of the best treats of the BA300s as a portable amplifier. The transition from lows to mids is smooth and the warmer tone adds extra fullness and body, making a neutral to forward midrange that sounds more natural and much richer. This is specially perceived with sets that have a cool/colder tuning or a thin midrange that with the BA300s sound simply more engaging and enjoyable. There is no loss of accuracy, and in fact a high presentation of detail, even though the amplifier focus on improving greater dynamics and more articulation. Vocals can particularly shine here with sweeter and shiny texture; the thicker low-end adds fullness to male voices, while there is a tad of extra brightness suited for female vocals. This is not to be confused as more intimate, close sound, but is rather the opposite case – despite the forward and fuller texture, it is more spacious and airy.

Treble is much less affected by the BA300s but there are still some noticeable changes to note. The richer, fuller tonality of the amplifier levels down some of the extra brightness with brighter ear/headphones. However, it is mainly on the higher treble area that may sounds smoothened down a bit and less aggressive. It does help to cut unwanted sharpness. Even so, there is a more gain on the body and forwardness of the lower treble that may result sounding more ‘hot’. The extension and treble dynamics, again, are improved, and overall the treble tonality is more natural.

The presentation is another area where the BA300s shines. It is louder with a great out of the head and surrounding effect. The soundstage is larger in all dimensions, width, depth and even height. It does not affect the forwardness of the sound, vocals are not less forward, yet there is more distance between elements. Imaging is also as impressive and creates a more immersive feel; it could be described as a very ‘holographic’ 3D effect. Timbre as well is worth praising – the richness and touch of musicality contribute to more realistic and nicer harmonics overall.


iBasso IT04

For the IT04, the small impedance cable is recommended to get no hiss, dark background out of the BA300s, and also for better sound results. The extra impedance my not be reflected much on extra volume needed, but does help in smoothing a bit of the extra loudness the BA300s may bring to very sensitive sets. In sound quality, the IT04 + BA300s combo is excellent. There is already a very good stage size from the IT04 alone, but when combined with the tube amp it gets even much more impressive. The end to end extension is highly improved, a larger sound field effect, more depth and better layering. Bass is more powerful and yet tighter and refined. Probably the best low-end the IT04 showed so far. Midrange is just a little more forward with more body, especially on the upper-mids, less lean and fuller in tone. Treble is smoother a bit, but gains in extension and detail, also being more open and airy. The presentation is more musical and euphonic.

iBasso IT01s

Second in-ear model from iBasso, and also well improved with the BA300s. Not as a high gain in sound quality as when paired with IT04, but still impressive. Tonality changes a bit towards to darker and has thicker texture overall. Bass is more dense and mid-bass forwarded, with a warmer midrange. Treble is smoother and less revealing, but greater detail is still there. Soundstage is certainly improved, not as IT04’s good, but does sound wider and more extended.

Dita Audio Twins – Fealty & Fidelity

Both paired with the own Dita 4.4mm cable. From the two Twins, the Fidelity pairs better with the BA300s. Originally it has a more linear, neutral response with a gain on the treble region, what can sound aggressive and less forgiving. The BA300s tube type of sound matches nicely here. It won’t sound darker, but rather fuller and better balanced. The bass gains more body and a bit more solid impact. Just a bit above neutral in quantities, so more engaging and relatively more ‘fun’. Similarly, the midrange sound more natural, with a less cold tonality, and more forward and sweeter with vocals. Treble is as bright, though slightly more enhanced on the lower treble over the upper-end. Soundstage is larger, even though the Dita Twins already present very good stage dimensions.

Sendy Audio Aiva – (Planar open-back over-ear headphones)

This is probably the best synergy so far. You could say the BA300s amplifier was made for something like the Aiva planar. It is not a very hard to drive set for a plana driverr, but does require the extra power to sound best, especially in terms of speed and dynamics. Also, the presentation is neutral with strong treble emphasis, so not the most comfortable to use with any audio player. The tube amp is what the Aiva really needs to sound amazing. First of all, the bass is nicely enhanced, more body and more realistic texture. It is still far from sounding bassy, but the added warmth is just perfect to bring the best balance. If the mid-bass gain is more pleasant, the sub-bass is more impressive. It is more extended and easier to hear, with a bit more real rumble yet effortless and fast. Speed is superb and has more dynamics and better layering. Midrange too, is a bit more forward and natural, nothing out of balance but it is richer, musical and enjoyable; vocals sound more realistic and not cold. Treble on the Aiva is bright, and remains bright out of the BA300s too, but less aggressive or tiring like when paired with something like the R6 Pro, keeping all the high micro-detail level. Best part is yet on the improvement on the soundstage. The Aiva sounds open, but the stage is not too large. Here it is noticeable bigger, with a more out of the head feel, greater depth and much wider surrounding effect that still does not lose in having a well positioned centered midrange. There is better separation and more sense of air, and all in all, will sound just epic.

With Hiby R5

Out of the three DAPs supporting 4.4mm balanced output, the R5 shows the best synergy with the BA300s amp. Differences are not huge using the amplifier with these various sources as all have little coloration and strong transparency, just that the R5 is more transparent, or rather, less authoritative, when connecting an external amplifier. Moreover, the change and gain in sound quality is most noticed. The R5 is rather neutral and linear sounding player, detailed, controlled, but not best in treble performance and around average in soundstage (though well positioned for its price bracket). Clearly, the addition of the BA300s brings larger and extended bass response, much greater soundstage and more realistic quality of treble. Very clean midrange with richer and musical presentation that the ‘stock’ R5 can be missing.
Also, the BA300s might have been design to match the Sony ZX300 player for its dimensions, and it is very similar to the R5 size (the BA300s is a bit longer), making it perfect for a portable combo.

With iBasso DX160

DX160 shares the same Cirrus DAC chip as the Hiby R5, and while also share some sonic technical characteristics they do sound different in some ways. The DX160 is not exactly much colored next to the R5, but has a more iBasso kind of signature. Thus, it is a bit reflected over the BA300s match. Soundstage is as good as with the R5 pairing above, though the improvement is relatively lower, simply because the DX160 already offers a very good stage for its price. The low-end is a bit more pronounced than neutral too. Nonetheless, you still get better layering with the BA300s, stronger bass impact and more controlled, translated in extra mid-bass kick, and a more forward midrange with more air and 3D presentation.

BA300s VS iBasso DX220 – AMP1 Mk2 & AMP9

An interesting comparison as the DX220 as current flagship DAP costs as much as the R5 or DX160 together with the BA300s, and also the size of the DX220 device is already large, close to the combo of this more compact players when stacked along the BA300s. The DX220 is enough as a standalone portable player, and the exchangeable amplifier modules make it even more versatile that can discard the need of extra amplification.

In terms of sound quality, with the included stock amp module AMP1 (Mk2) the DX220 already stands out in soundstage, timbre and detail, and it is quite powerful too. The BA300s as an external amplifier (with R5 or DX160) still performs better. Just starting from the extension and soundstage, it is higher on the BA300s, offers even more impressive dynamics and more driving power. It has a more open presentation and resolution. The AMP1 is more neutral on the bass next to the BA300, and has a leaner midrange in comparison.

Switching to the new AMP9, the first tube-amp module with small dual NuTube amp, the sound is already different enough on the DX220 than with the AMP1, but also different from the tube powered sound of the BA300. Obviously the BA300 is more powerful and, well, is also fully balanced, contrary to the AMP9 which limits to single 3.5mm output. They share that kind of ‘tube’ amp sound, having a richer, more enhanced low-end response and fuller midrange overall. But treble is more limited and smoother on the AMP9, while on the BA300s it is less affected and even improves the treble extension. Soundstage is where AMP9 losses next to the stock AMP1 on the DX220, and even in micro-detail, and does not have the same driving power (even with the new added AMP9 High output gain). So obviously the BA300s clearly wins in that regard.


All in all, the Oriolus BA300s provides an excellent addition to the portable audio. Build quality is very solid and the form factor is portable enough to carry along a portable player that supports full balanced output. Battery time is low compared to other portable amplifiers, but considering the need to power the real tubes inside it is a fair performance. More importantly, the sound quality is where the BA300s stand out in more than one way. Greater dynamics, soundstage, timbre and simply more musicality.
haven't tried with those IEMs yet. sorry
What kind of interconnector do you need with Ibasso DX160? Is it 3.5mm lineout to 4.4mm input in Oriolus? There appears to be different versions of the Oriolus with varied interconnectors? Thanks if you can reply!
For the DX160, you need a 4.4mm to 4.4mm. The one I got is the G4 ver., which is a dual 4.4mm+3.5mm that connects to the DX160, but the 3.5mm is not really needed.
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Pros: Adds smooth, organic, lush sound to ZX300 sound signature and improves power considerably.
Cons: Kind of a one trick pony designed to be paired to Sony DAPs.

disclaimer: I’d like to thank Steven at Xtenik for providing the Oriolus BA300s for review. Since I have a couple of Sony DAPs that the BA300s is targetted toward, it seems like a natural fit to review this little tube amp. If you have a ZX300, I recommend you follow up with Xtenik here or for more information, the Oriolus corporation here.

The BA300s is kind of an odd quadrupling down on a single market. First, it is an analog tube amp with balanced only with no options for single ended input or output. While this makes the circuit design cleaner and requires fewer parts, it also cuts off the larger end of the market by not having the option for single ended. Secondly, its only input and output is 4.4mm TRRRS connectors and the only cable provided is a male to male 4.4mm. Very few DAPs outside of Sony and a few modular types sport the 4.4mm outputs to utilize this (Even Oriolus own DAP doesn’t have a 4.4 output), and even fewer headphone and in-ears ship with the 4.4mm jack as standard. There is a reason for all this though, the BA300s is targeted at Sony DAPs and in particular the NWZX300. Why? Simple, Sony uses a digital amplifier in its DAPs so the problems that are often associated with passing a signal from an analog amp to another analog amp are avoided, and tubes have a warming softening effect on what sometimes gets called the cold sterile sound of digital amplification. So I had two questions going in, does it do enough for the ZX300 and WM1A to really be worth spending the $400 or so US to purchase it and how well does it pair with things outside its target market. Read on, the results may surprise you.

Unboxing / Packaging:

The little amp comes well packed in a black book fold box with a slipcover over the exterior. On the front of the slipcover is a large photo of the amp with the name and model, specs are on the reverse and the side has a pair of QR codes with the designers image in the center. The left one is a Baidu link while the right takes you to Weibo. Admittedly my Chinese skills are basically non-existent so beyond that, I am not much help. Inside the box, a warranty card, manual, and a pad designed to sit between amp and player rest on top.


The BA300s is roughly the same size as the Shanling M2s for those familiar with it. For those who are not, 5 inches tall, 2 1/4 inches wide and 3/4 of an inch thick. Weight is just under 6 ounces. The shell is solid aluminum with a window in the front panel. Otherwise the device is slick on the front and rear. The sides have finger grooves at the top and bottom, but are otherwise slick. The 4.4mm input and output jacks are found on the top of the unit with the power switch centered between the two. A micro-USB port on the bottom left of the unit handles charging responsibilities and an LED indicator to the right of the port shows charging status. Overall, its a very simple device externally. Removing the faceplate is accomplished by removing two small screws on the bottom that allow for lifting the front panel off the unit. this exposes the electronics, tubes, and battery (more later on that).


The BA300s is a very simple design, it is a pure +3dB amp with no volume pot in the path. It is designed to use with the headphone out of the source device so volume control is handled by the input device and not at the amp. Output power is rated at 350mW (32Ω Load) with a SNR of -111dB. (Roughly the same output power as the nano iDSD BL for comparison sake). The heart of the Ba300s is a pair of 6N16B tubes. These are a Soviet era design similar to the 6021 but not pin compatible. 6N16B are dual triode tubes were originally designed for aircraft use and have several features that make them a good choice for portable gear. They operate at low voltage and minimal heater current so battery life is prolonged, They were made to withstand shock and are rated for a 10,000+ hour service life. Mu is roughly 25 so these fall into a class of low gain, high drive current tubes so while usually seen in pre-amps stages and tube buffers (Cayin idac-6), they are a good choice here for driver tubes in this application.

Battery Life:

The battery in the BA300s is a 4000mAh rated lithium polymer cell and should be easy to replace when and if the day comes as two small star screws hold the face plate on, and the battery is attached via a quick-connect rather than being soldered to the board. I’m happy to see a design that will allow the end-user to replace a battery as far too commonly today this is not the case. The pack takes roughly 3 hours to charge using the Micro-USB charge port and standard charger. I found the circuitry was not designed to utilize a 2.1 Amp charger and would continue to draw the same current as when a standard charger was used so no need for specialty wall-warts. Once charged, average battery life was a bit over 6 hours so the amp will last most of a work day on a single charge. A word of caution here, this amp should not be used while charging as doing so produces an audible hum.

Sound and Synergy:

First off, the BA300s is going to add warmth to whatever you attach it to. If you are looking for a dead neutral amp, this is not it (in fairness tubes rarely are). If you want something that adds musicality though, the BA300s does in a big way when paired with the right DAP. It is about as organic and analog a sound as I have heard in a portable. Sound is very natural and flowing with good slam and really good mids. I found the BA300s pushes the mid-bass and lower-mids slightly forward which adds a nice warmth to the overall without detracting from the details. Because of that warmth, pairing is best with headphones that are a bit cool or at least not overly warm.

I found the synergy good between the WM1A which tends to be slightly bright and a little thinner on the low end than I like. The BA300s gave it more body in the low end and bit of warmth where it needed it, but did push mids slightly more forward. With the WM1a already doing so a bit, this could occasionally become quite noticeable. The EQ on the WM1A is good enough to allow for tinkering and removing that extra mid presence, but be aware that you may want to. The other nice thing about the pairing of the WM1A and the BA300s is notably increased output power. The primary knock on the Sony players with their digital amplification stage is that their output power simply cannot rival that of most analog DAPs. By adding the BA300s, the WM1A becomes useful with a broader range of headphones which is much appreciated.

Much as I wish I had a WM1Z on hand, I have not been inclined to spend the $3k to do so.

Unsurprisingly, the best pairing was with the Son y NWZX300, its intended target. The size is a near match although the BA300s is a bit thicker by comparison and the sides on the DAP are a bit more rounded off than the amp. Nitpicking for sure as the two are quite literally made for each other. I find the mids to be a bit thin on the 300 and pairing it with the BA300s brings those same mids to the forefront without getting edgy or out of balance. Output power is improved dramatically as well with the relatively anemic 200mW @ 16Ω rated ZX300 (balanced) being upped to 350mW @ 32Ω. Pay particular attention to the Ohms in the above as the reality is that the ZX300 is closer to 100mW at 32Ω so this is quite a leap and puts it in the same class as the WM1A in output power. If you wanted a WM1A with better output and a more organic and smoother sound, the combination of ZX300 and BA300s may well be exactly what you were hoping for.

I bought a couple of 2.5 to 4.4mm cables to be able to test other balanced daps. If you need one, I highly recommend Dyson Audio as build is great and price is more than reasonable (If he doesn’t have them listed on the page, email him).

First off, know that most of these daps have analog output stages so do show increased noise when paired with the BA300s. On some it wasn’t enough to be noteworthy, on others it was. This Amp was really designed with Sony in mind and any pairing outside that is an experiment.

What I found is kind of expected after learning the character of the BA300s. The Sabre based DAPs that often get accused of being overly clinical and dry benefited most by the warming and smoothing of the sound while the warmer sounding DAPs sometimes sounded like they got a double dose of that some smoothing and warmth. I found the pairing of the little Pioneer quite good as the noise floor is low enough on the 300R to not be over powering when paired to the BA300s. What was more common was that pairings were very source dependent. Something sounded good on the Opus#1S, AK70mk2, and Shangling M3s while others were overly warm and got a bit fuzzy at times.

The other pairing that I found to be quite good was the Hiby R6 Pro. With its ESS dacs and somewhat clinical presentation, the BA300s really turned it into a more lush and musical beast. I had more or less written off the R6 Pro as I have been eyeballing the DX220 or Cayin N6ii but now have to reconsider it after a friend loaned me his for this test.

Pairings of headphones was also a bit of an experiment. Some things became a bit too relaxed, while others the added body and warmth really brought to life. I found it best to start with models that were not overly mid-forward as the bloom from the amp tended to overpower. Models with a slightly recessed mids and a slightly bright signature benefitted most. Bass punch was also typically improved slightly so models that are bass forward or loose in the bass will be very much so when paired to the BA300s.

I borrowed a pair of the Oriolus Finschi in-ears to see how well the amp paired with them, knowing that Oriolus had targeted a single DAP, it would be interesting to know if they targeted a single model of in-ear as well. The Finschi is a bit mid forward to begin with and to my ear, not a great pairing with the ZX300 and BA300s as the mids began to dominate the rest of the signature.

Thoughts / Conclusion:

So, bottom line, should you consider buying the BA300s? Simple answer, if you own a Sony DAP with balanced outputs, then yes, if not, maybe not so much. Those with the ZX300 will really appreciate what the BA300s does for its sound signature. It is much more lush, thick, and smooth sounding and makes the somewhat sterile at times (speaking from personal experience) sound signature much more organic. I came away thinking I’ll likely not listen to my ZX300 much in the future without it paired to this amp, it makes that much of a difference.
Erfan Elahi
Erfan Elahi
any comparison with sony pha-3 ?
Pros: The magic of tubes in balanced, very good sonic improvements, portable, relatively light, good construction, adequate amplification to power a good number of difficult headphones, acceptable usage time, input accepts both single and balanced sources, simple interface.
Cons: Output is only in balanced, micro usb charging port could have been improved charging speeds if usb-c was used.

Introduction: For the first time on AudioBuko, we have Oriolus in the house, a company that is no stranger to the audiophile world. Oriolus is a brand of Cyras Co., Ltd. Japan, which began operations in 2015, and started making audio products like hybrid IEM designs and then later on, producing some of the more rare and interesting portable amps in the market, analog type portable amplifiers. Going through their lineup of amps like the BA-10 OAK and the NuTube VFD powered NT-1, their latest amp, the BA300S, is the most portable and least complicated amp to date. Made with a 4.4mm balanced input and output as well as having similar sizes to the ZX300, WM1A and WM1Z, it's pretty obvious that the target market are Sony DAP users. Now Sony players are not known for having the biggest power output compared to other DAPs in their class, but they sound amazing, and that creates a situation where users may need that magical touch so those hard to drive headphones can sing well, enter the BA300S with its hope of answering those wishes.

I'd like to thank Oriolus Japan for the discount on the BA300S so I can review the Oriolus BA300S in exchange for my honest and unbiased review. You can get more information at the Oriolus Japan website where it's listed at $415 USD and it's where you can get more information that I might not have covered at the time of this review.

Tube Type: Dual 6N16B Type Vacuum Tubes
Gain: + 3dB Maximum Output
Power: 350mW (320HM)
Signal to Noise Ratio: -111dB
THD + N: 0.02%
Frequency Range: 10Hz-50KHz (+/- 0.5dB)
Net weight: 165g
Size: 120 x 57 x 16.5mm

Paraphrased from the manual, (those in parenthesis, are my own words):
BA300s uses two micro-tubes for amplification, Current-Mode Operational Amplifiers (they are flexible analog type amplifiers) with extended output and 4.4mm balanced input and output (can also accept 3.5mm single end and 2.5mm inputs). Superior power management ensures the performance of the whole amplifier. The amplifier does not set the volume control (all volume controls and effects are done from the source). The gain of the whole amplifier is +3dB, which improves the output amplitude of most front ends. The signal is amplified by micro-tubes, and the output is rich, satisfying the different sound experience of the user. Built-in lithium polymer rechargeable battery charges to full in 3 hours, with a battery life of 7 hours.

From my tests, the BA300S pushes out 3dB more from your current gear which proves the tech specs claim (You can CLICK THIS to see my setup). And using the Focal Elear and the WM1a at half max volume, the BA300S does a last a little over 7 hours of use, your mileage may vary.

Unboxing: The Oriolus BA300S came in a nice box, with a cardboard sleeve like cover for the internal hard cardboard box. There are pieces of branding and information on the outside of the box while the inside black box has a nice Oriolus branding on the center cover and Raosound Studio at the bottom right.

What's inside:
1. 4.4mm signal cable
2. Micro USB charging cable.
3. Velcro (not in the package, instead there is a sticky gel pad)
4. Warranty card.
5. The manual

Note: There was an additional 2 interconnects in the same style as the stock 4.4mm to 4.4mm (middle of pic) interconnect jacks, one is a 4.4mm to 2.5mm interconnect )bottom) and the other is a 4.4mm to 3.5mm jack (top).

Accessories are subject to change without notice. (and this explains the above information).

The extra accessories are, likely a sign of things one can pay for in extra to the package, as you can see the box was meant for one 4.4mm to 4.4mm interconnect but can allow unbalanced input or balanced from a 2.5mm source.

The sticky pad is quite effective in attaching both the BA300S to any player with any surface (even the WM1A/Z with its textured back) and is like silly putty, it can stretch when being peeled off but returns to that pad like shape. It can accumulate dirt, dust from use, either use a tape to take the dirt and stuff from one side (and do the same for the reverse side) or wash it, it's reusable and does a pretty good job of isolating the heat from both devices and wont bleed into each other.

Build/Design: The BS300S' matte black rectangular casing is made from sturdy CNC'd Aluminum which was likely chosen due to weight, ease of sourcing, cost and to make heat absorption and dissipation easier (Aluminum has a thermal conductivity of 237W/(mK), which is over half of the much more expensive and heavier Copper at 401W/(mK) and is more conductive than another popular material, stainless steel at 16.3W/(mK)). This means that you will feel the warmth that the BA300S' generate when in use, vacuum tubes generate a bit more heat than digital amps so you might be a bit surprised at how warm it gets, it's natural and it won't burn your hand, promise. Just make sure you it's not covered in leather or some other heat restricting material so it can dissipate the heat normally.

There are indents on the top and bottom part of the amp, one on each side to help guide those stacking bands (or plain old rubber bands). On the back are some information about the device including the model name.

At the bottom is the micro usb port for charging and a very small led that turns solid red when charging.

On the top of the the BA300S are two 4.4mm balanced plug ports ringed in Gold, too subtly carved on top of each port with IN and OUT. In the middle is a switch with a clear plastic lever that lights a solid red when flicked to the on position, the On and Off indicator is also subtly carved on the top and bottom part of the lever. Also note that when the battery is insufficient or getting low, the red led blinks fast.

On front, near the bottom, is the Oriolus brand carved into the cover and painted over for subtle branding, and the most visible and in my opinion, beautiful part of the amp (at least when you allow it to be seen) is the viewing window that shows both tubes and is also houses an led indicator. When you turn the amp on, the indicator led lights red, meaning the tubes are powerered and warming up; when the indicator led turns blue, the tubes are sufficiently warmed up and you can make out the orange glow of the tubes.

On a side note, it might have been nicer if the indicator leds did not shine directly onto the tubes, because the blue light makes it harder to see the soft orange glow of the vacuum tubes which can be mesmerizing to look at. The tubes are dual 6N16B type vacuum tubes, y'know, just in case you were wondering.

Sound Analysis: During my initial impression of the Oriolus BA300S I inadvertently called it Pandora's Amp, mostly because when I first listened to it, it's like the music that I knew, the music that I loved and cherished with my favorite combo (Campfire Andromeda/Focal Elear) suddenly was JUST better, and internally I felt there is no turning back. I had to scramble a bit to take down notes as to what changed, writing in my usual near-unreadable script. The more I listened, the more I realized that this is no ordinary amp, a device that on the base end, magnifies the source; The BA300S does not just amplify the music, it enhances the listening experience, the tubes in the process amplification, giving a portion of the stereotypical "tube amp" sound to the output you hear, making it quite a unique listening experience. So enough waxing poetic, letting the amp run itself through 200+ hours of use before doing the review proper, I let it sufficiently heat up with use before doing the review which was mostly done on the Sony WM1a, though I have used the Sony A35, Hiby R6, and Audirect Beam to corroborate the improvements provided by the BA300S. Headgear used included the Focal Elear, Campfire Audio Andromeda and Atlas.

Note that there is a slight hum (natural on amps like this, which is actually pretty low in comparison as some source shave noted) that is more apparent on sensitive IEMs like the Andromeda and cellular calls/sms give that interference sound if it's very near the amp. Beyond the noise numbers, real world effects of the hum are not as annoying as one would think (it's not a hissy fit which I hate) giving me the pleasure of hearing the Andro sound like this is worth the minor inconvenience (we do listen for pleasure here) and cans like the Elear will render it forgettable. The improvements mentioned below will be in comparison to the source at 85dB and with the amp at the same level of sound output.

Bass: In Dragonborn, there is more bass quantity that's quite palpable, it doesn't go overboard or become overwhelming and bass impact is greater with each it of the war drums, it's quite satisfying, there is a little more rumble linger in each instrument and is reflective of the slightly slower speed of decay. Lithium's bass guitar crunches through the music with a bit more realism and resolves well and sounds pretty natural. Way Down Deep shows a little more deepness to the reach of it's drums, more sense of depth and evidently displays a bit more linger. Overall, there is a little more sub-bass extension, more rumble, some more texture, impact, warmth and smoothness.

Mids: Pandemic's mids are more spacious, it gains some distance between the instruments and sounds more spacious. There is also a bit of a nudge in the forwardness of the mids with equal amounts given to both the upper and lower mid section of the frequency. There is a small amount of thickness added to the notes and a vibrancy that makes the area more present and more emotive when called for.

Treble: Has the least amount of boosting done by the BA300S but it does so in a manner that is still evident, Hit The Lights, there is more shimmer and sparkle with the hats and cymbals played in this track, the sense of air is enhanced to give more space. In Question Of Lust, treble reach is raised a bit and there is more presence in the cymbal crashes area, giving a better sounding expansion to the sound it delivers then decays smoothly. Overall the changes here are not as much as with the 2 other frequency ranges but they do add more to the pot and help give a better listening experience with space, shimmer, sparkle and smoothness!

Soundstage: There is a bigger stage granted when using the BA300S, almost an inch for the outer reaches of the ear in distance and a slightly less additional amount of space granted in he other axis of front/back, up and down. This additional space does give a better overall sense of depth, height, width and with the right recording, frontal and back space can be perceived as bigger as well.

Conclusion: The Oriolus BA300S is quite a marvel, a portable tube amplifier that can provide additional power to drive most headphones and an enhancement to the sound that is quite frankly near magical. The vibrancy BA300S adds to the music is the special ingredient to the whole as most amps can add the same boosts in the frequencies and stage, but the sense of extra life, energy, warmth and emotions you hear with the BA300S is unique to tube powered ones, and the Oriolus BA300S delivers it all in an uncomplex and sleek portable form with enough power to last up 7 hours. The BA300S is able to use both single and balanced sources so nearly any music source will benefit from this amp though the obvious brand that it targets for synergy is Sony, other manufacturers, especially those whose tonality is near neutral will quite enjoy the flavor this amp will bring to the table. The simplicity of having no separate volume knob and only one switch to bother with is pretty brilliant.

Sound testing was done mostly using a Sony WM1a and the BA300s volume matched to 85.X db and calibrated using a 1kh tone on a dedicated DB Meter. More information about my methodology will be available on the About Me page (once I find the time to write it up.)

Just ordered mine this evening, the new G4 variant which comes with. 4.4mm + 3.5mm ground. Can't wait for it to arrive!
Great review! Do you think it will pair well with ATH-AD2000x terminated with 4.4mm balanced plug? Does it have "enough juice"?
Erfan Elahi
Erfan Elahi
any comparison with Sony PHA-3