General Information

TTR Surround's next iteration of the widely successful Co-Donguri earphones. With Brass front cabinet and the same spectacular design and build as in the Co Donguri Shizuku earphones. Ocharaku's patented Tornado turbo circuit is also implemented in these earphones.
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100+ Head-Fier
Pros: Price! Balanced sound with a bright tilt. Tight bass, great detail
Cons: None really. To nitpick: slightly dry sounding
Simple Man’s review – Co-Donguri Brass $34 (co-Donguri Shizuku $38)
This is called simple man’s review because they are based on the sound of these earphones directly from my smartphone using 320 Kbps mp3 tracks. No expensive gears nor lossless tracks,no EQ, and all that hi-fi stuff.


About the manufacturer, and a little ramble about my relationship with their creations:

TTR, Tune & Tone Root, corporation is the name of this company, nick-named “Surround”. A Japanese earphones manufacturer closely associated to Ocharaku, the even more popular earphone manufacturer started by Makoto Yamagishi in 2010 – Designer and maker of the famous Sony EX 1000 / 800ST series, a cult classic in audiophile circles. TTR borrows the patented Tornado Equalizer from Ocharaku, and it also employs the same basic housing design used in Ocharaku’s Donguri Keyaki series.

It was love at first “sight” when i first bought and listened to the original co-Donguri Shizuku (the predecessor of the co-Donguri Brass). Although the Shizuku is now discontinued as per the official site, we can still buy it from Amazon Japan or cdjapan until stocks last.

The mesmerizing highs (that bell-like clarity) in the presence region totally entranced me, and i couldn’t stop myself from buying all of the TTR models, namely, co-Donguri, Raku, Syou Kurenai, Chonmage 3, and i even went on to buy the Ocharaku Keyaki Ti Plus, and the FLAT4-NAMI. These earphones essentially made me spend more than 1000 dollars on earphones all within a couple of months. I wanted them all! The co-Donguri is how i went on to appreciate treble, and almost became a treble junkie, until the Final E series dragged me down from hot highs to show me that there is more to music and that there is magic in in the warm lows as well.

And here, with the co-Donguri Brass they have now employed Final’s eartips to replace the spin-fits that was the default earlier. This in my opinion is a great move, and suits the earphones and the sound signature much better than the spin-fits.

Embracing the best of both worlds, Ocharaku's patented Tornado Turbo Circuit and Final's eartips, (both best worlds are in Japan by the way), the TTR strives to give us the best musical experience. I salute to them!

Now, since i didn’t do a full review on the original co-Donguri Shizuku, i take this opportunity to do a kind of a side review for it. Wherever applicable, i will drop notes on how the Brass stands up to Shizuku, and how the Shizuku differs from the Brass. Where there are no extra notes in italics, there we have no difference between the two.

Product Specs:
Driver: 10mm dynamic, with Tornado equalizer
Frequency response: 5 Hz- 40KHz
Impedance: 18 Ohms
Sensitivity: 106 dB/mW
Mass: 22g (vs 16g Shizuku)
Cable: 1.2 m (3.9') OFC Ritz [4 core] non-detachable cable with 3.5mm L-type connector (vs non OFC specified cable in Shizuku)

Donguri Brass 5.jpg

Build – 5/5
The IEM housings, being made of brass, are quite weighty, especially when compared to Shizuku which were rather light. Once seated in the ears, you don’t feel the weight anyway. The build per se is top notch. To handle the extra weight they’ve added a cable that is slightly (very,very slightly) thicker than the older model, which is really thoughtful. They look great and feel solid. Unless you decide to use these IEMs as a nunchuks, i think these can be useful in the absence of one, i don’t see the wires giving away with any normal use. I could have subtracted 0.5 due to the extra weight, but, considering the price and the slightly thicker cables i chose not to punish them for this. (The Shizuku will not suffer this criticism due to lighter weight). The L-shaped connectors are great, Y-splitters are awesome, and the neck cinch seals the deal leaving nothing wanting with the earphones. The co-Donguri brass comes in punchy colours and are aesthetically more pleasing compared to the colour choices of Shizuku. Those who prefer a balanced output also are served for 10 extra bucks, they have both the 2.5mm and the 4.4mm connector versions, which is cool. (The Shizuku comes only with a 3.5mm connector)

Donguri Brass 3.jpg Donguri Brass 4.jpg

Accessories – 3/5
Bare minimum. No carry case, small and large eartips, Final E type (Spinfits for Shizuku), in the box. That’s it. A cheap box would have got them 5 points for the price.

Isolation & Sound leakage – 4/5
Isolation is quite good for an IEM with a tiny vent on the outside. The Final E type tips are perfect for these, and i use them now also for the Shizuku, as well as the other Donguris and Ocharakus.

Eartips, a small comparison: Spin-fits vs Final E type:
Both of them bend inside the ear to align with the ear canal. The spin-fits bend at a greater angle compared to the Final E type. The Spin-fits, however, at certain positions create a little hollow in the ear resulting in seal issues, which can nevertheless be rectified by re-positioning the tips. The Final tips don’t suffer from this malady and this aspect is what makes them better, IMO. On the other hand, the Spin-fits can enter the canals a little deeper due to their longer stem. So, they still got that going in its favour.

Microphonics – 4/5

I wear them over the ear, and this way it’s a 4/5. Straight down i’d give it a 3/5.

Fit – 5/5
Both ways possible, and fit is secure, and easy to acheive. Full score.

Drivability – Very easy to drive, gets very loud with 60% volume in my HTC 10. I don’t think anyone with any source will have trouble driving these.

Before we get to the sound:
You must know that i don’t listen to trance, EDM, or bassy stuff, no metal stuff, so, take my opinion about the extremes of the sound spectrum, and speed,etc., with a grain of salt, as they are just based on the kind of music I listen to- namely Jazz, blues, some progressive rock from the 70s/80s and some classical music. However, to give a fair review, i include some of my favourite Daft Punk, Tool, NIN, and some Pop songs among my test tracks.

Sound –
I’ll simply call these earphones “Brass” and it’s predecessor “Shizuku” for convenience’ sake. And I’d like to mention here that i firmly believe the drivers inside the earphones are the same, with no difference in tuning, whatsoever. The differences noticed are due to the different metals used in the housings (light Aluminium vs heavier Brass). Again, this is my belief not based on facts. Maybe, just maybe, they have tuned the highs slightly, but i doubt it. A casual listener would be hard pressed to admit to any sonic differences between them with a short listen. That said, there is slight difference that we can clearly perceive in each segment of the sound spectrum, and all together makes up for a considerably different sound presentation. The difference is not day and night, it would be different times in the day.


The bass on the Brass is authoritative. It digs deep and does not have any noticeable mid bass hump at all. It’s feet are firmly grounded in the sense that the bass is tight with less decay. It seems that the bass in the Brass has slightly more definition and weight also. It’s not at all boomy and extremely well behaved. Bass nicely done. The Shizuku on the other hand does not dig as deep, or we can say it flaunts a little bump, a luscious mid-bass hump, which is more appealing than the sub-bass presence. It also has a slightly slower decay which helps in timbre of certain natural instruments in the bass area. The slight mid-bass hump also helps the mids by adding a little bit of warmth.

That said, neither of these earphones will satisfy bass-heads. It’s not made for them.

Brass nicely decided to lose the little mid-bass hump that the Shizuku had. It sounds like a good move and i thought so as well. When listening to the Shizuku i always wondered how it would sound if they lost that little sexy hump. I don’t wonder anymore.

So, losing this little hump took away certain other things as well. As i mentioned, it took away the little warmth that Shizuku added to its mids. As a result, the mids sound a bit clinical. Vocals sound dry. First time i heard what dry vocals really meant. Vocals, especially male, sounded a bit as if the singers throat was parched dry and he badly needed a glass of water. They get that raspy quality to the voice which can be sexy sometimes. It’s good in a sense that you can catch more details in the voice, but i think the lack of warmth makes it a little less musical. Those leaning towards “analytical” would surely appreciate the mids presented by the Brass. The upper mids, the region where female vocals and high bows of violin lies, are also a little straightened out in the Brass. The Shizuku also had a little bump here to accent the high-mids. This gave the Shizuku that magical mesmerising bell-like sound which is always mentioned in any impression of the co-Donguri. The Brass also has this bell-like quality to it, but the notes are a little heavier in this case, and it does not float up to magical altitudes like it does in the Shizuku. The Brass plays a bell like “Ding” where the Shizuku goes “Ting”. Heavier notes vs lighter notes, only slightly but you can hear the difference. This also works a little in favour of Shizuku when it comes to instrument separation. The notes being slightly thinner have slightly more room for themselves. When it comes to details (micro), however, the Brass has a slight edge. And this edge is sharp. This takes us into the domain of Treble.

The Brass presents more micro details, easily perceived, as it’s signature appears more linear. The Shizuku, when you move past the high mids, has a certain drop in the sibilance region of lower treble which makes them sound more musical and easy to the ears, also sacrificing some micro details in this area. Nothing alarming, but you can hear it in comparing the two. This also aids in the perception of better instrument separation with the Shizuku. The Brass, being more linear, shows some details close to sibilance region more than the Shizuku. So, you notice a bunch of details floating around the treble instruments flirting with sibilance. I say flirting because it is in fact pleasurable to some extent, and not repelling or annoying. But it is, nonetheless, better if not present, atleast for me. I also think the high treble is also more present in the Brass compared to the Shizuku. The Brass does not shy away from presenting high frequencies as recorded, where the Shizuku takes a slightly more forgiving approach.

Needless to say both the earphones are slightly tilted towards the upper-mids and treble.

Soundstage: Both the earphones have a very decent soundstage, with decent width and height. The Shizuku sounds slightly more airy compared to the Brass. They both have a nice round soundstage, which means not super wide, but with equal height as width. This is applicable for the entire Donguri line-up. They all have good height and good width, and they are all very satisfying in their presentation. There is not much to say about the depth of the sound stage.

Separation: The instrument separation is very good as it is with the Brass. Only it falls a couple of inches shorter than the high bar that Shizuku set already. Brass, going for a linear approach went for more micro details at the expense of instrument definition and separation.

To sum up the differences between the Shizuku and the Brass, I would say that the Shizuku is a 9 AM feeling on a nice summer day. It’s nice and super clear and you feel great to be out and about. The Brass is high noon on the same day. It’s extremely clear where a shadow isn’t cast to obscure the details. One might even break a sweat if one ventures a walk outside at this time of day. But hey, sweat isn’t bad now, is it?


I choose not to do further detailed comparisons with other brands because these are very unique. I’ve listened to a number of earphones and i can confidently say that the Donguri (the entire line-up) is like no other. No one goes for this tuning. Even FLAT4, with is great wide soundstage, is very different compared to this presentation. For example, a cymbal crash in the Audio Technica E40 or the Sony EX800 will hit at the right extreme of the soundscape. The same crash in the Donguris will play almost at the top of your head, close to the center of the soundstage, very slightly to the right. The presentation is very unique indeed, i believe it’s the shape of the housing.

However, i’ll do a quick compare of all the Donguris from Surround in the following manner:


Bright > Raku > Brass > Shizuku > Syou Kurenai > Slightly warm
Syou Kurenai > Brass > Shizuku > Raku
Treble: Raku > Brass >= Syou Kurenai > Shizuku
Detail: Syou Kurenai > Raku = Brass > Shizuku
Clarity/definition: Syou Kurenai > Shizuku >=Raku > Brass
Separation: Syou Kurenai > Raku > Shizuku > Brass
Soundstage width: Raku > Syou Kurenai = Brass = Shizuku
Timbre: Shizuku > Syou Kurenai > Raku > Brass
Vocals: Shizuku > Syou Kurenai > Raku > Brass

Just to put things in perspective.
Brass = $34; Shizuku = $38; Raku = $100; Syou Kurenai= $230

Overall Sound rating of Co-Donguri Brass: 9.0/10
Vocals 4/5
Soundstage 4/5
Instrument Separation 4/5
Detail 4.5/5 (up by 0.5)
Timbre 4.5/5

For me, the predecessor, Shizuku, will score a 5/5 on all those points above, except details maybe.

Conclusion –
The Co-Donguri Brass is another incredible offering by TTR Surround. Amazing sound at an unbeatable price. The Brass possesses a very balanced signature which presents music in a cold and dry manner. It brings the micro-details to the forefront to satisfy the analytical listener who wishes for a dynamic sound. Even though i feel the older Shizuku suits my tastes better, i really commend TTR Surround for striving towards improvement and perfection. This constant experimentation is the key to success, and this is what keeps us audiophiles forever addicted to this dear hobby of ours. 5 stars for TTR Surround!
@iems0nly Thanks for responding. You said in the review that it "does not have any noticeable mid bass hump at all." Did the sound change over time or did you just change your opinion? Is there any where to buy this under $40 that you know of? Here, , it is $33, and the shipping is $7 minimum.
@HeadFUONEZ the mid bass hump is hardly noticeable is what i mean, and my opinion of the sound stays the same. if you compare it with neutral signature IEMs, like etymotic, there is a relative lift in bass quantity. Donguri goes for a balanced sound with a bright tilt. i bought my unit from cdjapan.



500+ Head-Fier
I just discovered this IEM thanks to your review, it seems to be a great bargain! Were can I buy the Shizuku with delivery in European Union without taxes?


100+ Head-Fier
I just discovered this IEM thanks to your review, it seems to be a great bargain! Were can I buy the Shizuku with delivery in European Union without taxes?
Hey @Rollk2 : Sorry for the delay, i didn't see this comment until now. should do it with only shipping charges. That's how i got them delivered to Germany.