Intercity, a fairly obscure, boutique Japanese audio brand that gone out of business circa 2013, just after their 25th anniversary. The MBA-1 Platinum Edition is their flagship of the year, spotting the Alps RK501(the same thing that is inside Sony DMP-Z1), which is still considered obscure for us out of Japan.

Now let us shift our focus back to the HD-1L Limited Edition. It is a plain looking box, with gloss black piano finish, and minimalistic operation. The unit was priced around 99800yen when new.



The front panel spots 2 headphone out with 6.3mm jacks, a volume control and a switch with a red light indicator. As simple as that. No gain control, no bass-boost, nada. The rear features a set of RCA input, and the headphone amp does not have any pre-amp control.

Since the amp was meant for the Japanese domestic market, it only has a 100V power input. It features a "MVP3" module, a current feedback feedback system. The circuit design claims to eliminate phase correction and reproduce the music with a completely flat frequency response. The board design is optimized for analog circuits, has achieved a vast dynamic range and excellent spatial reproduction.


Note the pair of 15000uF capacitor at the power circuit and a pair of Burr Brown OPA2134 op-amps at the DC-Servo(?) circuit.

Specs:

Measurements:



Sound Impression:
Let's get into it.

The first thing that pops to my mind, "Liquidy, Buttery smooooooooth". The overall presentation of music is fairly neutral, there aren't many coloration in the outputs, at least to my ears. It is polite, delicate, yet has a constant reserve of power on tap when you call for it. It has no issue powering my AKG K240 DF(thing is a lean and picky headphone which needs power with 600 ohms impedance), AKG K340, even the Pioneer SE-300(piezoelectric driver and needs a whole lot, whole lot of power to run) sounds musical with it and still have quite some headroom of volume to spare.

We starting with the Bass, the HD-1L Limited Edition holds it down with precise control. Although you can say it is a little reserved on the quantity, but you get the controls, nimble delivery to the ears. It sounds delicate, just tip-toeing with the music between the bass notes. It doesn't bloat nor once go out of control.

Mid-range is smooth: vocals are just flowing out with a smooth pace and gliding to your ears. But by no means that it lacks the texture. The vocal, is just sitting in the middle of the scene, waiting for you to enjoy. Instruments and separation are well placed, soundstage is decently wide, with good depth in it. Layering of vocals, instruments are well defined, even with messier tracks.

Treble wise it might carry just a tinge of brightness, but it is not the intrusive kind. Texture of the crash, cymbals are crisps and treble is well extended.

Coming previously and mainly from the Graham Slee Solo SRG II, this is just a delight to listen to. Still has the same smoothness, but better in terms of power delivery, clarity and spaciousness.

On certain genre or headphones, you may want to have a little more "bite" or aggressiveness in the pacing. It can feels a little reserved hence the feel of "delicate" in the delivery of music and pacing. Still, it is like a gentle wave of music you can ride on instead of the riptide pulling you under.

Gear Tested:
AKG K240 DF/K340, Beyerdynamic T1 Gen 1, Grado PS500, Fostex T50(1970s), Sennheiser HD580 Precision, Yamaha HP-50A with Chord Hugo as DAC out.

Conclusions:
Well, for the scarcity of the info online, I am lucky that I jumped the gun and bid this from Japan Auction and get it at a decent price. And at the price I have paid(around 190-200USD), I believe nothing could really come close even compared to the more modern options. If you encountered one, I would recommend to try it out, you might be surprised!

Disclaimer : The review unit is provided by Stars Picker Audio Library and will be returned and pass to another reviewer for review purposes. The package included TWS600 and extra eartips for tip rolling.

Introduction : This is my first TWS earphone I've ever tested and reviewed. All I've using are wired headphones (Modded Hifiman HE4XX, Modded Beyerdynamic DT880 250ohm 2003 ver., Alessandro MS1...) and IEMs (Campfire Nova Custom, Sony MH-755, Tin T2, Final Audio Design Heaven 2 DIY Ver...).

Source : Sony NW-A45, Sony Xperia XZ Premium

Apps : foobar2000, HiByMusic

Song Genre : Rock & Roll, Vocal/Jazz, some Pop and Hip-Hop

I am listening mostly Rock & Roll and Vocals, some Hip-Hop and Pop, so I am very leaning towards V & U-shape, fun sound signature. I am not a basshead by all means, but I like deep and full-bodied bass. For highs, I am not terribly sensitive to sibilance, but I still like them rolled off just enough not to cause a needle city in my ears.
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I will splitting the review in seperate sections:

1) Packaging
2) Design
3) Accessories(Eartips)
4) Usage and Charging
5) Connectivity
6) Sound
7) Tip Rolling
8) Comparison with Haylou GT1


It comes with a standard cardbox box, felt sturdy and premium, but looks generic for the product this price. Upon opening the box, you will be greeted with earphones(Left & Right) and Charging Case.

The charging cable, warranty cards and instruction manual(English, Chinese) are included inside the box.

*Side Note* On the instruction manual and info, Hifiman insisted that there should be a 10~20 hours of break-in/burn-in period, which I believed is properly done by previous users(5 days of testing and review by 5~6 users before me).


The TWS600 are small, fits snugly in my ears and I have no problem fitting them. But I wish they have some textured surface as they might slipped through my hands when I removing them from my ears.

As the design choice, they look like beans and the swirling design on the face is not my taste. But at least they looked different from other generic TWS earphone on the market.

The button is placed in the middle of the earphone. Clicking either one of them once will play/pause the music. Double click on the right side will increase the volume and on the left will do the opposite. Triple click on the right side will skip the song forward and the left will do the opposite too. But the problem is when you clcik the button, it will push further into your ear canal, which might cause some discomfort. Your mileage may vary due to ear canal size and fitment. If they decided to put touch function to replace the button, it would be a good option as well.

The charging case, it looks slick and slim, with the Hifiman plaque on top. The charging case uses the USB-C charging port and sits on the rear left side. It is recessed and sits nicely inside.


The original package includes 9 pairs of eartips:

- 1 pair of triple flanges eartip
- 3 pair of double flanges eartip

- 5 pair of silicon eartip ->3 narrow bore and 2 wide bore

Extra eartips are provided for tip rolling. These include:

- Acoustune AET-08,
-SpinFit CP-500,
-Sony EP-TC50.
All these eartips are available in S,M,L sizes.

*Side Note* I will be using most of the tips in M and L size. I will discuss how the eartips affect the sound in the later chapter.


The charging of the TWS is easy, just slide the earphone into the left and right slot respectively, and it will sits nicely.

The button on the left and right will play/pause, increase/decrease volume, skip tracks forward and backward. But the present of physical button means you will have to press the button and eventually it will push into your ears. If it using touch sensitve surface instead of button, it might improve on the experience of the user. But it is just my nitpicking on this tiny earphone here.

The charging case was around 40~50% when I received the unit. Charging the case to full power by laptop is quite fast, less than 2 hour and it is fully charged.

The claim from Hifiman is that the earphone will last 5.5 hours and extra 33 hours from the charging case.

I tried it on my office hours, which lasted for around 3~4 hours of playing time and it is still going strong(playing FLAC and some DSD files).


Out of the box, it is recommended to activate both side of the TWS earphone and put it back to the case, and it will pair the left and right unit together.

But in reality for first time user, it was finnicky to connect sometimes. It will sometime connect just to one side and you will need to put them back to case in order to pair the earphones together.

After leaving inactive for 10~15 minutes, it will shut down and you will need to switch it on again.

While wearing the TWS and walking around to different rooms with music on(the player stays on the table 10~15m away), the connection stays pretty well and without any disconnection. Althought on some room with hallways and bends, the music will stutter. But it is expected as that specific room is bad for wifi and cell reception.

While playing musics, it will sometimes buffer or stutter, but it will resumes just fine after half a second or so. It does not occurs too often but sometimes breaks your enjoyment of music. I have encounter some other problem with it's connection with laptop. It connects just fine but there is a lot of hissing and noise even with no music playing. The noise is audible and the music also stutters when it is connected to PC. I have no idea what is affecting the music to stutter.

For calling, the sound is crystal clear, no delays or any buffering during call. The person on the other side of the phone call can listen to my voice loud and clear. Very nicely done on this part.


For sound, it's a mixed feeling for me. For the general sound signature, it's like n-shape or A-shape, a really mid-centric type of earphone.

The bass does not have body nor extension. For the bass presence, it's there, but it is just like rock skipping through water and without any significant impact or 'Oomph'. In the live version of Hotel California by Eagles, the bass at the beginning should felt deep impact. But in this earphone, it just feel like what I've said earlier, it just like the bass just skimming through the song. Also from other Hip-Hop and beat heavy songs, the bass is just merely a presence in the flow of the song, no "Oomph" when the beats drop.

The mids, it felt decent and excels relatively well on vocal centric song. The female vocal might not be as lush as other dedicated IEMs, but it is decent. But for some male vocal, it does present some peaks here and there, but does not sound wonky or weird.

The high/treble, I did not felt too much sparkle nor presence. It felt somewhat lackluster and leave me disappointed just a bit.

For the details, it is decent, with musics' detail to be presented to the listener, but never to-your-face type.

For the soundstage, it is narrow and just stuck to both side of your ears, barely gets any further from there. The sound felt compressed and congested on the mids with the stock tips on(Narrow bore, L size). Tip rolling is suggested and will be discussed next.


With Acoustune AET-08 eartips, the sound loosen up a bit and felt more airy, but the bass and highs are still missing albeit being improved just a bit. Overall, much more enjoyable than the stock one.

With SpinFit CP500, it felt similar to the Acoustune tips. It does move the mid a little further away, but still peaky.

With Sony EP-TC50, it makes the sound more towards V-shape, improving the bass response a little, but it still not getting anywhere near thumping nor jaw vibrating. Overall, it makes it more warmer sounding.


I grab my colleague's Haylou GT1 for a quick comparison with Hifiman TWS 600 and it presented something quite interesting.
For Haylou GT1, it's almost 10x cheaper than Hifiman and it is your typical V-shape sound signature, but it is less resolving and a even slightly smaller soundstage than Hifiman. Both of these TWS are only connected via SBC. Haylou is more engaging and fun, but it might wears your ear out faster in complex tracks. It's mids is way more recessed than Hifiman which is almost a complete opposite of TWS 600. If Hifiman can bump up the bass and it's quantity and quality, slightly tone down the mids, I would chose the Hifiman more.

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Conclusion, for the price of ~159 USD (RM629) for the time of writing this review, I feel like it falls a little bit short in terms of sound quality and price point. Awkward button placement on the shell means you will need to push the earphone further into your ear to push the button. Bass shy and recessed highs, but it might excels in vocal heavy tracks.

If you wanted to try something different, you can consider this TWS and try it yourself. Also I would strongly suggest tip rolling to experiment with the sound by yourself. For me, Acoustune and Sony tips are the best for this. For functionality, it works perfectly fine albeit with it's quirk(except my laptop which I couldn't figure out why), and phone call quality is all crystal clear and crisp.

Thanks for reading!

Final Audio Design Heaven II DIY Edition



Intro
I bought this kit at my own expenses, without any affiliation with Final Audio Design and it's staff. All opinion in this review are solely my own, and I am not being paid or given any compensation for writing this review. All the picture shown here are taken by myself.

The kit was sold as a Do-It-Yourself model and without any warranty. The idea is to let the user to experience the assembly process of the earphone and contains removable nozzle and multiple filter materials to tune the sound to the user's preference.

Technical Specification
The Final Audio Design(FAD) Heaven II DIY Edition is a single-driver balanced armature universal-fit IEM. Unfortunately there is no exact specification provided and I would assume it should be the same or similar to the normal edition of Heaven II.

The kit contains an Instruction Manual(on the left), BA & Cable Assembly, Housings, Nozzles, Eartips, Filter materials, Glue and Tools. The instruction manual gives a detail step-by-step assembly process in clear pictures and instructions.

I will briefly show and explain each process taken to build this IEM.

Step 1: Fixing BA into the rubber housing.


The BA model is 31105, but I couldn't found any details on the internet, I presume it's custom made or developed by Final Audio Design.



The BA sits snugly inside the rubber housing. All the parts will be fixed later with the glue provided.

Both side after fixing the drivers.

Step 2: Gluing the strain relieve and BA in the housing.

The kit provided glue to fix all the items in the rubber housing. It is some sort of clear glue which is very viscous and somewhat annoying to glue. It can be clean up using wet tissue but leaves some residue behind which needed to be clean after the glue completely dries.

Step 3: Fitting the retainer clips.

The kit provides a pair of stainless steel retaining clips. It can be expanded and enclose the wire portion snugly. Both side is slot into the holes aligned with the rubber housing.

The metal clips will click into place with the outer metal housings.

Step 4: Nozzle and Housing Assembly.

Removable nozzles with metal mesh.

The housing with rubber seal. The angled part is faced towards the rear.

The kit provided 6 types of foams and materials for filtering. It ranges from unfiltered, low to high density foams. Unfortunately in my case, all the filters disintegrated due to aging(I presume it was stored for some time). I run the IEM without filter for this test(Would probably play around with the filters in the future). The instructions also encourage the user to try with different materials to find the preference sound.

The nozzle and housing assembly. The nozzle is screwed on and can be easily removed.

Step 5: Gluing the outer housing to the wire and BA assembly.

After gluing the rear portion of the housing, slide the assembly into the metal housing. After a satisfying click, the assembly is finished. Time to listen!

The kit also provided 6 pairs of eartips. 3 pairs of wide bore(S,M,L) and narrow bore(S,M,L) for tip rolling. I prefer the wide bore which boost a tad bit of low end compare to narrow bore tips.


First of all, Heaven II is slim and light weight, it should fit straight right into your ear. It is very comfort and I have no problem wearing it for a long time. With the provided tips, it isolates quite well against some ambient noise.


The source for testing are my smartphone and my Sony NW-A45 Walkman. Both running Heaven II unamped and without any EQ. The eartip is the stock wide bore medium provided along the package.

Bass : The bass is adequate, but lacks some extension to the deep down. It is punchy, accurate and not overshadow any aspect. But a little more oomph and quantity would really appreciated. But being a single BA configuration, the bass is accurate and the speed is appreciated during complex instruments and songs.

Mid : This is where the strong suit of the Heaven II. The mids are lush and natural, but not in a clinical style or signature. The male and female vocals sound so desirable and really articulates. In live recordings, they sounded natural and smooth. A slice of Heaven in your ears.

High : For the treble, it does not extend as much as the mids and rolls-off a little. This is good which I can listen for quite some time without fatiguing highs. But it still have some sibilance on certain track, YMMV. In this case, I think the high, like the bass, is taking a back seat in this IEM.

Soundstage : The soundstage might not be crazy wide, nor the best details, but it has good imaging, and good amount of airiness on top. It is intimate and relaxing.

I bought this unit from a fellow member in an audio marketplace section in my local internet forum. It is priced around US$60 at the time I bought it. For this price, it provided the pleasure of DIY, building your own IEM as well having your own signature in sound which made available by the removable nozzle feature. I really appreciate the process of going through the assembly, giving some patience and rewarded by the listening session with a slice of Heaven(Pun intended).

Conclusion
I am really satisfy with this IEM for it's price range and it's mid-range performance. The materials from construction wise and sound quality are impeccable. It really separates itself from clinic, analytic sound; instead it provides a relaxing, intimate listening session for you to relax and unwind.

In the end, this is my first full-length review of an IEM in this forum. If you have any question, feedback or suggestion, you are more than welcome to comment or message me. Thanks for reading and have a nice day!