Quality Handmade IEM’s from Vietnam

Joinhandmade – Jelly Ear & Jelly Galaxy

Impression by TrollDragon

Today I am presenting my impressions of the Jelly Ear and the Jelly Galaxy IEM’s from Joinhandmade, a new personal audio manufacturing company based in Ho Chi Minh City, Vietnam.

A little over a month ago I was looking around Google images at various headphones and IEM’s when this picture of a box with a white hand on it piqued my curiosity. Upon dropping the image back onto Google’s reverse image search I found links to https://joinhandmade.com from Vietnam. The page text was all in Vietnamese at that time and Google translation leaves a lot to be desired; I noticed there was a Facebook link and I contacted them that way. Within minutes, I received a reply from one of the founders of Joinhandmade. We had a little discussion of their product and I expressed great interest in reviewing the Jelly Ear Balanced Armature IEM.  Hùng agreed to send me the IEM for evaluation and he also included a prototype of their new Jelly Galaxy, a Dynamic Driver IEM to try.

Joinhandmade is new to the manufacturing of IEM’s but they are not a new player to the personal audio industry itself.  They have previous experience operating a business called 7xu.vn where they sold name brand personal audio equipment and started creating custom headphone and interconnect cables. Eventually all of this customization evolved into exploring CIEM’s, offering a reshell service and gave them some insightful experience into creating their own line of IEM’s which I will present to you now.


Jelly Ear

The first thing that impressed me about this product was the packaging, it’s a wooden box. This is ingenious.  Is there any better way to protect your product for worldwide shipping than packed inside a wooden box?The box has the product name, Serial number of the IEM’s and a “made in Viet Nam” burned into the wood.

JE_Box JE_BoxOpen


The content of the box is rather spartan with only a plastic case containing the small and large foam tips.

Jelly Ear Specifications

  • Driving Unit: Balanced Armature
  • Impedance: 22 Ohms
  • Sensitivity: 107 dB @ 1000 Hz
  • Frequency Response: 50 – 22000 Hz
  • Distortion: Less than 0.1%
  • Body Material: Acrylic
  • Cover Material: Silicate
  • Cable Material: Bronze – Teflon
  • Cable Length: 1.2 M
  • Plug: 3.5 mm


Build Quality

This is one aspect of the Jelly Ear that Joinhandmade takes a great pride in–each unit is hand built by a team of skilled artists. Each Jelly Ear requires 48 hours of processing and goes through 21 phases of finishing. The molding of the 2 body layers, cable and clew knitting and even the surface abrading is all done by hand.
I can attest that the build quality on these units is top notch, there are no seams and no rough edges. The ear hook is made by whipping nylon cord over top of the cable, which in my humble opinion works exceptionally well. The exact same whipping is also applied to the Y Split and at the end of the slim 3.5mm TRS plug.

The only issue I have with these is the cable, since it is Teflon coated and tightly braided it is very stiff and has quite a bit of memory to it. The mechanical noise of the cable is minimal since it is worn over ear, they do not include a shirt clip or chin slider so you will have to provide your own clip or get creative with wire routing.

I have been informed by Joinhandmade that the next version of the Jelly Ear slated for release in the new year will have a totally redesigned cable very similar to the cable on the Jelly Galaxy in the next review. 


Fit & Sound

I personally found the Jelly Ear to be very comfortable and easy to get a good seal with, I switched to a pair of my surplus silicone tips in the above picture as I find the provided foam tips do not seal very well for me. The ear hook is very comfortable and nicely stays in place as you go about your activities while using these throughout the day.


Since this is my first experience with a Balanced Armature IEM, I was unimpressed by quantity and quality of bass that  these these deliver. The more I used them with different genre’s of music, I found that the bass extension and quality is actually quite good. There is just not a lot of it, since Balanced Armature’s do not move any air, drums don’t have that nice thump I am used to but the sound of the strings on a standup bass guitar are very tight and quite detailed.

Testing these with Allan Parsons Sound Check CD reveals that the bass does go down to 25 Hz and drops off very quickly below that frequency.


Forward is the name of the game here, but I guess that is what BA’s are know for, very detailed and clean. Hammett’s lead guitar and Hetfields vocals on Metallica’s legendary track “One” are great, it’s just when the drums kick in that you are let down with the sound. These are by no means a good choice for Rock or Metal music, they are fast and articulate keeping up the pace of the music, just lacking in the lower end where the sound of the kick drums are required.


The treble on these are a dream to me, not bright or hot in the least, cymbals and the upper register of the trumpet does not make me wince like some IEM’s do. I am a little treble sensitive and these are quite good, they might not have the detail many are looking for but for my ears they are perfect.


The Joinhandmade Jelly Ear are very easy to drive from the Colorfly C3 and the FiiO X3. I did not find the EQ ability of the X3 able to bring out any missing bass quantity on these as it is simply not part of the BA driver, now if these were a multiple BA with a tuned bass driver or possibly a BA/Dynamic combo I could see them being great for all genres of music.


 If you are looking for a very unique, single BA IEM and you listen to acoustic or jazz, then these might just be something to consider. There is a dizzying and confusing selection of IEM’s in the $100 – $150 market so you have many choices. Just the knowledge that these are all hand manufactured by a small company in Vietnam that is trying to get a foot hold into the very competitive personal audio market is a purchasing factor on it’s own, in my humble opinion.

I have really enjoyed my time with the Jelly Ear and everyone who saw me using them were very curious about their origin, when they found out that they did not come from one of the major manufacturers, people were very interested to try them out. So I let them listen to some really great tracks from albums like Roy Hargrove’s “Ear Food” and Dave Brubeck’s “Time Out” as  those tracks are a joy to listen to on these. As I discovered, as well as those who listened to them, they are not the most analytic IEM’s on the market but we all need to just kick back and listen to some great tracks sometimes and leave the critical listening for another time and place.

I would like to personally thank the Joinhandmade team for the sample of this finely crafted product that I used in this review. I also look forward to future hand made quality products  from the team at Joinhandmade.com.

Also I do believe that all the Jelly Ear’s will be shipping with silicone tips instead of the foam tips as shown in this review.

Constructive criticism is always welcome.





Jelly Galaxy

The Jelly Galaxy is Joinhandmade’s dynamic driver IEM. This version I have is a prototype and very close to the finalized product.

JG_Box JG_BoxOpen


The accessories included with my Galaxy are different than what will be included with the finished product. The ones I have included a foam tip and a sample silicone tip.

The finished product comes with S/M/L silicone tips in a new packaging insert like in this picture that was posted to Joinhandmade’s Facebook page. Notice the nice cord whipping of the strain relief on these.


Jelly Galaxy Specifications

  • Driving Unit: Dynamic
  • Impedance: 16 Ohms
  • Sensitivity: 113 dB @ 1000 Hz
  • Distortion: Less than 0.1%
  • Bodies Material: Acrylic
  • Covers Material: Silicate
  • Cable Material: Bronze – Rubber
  • Cable length: 1.2 M
  • Plug: 3.5 mm

Build Quality

Just like the Jelly Ear’s build quality, meticulous attention to detail is given to creating the Jelly Galaxy. There are no seams or rough edges to be found anywhere since the manufacturing process is done completely by hand. This attention to detail creates an IEM that can be used outside in the elements or in the gym, without having to worry about rain or sweat getting inside the unit and causing trouble. As a cosmetic touch, there are flakes of reflective silver mixed into the housings to add a sparkle for that Galaxy look when light hits them.

The cable on the Jelly Galaxy is a great improvement over the current Jelly Ear’s cable. The change from a Teflon jacket to a “Rubber” jacket (not the type of rubber that sticks to everything) and a looser braid has made for a great cable. There is no shirt clip or chin slider on this cable either and it does have a little mechanical noise, but that can be alleviated with a user-provided shirt clip. I do not have any pictures of the Y Split since my unit is a prototype and has a bit of glue on it that would not properly represent the build quality of the finished product. The Jelly Galaxy has an ultra slim 3.5mm TRS plug with a housing that is made from the same material as the body.

Fit and Sound

The Jelly Galaxy is a very light IEM and very comfortable, you can easily forget you are even wearing these when the music stops. I  switched over to some surplus silicone tips on these as well for for a good seal while listening.

The sound of these will be different than the finished product as Joinhandmade has increased the lower bass and removed a little of the midrange and treble. Therefore I really can’t give you an impression of what they will sound like, but if the changes are not too drastic then they will be a great earphone for EDM and POP music. I enjoy the sound of the prototype as it is, but it could use a bit more sub bass, which is probably the reason for the changes in the final version. The treble is not bright, hot or sibilant which is a welcome relief unlike a few other IEM’s I have reviewed previously. If I receive a finished version of the Jelly Galaxy I will update this review to reflect the changes.


The Jelly Galaxy is easily driven from the Colorfly C3 and especially the FiiO X3, with the X3 you can turn up the bass and the Galaxy handles the EQ adjustment quite nicely.


So if you are looking for a nice hand made, quality product from a group of artisans who put care into each build, then look no further than the Jelly Galaxy from Joinhandmade!

I would like to personally thank the Joinhandmade team for this sample of the Jelly Galaxy Prototype that I evaluated in this review.

Constructive criticism is always welcome.


Categories: IEM, Impression

A Musical Union of Ebony and Aluminium


Review by TrollDragon


Way back in April a new Sponsor on Head-Fi called RockJaw created a post looking for members to test and review a new product line consisting of multiple IEM’s and headphones. I applied at once and was accepted by RockJaw’s representative Rockbob.  This is going to be a great experience for myself as well as quite a few others, since we get to evaluate the new products and our opinions will be factored into the final retail products.

With all the formalities and details looked after, a large box of RockJaw products appeared on my doorstep, multiple IEM’s and a pair of headphones. I have spent several weeks with the ALFA GENUS IEM’s out of various sources and will now present my review.


I usually do an overview but the product we have is with beta packaging. The complete product line will have a totally revamped, nicer looking packaging in the near future.



Case CaseOpen

The slide out storage case is a great way to store your IEM’s or pack them for travel. Too thick to be used as a daily carry case, i believe RockJaw are going to provide a soft pouch with future versions.

ContentsAccessories consist of nice silicone tips in S/M/L and two pairs of tuning filters in Silver (Enhanced Bass) and Black (Monitor Class). I understand that with the final product there will be a third filter tuned between the Silver and Black. These filters and IEM body are nicely threaded allowing an easy way to switch filters without fumbling to get the thread started. I can see that once you have found your desired sound signature by experimenting with the filters at the beginning, most people will stick with the one they like best and store the other two sets back in the case.

Filters The build quality of the ALFA GENUS is exceptional and looks very solid with it’s aluminum strain reliefs and ebony wood body. I feel these will hold up to a fair bit of rough usage, the cable is a flexible shiny black PTFE material I do believe. There is a little bit of mechanical noise in the cable which can be alleviated by using the provided shirt clip or by wearing them up.


Fit & Sound

AG_C3_MiuAudio AG_X3

The ALFA GENUS are one of the easiest IEM’s to get a good fit on that I have used so far and the large tips provide an excellent seal.
I have run these out of a Colorfly C3 amplified with a Miu Audio MRA DIY amplifier and a FiiO X3 on low gain, switching between the two for my review. In my opinion the ALFA GENUS are very source dependent and will not have a great synergy with all devices.

Silver Filters

I started with the silver filters installed and found the sound to have an amount of bass that was just about unlistenable to my ears. The bass is overwhelming and very boomy, it bleeds up into the lower midrange and will muffle voices quite easily. I tried the silver filters with a 3rd generation iPod nano and they seem to be a little more tolerable from that device. I do like a nice solid punchy bass that digs deep where you can feel the impact on EDM tracks, but  somehow I doubt that bass heads would even like the silver filters. I never even bothered with testing the treble on the silver filters since the bass was so overwhelming.

Black Filters

Now the black filters are at the other end of the spectrum, some will find them a little too far at the end. The bass on the black filters is acceptable to my ears, not boomy and doesn’t bleed into the mids. Some might find it a little anemic, which is why RockJaw has created a filter in between the two provided. This new filter should fill the gap perfectly regarding bass. The treble on the black filters can be a little sharp to my ears depending on the source and the genre of music played. I found Paul Simon’s Graceland 25th Anniversary Edition very sibilant at points and actually starting to get annoying, with the FiiO X3 I was able to bring the treble setting down to -5 and take some of the edge off. This could not be done on the Colorfly C3 since it’s EQ was programmed by simians and is basically unusable.

Now Jazz at the Pawnshop was a little sharp in spots but not unlistenable by any means. Some of the users in the RockJaw test group do not find these sharp or sibilant except with overly bright tracks. It is highly possible that I just may be a little too treble sensitive.


I am personally looking forward to the new filters for the ALFA GENUS with high anticipation. If they will increase the bass presence by a small amount while taking some off of the brightness, then these IEM’s will be a serious contender in the sub $100 bracket that will please the vast majority of listeners with a sound that can be custom tailored to your liking.


I would like to thank RockJaw and Rockbob for the samples used in this review, RockJaw is a definitely a company to you should keep in your radar when considering your next IEM purchase.

Categories: IEM, Review

A leather case for the X3

Nerb Handcraft

FiiO X3 Leather Case

Review by TrollDragon

Nerb Logo


Quite a while ago in the FiiO X3 thread on Head-Fi, there was a post with a very interesting looking leather case for the X3. I wanted to get one of these cases for my player but there were no details of how to acquire it in the thread. With a little reverse Google Image search; I discovered the creator of this case was a company called Nerb Handcraft,  who produces finely handcrafted leather goods in Bangkok, Thailand. This was great–I contacted them on Facebook and inquired about the X3 case. I was informed that is was a custom production run for one of their customers and if they were ever going to produce any more of them they would let me know. Well a few months later there was a status update on their Facebook page that the X3 case was going to be made again and available for sale.

This was great news, so I contacted Nerb via Facebook and they were very friendly and very prompt to reply to my questions. I was given the option of brown or tan so I made my choice and ordered the case. Today an XpressPost package arrived from Thailand tied with string; a nice little nostalgic touch. Who does that these days?  Packages usually have so much shipping tape wrapped around them it’s crazy. The package from Nerb didn’t have a piece of tape anywhere to be found,  inside or out. You will be able to see in the upcoming pictures, that the packaging is quite environmentally friendly.



The shipping box in all it’s glory!

Shipping Box



The Contents

Inner Box Contents

BagThe inner packaging is exceptional! This box is tied up by a strip of leather with a Nerb stamped fob in the center. Upon opening this box, you are presented yet with another surprise, a drawstring cloth bag stamped with the company logo in ink.

We are now going to get down to brass tacks, after opening all of this great packaging the cloth bag finally reveals a leather case for the X3.

Case Back Case Front

The exquisite smell of leather is the first thing you notice; you just have to pick it up and smell it again.  In my opinion, all cases for electronic devices should be made from leather.



The FiiO X3 Installed

Case & FiiO X3 Installed

As you can see by the above picture, the holes lineup fairly well with the X3’s buttons and since the leather is quite thick, you will have to use the end of your finger to push them.

Top and Bottom View

Top Jack USB & Line Out

Left and Right Side Views

Hold Button Memory Slot

There are openings in the case for all the ports and switches–the only thing missing is the reset hole at the top for resetting the X3. This hole could be easily made yourself or Nerb might just include it in their next case builds.




The Nerb FiiO X3 Case has an excellent look, feel and smell to it; the leather is thick and the workmanship top notch. Since the leather on the case is substantial, you will have to use the end of your finger to push the buttons. Installing the X3 into the case requires a fair bit of pushing as the case is very snug. Removing the X3 from the case is a bit of a chore since there is nothing to grab onto.

The only thing that needs to be redesigned on the case, in my opinion, is the area around the headphone jack. You will need a headphone plug with a long shoulder on it like the ones made for cell phone cases.  Plugs without this shoulder will get caught up in the stitching or be too large in diameter for the hole.

So if you are looking for a great little leather case, send a message to Nerb Handcraft on Facebook; this seems to be the only way at the moment to get in contact with them.  Tell them Charles sent you, or you saw a review on Head-Fi.

Nerb Handcraft
Finely handcrafted leather goods in Bangkok, Thailand


Constructive criticism is always welcome.


Categories: Review | Tags: , , , ,

Vacuum Tube Hybrid Amplifier


MKTP1 Vacuum Tube Modular Preamplifier

(EH 6922 tube)

miuaudio logo

In my previous review for Miu-Tech of Hong Kong, I built and reviewed their MRA DIY Portable Amplifier which is a great little DIY amplifier kit. In this review however, I am taking a look at their hybrid headphone and preamplifier, the MKTP1.

A rather large box for a tiny little amplifier…

Box Box_Open

As you can see from the open box picture, the amplifier is well surrounded in molded fiber board. A hefty power supply and an RCA to 3.5mm TRS audio cable are also included.

ContentsThe only thing that didn’t come with mine was an AC cord, which is not a big issue; the AC adapter has a standard IEC C14 socket that takes a C13 computer cable and I don’t think there is anyone out there that does not have a few spare C13 cables in a drawer.

The Amplifier

MKTP1_FrontFront Panel

The workmanship you find after you get the amplifier unpacked is excellent–the machined aluminum front plate with recessed TRS jacks, an aluminum volume control and hex screws holding it to the case. The TRS jacks are recessed in larger holes to accommodate plugs with bigger ends like the Grado mini adaptor cable I use on the DT880’s. Everyone who sees the amplifier finds the acrylic tube protector a nice touch.

MKTP1_BackBack Panel

The same attention to detail is also evident in the back panel, a Line Out TRS jack, RCA Line In jacks  and the power adapter connector.


Tube Rolling

Part of the fun of owning a tube amplifier is the ability to experiment with different tubes that are available on eBay and from other sources. The tubes you can roll in the MKTP1 are a little limited compared to a full size tube amplifier, but there is still a great variety of available compatible tubes that you can try.

Tube rolling is not for everyone. I got involved in it with my Little Dot MK IV amplifier and the LD Tube Rolling thread on Head-Fi. Chasing the little “Fire Bottles” can be an expensive hobby if you allow it to be as there are always “Better” tubes that are just out of reach. The sellers on eBay know how much demand there is for popular NOS tubes. They also know quite well how much these tubes can be sold for; it is like anything, the higher the demand, the greater the price. Occasionally some have found a very good deal on excellent tubes that the seller either didn’t know what they were or the auction was badly worded etc… But you have to scour eBay globally and possibly haggle with the sellers and at some point in the game, the work involved acquiring these tubes outweighs the sonic benefits gained.

When the MKTP1 arrived I listened to it for a few days in its stock format, which I must say is very enjoyable. Then the case was removed and the rolling began; I have a few compatible tubes and quite a lot more that are not. Well I rolled them all with a few minor modifications, I don’t recommend this as it is not really advantageous to roll tubes that you can’t just plug in, adjust the bias trimmers and enjoy. I rolled the incompatible ones just to see if this amp would run them and I was very impressed with the results.

At one point I had a Reflektor 6H9C octal socket tube running just for a “lets see if…” scenario, it worked with modifications and is not really a tube you would use.

The MKTP1 is not a rolling friendly amplifier compared to others that are on the market.  The board has to be removed from the case and you have to have a voltmeter to measure the bias voltages with the new tube installed and the MKTP1 powered up without the case.

*Note When working with regular tube amplifiers there are always LETHAL VOLTAGES present that will kill you instantly. The MKTP1 has none of these voltages so you can change tubes and run the amplifier safely without the case installed.

To change the tube or the opamp you first need to remove the acrylic tube protector from the top of the case. It is a little hex head screw but the 6mm Torx screwdriver will fit perfectly.
Then you can pull the stock tube straight up and out.
Tube Socket
After the tubes are removed:

  • Remove the volume knob and unscrew the nut & washer from the volume control shaft.
  • Remove the 4 corner screws from the back plate and slide the board out of the case.

*Note The 7806 voltage regulator on the bottom side uses the case as a heat sink so the case can get rather warm after a long period of use. When changing a tube you won’t have the board out of the case long enough to cause the regulator any trouble with no heat sink.

Get a jewelers flat blade screwdriver and your voltmeter handy, set the voltmeter to DC Volts if it is not an auto range model the scale should be 20V, now look at the following board layout.
Board_TopDepending on which tube you are installing, you might have to move the jumper at the top of the picture. If you are installing another 6DJ8 tube it should already be set on the 6DJ8 side. If you are installing a 12AU7 tube then you need to move the jumper to the other pair of pins. The following voltage measurements are the same for both tube types.

Install your new tube and power up the amplifier.  Your headphones do not need to be plugged in to adjust the bias.

Push the Negative or Black probe into the board via marked with a Ground Symbol in the picture.

Push the Positive or Red probe into the top or bottom via surrounded by the white silkscreen box next to the tube socket, one via is marked with a 1 the other with a 6.

Measure the DC voltage on each hole and adjust the A trimmer pot for via 1 and the B trimmer pot for via 6. The voltage reading should be the same value for both sides and be between 6 and 8 volts according to the online manual for the MKTP1.

Opamp rolling is the same as it was in my previous review of the MRA DIY amplifier except in the MKTP1 there is only one opamp.

*Note The NE5532 that comes stock with the MKTP1 is an industry tried and true opamp that is used in many high end audio products, so changing it out would just be a mater of personal preference rather than performance.

After everything is changed and the measurements are done you can test it to see if there are any problems by plugging in a set of headphones and your source–if it sounds okay then put it all back together in the case and enjoy.

Tested Tubes


Electro Harmonix 6922EH

This is the stock tube that ships with the MKTP1, still made to this day in Russia at the ExpoPul Factory (Reflektor) at Saratov, Russia. You can see by the date code on the above tube it was manufactured approximately 1 year ago (April 2013) and is a new tube not NOS. The ExpoPul factory makes two-thirds of the world’s vacuum tubes used for music, Tung-Sol’s, Sovtek’s, Svetlana’s and Genalex Gold Lion’s all these tubes are manufactured at Saratov under the management of the New Sensor Corporation.

The sound of the 6922EH tube is very clean.  It is a good all round “neutral” tube that is very popular and used by many manufactures of high end audio gear. These could very well be some of the reasons miuaudio chose the Electro Harmonix 6922EH as the stock tube for the MKTP1. It is inexpensive, has a great neutral sound, readily available and very popular.

Mullard ECC88 (6DJ8)

This tube was, I believe, manufactured in Britain in 1964. The code on the bottom of the tube is “B4L1″ someone can correct me if I am wrong. The ECC88 went in nicely and a little bias adjustment later I was listening to the Mullards’s detailed, warm and musical sound. This is a good tube to use if you can get one for a reasonable cost.

Voskhod 6Н23П (6N23P)

This tube was made at the Voskhod – Tube Plant in Kaluga Russia around April of 1978. This is one of my favorite Russian versions of the ECC88/6DJ8 type tube. It has the most bass compared to the other two tubes and can be a little too dark for some listeners or setups.

*Note many tubes were tested in the MKTP1, I don’t have any compatible 12AU7’s but I did have a pair of Sylvania 5751’s (12AX7) that I tried and did get to work after a few modifications.


Test Setup

The MKTP1 inital setup was with my FiiO X3 and beyerdynamic DT880 Pro’s. The MKTP1 can drive the DT880 with authority and the volume control at 10 o’clock provides a very respectable listening level.


DT880_MKTP1 DT880_Glow

The album I use for a lot of my testing is Jethro Tull’s “The Best of Acoustic”, 24 tracks of Tull’s best acoustic songs. This is an excellent album for the DT880’s as they faithfully reproduce the instruments in realistic detail with a nice soundstage. The acoustic guitar work and Ian Anderson’s flute on the track “Salamander” will give you chills.

Jethro Tull
The MKTP1 has a neutral sound, not overly warm or bright. The stock 6922EH is a tube used in many high end preamps so it doesn’t colour the sound in any way. It provides an excellent level of richness and detail to the MKTP1 that one would expect in higher end systems. I like my headphones neutral as well as my amplifiers unless I want that bass thump of EDM and then I have Ultrasones for that purpose.

My DT 880’s are always plugged into my Little Dot MK IV, which is an amplifier that punches well above it’s price point with some cheap replacement tubes. If I didn’t have a regular OTL tube amplifier for the beryer’s then I would be very satisfied with the MKTP1 as my main desktop amplifier. I have used this amplifier steady for the past 3 weeks I have done a minor modification to support one of my favourite tubes from the 60’s, the Westinghouse 6BQ7A which I find very euphonic in it’s presentation, smooth and musical.




The miuaudio MKTP1 is a very proficient tube hybrid amplifier that competes well with more expensive tube amplifiers, it will drive 250 Ohm headphones with authority as well as lower impedance headphones. (Sounds great with the Koss Porta Pro’s as well.)

If you are looking for a hybrid desktop amplifier with a small footprint, great sound and is versatile with Line In & Out, then look no further, the miuaudio MKTP1 for $107 USD from the Miu-Tech store will meet your needs.

I would like to thank Ivan Lai for the review sample and to thank you for taking the time to read this review.
Constructive criticism is always welcome.


Categories: Review | Tags: , ,

A Portable DIY Amplifier

miuaudio MRA DIY Amplifier

Review and Build Log by TrollDragon

miuaudio logo
Head-Fi-LogoBack in February I contacted Ivan Lai of Miu-Tech in Hong Kong to review a few of their products. I was generously sent a pair of amplifiers for review, a nice little Do It Yourself portable and a Vacuum Tube Hybrid desktop. This review is for the MRA DIY amplifier kit, it is an M47 style amplifier with the second opamp on each channel configured as a voltage follower providing more current for a low impedance output.

Upon opening the box you are presented with a schematic of the amplifier, a static bag full of components, the case parts and a silicon band to attach the amplifier to you source.

Box Box_Open

The amplifier comes with absolutely no instructions other than the schematic, the parts are well labelled and separated into small zip lock type bags. This is very helpful as it allows you to easily sort and retrieve the required components quickly throughout the build process.

The printed circuit board is a quality made board with excellent traces and a great silk screening providing component layout and polarity. This is the board with the gain switch and all the resistors soldered in place.
Board*Note R1 & R2 were removed from the board after the picture was taken.

I recommend putting all the resistors on the board first, they are a small component that requires one leg bent over 180° to accommodate vertical mounting. The resistors are the most time consuming part of the build and install much easier when there is nothing else on the board. The board was very easy to populate and solder, those with previous kit building experience could quickly put this amplifier together in a half an hour. Those without kit experience or basic electronics knowledge need to be aware of the correct orientation of the electrolytic capacitors, opamps, rail splitter and LED.

There are a few issues that should be addressed before the board is fully populated.

  • The Rail Splitter circuit.

    The opamps in this audio amplifier require a positive and negative voltage to operate. This can be achieved with the included TLE2426 Rail Splitter or the pair of 4.7K resistor’s as voltage dividers.
    TLE2426The schematic of amplifier shows both options in effect at the same time which is strange, in every schematic I have seen of a TLE2426 virtual ground, the resistors R1 & R2 are not installed. So I did not bother installing them on the board. If anyone knows a reason why the resistors should be there then please let me know.

  • The Potentiometer.

    There is a little tang on the bottom of the potentiometer to stop rotation when it is chassis mounted. If this tang is left intact, the front cover will not install flush with the case.
    PotentiometerGrab this tang straight on with a pair of pliers and just bend down and away from the shaft; it will snap off cleanly.

  • The Case LED

    When you mount the case LED on the bottom of the board, bend the pins of the LED through the mounting holes so that it sits flush on the edge of the board with no overhang. If it sticks out past the board the front panel will not mount flush with the case properly. Also install the LED before you install the input jack, trim the legs that come up through the board as flush as you can. The edge of the input jack mounts directly overtop of one of the leads and if you leave that lead long the input jack will not mount flush or line up with the hole in the front panel mount.


After the board is fully assembled it is time to test the amplifier for functionality before you put it into the case. It’s easier to repair any mistakes if something is wrong.
AssembledThe easiest way to mount the board in the case is to push the front panel onto the volume control and audio jacks, then slide the board into the case making sure it lines up with the little channel on the sides of the case. If you try to install the board after the front panel is screwed on, it is just about impossible to get the two audio sockets lined up and pushed through the holes.

Case Finished


Operation & Results.

I removed the two thumb screws on the back of the case to install a brand new Energizer 9V battery. Turning the unit on, I measured an average 12mA of drain on low gain with a normal listening level of about half way on the volume control, this should give you a good bit of life out of a standard 9V battery. The audio sockets click nicely and hold tightly onto any TRS jack you plug into them. It is good to see quality audio sockets included with the kit, the sockets on my FiiO E11 are starting to get quite sloppy from use. The volume control is very smooth and free from any wiper static, the on off switch attached has a positive click and a solid feel to it.

Using the Ultrasone HFI-780’s with low gain on the MRA and the Colorfly C3 as a source.

Sound & Impressions

Headphones tested:

  • German Maestro GMP 8.300 D Professional (300Ω)
  • beyerdynamic DT880 Pro (250Ω)
  • Ultrasone HFI-780 (35Ω)
  • JVC HA-S500z (32Ω)

Sources used:

  • Colorfly C3 (Headphone Out)
  • FiiO X3 (Line Out)

The MRA DIY amplifier has a very nice clean sound and black background with the KIA 4559P Bipolar Dual opamps supplied in the kit. You can change out the stock opamps with many other popular opamps. The LME49860, LME49880, LME49720, LM4562, OPA2107 and the ever so popular AD8620 were all tried in place of the stock 4559P’s with very similar results. The AD8620 was the only one provided a nice crisp sound to the amplifier over the stock opamps, the others all sounded very similar to the 4559P’s except for the LME49880 which distorted because of too low of a supply voltage.

Opamps Board_Opamps

RollingSome of the above opamps are not utilized or run within proper design specifications for this amplifier and were tried on a whim. The stock opamps were put back at the end of the test as they do sound very good.

Comparison to the FiiO E11 amplifier gave very good results. I connected the FiiO X3’s Line Out to both the E11 and MRA inputs with a DIY splitter, hooked up a headphone switch to both outputs and played quite a few test tracks. Using the headphone switch I could easily and quickly jump between both amplifiers for a sound comparison. Matching the volume as best as you are able to by ear with the DT880’s, I found it very surprising that both amplifiers actually sound identical at a moderate listening level. Once the MRA got up to about 80% of maximum volume I started to notice distortion that was not there in the E11, I figure that the MRA could not provide enough voltage swing for the DT880’s and both amplifiers were on high gain. I didn’t try any other opamps in this configuration as the DT880’s were tried just to see if they would work and they did. This was not an optimal setup as the DT880’s are not a portable headphone and really shine when driven from an OTL tube amplifier.

A different story for the HFI-780’s though, switching the amplifiers back to low gain I tested out some EDM tracks, again the amplifiers sounded identical and this time I could not get the MRA to distort without going deaf first. Now if the MRA just had a bass boost is would have been nice to compare that with the E11’s as well.

My time using the MRA DIY amplifier out and about were with the GMP 8.300 D’s and the low output Colorfly C3, even though the GMP’s are 300Ω, they are very easy to drive and the amplifier didn’t struggle with them at all or distort. I find the 8.300 D’s to be a nice, neutral, closed headphone very similar to the sound of the DT880’s.


Conclusion and Recommendation

This is a DIY amplifier kit for someone who wants an easy project that has excellent results in the end. Pair it with a $10 soldering iron and it makes a perfect gift for that budding Audiophile who has an interest in electronics and audio, the enjoyment they will receive from using an amplifier that they built themselves is a great thing.

I highly recommend this amplifier to anyone who wants a kit that looks nice, has a great sound and is very easy to build. I really enjoyed working with and building this amplifier. The miuaudio MRA DIY kit is available for a very reasonable $42USD from the Miu-Tech Store.

I would like to thank Ivan Lai for the review sample and to thank you for taking the time to read this review.
Constructive criticism is always welcome.


Categories: Review | Tags: , ,

Top of the Line Impressions

Burson Conductor SL / Audeze LCD-3

Impressions by TrollDragon



When Burson Audio of Melbourne Australia posted on their Facebook page for Head-Fi’ers to apply for the Conductor SL & Audeze LCD-3 loaner program, I gladly jumped at the chance to try these two top tier products. Well I was selected for this round and have spent a glorious 3 weeks with the Conductor SL and LCD-3’s reliving all my music through this amazingly well paired combo.

The Conductor SL arrived equipped with Burson’s Cmedia CM6631A USB module installed. Two DAC boards were supplied as well for comparison,  the TI  PCM1793 and the ESS Sabre32 9018.


The boards were extremely easy to change after the cover was removed. Locate and remove the 4 screws holding the DAC board in place, lift straight up and away. Line up the pins on the new DAC board with the sockets on the main board and push down till it seats. Check that the pins are inserted properly, reinstall the 4 screws and close up the unit.

I enjoyed the sound of the ESS DAC quite a bit better than the TI. The ESS was very clean, crisp and detail oriented to my ears which gave it an nice overall neutrality. The TI DAC on the other hand has a much warmer sound and I only listened to it for a day in the unit. The sound was close to that of my FiiO E17 with none of the ESS’s neutrality and since I was already familiar with that similar sound, I wanted more time with the ESS.

The design of the Conductor SL is quite unique, all the parts are modular. If you wanted to change out the Alps volume  potentiometer with a stepped attenuator it should probably be easy to do since everything plugs onto the main board. You will notice from the pictures that it’s all discrete FET’s (Field Effect Transistors) which Burson says gives the amplifier a transparency that cannot be achieved with opamps.

Dual power output controlled by the front panel gives 0.18W per channel in Low and 2W per channel in High, which in turn will allow you to drive anything from 5Ω IEM’s to 600Ω beyerdynamic’s. Power to spare while driving the 45Ω LCD-3 and my 250Ω beyerdynamic DT880 with the volume control at 10 & 12 o’clock respectively.

Three types of input, USB, Toslink and RCA allows you to connect the Conductor SL to just about anything. The only thing I would like to have seen included with this unit is a line stage, but I understand that is available on the higher model. A Line Out option into the Little Dot MK IV would have been a good test of the two DAC boards through some nice Soviet 6Ж5П driver tubes.

Over all the Conductor SL with the ESS9018 DAC is a very clean crisp detailed amplifier providing more than adequate power for the two headphones I have tried with the unit. At a friends house we also tested a pair of Denon HP700’s but quickly put them away and didn’t speak again of that…


The Audeze LCD-3’s arrived in their rugged IP67 rated  SKB travel case with a custom molded foam insert that keeps the headphones nicely protected. I have one problem with most all cases that the manufacturers provide for headphone storage. Why do they build them in such a way that you have to fully retract the yokes in order to put them back in the case? I do not want to adjust my headphones every time I take them out or put them back in the case. Craft the foam insert so the cup area is the same as the current insert, but allow a wide cut out for the headband to fit regardless of yoke position.

Upon lifting these from the case I was immediately blown away by the weight of them, after you’ve handled the LCD-3’s for a while the DT880’s feel like a set of Porta Pro’s. The LCD-3’s are not something you would want to swing your head around while wearing as they would fly off your head and seriously hurt someone near you. :)

Luxurious leather pads and headband give the LCD-3’s a very comfortable fit considering the weight of them.
I found the DT880’s to be one of the most comfortable headphones I have tried but these are just that much more so. Some listeners have felt the weight of them was hard on the neck but I didn’t find this to be an issue at all and I have some long sessions with these.

I am not going to attempt to try to describe the LCD-3’s sound in detail, since there are many reviews on Head-Fi from those who are quit a bit more fluent in sound speak than I could attempt. I have only compared these to the DT880’s and to my ears there is a night and day difference between the two headphones. The DT880 is a great neutral headphone who’s sound I enjoy across a wide spectrum of genre’s. Listening to the same music through the LCD-3’s was amazing in my opinion, every quality the DT880’s have, the LCD-3’s has in spades above them. I find the DT880’s a little lacking in the bass department, the bass is there but for any type of electronic music I’d rather listen to my Ultrasone’s. Then you listen to the same electronic music through the LCD-3’s and bass is there very strong and deep. Acoustic, Metal, Progressive Rock, World Music and so on, there wasn’t a genre that I could throw at the LCD-3’s that wasn’t reproduced in a very enjoyable way. The LCD-3’s are quite a bit more open than the DT880’s, and I don’t have a “Perfect” listening environment so when you crank up the power, there is no peace and quiet for anyone around you or even in the next room. The recommended from Audeze is 1-4W of power to properly drive them and they will take a momentary burst of 15W if only for a few milliseconds, which is incredible considering the DT880’s maximum power rating is a very tiny 100mW.


The LCD-3’s were auditioned with the Little Dot MK IV. A pair of Soviet 6Ж5П’s or the Hytron 6CS6 tube’s pictured below, brought a very warm and liquid smooth sound that solid state amplifiers do not provide.
Here are a few pictures of the Burson Conductor SL9018 and Audeze LCD-3, all copper stands pictured are my own DIY creations.
I would like to take this opportunity to thank Burson Audio of Melbourne Australia for the opportunity of experiencing the Burson Conductor SL9018 and Audeze LCD-3. It was a glorious 3 weeks that went by way too fast, now I want to hear the T1’s, HD800’s, LCD-2’s, LCD-XC’s and as many as I can. ;)


Categories: Impression | Tags: , , , , , ,

DUNU Landmine DN-23 Review

DUNU Landmine DN-23

Review by TrollDragon


This is my third review for the Chinese IEM manufacturer DUNU, in this review I will be looking at the Landmine DN-23 in-ear monitor.


DUNU provides aesthetically pleasing packaging which is consistent across their complete product line. The packaging consists of an outer sleeve that has a picture of the Landmine DN-23’s on a totally black background.

When the sleeve is removed, the box underneath, complete with side flap and magnetic catch, opens to reveal the DN-23’s in a very pleasing manner with the hard storage box below.

The Box Contents:

  • The Landmine DN-23 IEM’s
  • Rigid EVA protective case with a DUNU logo zipper pull.
  • Soft leather-like draw string pouch
  • Cable Clip
  • Airline Adapter (Does anyone even use these?)
  • 3.5mm to 6.5mm Adapter
  • Sony Hybrid’s in S/M/L
  • Large Bore’s in S/M/L
  • Double Flange in M
  • Warranty / Maintenance Card

(I would still like to see some foam tips in a S/M/L included with newer product.)

The DUNU Landmine DN-23

The Specifications of the DUNU Landmine DN-23

  • Driver HQ(10mm)
  • SPL 120 +-2dB
  • Impedance 16 Ohm
  • Frequency Response 16Hz~22KHz
  • Noise Attenuation 26dB
  • Weight 28g
  • Cord Length 1.2m
  • Plug Type 3.5mm (45° Angle)
  • MSRP $85

Like the Detonator DN-22M which I have previously reviewed, the DN-23’s are manufactured very well, the body is all metal, hence the 28g weight. The chrome finish on these is extremely well done; DUNU logoed aluminum end caps provide a nice touch. A red and green band around the body of each earphone denotes the R and L designations.


A non detachable cord terminated with a 45° angled 3.5mm TRS jack has a rubbery coating and very little memory, it is a nice rubber coating that does not stick to everything like silicone does.

The Y Splitter and slider have a nice aluminum look to them and the slider moves very smoothly on the cable.

Standard DUNU cable management is included on the cable and is a handy feature for keeping the cable in check. As you wrap the cable around your fingers the cable strap holds everything together with no tangle when you want to use the DN-23’s again.

I have found the cable to be quite microphonic.


I tested these with the Colorfly C3 and an iPod Nano 3rd Generation, the two players had absolutely no problems driving the DN-23’s to well above a tolerable listening level.

c3 Nano

I even plugged the DN-23’s into the FiiO E11 that is always strapped onto the C3 and there was a very prominent hiss to them. I was just testing out the Bass Boost on the E11 with these, a resistance adapter will solve the hiss problem on the E11 but you really don’t need an amplifier with these.

The Sound:
To quote Wreckx-N-Effect
“All I wanna do is zoom-a-zoom-zoom-zoom and a boom-boom”
The bass on these just deliciously sweet, I just kept digging out Bass-centric music to throw at them and they performed flawlessly.

I tested these with the following albums:

Grand Master Flash and The Furious Five: Greatest Message’s
LFO: Frequencies
Bob Marley and the Wailers: Personal Compilation
A State of Trance 500: CD2 Mixed by Paul Okenfold
Infected Mushroom: Army of Mushrooms and Friends on Mushrooms Volume 1
Juno Reactor: Shango and Gods & Monsters
Daft Punk: Random Access Memories
Metallica: Self Titled (The Black Album)
Rammstein: Made In Germany
Led Zeppelin: Mothership
Rush: Gold
Plus many more throughout the test period.

To my absolute enjoyment, I have found the DN-23’s to have the familiar V shape of the Ultrasone HFI-780’s that are my current goto headphones for EDM and other bass-centric music.

The bass on the DN-23’s is a warm and sturdy bass, not the loud overpowering tubby bass of a few other inexpensive IEMs I have tried. The DN-23 could use a little more quantity of bass, but these are not sold with an “Extreme Bass” sticker anywhere to be found on the box. It does have a definite presence that makes one want to dance and bop around… the Daft Punk RAM album will have you up and moving in no time while wearing these. These have sweet non sibilant highs that are a pleasure to listen to, the Rush and Rammstein albums that I listened to played very nicely with the DN-23as well as the EDM.

Final Thoughts:

The DN-23 is another exceptional product from DUNU-TOPSOUND that I will enjoy as my “on the go” IEM, I’m going to refer to these as my mini “Sones” which I do enjoy and they get quite a bit of head time these days. In my opinion there are not many items worth the MSRP, but the $85 asking price is very reasonable and I will recommend them to friends who are looking for a great little IEM.

The metal construction on these is heavy which might be a deal breaker for some, personally I find it gives them a sense of quality as soon as you lift them from the box and this is something that you don’t find in many products these days.


  • Solid value for the $85 MSRP.
  • Generous accessories.
  • Outstanding DUNU build quality.
  • Nice cable with minimal memory effects.


  • Metal construction might be too heavy for some.
  • Cable is quite microphonic, it can be minimized by wearing over ear and with the clip.
  • No foam tips included.

Like a good cigar, the DN-23’s are one of life’s little pleasures to be thoroughly enjoyed.

I would like to take this opportunity to thank Rocky and DUNU for the sample I received for review.

Thanks for reading.

Categories: Review | Tags: , ,

DUNU Detonator DN-22M Review

DUNU Detonator DN-22M

Review by TrollDragon

 Head-Fi-Logo DUNU-Logo  Icrontic-Logo

 In this review I will be looking at the Detonator DN-22M from DUNU.

If parts of this review are very similar to my review of the Tai Chi DN-19, that is because DUNU keeps a nice consistency with product packaging and accessories. I would like to present to you their first model with a microphone specifically designed for smartphones.

The Detonator DN-22M and the protective case just below them.


The attention to detail that DUNU puts into their product presentation is impressive, just like the Flagship Tai Chi model these Detonator’s have the exact same packaging, consisting of an outer sleeve, with an inner box that has a side flap magnetic catch.

The Box Contents

  • The Detonator DN-22M Earphones
  • a rigid protective single zipper case
  • the familiar soft leather-like draw string pouch
  • the alligator like Cable Clip
  • a generous quantity of tips are included
  • 3 pairs of Sony Hybrid in S/M/L
  • 3 pairs of Large Bore in S/M/L
  • 1 pair each of Double Flange and Triple Flange M

(I would like to see DUNU provide some “Comply” style tips in the future, one pair of S/M/L would be a nice addition.)

The soft leather-like draw string pouch  has the company logo stamped into the material with a name tag sewn into the side seam. The drawstring is knotted and the ends are melted to prevent fraying. The rigid protective case is nicely styled EVA case with the DUNU logo on top. It is only single zippered so you will have to zipper all the way around to open and close the case.

The zipper has a unique pull tab in the shape of the DUNU logo’s stylized “D”

Logo on Zipper

The DUNU Detonator DN-22M

The Specifications of the DUNU Detonator DN-22M

  • Driver: HQ(9mm)
  • Microphone: -45 +5dB
  • SPL: 112 +-2dB
  • Impedance: 16 Ohm
  • Frequency Response: 20Hz~20KHz
  • Noise Attenuation: 26dB
  • Weight: 27g
  • Cord Length: 1.2m
  • Plug Type: 3.5mm (45° Angle)
  • MSRP $49.99

Like all other DUNU earphones the Detonator DN-22M are manufactured very well, the body is all metal hence the 27g weight. The finish is a nice gunmetalic chrome with logoed aluminum end caps. A red and green band around the body of each earphone denotes the R and L designations. Unlike the DN-19 these have no Braille marking for R & L that I could find.

A 90cm non detachable cord terminated with a 45° angled 3.5mm TRRS jack has a rubbery coating and very little memory. The standard DUNU cable management strap is included on the cable and is very handy. The Y Splitter has a puffy DUNU logo and a slider. The 35cm cable from the splitter to each earphone is one half the thickness of the main cable, the left cable has a microphone/single button module 15cm from the earphone. When you wear the DN-22M with the cable down, the microphone sits a bit below the jaw line and the cable itself is quite microphonic. If you wear the cable over ear, the microphone sits just below your ear at the end of the jaw and the cable noise is reduced quite a bit.

Driveability and the Microphone:

I tested these earphones on my Colorfly C3 and HTC Desire HD, both these devices powered the DN-22M very well considering the Desire HD has a very poor level of audio output.


The microphone/single switch module worked very well with the HTC, it allowed you to answer/hangup phone calls and pause/play audio. The audio quality of the microphone and sensitivity surpassed that of the HTC’s internal microphone.

Just as a test I plugged the DN-22M into my FiiO E17 / E09K combo, with the volume control at 9 o’clock there was good volume for listening.

Earphone Fit:

These earphones fit very well in my ears with the large Sony Hybrid tips, the earphones are round and straight so there are no issues with depth like I had on the DN-19’s. Considering the weight of the DN-22M, they are really quite comfortable to wear for extended periods.

The Sound:

Since I managed to get a proper fit easily on the DN-22M I had a chance to listen to quite a variety of music with them.

The first album I listened to was Chesky Records
I-Ching “Of The Marsh And The Moon”

The second album I listened to was Juno Reactor
From the Land of the Rising Sun Inside the Reactor II

The third and final album was another Chesky Records
David Hazeltine – Manhattan

The sound of these earphones is quite good for the price point of $49.99


The Bass on these headphones has an abundant lower register so I found them quite enjoyable. The stand up bass in the tracks of the Manhattan album sounds good and well defined not over powering any of the other instruments. The Juno Reactor album has quite a bit of Bass on it and can be a little too much for some, the music is electronic and therefore quite different than the standard instruments of the Manhattan Jazz album. These earphones do not have the most bass I have heard, but they put out a satisfying amount.


The Mids are good, the piano on Manhattan is right there in front of you, very clean and well defined. It is very enjoyable to listen to. The “Restaurant” sounds from the I–Ching album are very well reproduced, the people there are talking and clinking tea cups right around you. The yanggin and erhu are faithfully reproduced from this incredible album. I you have not heard the album then please pick up a copy, it is an amazing journey for the ears. On the DN-22M it sounded as good as on full sized headphones, just with a much smaller soundstage.


I am not a fan of sharp or piercing highs, the highs on the DN22-M’s can get a little piercing with certain songs and instruments, cymbals can get a little loud and sharp on certain tracks. I had some Infected Mushroom queued up to listen to as well, unfortunately some of their tracks can get a little harsh and piercing with synthesized very high pitched voices under full distortion. These tracks were definitely not fun to listen to on the DN-22M without some equalization.

Final Thoughts:

The DN-22M is another quality product from DUNU-TOPSOUND that is every bit worth the $49 asking price in my opinion. Be aware though that they are all metal and a little heavy, but for those of us with large deep ears they fit well and are very easy to get a good seal with. Excellent isolation and a good quality microphone, so if you have a smartphone and are looking for a quality pair of IEM’s, give the DUNU Detonator DN-22M a try and see if you don’t agree.


  • great value for the price point of $49.99
  • abundant accessories
  • quality DUNU build
  • microphone works with most smartphones (HTC & iPhone)


  • weight might be too much for some
  • microphone in a bad place for over ear use

I would like to take this opportunity to thank Rocky and DUNU for the sample I received for review.

And I would like to thank anyone who actually read to the end of this review.
Also, I am not a photographer.

Constructive criticism is always welcome.

Categories: Review | Tags: , ,

DUNU Tai Chi DN-19 Review

DUNU Tai Chi DN-19

Review by TrollDragon


In this review I will be looking at the Tai Chi DN-19 from DUNU.

DUNU is a Chinese manufacturer of earphones with headquarters in Taiwan. They have been in the OEM manufacturing business for years and have just recently started making their own brand of earphones.

I would like to present to you their Flagship model the DUNU Tai Chi DN-19.



Opening the box on these earphones, I was immediately impressed with the attention to detail that DUNU puts into presenting their product. Once you remove the outer sleeve of the box, you find an inner box with a magnetic catch on the side. Under the cover flap the earphones are presented in a very aesthetically pleasing way. The earphones are in the velvet moulded carrier, with the hard case just below them.


Upon removing the carrier from the box, there is a very generous collection of accessories included for these earphones.

  • The beautiful DN-19 Earphones.
  • A velvet lined and crushproof metal hard case.
  • Soft leather like draw string pouch.
  • 3.5mm to 6.3mm  adapter
  • Airline adapter.
  • Flip top accessory kit.


The attention to detail that DUNU puts into the accessories is impressive. The metal hard case is divided by a rubber insert and is lined with velvet. The DUNU logo is stamped into the cover, with the companies web address on the bottom.


The soft leather-like draw string pouch  has the company logo stamped into the material with a name tag sewn into the side seam. The drawstring is knotted and the ends are melted to prevent fraying.


The flip top plastic accessory case is stamped as well with the company logo. Upon opening the case, you are presented with a multitude of goodies in a velvet lined box.

  • 3 pairs of Grey silicone tips in Small / Medium / Large
  • 3 pairs of Black silicone tips also in Small / Medium / Large
  • Another set of Medium tips come preinstalled on the earphones.
  • 20 “Port” plugs for sound tuning
  • Spare pair of ear hooks, one pair comes preinstalled on the earphones.
  • Retaining clip for the wire
  • Soft, cleaning cloth with the companies logo and web address stencilled on.

Moving on to the main attraction The DN-19’s themselves.


The Specifications of the DUNU Tai Chi DN-19

  • Driver: HQ(10mm)
  • SPL: 100 +-2dB
  • Impedance: 16 Ohm
  • Frequency Response: 16Hz~26KHz
  • Noise Attenuation: 26dB
  • Weight: 18g
  • Cord Length: 1.3m
  • Plug Type: 3.5mm (Right Angle)
  • Around $130


These earphones are beautiful. The shape is very pleasing to the eye with a faint Yin-Yang symbol on the back of each one. The bodies are moulded in a glossy brown plastic with a metallic speckle finish. The cord is not detachable from the body but has a nice strain relief where it enters the body. On each associated strain relief is a very small R & L to mark the Right and Left earphone. The Left strain relief has in Braille three vertical dots, which is the symbol for L. Mind you, the dots are very small and I don’t really know it they could be read by someone who reads Braille.


The cable is of a very nice quality and has a good length to it. It’s 35cm from the start of the ear hooks to the Y splitter, continuing 80cm from the Y splitter through a very useful attached rubber cable tie strap to the right angled gold plated 3.5mm plug. The Y splitter has a slider to take up the slack if you so wish — it kind of reminds me of the kids cowboy hat chin strap slider from years ago.

The information from DUNU states that the cable has “Patented silver wires transmission time fixing technology provides balanced extension and excellent recognition.”

I am not sure what that means exactly, but it appears that DUNU uses silver wire on these earphones. The wire with coating is 2mm in diameter and twisted from the plug to the Y splitter then it is separated out into a 1.5mm twisted pair to each earphone.

The coating on this wire is transparent and has a rubbery type feel to it but not so rubbery as to catch on your clothing. I am sorry to discover that it does suffer from a bit of a memory problem, which might disappear with use, but somehow I don’t think it will.

The right angled plug fits very well into whatever you are plugging it into. With a length of  2.5cm from the end of the tip to the start of the 90 degree strain relief, I don’t think you would ever encounter any device with or without a case that would not accommodate this plug. It clicks into place nicely. Some 3.5mm plugs just don’t feel right when you plug them in, they are sloppy and loose. DUNU has the specifications right with this plug though it clicks into place very nicely.

The Sound Tuning Feature.

The DN-19 is a “Tuneable” earphone, it has a sound port on the side of the body that can be blocked or left open to tune the “Sound” of the earphone to your liking. There are matching silicone tips that go with each tuning mode.


The black tips with the sound port open provide the greatest amount of bass on these earphones and the grey tips with the sound port plugged decrease the low end bass quantity.



I tested these earphones on my Rockboxed Sansa Clip+, iPod Nano 2nd Generation, iPod Nano 3rd Generation, HTC Desire HD and finally the headphone output of my Corsair SP2500 Control Pod.

All of these devices powered the DN-19 with relative ease. The headphone output volume was set at a moderate level, all except for the HTC Desire HD which has the most useless headphone output amplifier of the lot and had to be turned up quite a ways. I don’t listen to music through this phone so it was not a problem for me.

Earphone Fit.

Here is the greatest problem for me with these earphones:  no matter which configuration I try, which size tips, I cannot get a good fit. If the sound nozzle was 2 to 4mm longer I think these would be amazing earphone for my ears.

I have a deep set ear canal and cannot get these earphones installed without the body of them coming to rest against my cavum concha which in turn causes the sound port to irritate my tragus.

I’ve tried earclips on and off, all the tips supplied and even different tips from another earphone to no avail.

I contacted Comply to see if they had a T / Ts series that would fit the DN-19. Since they only provide recommendations for tips that they certify on earphones, I was told that due to safety / insurance reasons they could not recommend a Comply tip for the DN-19 since they don’t own one to certify the tips on.

I took a pair of hearing protectors, shortened them up and used a leather hole punch to make a tunnel, I attached them to the sound nozzle, rolled them up and put the DN-19’s in my ears. It was by no means perfect but provided me a bit better sound than with the supplied tips. After the Holidays I will look into get a set of Comply tips and experiment a bit.

The Sound.

Since I cannot get a good fit with the DN-19’s this section will be very sparse. Using the large black tips I am able to get a bass less sound from these earphones. (Tried all the tips and these provide the best sound to me at this point)

If I press on the backs of the DN-19’s while they are in my ears I can get bass to appear in the audio. *NOTE* This is by no means an accurate representation of these earphones and do not do them the justice they deserve. I will update this section when I get some foam tips and possibly a better seal.

Since I am new to earphones, I do not like earbuds  as they will not stay in, and the only other pair of earphones I had was a set of Maxell Peanutz which went immediately into the trash after my limited attempt at hearing the DN-19’s. (I even tried the tips off of the Peanutz, both the double and triple flange.)

I put the medium black tips on the DN-19’s and gave them to the wife to try out… Well they are gone now, she has claimed them. She listens to a 2nd Generation iPod Nano with some low bitrate music on it. I took her Nano and loaded it up with ALAC versions of her favourite music and had her listen to the DN-19’s with that.

Her Sarah McLachlan, k.d. lang, Little Big Town and 70’s Classic Rock favourites almost sounded like totally different music through the DN-19’s. She used to try and listen to her music through a pair of Sony MDR-V150’s.

It is really a great thing when your can help take someone’s music listening to the next level!

Final Thoughts


The limited sound I had the chance to experience with these was very good when I managed to get a reasonable fit.

The build looks and feels very durable.

The accessory kit and hard case.


The only con I found with these earphones is the fit for me, personally, I believe if the sound nozzle was 2 to 4mm longer they would solve that problem.

I would like to take this opportunity to thank Rocky and DUNU for the sample I received for review.

And I would like to thank anyone who actually read to the end of this review, this is my first review and first experience with a high quality earphone product.

Also, I am not a photographer.

Constructive criticism is always welcome.


Categories: Review | Tags: , ,

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