I m lucky enuf to have 2 unit of D2 with me, here's the impression on both.
D2 viper is fully run in and D2 Boa runned around 20 hours, Thus the sound can be alot more better after fully run in
just to give the technical differences, D2 viper is charged through Ac but D2 Boa is charged through USB, thus D2 Boa is double efficiency on power saving

Ruthie Henshall - Songbird (795k)
D2 boa have clearly better separation on the special 2 layer vocal of the songs. but due to short period of burn in, the vocal still abit rough, i m sure that it will goes well after run in, but i found that it give more power to the piano. it is more lively. As for D2 viper, it have smoothen sound, but less response on low frequency, when the songs going to end, the separation on viper seens to be abit mixed. i m very impressed by D2 Boa on this songs as it have less electric input, but even strong on low frequency response, with better separation on this songs.

Elissa Lee Koljonen - O mio Babbino caro
D2 viper having warmer singatuer, D2 Boa has brighter signature at this moment, it might due to run in hours as it is only 20 hours now. In this songs, D2 viper having smoothen sound, which give better feels as for the warm enjoyment feelings, D2 Boa give better thickness on instrument, but abit harsh due to its bright, with the enhanced separations, it give you lively and involved feels and thus less on Relax sound. I prefer the Viper here, as for warmer sounds

Diana Krall - I've Changed my address
In my opinion. this song is extremely hard to tune, D2 Boa more aggressive signature which compare to Viper Layback. both 2 are not to the extreme, but just no minor position differences, it is not like Grado vs Sennheiser There is some instrument solo at the middle on the songs, D2 Boa clearly wins on the this parts as for its aggressive, separated sound, the instrument sound more accurate, however, viper giving more transparent feels, as for more relax feels as for the layback signatures, but slightly slow in the response make it sound abit lag. I can concluded that, it have different feels on both, there is not clear winner on this songs

Jim Keltner & Ron tutt - Drum Improvisation
D2 Boa is a clear winner here, it have better speed, and deeper in drum impacts, D2 viper sounded like a sleeping drum, which give me unexcited feels on the drum, unlike D2 Boa, with the better separations, u can clearly feels the differences on the strength that the drummer had, The speed is more accurate without any delayed, and you can feels the shape of the drum.

Karen Kong - Li Dao
D2 Boa have thicker vocal, but D2 viper had better vocal response, i assume D2 boa will have the same response after burn in, with more pounchy sound. D2 Viper give better control on high but less extension. I will not concluded which is bettter here, as this is more towards a balances songs, with no extreme here.

The Spirit of Gambo - Martin Minoit au Marche
The performance on this songs is quite similar, this might due to the limitation on my headphone as i clearly understand that HD580 do not performed well on high frequency, i canot define well on this songs, just that, the extension on viper is more control, but Boa go further high when compare to viper, this might arise as for brighter sound for unfinished burned in.

Chloe - Vincent ( Live version)
D2 Boa is a clear winner here, the vocal is very refined, even it only have 20 hours of burn in, it present the vocal in better position, not only the thickness of vocal, it is more real, more real, just like what she is singing in front of you, this might constructed by alot of issues, speed, defined, thick and etc. D2 Viper having blurer vocal, D2 Boa is a clear winner here .

F.I.R. - Blue Doors Ahead
D2 Boa having bigger soundstage here, but D2 Viper having clearer presentation on soundstage, personally i prefer D2 viper one even it is abit more narrow, but it give better transparency, which i dont feels any EQ here, but i will think that alot of the users will prefer wider soundstage, i m the extreme here, which i shall not concluded it might affected due to my personal preferences

Finally it reached to the end, i m very impressed on the sound of D2 Boa, even it is not fully runned in, some parts of it have significantly better than D2 viper , but as a D2 viper owner here, i proud to own Viper as well, as it give me good enjoyment. D2 Boa is sold at RM550, with this unbelievable prices, i will think that there is hardly any portable DAC can beat the sound of it with this attractive prices

here come with some pictures









This post has been edited by yuheng: Jun 13 2008, 01:11 PM

OMG this is really tempting..... I'm starting to get really confused on wat to get....

ya,i was tempted also.but economy in recession,not afford to buy now.

lol
i saw my cable there.. hahaha

hehe,lot of forumer like to use ur cable ma.

Limited to 10 units again

actually. both the Van Den Hul VS PcWork Customise were made from me.
=)
and the VDH is low on stock, while PcWork cable is only available in limited quantity. i provided them one shoot to yuheng.
warrenty for cable is provided by myself.
=)

Van den Hul were stocked from Perfect hifi, authorized VDH dealer in Malaysia. and it's guaranteed that it's original VDH cable.

Specs for VDH cable
VDH D102 MKIII + 2 X Canare F-12 Plug + WBT Silver soldering Lead.
=)


This post has been edited by PcWork: Jun 15 2008, 03:21 AM

One question about the Boa yuheng. Is it capable of running directly off USB power when used as a dac, bypassing the battery?

i have the same doubt as well.

the boa do not bypass the batteries (its just charge the batteries if u put it in charging mode) and the d2 boa still run completely on the batt..btw i own 1 so i know.. got myself a boa from yuheng last week.

i think they implement this design to use the battery as a filter for the power noise.

i bought one too. but haven't get it. wait i go back KL then i test it kao kao. hahaha

urghh, i dun really like using the battery all the time, it would be better if it could use ac instead

i doubt it will has different. if you don't use the rechargeable battery, it will slowly discharge itself too. which, same as if the boa is using lithium ion battery, that when you use it to 99%, it charge up to 100% again.
and the charging of litium ion is differ with Nicd / NiMh. (i do hope it uses lithium / lithium ion)
so memory effect is quite minimum.

after i get involved to some amp constructing, i finally knew that, most of the amp didnt not designed to be charged permenantly/commonly.
D2 boa do really innovate the switch as to retain the battery life.

very agree to ur comments, but most of the amp using rechargable battery. and same in BOA or even secret amp. , As there is the only ways to control the sizes of casing

u mean, boa has a switch to retain battery life?

It's not the memory effect I'm worrying about or anything, it's just a hassle having to turn on the recharging switch when it runs out of battery, and turn it off again when it's complete charging. Since iBasso they recommend not to leave the charging switch on after finish charging.

Even it doesnt bypass the battery, as long as it's ok for me to leave the charging switch always on, it would be fine for me. But iBasso said better not to.... =_=

it having a on-off switch for charging.
i think that is the good ways to maintain its convenience and user-friendly with low costing involved

wah
like that?
so if, i want to use the things for continuestly. i have to flip the switch on and off?
when it's full. off, using battery only..
then when it's empty. on again, so that it charge the battery??? even though in both case i running with computer usb?
so.. the battery can last how long?
and... how do i see if it is full / empty?
can i just switch the charging switch to OFF. so it don't charge. and directly use USB to run it? as a DAC?



This post has been edited by PcWork: Jun 21 2008, 02:27 AM

I remember the USB "powers" the DAC and "charge" the battery at the same time, so it might work i guess. But it's better to ask yuheng or aizen to confirm.

it can be charged and used together, when the battery is weak, the power indicator light will be blinking, then u just need to switch on of the toggle switches, when it is full, the battery light will be off, and u can just switches the toggle light again, the Lit-ion battery shall be quite lasting, no worry dude, i m the distributor, i can get whatever spare-parts for replaces

the battery can last for 40 hours+-, for our usages, i will think that, it can last for 2-3 days per charges.

yes, the most important thing, it enable you for charge and use simultaneously