Have you try contacting yulong directly?
http://www.yulongaudio.com/en/contact.asp
http://www.yulongaudio.com/en/contact.asp
I would also contact Grant Fidelity, even if you didn't buy from them, I think they are the official US rep for Yulong.
This is one of the reason I sold my DA8, Yulong isn't very good at customer service.
Hello again,
I want to report that the sound quality of my DA8 unit has finaly improved, yet it took very long time (nearly a year) until it finally bested my internal soundcard in SQ. It remains a mystery to me how it's possible that it needed so much time to break-in.
Unfortunately it's not yet the happy ending of my DA8 story.
During the break-in period the noise floor became much lower and sound cleaner, which revealed other problem.
Now I can clearly hear high pitched background noise in headphones connected to internal headamp every time USB input is receiving signal(48kHz and higher) from PC.
My only choice for now is to use Optical SPDIF input, it produces clear sound without the background noise(up to 192kHz).
USB input is producing noise when it's receiving data via USB connection, even after I switch the input to some inactive(AES/EBU or coax) input, the noise can still be clearly heard in headphones connected to internal headamp.
To stop the noise, I have to stop/pause playback on the PC, use resampling to 44.1KHz or SPDIF optical input.
I have tested 3 different USB cables (pins 1&4 covered, separated power) with no success on 4 different PCs, so I'm quite sure it's DAC/Int.headamp related problem. The balanced output doesn't seem to be affected by the problem, only internal headamp.
The background noise can be clearly heard when playing PCM signal 48Khz and above, DSD128 DoP and all DSD native modes. The higher the PCM frequency or DSD mode, the more apparent the noise is. So DSD is useless, as is USB input (except signal 44.1 Khz).
I have started to consider buying external headamp, but I think it's not fair I have to buy other expensive device to fix a problem.
Wanted to use my DA8 as 2in1 solution via USB which is not possible
I have contacted my seller (Kidultdiagnostic.com) for help twice, after few messages they promissed to contact Yulong and organize my unit inspection and repair, but then they suddenly stopped responding.
During the break-in period the noise floor became much lower and sound cleaner, which revealed other problem.
Now I can clearly hear high pitched background noise in headphones connected to internal headamp every time USB input is receiving signal(48kHz and higher) from PC.
My only choice for now is to use Optical SPDIF input, it produces clear sound without the background noise(up to 192kHz).
USB input is producing noise when it's receiving data via USB connection, even after I switch the input to some inactive(AES/EBU or coax) input, the noise can still be clearly heard in headphones connected to internal headamp.
To stop the noise, I have to stop/pause playback on the PC, use resampling to 44.1KHz or SPDIF optical input.
I have tested 3 different USB cables (pins 1&4 covered, separated power) with no success on 4 different PCs, so I'm quite sure it's DAC/Int.headamp related problem. The balanced output doesn't seem to be affected by the problem, only internal headamp.
The background noise can be clearly heard when playing PCM signal 48Khz and above, DSD128 DoP and all DSD native modes. The higher the PCM frequency or DSD mode, the more apparent the noise is. So DSD is useless, as is USB input (except signal 44.1 Khz).
DA8 review:
.....
Cons:
The first thing I noticed when I fired up the da8 is my soundstage morphed from amazing 3D in my previous setup, to a unison kind of soundstage. The difference is astonishing, literally night and day. I did A/B comparisons on multiple music sources switching from the da8 to the onboard burr brown dac on my preamp. Where the vocals would previously be directly in front of me, or to the left or right (depending on the source) and slightly behind the speakers, and the acoustic guitar slightly to her right with the old dac, with the da8, the vocals and guitar now come from the left and right speakers only. The 3D imaging has been completely obliterated.
It seems people here have had good experiences with this dac. I wonder though if anyone else has experienced the break up of 3D imaging, or if the imaging could possibly fix itself over time. Someone posted that it took nearly a year for their da8 to break in and sound better than the sound card in their computer. It's not worth it to wait for the sound to magically acquire sonic benefits that my system already has, and without the convenience of a remote.
Summary: The sound, for whatever reason is better on my old preamp, and I see no reason to keep this dac. The da8 will be heading off to classified heaven to recoup some costs, fortunately, I got it on sale and will therefore lose a bit less than if I paid full price.
Wow, that's doesn't sound good. I've compared some desktop DACs around DA8 category, but never noticed the 3D holographic imaging destroyed when switching to DA8. Yes, it is not the best DAC for holographic imaging, but it is not that bad either. And yes, imaging improved on DA8 II, but it is not that bad on DA8.
Personally I don't believe those 1 year break-in. 1 day usually enough for DAC.
Could it be there is something wrong with your DA8?
I did A/B comparisons on multiple music sources switching from the da8 to the onboard burr brown dac on my preamp. Where the vocals would previously be directly in front of me, or to the left or right (depending on the source) and slightly behind the speakers, and the acoustic guitar slightly to her right with the old dac, with the da8, the vocals and guitar now come from the left and right speakers only. The 3D imaging has been completely obliterated.
The channel crosstalk of DA8 ll is about 130dB, THD =0.0002% - well below the threshold level of some audio analysers. I`m just can't to imagine how it can to destroy or to alter the stereo image.
That DAC will benefit from usage with the dual mono amp, or 2 separate mono blocks.
Which Burr Brown dac is it?
In my experience these numbers are mostly good for bragging rights. The crosstalk is not the only parameter to alter soundstage.
DA8 was the best dac in my possession at quoted specs, but one of the worst sounding in 500€+ range.