[teiki arii]

Do you remember? I am sure you do!

Antoine my friend, who is an engineer in Audio Pro, exchanged all IC-OPAs by his class A AZP discret OPAs... 
I mean he changed IC-OPAs for AZP OPAs at conversion I/V stage, Low-Pass filter stage, buffer stage and headphone output stage! Antoine had to upgrade just a little the Power Supply, had to fix bias conversion I/V on AZP OPAs and that's all. You can't imagine what benefits this upgrade had brought along, by an inextinguible margin as deep as Helm's Deep. It's fantastic! It outperforms the DAC with IC-OPAs! If I had to give a personal value, I would give 70/100 before upgrading and 88/100 after upgrading. The DAC is used in his symmetric version (with XLR outputs) in my full symmetric system.
Nevertheless, I confirm (in my system) that Upsampling (at the max allowed by the DAC) before entering DAC seems to be better than letting the DAC doing it. I like very much USB mode now (without any USB power supply), more versatile while I still like very much Toslink mode between my Macbook Pro late 2011 (16Go RAM) and the DAC. Even if I still am not convinced by the internal preamp mode, it is quite better but still less good than a very good preamplifier. It is more noticeable by XLR outputs than by Headphone output. therefore, headphone output has become very very enjoyable even with my "very agressive" gold SR-325i Grado. 
I won't give you any review, the main reasons are because of my limited vocabulary (I'm a foreigner, don't forget it) and because I think reviews are a kind of lies. Anyway, I actually let you know that transformation is outstanding, extraordinary. I cannot find a single weakness in this upgrade. I confirm what I have already written: if you find some IC-OPA "highly regarded", I have not that skills to qualify nor to describe impressions that AZP OPA can offer you... It's amazing and yes, this DAC is fantastic with the proviso that you first, you change IC-OPA for real first class ones. I have to tell you that this OPA are not to be sold in anyway, because they are prototypes and Antoine doesn't want someone to practice reverse engineering. He wants to keep property on it. If I tell you that today, it is for several reasons: no matter you find a good USB cable nor you use SSD in your computer or anything. If you do not optimize the power supply nor you don't change IC-OPA for betters, whatever you have very nice cables or a very good system, your system should sound wrong, not bad I agree, but not according to my experience. That's the point.
I have never heard any DAC as good as this upgraded one, never forever... Is it possible that I can find a better one? For sure, but I could live with this one all my life without dropping it, because I do not feel the need to. Nevertheless, I know I will sell it one day, I am waiting for a new symmetric peamp/DAC made by Antoine in a few months (or years?

).
Best regards.

​

 

[igormsk]

I've got 3 headphones - HD800 (300 ohm), DT660 (32 ohm) and IEMs Shure SE215 (20 ohm). With HD800 the integrated amp is absolutely silent, but with DT660 I hear hiss all the time no matter how high I set the volume - it's quite anoing when playing music without much dynamic range compression (nearly all recordings of classical music). When I plug my SE215 the hiss becomes so loud that makes listening to music unenjoyable.
 
I also tried plugging the same headphones into Questyle CMA800R and Audio-GD NFB10.32 and got the same result - silence with HD800 and hiss (even louder than on DA8) with the other 2 headphones
Changing volume on the CMA800R and DA8 doesn't affect the hiss at all. On NFB10.32 the hiss volume changes significantly with volume settings (but not with gain settings) and is just audible on normal listening levels with DT660 and really disturbing with SE215.
 
Is there something wrong with my power at home or is this integrated amp not suitable even for full size DT660 headphones? Would Yulong P18 help me to get rid of this hiss issue with low resistance headphones?
Before ordering P18 I could borrow http://www.furmansound.com/product.php?div=04&id=AC-210E - would it make sence?
 
If I plug DT660 into my notebook directly I don't hear any hiss (with SE215 there is some hiss but at a much lower level than on CMA800R / DA8 / NFB10.32).

 

[i019791]

 
I've got 3 headphones - HD800 (300 ohm), DT660 (32 ohm) and IEMs Shure SE215 (20 ohm). With HD800 the integrated amp is absolutely silent, but with DT660 I hear hiss all the time no matter how high I set the volume - it's quite anoing when playing music without much dynamic range compression (nearly all recordings of classical music). When I plug my SE215 the hiss becomes so loud that makes listening to music unenjoyable.
 
I also tried plugging the same headphones into Questyle CMA800R and Audio-GD NFB10.32 and got the same result - silence with HD800 and hiss (even louder than on DA8) with the other 2 headphones
 
Is there something wrong with my power at home or is this integrated amp not suitable even for full size DT660 headphones? Would Yulong P18 help me to get rid of this hiss issue with low resistance headphones?
Before ordering P18 I could borrow http://www.furmansound.com/product.php?div=04&id=AC-210E - would it make sence?
 
If I plug DT660 into my notebook directly I don't hear any hiss (with SE215 there is some hiss but at a much lower level than on CMA800R / DA8 / NFB10.32).

I suppose you have tried the lowest gain option on all amps.
You should check the amps at another place first.
For the NFB-10 there is a mod which significantly drops the low gain - you may ask Audio gd for details.

 

[igormsk]

Thank you for the idea - I will try the DA8 at my office tomorrow.

 

[Khragon]

Anyone have to deal with Yulong for issues? I got pretty good experience with Woo and Schiit, both are American company. I am skeptical of Chinese company not giving good support.

 

[Jd007]

Anyone have to deal with Yulong for issues? I got pretty good experience with Woo and Schiit, both are American company. I am skeptical of Chinese company not giving good support.

if you are in north america you should be dealing with the NA representative, grant fidelity, for the best support

 

[Khragon]

I would think that grant fidelity support is only as good as yulong support.

 

[Jd007]

I would think that grant fidelity support is only as good as yulong support.

there is no language barrier, and grant fidelity has very fast response time from my experience. never had to deal with actual product support though as my unit has no problems. maybe someone else can chime in for more info

 

[Gradius]

I just read about noise issues due router/wifi.
 
Well this is why you should NEVER use WiFi:

 

[project86]

That "Acoustimeter" was designed and created by Alasdair Philips of EMFields, who also runs a quack organization called Powerwatch. EMFields makes all kinds of wacky accessories: Bed canopies (think mosquito net but for blocking radiation), shielded sleeping bags, special paint and window films for keeping the junk out. They also do "Protective headnets" which are just inches away from being literal tin-foil hats. 
 
Please don't take these guys seriously.
 

 

[mrcasey]

  That "Acoustimeter" was designed and created by Alasdair Philips of EMFields, who also runs a quack organization called Powerwatch. EMFields makes all kinds of wacky accessories: Bed canopies (think mosquito net but for blocking radiation), shielded sleeping bags, special paint and window films for keeping the junk out. They also do "Protective headnets" which are just inches away from being literal tin-foil hats. 
 
Please don't take these guys seriously.
 

 
Come on....admit it project86....you just didn't like the fit of the hat on yourself....

 

[Bjorn2379]

Hey guys, a question. I've been enjoying my DA8 for awhile now but I am thinking about getting an amp. Can you recommend a good tube amp to drive my LCD 2.2 & HE5LE? I've been looking around & what really catches my eye is the Decware Taboo III.

 

[Zashoomin]

Hey guys, a question. I've been enjoying my DA8 for awhile now but I am thinking about getting an amp. Can you recommend a good tube amp to drive my LCD 2.2 & HE5LE? I've been looking around & what really catches my eye is the Decware Taboo III.

Well it all depends on your budget but I will say that the Taboo is very very good.  Could you give us an idea of about how muich you are willing to spend?

 

[Bjorn2379]

I'd say $1.5k.

 

[project86]

How about your preferred sound signature? Some great choices in your budget, but they all have their own flavor.