[f198]

Hi,
 
Somebody has some experiences, impressions to share about HiFimeDIY Sabre U2 Async?
At least I want to know if it will be a good choice for a low impedance headphone like Sony MDR-7550 (16 ohms).
 
These are some specs from the product page:
(http://hifimediy.com/index.php?route=product/product&path=62&product_id=123)
**********************
Output levels:
Open 2.2Vrms
4.7Kohm 2.1Vrms
1.8Kohm 1.9Vrms
510ohm 1.5Vrms
330ohm 1.3Vrms
30ohm 1Vrms
Note: Normally amplifier inputs are from 10K to 100K ohm. Normal headphones are from 32 ohm to 250ohm.
**********************
 
Thanks a lot !

 

[ClieOS]

You might get away by plugging in the MDR-7550 directly into the Sabre DAC but in the long run you will want to have an amp in between. The Sabre chip really isn't meant to drive a headphone load directly and the 240 ohm output impedance won't help you either.

 

[Soundsgoodtome]

It'll drive it to an extent but as mentioned you'll want an amp down the line. My low impedance portables sound fantastic through them, even the full sized SRH1440. Those however are easy to drive.

On the 250OHM Beyers, there's clipping.

Currently, I'm using it as a transport for the Matrix Mini-I. The Async version has an optical that works fantastic (better than onboard toslink).

 

[f198]

  It'll drive it to an extent but as mentioned you'll want an amp down the line. My low impedance portables sound fantastic through them, even the full sized SRH1440. Those however are easy to drive.

On the 250OHM Beyers, there's clipping.

Currently, I'm using it as a transport for the Matrix Mini-I. The Async version has an optical that works fantastic (better than onboard toslink).

 
Can you comment on the sound quality, it is bright or smooth? Also can you detail a little bit at why I'll want to amp with low impedance headphones ? Thank you.

 

[Soundsgoodtome]

It's on the smooth side but keeps clarity to a decent level. It's not analytical but considering the price, if it were in a fancy aluminium case with more jacks and a bloated brand name, the little bugger can fetch $200 sound-wise.

Is your headphone 250ohm? My 250ohm Beyers benefitted greatly with an e9 and the hifime sabre vs the sabre alone.

 

[ThurstonX]

   
Can you comment on the sound quality, it is bright or smooth? Also can you detail a little bit at why I'll want to amp with low impedance headphones ? Thank you.

 
Just got mine.  I'm running it out a laptop (with the USB isolator, though not strictly needed) into a JDS Labs C5, terminated with a modded AKG Q701.  Compared to the laptop => C5 => Q701, the HiFimeDIY U2 is pretty smooth.  My first test listen is Rush's Clockwork Angels (24-bit 96 kHz).  I chose it because the guitars can be pretty harsh, esp. the title track.  I wouldn't say there's a loss of detail, but it's definitely easier on the ears, with more body.  I've got a Rockbox'd iPod Classic that outputs 16/44.1 via line out to the C5, and while its DAC is far better than the laptop's, I doubt it can touch the HiFimeDIY U2.  Haven't had a chance to compare directly.  I really wanted to hear something 24/96 first  

 
The reason I went with HiFimeDIY over JDS Labs, for whom I have nothing but respect, is that the USB receiver on the HiFimeDIY will take 24/88.2, and even with the USB isolator it was $60-$70 less expensive.  Obviously the implementation is different, but on first impression I'm all smiles.
 
Just did another test with a troublesome track: Jethro Tull's Thick As A Brick (1997 remaster CD).  The vocals are very forward in the mix and always seemed harsh, at least in one or two parts in the first 5 minutes or so.  That may be a product of the remastering (loudness wars?).  Now the Q701 are very detailed cans, even modded to increase/improve the low end.  They tend to reveal the good and the bad.  In this case, there was no sense of smoothing, at least with the vocals.  Overall I'd say the DAC improved it by fleshing it out a bit more.  That's all in the first few minutes.  The mix becomes more balanced, and the U2 renders it well on the Q701.
 
Anyway, there are some anecdotal tests for you to chew on.  For me, $90 very well spent.  Now if I could just make it work with my Nexus 7...

 

[vkalia]

I am using this DAC as well, atleast until I get an Audio-GD NFB2.32.   I dont really have an A/B for it yet, but compared to "no DAC", it does seem to improve the sound a little, most importantly the overall dynamic range.   I havent spent a lot of time doing this comparison, although I do plan to do a more rigorous test once the Audio-GD comes in.

 

[Concept357]

I just received my U2 in the mail but I can't seem to get it to work with my PC. When I plug it in, my computer recognizes it as a 'Bravo-X USB Audio' device. Windows then proceeds to install some random windows drivers for this so called Bravo-X device and when I set it as the default audio device. All I get is a weird crackling popping noise from my speakers or headphones. 
 
Any help would be awesome. 

 

[Soundsgoodtome]

Are you using it as a transport (usb to optical) or dac? What Windows do you have?

 

[Concept357]

Are you using it as a transport (usb to optical) or dac?

It's plugged straight into my computer and I just plugged my 3.5mm speaker cable to it.

 

[Soundsgoodtome]

Mine doesn't show as Bravo-X. Sounds like a driver conflict, did you have a previous dac with Bravo-somethingrather? You'll need to go to your device manager and uninstall the bravo-x. Reboot the machine and plug to another USB port if possible. Is your computer on the internet? It might need to download the latest driver and not be getting it if it's offline.

I have Windows 7 Home Premium 64-bit.

 

[Concept357]

 
Mine doesn't show as Bravo-X. Sounds like a driver conflict, did you have a previous dac with Bravo-somethingrather? You'll need to go to your device manager and uninstall the bravo-x. Reboot the machine and plug to another USB port if possible. Is your computer on the internet? It might need to download the latest driver and not be getting it if it's offline.

I have Windows 7 Home Premium 64-bit.

I'm on windows 7 ultimate 64 and I just did what you said. The computer still thinks it's a Bravo-X USB audio device. It turns out the actual Bravo device is a digital processor that reduces jitter when converting digital to analog signals, just like our U2s are meant to do except for the fact that our U2s are actual DACs. 

 

[Soundsgoodtome]

I still think it shouldn't say Bravo-x and that could be your issue. Maybe load Windows in safe mode, remove the device again in device manager and reboot.

If that doesn't work, try HifimeDIY's website and see if they have a driver download. You can right click on the device under device manager and update the driver manually. I would also rule out a bad unit by trying another computer.

 

[Concept357]

  I still think it shouldn't say Bravo-x and that could be your issue. Maybe load Windows in safe mode, remove the device again in device manager and reboot.

If that doesn't work, try HifimeDIY's website and see if they have a driver download. You can right click on the device under device manager and update the driver manually. I would also rule out a bad unit by trying another computer.

I just rebooted my computer and it recognized it as itself: Sabre U2 Async USB audio! Looks like it fixed itself! Thanks for the help anyways 

 

[ClieOS]

'Bravo' is actually the trademark of the USB receiver chip in U2. Your PC probably only partially recognized the chip and didn't installed the driver correctly on the first run.