# HiFimeDIY Sabre U2 Async



## 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 !


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## 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.


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## 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).


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## f198

soundsgoodtome said:


> 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.


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## 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.


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## ThurstonX

f198 said:


> 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...


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## 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.


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## 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.


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## Soundsgoodtome

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


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## Concept357

soundsgoodtome said:


> 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.


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## 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.


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## Concept357

soundsgoodtome said:


> 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.


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## 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.


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## Concept357

soundsgoodtome said:


> 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


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## 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.


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## Concept357

Aw man. It's acting up again! My computer thinks it's a bravo-x again! 

Sent from my HTC One using Tapatalk


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## Soundsgoodtome

Go into safe mode and remove it from your device manager. Reboot and use another usb port if you can. Make sure you're online too


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## huoyachile

yes,My 250ohm Beyers benefitted greatly with an e9 and the hifime sabre vs the sabre alone.thanks


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## hearo

thurstonx said:


> I'm running it out a laptop (with the USB isolator, though not strictly needed)


 
  
 Hi, can you comment on just the sound quality of the U2 vs. the U2 + USB isolator? Trying to decide if the $30 USB isolator is worth it.
  
  
 Thanks!


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## ThurstonX

hearo said:


> Hi, can you comment on just the sound quality of the U2 vs. the U2 + USB isolator? Trying to decide if the $30 USB isolator is worth it.
> 
> Thanks!


 
  
 I wrote the following for another Head-Fier in a PM exchange.  Hope it helps.
  
  
 Finally got some time to do a quick test with and without the USB isolator in the chain.  To my ears it definitely improves the soundstage, giving it more width and an overall greater sense of space.  It's harder for me to tell if its cleaner power improved the clarity of vocals and instruments, but if I imagine it does, then that's a nice placebo effect   And in fact it may be doing so.
  
 Here's my setup and the tests I did:
  
 "vintage" ASUS P4C800-E Deluxe motherboard using onboard USB port -->
 Monoprice USB extension cable (6-feet) -->
 USB Isolator -->
 U2 Sabre DAC -->
 AudioQuest Golden Gate 3.5mm-to-RCA cable (0.6 m; shortest one they make) -->
 Schiit Lyr running 1966 RTC (La Radiotechnique) E188CC / 7308 tubes -->
 plusSounds custom cable for HiFiMAN HE-500 (I've done three mods to the HE-500: re-grilling, jergpads v2.5; felt on the driver frame)
  
Songs used (all by Hugh Laurie)
 "St. James Infirmary" from _Let Them Talk_
 "You Don't Know My Mind" from _Let Them Talk_
 "Kiss Of Fire" from _Didn't It Rain_
 "Didn't It Rain" from _Didn't It Rain_
  
 Listened with the USB isolator, again without it, then finally with it.
  
 I picked those songs for their dynamic arrangements, mostly acoustic instrumentation and multiple vocal tracks, not to mention the quality of the mix and production.  I tend to listen to rock, but felt it would be harder to pick out any change.  There's no reason to think the expanded soundstage and better instrument separation wouldn't present themselves with whatever genre, esp. with well-recorded, mixed and produced music.  Source is definitely important.
  
*NB:* it's worth noting that I was quite focused on the music, not using as background while surfing the Net or doing anything else.  I guess it would be less apparent if you weren't "just listening."  So while there's nothing wrong with the DAC by itself, I feel pretty confident in recommending the isolator for all the reasons given on the HiFimeDIY site.  For me, it's not snakeoil, but I'm not an engineer.


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## hearo

thurstonx said:


> I wrote the following for another Head-Fier in a PM exchange.  Hope it helps.
> 
> [...]


 
 Very helpful. Thanks!


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## jimath-700

I know it's possibly a dead thread but I was wondering if anybody had used a Sabre u2 and a Schiit Modi and if so which is better or if it is worth the price difference. Thanks


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## imackler

jimath-700 said:


> I know it's possibly a dead thread but I was wondering if anybody had used a Sabre u2 and a Schiit Modi and if so which is better or if it is worth the price difference. Thanks


 
  
 I'm curious, too!


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## Les H

In a few days I'll have an answer.  I have had a Modi for months and really like it.  The U2 is on its way here.  I'll be comparing them closely.
  
 Les


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## jimath-700

That'll be awesome will be interested to know.


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## Les H

I also ordered a USB Isolator and I'll be comparing the effect of that on both DACs as well.
  
 When I can start depends on the speed of the USPS.  Oops.


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## ThurstonX

In an impromptu test the other day, my brother briefly compared the U2 Sabre + isolator to his iPod Classic using some Focals (can't recall which model) driven by a JDS Labs C5.  He was not impressed with the bass on the U2 Sabre in comparison to the iPod, calling it "flabby."  He did like it compared to running straight out of my seriously crappy, seriously old HP dv7t 
	

	
	
		
		

		
		
	


	




  Like I said, a very brief test.  He's a serious prosumer gear head with a nice little home studio in Tokyo.  He's probably as far from audiophile as can be, while being serious about music (he listens to everything when not making his own).  YMMV.


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## Les H

The USPS has been very efficient in moving the U2 from the Oregon warehouse to my location in California, so it looks like the U2 will arrive today and I'll start using it and comparing it to the Modi (and other sources).  So we will all have more information about the relative performance of these units.    Les


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## Les H

Thanks to the Post Office's efficient transit the U2 DAC and USB Isolator arrived today, 1 business day after being shipped.
  
 I have just hooked them up to a laptop as an initial test.  Everything is working, a good start.  Output is to a Fiio E11K amp (a nice piece for its price) and Senn HD600's.  There will be other amps and 'phones for analysis.
  
 At the outset, I can say that the USB isolator does improve things noticeably.  Of course this is on a probably noisy laptop with a crummy power supply.
  
 I want things to break in for a few hours at least before I report any initial opinions.
  
 More later.


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## jimath-700

les h said:


> Thanks to the Post Office's efficient transit the U2 DAC and USB Isolator arrived today, 1 business day after being shipped.
> 
> I have just hooked them up to a laptop as an initial test.  Everything is working, a good start.  Output is to a Fiio E11K amp (a nice piece for its price) and Senn HD600's.  There will be other amps and 'phones for analysis.
> 
> ...


 
 Any thoughts on modi Vs sabre u2?


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## junkers

jimath-700 said:


> les h said:
> 
> 
> > Thanks to the Post Office's efficient transit the U2 DAC and USB Isolator arrived today, 1 business day after being shipped.
> ...


 
 Same question from me but vs the ODAC.


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## Yodeb

Hello, I want to buy this DAC for use directly with a Takstar TS671 of 120ohm ... Does it work well?


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## Yodeb

I wonder if the bi-amplified (this dac have an amp) noise gets to sound. Thanks.


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## Lycosa777

yodeb said:


> Hello, I want to buy this DAC for use directly with a Takstar TS671 of 120ohm ... Does it work well?


 
 Worked fine with my HD600s (300ohm) so id say it should work absolutely fine with your Takstar unamped.


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