[zilch0md]

Hi Alex,
 
This blog entry at the CEntrance site says that they conducted a survey, determining that the typical USB port can deliver 500mA at 5V.  
 
They then designed the DACport to start out drawing only 60 mA, but during normal operation it demands no more than 400 mA.  
 
These numbers are for their DACport, which has a both a DAC and a headphone amplifier.  
 
I would imagine that their DACport LX (the device I reviewed) must therefore have a peak demand of something less than 400 mA (given that it's just the DAC, without the amplifier.)
 
Do you have an ODAC and, if so, is it exhibiting symptoms similar to what I described in my review?
 
Thanks,
 
Mike

 

[adydula]

Hi Mike,
 
I have (2) ODACs and (2) O2 Amps.
 
I have run them off of USB 2.0 and 3. ports on 2 desktops and 2 laptops all with none of the issues you report
in your review.
 
Complete classical pieces are handled very well to my ears. I have listened to the ODAC now for 2 weeks with several desktop head amps and pcs....the only issue I have had with any dropouts was with my HRT MSii+ when moving to a new ASUS HTPC mini-itx motherboard that has both USB 2.0 and USB 3.0 ports. This was resolved with pre-buffering settings...
 
I never experienced any issues with the ODAC. It just works for me.
 
I dont know if you have tried to remove ALL other usb devices from your system and re-try etc...
USB 2. should provide 500 ma, USB 3.0 I think increased this to 750 ma if I remeber correctly....need to check the specs.
 
If I wanted to be sure and wanted to use a USB Dac, knowing what I know I would make sure that only the USB Dac is on a seperate hub/connection and nothing else.
 
Alex
 
Here is a good link to read up on powering devices from USB:
http://www.ti.com/lit/an/slyt118/slyt118.pdf

 

[zilch0md]

Alex,
 
Thanks for the link to that great article!
 
I expect to receive the two items pictured in my post on the previous page either today or tomorrow, but (bummer) I'm no longer in possession of an Objective DAC that I can test, so here's a proposal...
 
I can tell, just from reading your recent posts, that in addition to having two ODACs that you can test with my proposed "solution," it seems you certainly have the skills and equipment with which to do a much better job than I could, assessing whether or not the idea is viable.
 
If you are willing, and for the good of the ODAC user community, I'd like to pass the baton to you and just give you (for keeps) the USB injector and 5V power supply.  Seriously.  
 
I was going to try testing them with the CEntrance DACport LX I've bought, just to see if it works at all, but you seem to be far better equipped to measure voltages, check polarities, etc. -AND- to see how the ODAC performs with it.  
 
I think members following this thread would be much better served if you evaluated it, than me, even though your ODACs aren't exhibiting any problems, currently.
 
Later, if you find that this injector + power supply combo does a good job of providing power to the ODAC (providing correct voltage and polarity, for example), and you find that it introduces no issues with sound quality, you could, at your choosing, pass it on to someone who's actually suffering power-supply symptoms with their ODAC.   If, on the other hand, it doesn't work well with the ODAC, for any reason, feel free to keep it for other projects - there's no need to return them to me.
 
Send me a PM with your mailing address, if you're interested.  I really think you're the right guy for the job.  

 
Thanks!
 
Mike

 

[adydula]

Hi Mike,
 
The 5 volt Microtiek adapter...in one of the Amazon comments mentions its putting out 6 volts....so buyer beware.
 
You wont really know what the voltage is until plugged into the wall socket and measure the DC voltage.
 
The USB 2.0 spec is 5 volts +/- 5% or varies from 4.75 volts to 5.25 volts.
 
6 volts is on the high side of the spec....so even though it probably would work I would not really want to do this with a $99 ODAC....
 
I would do one of the three things: (If I experienced a power issue)
 
1. Use a seperate powered external USB Hub with no devices except for my ODAC.
2. Try with only the ODAC plugged into the PC in question and if its still bad then nuber one or three.
3. Try a differnent PC.
 
The Power injection device I would want to make sure that the device and cables do not allow voltage from the PC on the DC buss and only the 5 volts from the adapter.
You want to make sure you dont have two DC supplies hooked up from differnent power sources!
 
I will PM you as well..
 
Thanks for the kind words!!
 
I try to be frank and honest and tell the truth...I dont know everything and am not afraid to ask!! LOL!!
 
Alex!!

 

[zilch0md]

Thanks Alex!
 
I'll ship them to you when they arrive - and you can test it all to see if its OK with the ODAC.  (If you get as far as plugging the ODAC into it.)
 
Oddly, when I check this link at Amazon from which I ordered the power supply, I see no mention of 6-Volts.  It's described as a 5-Volt 2.0-Amp supply.
 
And when I check this link from which I ordered the MicroTik 5VUSB Injector, I again see no mention of 6-Volts.  (I didn't order it from Amazon.  I only ordered the power supply from Amazon.)
 
Where exactly did you see a specification of 6 Volts?
 
Thanks,
 
Mike

 

[adydula]

Mike...
 
Here on Amazon...
 
http://www.amazon.com/review/R3W0XV5E0C506T/ref=cm_cr_dp_title?ie=UTF8&ASIN=B001PUSERA&nodeID=541966&store=pc
 
But again I dont trust anything until I actually measure it under no-load and load etc..
 
Alex
 
Note also want to make sure the cable is not wired for dc from the USB pc port and only the injector is supplying the DC voltage.

 

[zilch0md]

Quote:

Mike...
 
Here on Amazon...
 
http://www.amazon.com/review/R3W0XV5E0C506T/ref=cm_cr_dp_title?ie=UTF8&ASIN=B001PUSERA&nodeID=541966&store=pc
 
But again I dont trust anything until I actually measure it under no-load and load etc..
 
Alex
 
Note also want to make sure the cable is not wired for dc from the USB pc port and only the injector is supplying the DC voltage.

 
I see what you mean, in that buyer's review.   Ugggh!   Well, I'll test the voltage when I get it and if it really is 6V, then I'll return it and order a different 5V 2A power supply that has a 1.3 x 3.5mm barrel connector.  There are several to choose from.  We will get there...
 
Mike

 

[zilch0md]

Alex,
 
I received the 5V 2A regulated power supply from Amazon, today.  
 
Best of all, it measures a steady 4.99VDC (center positive) on my multimeter.  

 
 
That reviewer who measured 6V must have received a lemon (or he has a bad voltmeter.)
 
I'm still waiting on the USB power injector:
 
 

 
I have some concern about whether or not the plug will fit the jack, but going by the specs for each of them, I think it will work  (1.0mm I.D. x 3.5mm O.D.   vs.   1.3mm I.D. x 3.5mm O.D.) 
 
Another question is whether or not the polarity will be correct.
 
It's pretty standard practice for the pin to be positive and the sleeve to be negative, though, right?
 
If this idea works, it will make a much smaller package (for transport) than something like a D-Link or Belkin USB hub.
 
Thanks,
 
Mike

 

[tdockweiler]

I've had my ODAC for maybe a week or two now I think. Zero problems with it now and it's a keeper.
 
I've noticed that it doesn't seem to be as revealing as my HRT MSII. I mean I don't seem to be getting detail overload or anything. I don't believe it's really analytical. That gives people the wrong impression. I doubt it'll really transform a headphone into something it's not.
The only major difference is that it sounds smoother than the HRT MSII. Larger soundstage and it seems like better imaging. I think maybe the HRT just is a bit darker overall.
I originally thought the HRT had fuller mids with the Q701, but now I don't know if this is true. I'd say the HRT made some Sennheisers a bit warmer maybe. Just a tad. That's maybe why I didn't like the MSII with the HD-600 or 598.
 
I know the science guys will hate this one (so just ignore it), but I can now barely tell the difference between any of my cables. With the HRT MSII it was stupid easy. I mean they were not dramatically different or something. I don't know what this says.
On my E9 + HRT I can't tell much difference between cables, but with the Micro Amp + HRT it was quite easy. I think the only difference is due to capacitance. I couldn't tell any difference between cables on my Q701 until I got my MSII. ZERO!
 
Believe it or not the headphone with the biggest improvement in sound is my $80 Koss Pro DJ100. Even more so than my Q701. Pretty surprised. The biggest improvement was in the size of the soundstage and how much better the bass was. I've never heard the bass of the DJ100 improving with any amp really (as long as it was well amped to begin with). The ODAC basically keeps the DJ100's signature the way it's supposed to be, but improving everything. I'm glad to report it doesn't make the DJ100 any warmer than it should be like the HRT MSII did.
 
BTW I'm listening to a 96kbps song right now and it sounds listenable. Don't ask me how I have one even in my collection. Wow, didn't even know that. Some recordings can sound much worse and be FLAC. I do have some 128kbs stuff that is unlistenable though due to the bitrate.
 
My KRK KNS-8400 didn't suddenly become even more analytical and less musical. Sounds just how it should. Sure wish it made my Koss Pro4AAAT and K240 Sextett listenable though

I think I have the world's worst Sextett. Way too dark and very muffled.

 

[LoveKnight]

Hi, Guys! I just want to ask one question. What do you think about the combo which is ODAC + C421 (OPA2227)? I have Fiio E10 and C421 but I think Fiio E10 is still not good enough for me. I want to upgrade a better DAC. Thanks for reading this question.

 

[Anaxilus]

E10 is not good enough.  It has/had low end bass roll off and a sort of typical low-fi grain synonymous w/ lack of resolution.  ODAC is much better.  I was considering an E10 until I tried one out of three different setups at a meet.   

 

[adydula]

tdockwieler....
 
I too think or thougt that the HRT and the ODAC were different in sound quality and I know I am biased towards the HRT....my Bias were/are...it costs more so it has to sound better, its asynch vs non-asynch, its in nicer package, it draws more current, it has lights on it that light up!! yadda, yadda, yadda..
 
So the one thing that i noticed with my HRT MSii+ is that the output is higher than the ODAC.
 
So when going back and forth the HRT will play louder into my cans and appears immediately louder, more clear, more alive etc...until i match the levels.
 
So this may be it at least for me...
 
I find if I set the volumes the same and play several songs they are identical to me....
 
After that its back to the music..
 
Alex

 

[Slickman]

 I just received my ODAC, I think. I'm not sure if I got the right thing now. From the pictures it looked like it was about the size of a DVD drive for a computer. I got it and it is TINY, I'm not expecting much from this small package. I'll have time to test it tomorrow.

 

[.Sup]

it sure is tiny.

 

[chrislangley4253]

Quote:

 I just received my ODAC, I think. I'm not sure if I got the right thing now. From the pictures it looked like it was about the size of a DVD drive for a computer. I got it and it is TINY, I'm not expecting much from this small package. I'll have time to test it tomorrow.

nope, that's it.