[Polarbear]

Quote:

Did you check for a ground loop first? If running off a laptop, try unplugging the computer to see if that removes the hum. There are also various plug adapters or cables you can get for cheap which will remove the effect of ground loops.

 
It's not a ground loop. It's tones and noise coming out of the DAC.
 

 

[axw]

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I have another question for the heavy weights here.  I have a Theta DAC that has a coaxial input.  Can I use my uDAC-2 as a go between from my iMac to the Theta?  
 
 iMac>USB>uDAC-2>Coaxial>Theta DAC?

Yes, you can, exactly as you describe.  The S/PDIF output on the back, next to the RCA outs, is for exactly that purpose.
 

I would suggest you test your Theta DAC with uDAC-2 coax output prior to purchasing the latter. I tried my Lavry DA-10 DAC with two different uDAC-2 on two different laptops -- none of the combinations worked. Spdif synchronization breaks every few seconds. NuForce support was not able to help me on this issue.
 

 

[replytoken]

Quote:

Now after reading this thread I opened a ticket directly at nuForce. I really hope they're going to send me a replacement board as soon as possible. A parcel from the US to Germany will probably take a while. It's really frustrating when you paid for a device and then it takes weeks until you (hopefully) get a working version.
 
Maybe somebody from nuForce reads this and can confirm that my odyssey will come to an end and I'll have a working DAC that plays music and not tones soon.
 
 

Welcome to Head-Fi; sorry to hear about your wallet!  (standard greeting to new members)  nuForce was very good about helping out those customers who had problem units.  If you have opened a ticket, they should work with you to get you a replacement bard that is very easy to install in your existing unit.  Sometimes it takes them a day or so to get back with you, but they should make good on your unit.
 
--Ken

 

[WarriorAnt]

Quote:

I would suggest you test your Theta DAC with uDAC-2 coax output prior to purchasing the latter. I tried my Lavry DA-10 DAC with two different uDAC-2 on two different laptops -- none of the combinations worked. Spdif synchronization breaks every few seconds. NuForce support was not able to help me on this issue.
 

axw,
 
It is a bit prophetic that you made this comment because tonight I did have a problem with the uDAC-2.  Although at first I did not suspect it.
 
Everything had been going fine for three days now using the uDAC-2 coax output to my Theta DAC when suddenly tonight it just stopped.  At first I did not realize it was the uDAC-2 because iTunes simply would not play. By this I mean I could switch the iTunes play button from the play symbol to the pause symbol and back but the music wouldn't start and the timeline indicator would not move.  The other iTunes functions were still working, I could move through the menu I just couldn't get it to engage. Thinking it was a software problem I repaired permissions, restarted the iMac. Nothing.
 
Then I noticed the Theta input signal light was not indicating a signal coming in. Forgetting about the iTunes weirdness I set up a transport to the Theta with a coax tossed in a disc and everything was fine. Thinking perhaps my Mac was the problem I went into the Audio MIDI Setup and checked out the menu there. Everything seemed fine.  So I tried the uDAC-2 RCA outs and nothing no sound from the Mac and iTunes still would not play. Thinking it was the Mac I started to unhook the uDAC-2 from the Mac using the USB cable first. When I did that iTunes started working again and I also got sound out of my Mac's system output.  I plugged the USB cable back into the uDAC-2 and a few seconds later no sound and iTunes stopped along with its timeline indicator.  unplug the USB and iTunes started again and music through the Mac could be heard.
 
So I switched out USB cables same problem.  I switched USB ports. Same problem.  I went to a USB powered hub. same problem.
 
Then I tried changing the format in  the Audio MIDI Setup from 96000.0 Hz to 44100. Hz and things started up again.  Back to 96000 and things stopped.  This happens on both the coax out to the Theta and the RCA outs to the pre amp.
 
So I don't understand what is happening. And I was just starting to dig the uDAC-2.    Anyone have an idea?  Is this SPDIF Synchronization break?

 

[HeadphoneAddict]

Quote:

Quote:

I would suggest you test your Theta DAC with uDAC-2 coax output prior to purchasing the latter. I tried my Lavry DA-10 DAC with two different uDAC-2 on two different laptops -- none of the combinations worked. Spdif synchronization breaks every few seconds. NuForce support was not able to help me on this issue.
 

axw,
 
It is a bit prophetic that you made this comment because tonight I did have a problem with the uDAC-2.  Although at first I did not suspect it.
 
Everything had been going fine for three days now using the uDAC-2 coax output to my Theta DAC when suddenly tonight it just stopped.  At first I did not realize it was the uDAC-2 because iTunes simply would not play. By this I mean I could switch the iTunes play button from the play symbol to the pause symbol and back but the music wouldn't start and the timeline indicator would not move.  The other iTunes functions were still working, I could move through the menu I just couldn't get it to engage. Thinking it was a software problem I repaired permissions, restarted the iMac. Nothing.
 
Then I noticed the Theta input signal light was not indicating a signal coming in. Forgetting about the iTunes weirdness I set up a transport to the Theta with a coax tossed in a disc and everything was fine. Thinking perhaps my Mac was the problem I went into the Audio MIDI Setup and checked out the menu there. Everything seemed fine.  So I tried the uDAC-2 RCA outs and nothing no sound from the Mac and iTunes still would not play. Thinking it was the Mac I started to unhook the uDAC-2 from the Mac using the USB cable first. When I did that iTunes started working again and I also got sound out of my Mac's system output.  I plugged the USB cable back into the uDAC-2 and a few seconds later no sound and iTunes stopped along with its timeline indicator.  unplug the USB and iTunes started again and music through the Mac could be heard.
 
So I switched out USB cables same problem.  I switched USB ports. Same problem.  I went to a USB powered hub. same problem.
 
Then I tried changing the format in  the Audio MIDI Setup from 96000.0 Hz to 44100. Hz and things started up again.  Back to 96000 and things stopped.  This happens on both the coax out to the Theta and the RCA outs to the pre amp.
 
So I don't understand what is happening. And I was just starting to dig the uDAC-2.    Anyone have an idea?  Is this SPDIF Synchronization break?

I had that happen a few times and I usually had to restart my Mac.  I could choose 24/48 or 16/96 as the highest bit rate, but 24/96 would pause the music.  I thought it was my upgrade to OS 10.6.2 that caused it, but it was actually an intermittent issue.  After a few weeks of the "pause music at 24/96", the sound started to become garbled after restarting the Mac and I knew it was time to contact Nuforce.  Nuforce replaced the internal uDAC-2 PCB for me, and it fixed the problem. Out of the two uDAC-2 that I have here, the other one never had the problem. As far as I know, I'm the only one that had a uDAC-2 fail that way.  They responded quickly to fix the issue for me though.

 

[Polarbear]

@ WarriorAnt
 
I have the exact same problems with the uDAC 2 on my iMac. iTunes and Vox don't play anymore and there is no sound coming out of the DAC at all when set to 96/24. I switched to all available USB ports (including an external self powered hub). The issue is the same on all USB ports so I don't think it's a USB problem.
 
I tried all settings in the Audio Midi setup and these are the highest ones that worked:
 
Input: 48/24 Output: 48/24
Input: 96/16 Output: 96/24 (This is especially weird. Why does it work when I set the input to 16 Bit ????)
 
As soon as I set everything to 96/24 it stops working. Maybe another iMac or Mac user can confirm this.
 
Now I'm not only waiting for a new board to fix the tone problem. I'm also not able to play 96/24, am I?
 
 
 

 

[WarriorAnt]

Thanks for the quick replies on this issue.  It's somewhat comforting to know the audio cosmos hasn't singled me out. 
 
What is the best way to contact NuForce.  Phone or Email?

 

[Polarbear]

Quote:

Thanks for the quick replies on this issue.  It's somewhat comforting to know the audio cosmos hasn't singled me out. 
 
What is the best way to contact NuForce.  Phone or Email?

I opened a ticket about it. Since a new daughter board for mine already has been shipped they asked me to wait and see if it fixes the 96/24 issue as well.

 

[WarriorAnt]

I started a ticket with the help desk and the response to replace the unit with another one came within minutes.   

 

[ESCS]

Anyone know how the Udac2 compares to Ipod touch, which is my primary source at the moment because my integraded(?) Realtek soundcard sucks.

 

[busyx2]

Most likely than not it's an OS corrupted issue, try re-installing the latest update 10.x.x whatever.   A hardware failure can't be just on the last 8 bits.

 
Quote:

@ WarriorAnt
 
I have the exact same problems with the uDAC 2 on my iMac. iTunes and Vox don't play anymore and there is no sound coming out of the DAC at all when set to 96/24. I switched to all available USB ports (including an external self powered hub). The issue is the same on all USB ports so I don't think it's a USB problem.
 
I tried all settings in the Audio Midi setup and these are the highest ones that worked:
 
Input: 48/24 Output: 48/24
Input: 96/16 Output: 96/24 (This is especially weird. Why does it work when I set the input to 16 Bit ????)
 
As soon as I set everything to 96/24 it stops working. Maybe another iMac or Mac user can confirm this.
 
Now I'm not only waiting for a new board to fix the tone problem. I'm also not able to play 96/24, am I?
 
 
 

 
Quote:

Anyone know how the Udac2 compares to Ipod touch, which is my primary source at the moment because my integraded(?) Realtek soundcard sucks.

The difference is not subtle...

 

[WarriorAnt]

Quote:

Most likely than not it's an OS corrupted issue, try re-installing the latest update 10.x.x whatever.   A hardware failure can't be just on the last 8 bits.

 

Doubtful it's a software problem.
 
Either way I'll find out today because the new unit will be here in a matter of hours.

 

[WarriorAnt]

The second uDAC-2 unit arrived yesterday.   From what I can tell it seems to be a used unit.  Circular scuffing on the volume knob may have been caused by the unit rubbing against the plastic packaging in transit, slight scratching on the RCA outputs could be my imagination.  However the unit does not function properly.  I cannot get it to communicate to the Audio MIDI Setup application beyond 48000.0 Hz 2ch 16Bit. At least the first uDAC-2 could go to 96000.0 Hz 2ch-24bit. With this unit 96000.0 Hz 2ch-24bit doesn't show up at all.  The units light is always on whether the volume control is in the OFF position or the ON position whereas the first unit the light was off and went on in respect to the Volume control.   This second uDAC-2 unit has severe distortion in the left channel when using the RCA outputs and also when using the headphone output. I have tried every possible troubleshooting scenario, including a reinstall of my Mac OS and a reinstall of the Audio MIDI Setup. Both units are duds.
 
My experience with the uDAC-2 has been an extreme disappointment and a complete hassle.  The time and effort I had to put in to troubleshoot both units was a real inconvenience and has left me with nothing, and now I have the hassle of packing both units and shipping them back.
 
I cannot recommend the uDAC-2.  Two improperly functioning units is more than bad luck, it's poor quality control.  

 

[Polarbear]

Quote:

The second uDAC-2 unit arrived yesterday.   From what I can tell it seems to be a used unit.  Circular scuffing on the volume knob may have been caused by the unit rubbing against the plastic packaging in transit, slight scratching on the RCA outputs could be my imagination.  However the unit does not function properly.  I cannot get it to communicate to the Audio MIDI Setup application beyond 48000.0 Hz 2ch 16Bit. At least the first uDAC-2 could go to 96000.0 Hz 2ch-24bit. With this unit 96000.0 Hz 2ch-24bit doesn't show up at all.  The units light is always on wether the volume control is in the OFF position or the ON position whereas the first unit the light was off and went on in respect to the Volume control.   This second uDAC-2 unit has severe distortion in the left channel when using the RCA outputs and also when using the headphone output. I have tried every possible troubleshooting scenario, including a reinstall of my Mac OS and a reinstall of the Audio MIDI Setup. Both units are duds.
 
My experience with the uDAC-2 has been an extreme disappointment and a complete hassle.  The time and effort I had to put in to troubleshoot both units was a real inconvenience and has left me with nothing, and now I have the hassle of packing both units and shipping them back.
 
I cannot recommend the uDAC-2.  Two improperly functioning units is more than bad luck, it's poor quality control.

Oh dear, I'm still waiting for my new board, but that doesn't sound good. I can understand that my retail dealer couldn't test my first replacement unit, but I expect NuForce to do so when they send me a new board.

 

[Bacci]

Just to clear up confusion about the compatibility between the udac 2 and the ipad:

Ipad running OS 4.2.1 >> usb camera adapter >> powered hub >> udac 2 >> headphones works perfectly well and sounds great.

Works out perfectly for my bedroom, as the powered usb hub doubles as phone charger and i can read the news (multitasking in ios 4.2.1) while listening to cd quality music.