[mrcasey]

Check this out:
 
http://en.wikipedia.org/wiki/Galvanic_isolation

 

[mrcasey]

 
Quote:

Thank you!
 
I've been thinking about it and I'm wondering since this is a purely digital device how the power supply can improve the sound. I could understand if there was an analog stage that better power might make a difference, but should it matter with a digital device like this who's only job is to output 1's and 0's? I assume regardless of power source the U18 outputs a bit perfect stream, so I just wonder how a better power supply can change that for the better.

 
 
[size=medium]I can tell you from my experience that the difference is very subtle at most and might not even be discernible at all depending on the other components in your system. I am happy I have the external PS just for peace of mind knowing that I have done all that I can to ensure the best sound quality possible (within the constraints of the product purchased). At times I cannot notice any improvement/difference and when I do it might just be placebo kicking in.  Some people notice these differences more than others.  [/size]
 
[size=medium]From Yulongs website:[/size]
 
[size=medium]“When powered through USB, its strong regeneration circuitry will provide low noise power source to ensure high voice quality”[/size]
 
[size=medium]Yulong has taken measures to ensure the U18 sounds great when powered through USB. My advice is to skip the external PS, at least for now, and enjoy the U18 powered through the USB cable.[/size]

 

[Bmac]

That's what I'm thinking too. I will be using the U18's optical out so the DAC will already be isolated anyway.

 

[preproman]

For only $75 - I think it's work a shot.
 
Look how much other external PSU are costing.
 
http://welbornelabs.com/psdac.htm
 
http://teddypardo.com/Products/Power%20Supplies/power_supplies.html

 

[Bmac]

It's not really about money for me. If I thought it would make a significant difference I would buy it, but the system this is going in is in the kitchen and keeping the box count down is a priority.

 

[mrcasey]

So, my U18 died on me.

 

[mrcasey]

Just KIDDING.  But, this thread has sure died.  Has anybody else recieved one of these yet?  I am curious to hear some opinions.  Still quite enjoying mine.

 

[Stephen Murphy]

I don't have one... yet. I just ordered one off eBay. I am currently using a cheaper HLLY type with the Tenor 7022 chip in it, but it won't do 88 kHz or 192 kHz. It does do 44, 48 and 96.
 
The HLLY also has a separate power supply like the Yulong and I find that makes quite a difference. I took a cheap USB cable and removed the tab for the positive power. That really dropped the noise floor and it sounds very good at 24/96. I am using it with a Havana DAC. Love it.
 
I would like to be able to play 24/88 files without upsampling to 96, so that is why I am getting a Yulong. 

 

[mrcasey]

[size=medium]It is defiantly nice to have access to 88 and 176 files without needing to resample them.[/size]

 

[Bmac]

I got mine a few days ago. I have a problem where when I turn the laptop on it doesn't recognize the U18 until I unplug the USB cable and plug it back in. Has anyone else experienced this?
 
Also, when playing files with different bit-depths or bit rates is it necessary to manually go into the U18's ASIO interface and adjust the audio format and bit depth?
 
Thanks.

 

[Stephen Murphy]

Does anyone know if the U18 has two separate crystals in it for 44/88/176 clocking and 48/96/192 clocking?

 

[mrcasey]

Quote:

I got mine a few days ago. I have a problem where when I turn the laptop on it doesn't recognize the U18 until I unplug the USB cable and plug it back in. Has anyone else experienced this?
 
Also, when playing files with different bit-depths or bit rates is it necessary to manually go into the U18's ASIO interface and adjust the audio format and bit depth?
 
Thanks.

If other devices have been installed in the past on a particular USB port this can sometimes cause confusion for your computer when installing new devices and drivers on the same port.  Try and use the same USB port for the U18 all the time and dont use that port for anything else.  Your computer might currently have other devices (such as different audio devices) associated with that port that are causing conflicts with the U18. Use Google to search on how to clean up old drivers from your USB ports.  Lots of info out there on this.  Also, confirm that you are using a USB 2.0 port.  
 
I do not use the ASIO control tab in the Yulong driver panel/window for the U18.  Instead, set the Audio CPL tab to 24/192,  You do not need to reset for different bit rates, it switches automaticly.
 

 
 
 
 

 

[mrcasey]

Quote:

Does anyone know if the U18 has two separate crystals in it for 44/88/176 clocking and 48/96/192 clocking?

 
I do not know.  I will try and find out.

 

[Bmac]

Quote:

If other devices have been installed in the past on a particular USB port this can sometimes cause confusion for your computer when installing new devices and drivers on the same port.  Try and use the same USB port for the U18 all the time and dont use that port for anything else.  Your computer might currently have other devices (such as different audio devices) associated with that port that are causing conflicts with the U18. Use Google to search on how to clean up old drivers from your USB ports.  Lots of info out there on this.  Also, confirm that you are using a USB 2.0 port.  
 
I do not use the ASIO control tab in the Yulong driver panel/window for the U18.  Instead, set the Audio CPL tab to 24/192,  You do not need to reset for different bit rates, it switches automaticly.

Thanks Mr. Casey. It's definitely a USB 2.0 port and I don't think anything else has ever been installed there (it's on the back and I always use the ports on the side), but it still isn't recognized at startup.
 
Thanks for the heads up on the control panel settings! I'm glad not to have to manually change the settings.

 

[mrcasey]

Quote:

Thanks Mr. Casey. It's definitely a USB 2.0 port and I don't think anything else has ever been installed there (it's on the back and I always use the ports on the side), but it still isn't recognized at startup.
 
Thanks for the heads up on the control panel settings! I'm glad not to have to manually change the settings.

 
[size=10pt]I would recommend you uninstall/reinstall the driver and try a different USB port. Later today (hopefully) I will post what I have found to be the best order of steps for installing the Yulong driver on a PC. I have no knowledge of Mac Computers.  [/size]
 
[size=10pt]*edit*[/size]
 
[size=10pt]instructions/suggestions now on page 8 of this thread.[/size]
 
[size=10pt]Additionally, check post #29 of this thread for some setup tips.[/size]
 
[size=10pt]Also, if you are you using an external PS for the U18, when plugging the U18 into your computer for the first time, it is best to plug in the U18 to your USB port without the external PS connected to the U18. Occasionally, when an external PS is connected to the U18, on the initial connection to your computer only, your computer might not recognizing the U18.  Once the driver is installed, the U18 is connected via USB only and the computer has recognized the U18, leave it connected via USB and then plug in the external PS.  Reboot your computer next, with everything (USB and external PS) connected.  At his point, and on all subsequent connections, you can just plug in the U18 to your computer with the external PS already connected.[/size]