I have bought this Tiny Box and it just make exatly what I want. It kills the background noise who come from the laptop ground. Just look at this Video I've made. http://youtu.be/FwZTB8CDDgM?list=UUlKEA3X9xfbh-DU_JemPhxw
Thanks to hifimediy for the cheap price.
The USB isolator works well filtering out the noise from my desktop USB port, connected to my Dr. DAC2 DX. I use Dr. DAC2 DX for Op-Amp rolling, and has been using it as headphone amp, connected to Yulong DA8. Yulong DA8 analog out connected to Dr. DAC2 DX analog in. Both DACs are connected to USB ports of my desktop PC. I keep getting high frequency noise on both of Yulong DA8 & Dr. DAC2 DX headphone output. I tried with AC power filter, didn't solve the problem. I found out that the noise came from USB connection to Dr. DAC2 DX. When I disconnected the USB cable, the noise disappear. So I tried this USB isolator from Hifimediy, put it in between desktop PC to Dr. DAC2 DX USB connection, and the noise disappear :D
USB isolator doesn't work for Yulong DA8. Yulong DA8 was not recognized by Windows when I used the USB isolator. But it works perfectly for Dr. DAC2 DX.
Thank you Hifimediy!
Bought this usb isolator - long delivery time and then it did not work. Was shipped from China and had to pay import TAX and handling expenses. Found that it only supply 200mA which is nowhere close to the 500mA USB normally deliver. Took it apart and the quality is poor with the loose wire soldering. Cannot recommend this. I have also bought the sabre which was better quality.
My experience with this isolator is very, very good. I ear much better the higher end of the spectrum, more details and more sepation, better soundstage... the expanse is very justified...
The HiFime USB isolator successfully filtered the noise from my laptop's power supply. I can now charge my laptop while using it feed a UBS DAC. Makes both my laptops dead quiet. Just plug the Isolator in front of your USB DAC so the Isolator can clean up the power first.