Hi,
I asked iFi a question about the use of the Jitterbug with the IP2 (I use one Jitterbug on my PC, and one at the OUTPUT of my iUSB, then an USB adapter + IP2 to DAC, with great results).
They replied that it was not in their policy to compare with other manufacturers products.
However they said a very interesting thing for people who own an iUSB (the first version) :
"With regards to USB filtering we normally suggest that you place the iPurifier 2 at the end of the digital chain for max performance.
However, if you own the iUSBpower, hook up the iPurifier 2 directly to this, so; PC > iPurifier 2 > iUSBpower.
Doing this you are in effect 80% close to the performance of our iUSB3.0 device."
I did several A/B comparisons, and it sounds better like this !
So now my setup is like this, and I won't change a thing : PC > Jitterbug > Starlight 7 USB cable > IP2 > iUSB > Jitterbug > USB adapter > DAC.