[MikeyFresh]

So I checked with the DAC designer at audio gd about the Amanero card in the master 11 being internally or bus powered. He confirmed it is internally powered and will ignore the bus power. The reason I asked is because I own the ifi iUSBpower and didn't know if I still need it or if I could sell it. The description of the iUSB basically says it's a power supply but doesn't do any reclocking or anything else to the signal portion of the USB. So, I remove it from the chain and start listening and the music is noticably darker. This prompts me to A/B with and without the iUSB. With it in the chain, there is more treble, tighter bass (though maybe a bit less) and overall a more accurate, resolving sound. The real problem is that I have no idea why. This isn't placebo, it's obvious. I have sent an email to ifi asking if the iUSB DOES manipulate the signal somehow, but curious if any of you have thoughts...

Probably the improved sound you hear is attributable to strict adherence to the 90 Ohm spec, and a cleaner ground. 
 
Are you using the IsoGround lift switch?

 

[johnzz4]

Yes, I'm using the IsoGround lift switch. I should be, right?

 

[MikeyFresh]

Yes, I'm using the IsoGround lift switch. I should be, right?

In my experience yes, I get better sound quality by using the IsoGround, effectively severing the tie with the computer's very noisy ground.