Recent content by Bryan T

I appreciated Cambridge Audio’s reply. And I’ll once again thank Amir for the effort he put in here.

I’d need to see a sketch of how your testing equipment is wired together, as I’m just assuming. I imagine you have something like: computer -> CXA81 -> AP -> computer. My setup is just: computer -> CXA81 And I heard no difference in hiss with the volume at 100% with or without a USB cable...

Got it. In my own setup, the computer only connects to the CXA81 in one way (USB). There isn’t another path back from the CXA81 to the computer. I suspect that’s a typical use case.

I don’t understand what you mean. My first sentence or my second sentence?

As I understand it, in his setup having the USB connection (regardless of whether USB is being used) completes the loop between the computer, the CXA81, and the AP. Most of us probably won’t have a loop like that.

??? I thought the USB was connected to the computer, completing the loop since the AP is also connected to the computer. ???

I’m confused about how this is wired. My interpretation was that your TOSLINK+USB experiment supported the ground loop hypothesis, not refuted it.

It is a quiet amp. Even with the volume maxed I struggle to hear any hiss more than a foot away from the tweeter. That is so far beyond how I use the amp (volume and distance to speaker) that it is basically an academic exercise. Unplugging the USB cable had no impact on the hiss in my setup...

I don’t hear any difference in noise from mine with or without a USB cable plugged in. What should I be testing for?

Presumably, I could test for this by listening for noise on a non-USB input with and without a USB cable plugged in, no? On Analog 2 with the volume at 100% I can hear noise up to about 16 inches away from the tweeter. I unplugged the USB input and the max distance didn’t change.

Fortunately, you can test it to see if it matters.

Thanks @amirm. I really appreciate the time you took to retest and troubleshoot with the CA folks.