Originally Posted by SAM64
Does it have a higher impedance? If so, I'd expect there to be more noise...due to the higher input impedance.
Since you've convinced yourself this is a ground loop, best of luck in eliminating it.
Oops, I was thinking of another amp I had been considering. Turns out this one has the same impedance for both balanced & unbalanced.
I haven't convinced myself of anything... I just don't know much about eliminating noise.
I take it then that the possible solutions I listed in post 14 would only solve a ground loop issue, and not some other issue? (Such as noise from the PC PSU/MB/etc? Those aren't ground loop issues?)
I already stripped my PC down to:
- my 30" monitor (which I powered off, but could bother disconnecting if I do this test again)
- the power cord, which I had going into a power strip plugged into an outlet on circuit 2. (can't reach any outlet for circuit 2 without a strip)
- the mini-HDMI to HDMI cable from my video card to the receiver
As mentioned, the noise was still there. In fact, with the PC, preamp, and amp on the same circuit, the noise was much worse. (The HDTV on the same power strip as the amp was causing noise, but this goes away when the amp is on a different circuit... didn't try the amp in another outlet of the same circuit)
I don't see how this could be an external component issue (outside of the PC), given that the noise changes (significantly) as things inside the PC change--when I load the CPU, load the GPU, unload the CPU, mildly load the CPU, etc.
What I asked (perhaps my intent wasn't clear) is: are there any reasonable solutions that don't involve changing something about the PC? (E.g., would a balanced to balanced pre-amp -> amp connection eliminate this noise? What about a ground loop isolator between the pre & the amp? Etc)
As mentioned above, I'd rather avoid changing the PC--doing so would require:
- ordering a new MB, installing it (which is a PITA), and then seeing if it works...
- ordering a new PSU, installing it (which is a PITA, but not nearly as much as the motherboard), and then seeing if it works.
- if one of the above works, I'm good until my next PC... at which point I order the parts, put it together, and if things aren't ok, spend more money and time installing different parts to see if they work instead.
So, any thoughts on whether a GLI or a balanced->balanced connection (i.e., new preamp) would eliminate (well, massively reduce) this noise?
I suppose I could just give a GLI a shot, as they aren't expensive...