I've had a listen to my GS-X using my Shure se535's and my HD-600's.
First with the mini rack, and then with the amp section on the top shelf of my main audio rack with the PSU in the same place, and I found no difference between the two positions, I even separated both units by over 3 feet, and there was still no difference. The interconnects I used were XLR's.
Using the volume knob as a clock, with no volume being 7 o'clock and full 5 o'clock, I first tried the se535's.
With no music playing and on the low gain setting, I started hearing a slight humming at about 12 o'clock which increased going to 5 o'clock.
I didn't try the se535's on the other two gains because IEM's are supposed to be used mainly on low gain.
As I've said, I did hear a humming around 12 o'clock, but when I started listening to some music, the highest I could go was 10 o'clock, but only for a short time. If I was to listen at that volume all the time, I'd end up going deaf.
I was also using my main source.
I then tried my HD-600's and again there was no difference between using the mini rack and the amp section being on the top shelf. This time I used the HD-600's on the medium gain, and again with no music playing, I could take the volume knob to full and I heard nothing. I then listened to some music and the highest I could go to was around 11 o'clock.
I did try the HD-600's on the high gain and humming came in at about 4 o'clock.
If anyone would like to do a similar test to what I've done, just make sure the music doesn't come on while the volumes on full.
P.S. I'd further like to say, I've put leather on the bottom of each of the four legs, and also on the eight metal feet which both units sit on.
