Ok so if we know it is the interconnection that causes the noise you should re-evaluate your gain structure and search for someplace that the noise floor is being raised.
Honestly, I am just guessing that this is a noise floor issue but it is the first thing that I would investigate if I were in your room.
One thing about using a Reamp instead of using a direct connection is that you can get really low noise.
The idea of using -10dBV instead of +4dBu out from the VS is good because what you need to do is pad down the output so it's not hitting the amp so loudly that you can't effectively use the amp's gain structure for coloring your sound.
I'm guessing you have the analog output of the VS turned down a whole bunch... and you are increasing the signal-to-noise ratio of the VS to guitar amp system. When you then turn up the signal at the guitar amp the higher ratio of noise is also amplified and it becomes apparent. (This is a massive over simplification)
The noise floor I am speaking of is primarily contributed by the analog output section of the VS and that is why it occurs regardless of the fact that there is no digital file playing back.
The genius of the Reamp and it's licensees is that it uses a transformer and pad system that is specifically tailored to reduce the board's output and get it into the amplifier without increasing noise.
An ideal generic reamping connection mimics a direct guitar to amp bridge of approx 6 kilo ohm to 1 Mega ohm.
The VS output is approx 600 ohm... way lower than 6k.
A pad can help but doesn't deal with the impedance bridge properly... your frequency response will do weird things... but with a guitar tone it may not matter.
A direct box used backwards will seem to work but it will actually increase the noise floor because it will step up the signal and you'll have to turn it down even lower to use it.
A in-line transformer can step the signal down but it's not ideal... the Reamp circuit is basically the step down transformer with the extra stuff that makes it all work as best as possible.
Now having said all that: regardless of what you use to connect the VS to the amplifier...
What I would do is set your VS analog output to something normal... what I mean is set the output of the actual hardware to it's nominal level.
Now take your actual track output level control and reduce it so that you are reducing the level digitally rather than later in the analog domain. When you reduce the level digitally there is almost no change in signal-to-noise ratios.
Trying that should take just a minute or two and maybe it will improve things.
It may not... but I hope it does.
In the end all that really matters is that you get a signal into the amp at a level that lets you use the amp as you want to.
If the above didn't help... try the opposite... put the track back to nominal level and and turn down the analog outputs of the VS. That will only take a few moments to try.
Find the gain structure on the outputs that produces the least amount of noise.
This issue may also be related to the way the TRS output of the VS reacts to being hooked up to the TS input of the guitar amp. You may be turning the system in to a white noise antenna by using a standard guitar cord.
If that is the case you'll see some benefit from making sure you have a plan to go from balanced to unbalanced without shorting "pin 3". A specially wired cable with a TRS connector on one side and a TS on another side would be a start.
see number 9 here:
http://www.rane.com/n110fig4a.gif You may want to keep in mind that a Reamp device will anticipate the balanced to unbalanced connection and you'll be able to use it to adapt two normal cables to work properly... so you will not need to make a custom cable like I just suggested.
Good luck and all the best,
mike