Pre-amp causing loud hiss from speakers

Your Rogue amps input sensitivity is 1V (high sensitivity). Your QS input sensitivity is 9V (very low). What this means is that the gain (and it's tube noise) from your pre-amp's tube section will be magnified substantially more with the Rogue and, especially when driving highly efficient speakers such as yours, will result in noise. This is not controllable by using your pre-amps volume control as it is in the circuit before the tube section which is always seen by the amp at it's full output gain.

Your problem could be that the tubes in your pre-amp are not 'low noise' enough for the Rogue Amp when it is amplifying your high efficiency speakers. If low noise tubes are not the problem and you still want to use your pre-amp with this amp/speaker combo you can try using in-line attenuators at the amp inputs to reduce the gain from your pre-amp. This may be inelegant but there is not much down side - it is nothing much more that a fixed value resistor in this kind of attenuator.

Hope that helps a bit.

I purchased a used BAT VK-300SE which had the same problem upon arrival.
I decided to work with the seller and had to return the unit to BAT.
It was fixed and worked flawlessly thereafter.
BAT said it had a bad "voltage regulator".
BAT graciously fixed it under warranty even after we explained that I was the new owner.
Like the late-great HP used to say: "If it works the first time, it's not high end"...

As Newbee correctly points out the gain architecture of the system is completely wrong for the extremely high sensitivity LaScalas, which will magnify any noise upstream.

For what it's worth, IMHO the Quicksilvers are much better sounding amps than the big Rogues and will have much lower operating costs as well. Add to that the lower gain which is correct in the context of your system and it may be time to move the Rogues on.

I will experiment more with the IC's and binding posts, but I fear as noted the gain architecture is way off - oh well part of the journey. I do wonder if it's not inappropriate here to ask what a set of Rogues would be worth with less than 30 minutes run time?

Thanks

Since you're in for a penny you might as well check one more thing. With the amp off, remove the interconnects from the amp. Replace them with, preferably, shorting plugs, but RCA caps would probably work as well. Turn the amp back on. What you are now hearing is the internal noise from the amp alone.

If the noise is not too bad you may be able to use line level attenuators such as those available from Parts Express between the preamp and amp and this will solve the problem without heroic efforts as Newbee suggested.

The other possibility is to call Rogue, they are most helpful and may be able to internally alter the gain of the amp.

Finally, Rogue is a hot brand and I would start at 20% off retail and probably be ready to accept 30% off retail. Just a guess here.