Balanced and Unbalanced outputs simultaneously

I have a question regarding balanced and unbalanced outputs. I have a Benchmark DAC 1 that has both unbalanced and balanced outputs. Currently I am using the unbalanced (RCA) outputs to my trusty tubed pre amp and then from there to the RCA inputs on my Bryston 4B ST. It sounds great and I love the fact that I can roll in different old tubes to change the character of the sound. However I want the best of both worlds on the pre amp side and was wondering if I could use the balanced outputs of the Benchmark to a solid state pre amp and then balanced outputs from the pre amp to the Bryston. Then all I would need to do is switch the input mode on the Bryton to go from balanced to unbalanced and thus from a tubed pre amp world to solid state. My questions are does the Benchmark provide a single to both outputs simultaneously or does plugging in a balanced cable disengage the unbalanced outs? Also can anyone see a problem with hooking things up this way? (I don't want to blow anything out but can't really see how that could happen since I suspect that the toggle switch on the Bryston would prevent that.

Any thoughts?? Doug