Havanese,
My suggestion would be to contact bluejeans cable or your favorite XLR cable manufacture and see if they would be willing to build you 2 splitter cables to go from your PRE to your amp. It is nothing more than one connector on one end using 2 cables to 2 connectors on the other end. In other words a single channel out of your PRE to 2 channels in on your AMP. Hope this helps.
Good Luck
My suggestion would be to contact bluejeans cable or your favorite XLR cable manufacture and see if they would be willing to build you 2 splitter cables to go from your PRE to your amp. It is nothing more than one connector on one end using 2 cables to 2 connectors on the other end. In other words a single channel out of your PRE to 2 channels in on your AMP. Hope this helps.
Good Luck