The only time I tried SE into balanced, the amp did not respond well at all, and it was fully differential. It made sound, but badly.
Many find that they don't need expensive XLR cables because the effects (or is it affects) of the cable get reduced. You didn't mention if your preamp has XLR outs.
Many find that they don't need expensive XLR cables because the effects (or is it affects) of the cable get reduced. You didn't mention if your preamp has XLR outs.