Polarity Invertng Rogue 66 W Bryston 4BST

Some folks claim detail can be lost if polarity is inverted. Although I myself have strong doubts about the true audibility of phase inversion (even though I do the same correction for my C-J preamp), it would be best to go ahead and follow the manufacturer's advice to reverse the polarity of the speaker connections positive for negative (at either the speaker end or the amp end, your choice - but not at both ends!), if for no other reason than to keep the playing field as level as possible when comparing to your old preamp. Also, it is possible that the new component will evolve a bit in its sound during a "break-in" period - this being true at least as much for the tubes themselves as for the circuit, the latter being another point about which there is some disagreement. But ultimately, whether it is the component, or your ears, that "break-in" over time, you would be doing yourself a disservice either way by rushing to judgement when dropping new gear into your system. Try a couple of weeks of frequent first use before drawing any ultimate conclusions and you'll be a lot more secure in your decision.