You did a/b/c test. I wonder how anyone could evaluate or put a grading of a preamp working with a particular amp especially amp of different brand without trying different alternatives.
Yes we did. We had AR Ref 10, Ypsilon, and Dartzeel pre, and constellation, Dartzeel, and Berning power. The Ypsilon was agnostic to the amp used, but Dartzeel sounded great with the Dartzeel power, on par with Ypsilon, but fell quite short of both Ypsilon and AR With the constellation. We also tried Ypsilon both passive and active mode. There was a lack of drive with the Dartzeel constellation combo that wasn't with the AR/ypsilon constellation