Thx for your help. I usually use the tube stage. Only had time for a quick test tonight. Couldn't hear a difference between passive and tube. Not sure, because I only listened to a couple of records tonight, but i left Loki switched off this time (it makes the little bit of hum I still have louder) and for some reason the music sounded better to my ears. More natural and less fatiguing. But as I said, for now it's only a short impression. Will do some more tests these days.