Thanks, JPerry and Melm, very good information. Right now, I'm running a Sumiko Blackbird(Hi) that has 2.5mV output so should be fine there. With my Jolida JD9 I've rolled the original 12AX7 tubes down to 12AT7s and find it sounds much better with those, could also just be the difference between the stock Tung Sols and the NOS GE 12AT7s, not sure. Some have said the Tung Sols are fine, but I'm not of that opinion after much swapping in and out of each pairs. The Blackbird is to be loaded at 47Kohms, but I find it sounds much more nuanced and clear at the 230ohm setting, all gain switches off through the HI outputs. With the 47Kohm setting, there was harshness and even a bit of audible distortion. Thanks, I will do the search again as I didn't find that discussion when I did so earlier.