a perhaps quite obvious question for the ones in the know, but here we go: where to measure bias on a NAP160 main board, I wonder? I am aware that there is that trim pot, that's okay with me, but I just have no idea as to where to put the tips of my multimeter? also, is there a chance to adjust DC offset on the output, too? if so, where, please? I'm asking as on my amp on one channel it's merely 7.5mV while on the other it's 27.5mV. your advice will be much appreciated. to note, otherwise the amp just sounds great, I only want to make sure that it performs at its best