So I put in the new KT-88's and went to set the bias. Both the manual and the back panel say set the bias for 100mV and set the balance for 0mV . So I got my meter out and the bias will only go to -100mV but the balance will go to 0 mV . So is this ok or do I have a problem somewhere ? Kind of need to know before I go and use it at practice later.