After several years of builing I am almost finished with my G7/Equinox Michrophone. The body is Equinox EQU47 (U47 copy) and the capsule is Equinox Q47-D. I have changed some resistors to lower the voltages to the capsule in the G7 circuit. Had problems getting the +B voltage up to 160 volt, changed the second trafo from a 220:15 to a 220:12 volt still the +B voltage (loaded) is "only" +145volt. Had problems with massive hum in the first test. But when I connected the "Heather 0" to the common inside the mic the hum was gone. In the drawing of the mic-pcb the common and the Heather-0 is connected, but they were not on the pcb. Have borrowed a Wunder U47 clone and compared the two michrophones. When talking into the mics I can hear no difference in the sound, so I guess the +145 volt is ok for me. But the noiselevel (steady noise - no hum)is 15-20 db worse in the G7. The tube is a Electro-harmonix (made in russia) EF86EH. I understand I could reduce the noise with a better tube. There are "loads" of different EF86 tubes on Ebay. Which tube should I go for to get the best signal-noise performance?